1. Software
  2. Bull
  3. AIX 5.1 - OpenGL 2.1

Bull AIX 5.1 - OpenGL 2.1 Reference Guide


Add to my manuals
621 Pages

advertisement

Bull AIX 5.1 - OpenGL 2.1 Reference Guide | Manualzz 
Bull
AIX 5L OpenGL 2.1 Reference Manual
AIX
ORDER REFERENCE
86 A2 71EF 00
Bull
AIX 5L OpenGL 2.1 Reference Manual
AIX
Software
April 2001
BULL CEDOC
357 AVENUE PATTON
B.P.20845
49008 ANGERS CEDEX 01
FRANCE
ORDER REFERENCE
86 A2 71EF 00
The following copyright notice protects this book under the Copyright laws of the United States of America
and other countries which prohibit such actions as, but not limited to, copying, distributing, modifying, and
making derivative works.
Copyright
Bull S.A. 1992, 2001
Printed in France
Suggestions and criticisms concerning the form, content, and presentation of
this book are invited. A form is provided at the end of this book for this purpose.
To order additional copies of this book or other Bull Technical Publications, you
are invited to use the Ordering Form also provided at the end of this book.
Trademarks and Acknowledgements
We acknowledge the right of proprietors of trademarks mentioned in this book.
AIXR is a registered trademark of International Business Machines Corporation, and is being used under
licence.
UNIX is a registered trademark in the United States of America and other countries licensed exclusively through
the Open Group.
The information in this document is subject to change without notice. Groupe Bull will not be liable for errors
contained herein, or for incidental or consequential damages in connection with the use of this material.
Contents
About This Book . . . .
Who Should Use This Book
Highlighting . . . . . .
ISO 9000 . . . . . . .
Related Publications . . .
Trademarks . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Chapter 1. OpenGL Subroutines. . .
glAccum Subroutine . . . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glActiveTextureARB Subroutine . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glAlphaFunc Subroutine . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Files . . . . . . . . . . . .
Related Information. . . . . . .
glAreTexturesResident Subroutine . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information . . . . . . .
glAreTexturesResidentEXT Subroutine .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
© Copyright IBM Corp. 1994, 2000
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
lvii
lvii
lvii
lvii
lvii
lviii
. 1
. 6
. 6
. 6
. 6
. 6
. 7
. 7
. 7
. 7
. 7
. 7
. 8
. 8
. 8
. 8
. 8
. 8
. 8
. 8
. 8
. 9
. 9
. 9
. 9
. 9
. 9
. 9
. 10
. 10
. 10
. 10
. 10
. 10
. 10
. 10
. 10
. 10
. 11
. 11
. 11
. 11
. 11
. 11
. 11
. 11
iii
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . .
Related Information. . . .
glArrayElement Subroutine . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Related Information. . . .
glArrayElementEXT Subroutine
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
File. . . . . . . . . .
Related Information. . . .
glBegin or glEnd Subroutine .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . .
Related Information. . . .
glBindTexture Subroutine. . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Related Information. . . .
glBindTextureEXT Subroutine .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . .
Related Information. . . .
glBitmap Subroutine . . . .
Purpose . . . . . . . .
iv
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
12
12
12
12
12
12
12
13
13
13
13
13
13
13
13
13
14
14
14
14
14
14
14
14
15
15
15
15
15
15
16
16
16
16
16
16
16
16
17
17
17
17
18
18
18
18
18
18
19
19
19
19
19
19
19
19
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . .
Related Information. . . .
glBlendColor Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Related Information. . . .
glBlendColorEXT Subroutine .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Related Information. . . .
glBlendEquation Subroutine. .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Related Information. . . .
glBlendEquationEXT Subroutine
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Related Information. . . .
glBlendFunc Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
19
20
20
20
21
21
21
21
21
21
21
21
21
22
22
22
22
22
22
22
22
22
22
22
22
22
23
23
23
23
23
23
23
23
23
23
24
24
24
24
24
24
24
24
24
25
25
25
25
25
25
25
25
27
27
28
Contents
v
Associated Gets . . .
Examples . . . . .
Files . . . . . . .
Related Information. .
glBlendFuncSeparateEXT
Purpose . . . . . .
Library . . . . . .
C Syntax . . . . .
Description . . . . .
Parameters. . . . .
Notes . . . . . . .
Error Codes . . . .
Files . . . . . . .
Related Information. .
glCallList Subroutine . .
Purpose . . . . . .
Library . . . . . .
C Syntax . . . . .
Description . . . . .
Parameters. . . . .
Notes . . . . . . .
Associated Gets . . .
Files . . . . . . .
Related Information. .
glCallLists Subroutine . .
Purpose . . . . . .
Library . . . . . .
C Syntax . . . . .
Description . . . . .
Parameters. . . . .
Notes . . . . . . .
Associated Gets . . .
Files . . . . . . .
Related Information. .
glClear Subroutine . . .
Purpose . . . . . .
Library . . . . . .
C Syntax . . . . .
Description . . . . .
Parameters. . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . .
Related Information. .
glClearAccum Subroutine
Purpose . . . . . .
Library . . . . . .
C Syntax . . . . .
Description . . . . .
Parameters. . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . .
Related Information. .
glClearColor Subroutine .
vi
. . . .
. . . .
. . . .
. . . .
Subroutine
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
28
28
28
28
28
28
28
29
29
30
30
30
30
30
30
30
30
30
30
31
31
31
31
31
31
31
31
31
32
32
33
33
33
33
33
33
33
33
33
34
34
34
34
34
34
34
34
34
35
35
35
35
35
35
35
35
Purpose . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . .
Parameters. . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information. . . . . . . . . . . . .
glClearDepth Subroutine . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . .
Parameters. . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information. . . . . . . . . . . . .
glClearIndex Subroutine . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . .
Parameters. . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information. . . . . . . . . . . . .
glClearStencil Subroutine . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . .
Parameters. . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information. . . . . . . . . . . . .
glClientActiveTextureARB Subroutine . . . . . . .
Purpose . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . .
Parameters. . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . .
Error Codes . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information. . . . . . . . . . . . .
glClipBoundingBoxIBM or glClipBoundingSphereIBM or
Purpose . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . .
Parameters. . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
glClipBoundingVerticesIBM
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
Subroutine .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
35
35
36
36
36
36
36
36
36
36
36
36
36
37
37
37
37
37
37
37
37
37
37
37
37
38
38
38
38
38
38
38
38
38
38
38
38
39
39
39
39
39
39
39
39
39
40
40
40
40
40
40
40
40
41
41
vii
Error Codes . . . . . . . .
Files . . . . . . . . . . .
glClipPlane Subroutine . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters. . . . . . . . .
Description . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . .
Related Information. . . . . .
glColor Subroutine . . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . . .
Parameters. . . . . . . . .
Notes . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . .
Related Information. . . . . .
glColorMask Subroutine . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . . .
Parameters. . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . .
Related Information. . . . . .
glColorMaterial Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . . .
Parameters. . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . .
Related Information. . . . . .
glColorNormalVertexSUN Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . . .
Parameters. . . . . . . . .
Notes . . . . . . . . . . .
Files . . . . . . . . . . .
Related Information. . . . . .
glColorPointer Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . .
viii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
41
41
42
42
42
42
42
42
42
42
42
43
43
43
43
43
43
45
45
46
46
46
46
46
46
46
46
46
47
47
47
47
47
47
47
47
47
47
48
48
48
48
48
48
48
48
49
49
49
49
49
50
50
50
50
50
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Related Information. . . . .
glColorPointerEXT Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
File. . . . . . . . . . .
Related Information. . . . .
glColorPointerListIBM Subroutine.
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Related Information. . . . .
glColorSubTable Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glColorTable Subroutine . . . .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glColorTableParameter Subroutine
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
50
50
50
51
51
51
51
52
52
52
52
52
52
53
53
53
53
53
54
54
54
54
54
54
55
55
55
55
56
56
56
56
56
56
56
57
57
57
57
57
57
57
57
58
59
60
60
60
61
61
61
61
61
61
61
61
ix
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glColorVertexSUN Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glCopyColorSubTable Subroutine.
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glCopyColorTable Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glCopyPixels Subroutine . . . .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Examples . . . . . . . .
Files . . . . . . . . . .
Related Information. . . . .
glCopyTexImage1D Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . . .
Parameters. . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
x
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
62
62
62
62
62
62
62
62
62
63
63
63
63
64
64
64
64
64
64
64
64
64
65
65
65
65
65
65
65
65
66
66
67
67
67
67
67
67
67
67
67
69
69
69
70
70
70
70
70
70
70
70
70
71
71
71
Associated Gets . . . . . . . .
Related Information. . . . . . .
glCopyTexImage2D Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . . .
Parameters. . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information. . . . . . .
glCopyTexSubImage1D Subroutine . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . . .
Parameters. . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information. . . . . . .
glCopyTexSubImage2D Subroutine . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . . .
Parameters. . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information. . . . . . .
glCopyTexSubImage3D Subroutine . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . . .
Parameters. . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information. . . . . . .
glCopyTexSubImage3DEXT Subroutine
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . . .
Parameters. . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information. . . . . . .
glCullFace Subroutine . . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
72
72
72
72
72
72
72
73
73
73
74
74
74
74
74
74
74
74
75
75
75
75
75
75
75
75
76
76
76
76
77
77
77
77
77
77
77
78
78
78
79
79
79
79
79
79
79
80
80
80
80
80
81
81
81
81
xi
Parameters. . . . . . .
Description . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . .
Related Information. . . .
glDeleteLists Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . .
Related Information. . . .
glDeleteTextures Subroutine .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters. . . . . . .
Description . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Related Information. . . .
glDeleteTexturesEXT Subroutine
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
File. . . . . . . . . .
Related Information. . . .
glDepthFunc Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . .
Related Information. . . .
glDepthMask Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . . .
Parameters. . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . .
xii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
81
81
81
81
81
81
81
82
82
82
82
82
82
82
82
82
82
82
82
83
83
83
83
83
83
83
83
83
83
83
84
84
84
84
84
84
84
84
84
84
84
85
85
85
85
85
85
86
86
86
86
86
86
86
86
86
Related Information. . .
glDepthRange Subroutine .
Purpose . . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . . .
Parameters. . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Files . . . . . . . .
Related Information. . .
glDrawArrays Subroutine. .
Purpose . . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . . .
Parameters. . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Related Information. . .
glDrawArraysEXT Subroutine
Purpose . . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . . .
Parameters. . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
File. . . . . . . . .
Related Information. . .
glDrawBuffer Subroutine . .
Purpose . . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . . .
Parameters. . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Files . . . . . . . .
Related Information. . .
glDrawElements Subroutine.
Purpose . . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . . .
Notes . . . . . . . .
Parameters. . . . . .
Errors . . . . . . . .
Related Information. . .
glDrawPixels Subroutine . .
Purpose . . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
86
86
86
86
87
87
87
87
87
87
87
87
87
87
87
88
88
88
88
88
88
89
89
89
89
89
89
89
90
90
90
90
90
90
90
90
91
91
91
91
91
91
92
92
92
92
92
92
92
92
93
93
93
93
93
93
xiii
Parameters. . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glDrawRangeElements Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Related Information . . . . . .
glEdgeFlag Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glEdgeFlagPointer Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Associated Gets . . . . . . .
Related Information . . . . . .
glEdgeFlagPointerEXT Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
File . . . . . . . . . . . .
Related Information . . . . . .
glEdgeFlagPointerListIBM Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Associated Gets . . . . . . .
Related Information . . . . . .
xiv
OpenGL 2.1 Reference Manual
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . . 99
. . . . 99
. . . . 99
. . . . 100
. . . . 100
. . . . 100
. . . . 100
. . . . 100
. . . . 100
. . . . 100
. . . . 100
. . . . 101
. . . . 101
. . . . 101
. . . . 101
. . . . 101
. . . . 101
. . . . 101
. . . . 102
. . . . 102
. . . . 102
. . . . 102
. . . . 102
. . . . 102
. . . . 102
. . . . 102
. . . . 102
. . . . 103
. . . . 103
. . . . 103
. . . . 103
. . . . 103
. . . . 103
. . . . 104
. . . . 104
. . . . 104
. . . . 104
. . . . 104
. . . . 104
. . . . 104
. . . . 105
. . . . 105
. . . . 105
. . . . 105
. . . . 105
. . . . 105
. . . . 106
. . . . 106
. . . . 106
. . . . 106
. . . . 106
. . . . 106
. . . . 106
. . . . 107
. . . . 107
. . . . 107
glEnable or glDisable Subroutine . . . . . . . .
Purpose . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . .
glEnableClientState or glDisableClientState Subroutine
Purpose . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . .
glEvalCoord Subroutine . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . .
glEvalMesh Subroutine . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . .
glEvalPoint Subroutine . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . .
glFeedbackBuffer Subroutine . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
107
107
107
107
107
111
111
112
112
112
112
112
112
112
112
112
112
113
113
113
113
113
113
114
114
115
115
115
115
115
116
116
117
117
117
117
118
118
118
118
118
118
118
118
119
119
119
119
119
119
119
121
121
121
121
121
xv
Related Information . . . . . .
glFinish Subroutine . . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glFlush Subroutine . . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glFog Subroutine . . . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glFogCoordEXT Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glFogCoordPointerEXT Subroutine. .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glFogCoordPointerListIBM Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
xvi
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
121
121
121
121
122
122
122
122
122
122
122
122
122
122
122
122
123
123
123
123
123
123
123
123
125
125
125
126
126
126
126
126
126
126
126
126
127
127
127
127
127
127
127
128
128
128
128
128
128
128
129
129
129
129
130
130
glFrontFace Subroutine . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glFrustum Subroutine . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glGenLists Subroutine . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glGenTextures Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Related Information . . .
glGenTexturesEXT Subroutine
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
File . . . . . . . . .
Related Information . . .
glGet Subroutine . . . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130
130
130
130
130
130
130
131
131
131
131
131
131
131
131
132
132
132
133
133
133
133
133
133
133
133
133
133
134
134
134
134
134
134
134
134
134
135
135
135
135
135
135
135
135
135
135
136
136
136
136
136
136
136
136
136
xvii
Description . . . . . . . . .
Parameters . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glGetClipPlane Subroutine. . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glGetColorTable Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glGetColorTableParameter Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glGetError Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glGetLight Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glGetMap Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
xviii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
136
158
158
158
158
158
158
158
158
158
158
159
159
159
159
159
159
159
159
159
160
160
160
161
161
161
161
161
161
161
162
162
162
162
162
163
163
163
163
163
164
164
164
164
164
164
164
164
165
166
166
166
166
166
166
166
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glGetMaterial Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glGetPixelMap Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . . .
Related Information . . . .
glGetPointerv Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Error Codes . . . . . . .
Related Information . . . .
glGetPointervEXT Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
File . . . . . . . . . .
Related Information . . . .
glGetPolygonStipple Subroutine.
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
166
166
167
167
167
167
167
167
167
168
168
168
168
169
169
169
169
169
169
169
169
169
170
170
170
170
170
170
171
171
171
171
171
171
172
172
172
172
172
172
172
172
173
173
173
173
173
173
173
173
173
174
174
174
174
174
xix
Related Information . . . . .
glGetString Subroutine . . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glGetTexEnv Subroutine . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glGetTexGen Subroutine . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glGetTexImage Subroutine. . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Parameters . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glGetTexLevelParameter Subroutine
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glGetTexParameter Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
xx
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
174
174
174
174
174
174
175
175
175
175
175
175
175
175
176
176
176
177
177
177
177
177
177
177
178
178
178
178
178
178
179
179
179
179
179
179
179
180
180
180
180
180
181
181
181
181
181
182
182
182
183
183
183
183
183
183
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Files . . . . . . . . .
Related Information . . .
glHint Subroutine . . . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Files . . . . . . . . .
Related Information . . .
glIndex Subroutine . . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glIndexMask Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glIndexPointer Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Related Information . . .
glIndexPointerEXT Subroutine
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
File . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
183
184
184
184
184
184
185
185
185
185
185
186
186
186
186
187
187
187
187
187
187
187
187
188
188
188
188
188
188
188
188
188
188
188
189
189
189
189
189
189
189
189
190
190
190
190
190
190
190
191
191
191
191
192
192
192
xxi
Related Information . . . .
glIndexPointerListIBM Subroutine
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Error Codes . . . . . . .
Associated Gets . . . . .
Related Information . . . .
glInitNames Subroutine . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Errors . . . . . . . . .
Associated Gets . . . . .
Files . . . . . . . . . .
Related Information . . . .
glInterleavedArrays Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Related Information . . . .
glIsEnabled Subroutine . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glIsList Subroutine. . . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Errors . . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glIsTexture Subroutine . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Errors . . . . . . . . .
xxii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
192
192
192
192
192
192
193
193
194
194
194
194
194
194
194
194
194
194
195
195
195
195
195
195
195
195
196
196
196
196
196
196
196
196
198
198
198
198
198
198
198
198
198
198
198
198
199
199
199
199
199
199
199
199
199
199
Related Information . .
glIsTextureEXT Subroutine
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Notes . . . . . . .
Errors . . . . . . .
File . . . . . . . .
Related Information . .
glLight Subroutine . . . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glLightModel Subroutine .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glLineStipple Subroutine .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glLineWidth Subroutine . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glListBase Subroutine . .
Purpose . . . . . .
Library . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
199
199
199
200
200
200
200
200
200
200
200
200
200
200
200
201
203
203
203
203
203
203
203
203
204
204
204
205
205
205
206
206
206
206
206
206
206
207
207
207
207
207
207
207
207
207
207
208
208
208
208
208
209
209
209
209
xxiii
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glLoadIdentity Subroutine . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glLoadMatrix Subroutine . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glLoadName Subroutine . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glLoadNamedMatrixIBM Subroutine . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Error Codes . . . . . . . . . .
Files . . . . . . . . . . . . .
glLoadTransposeMatrixARB Subroutine .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Error Codes . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glLockArraysEXT Subroutine . . . . .
Purpose . . . . . . . . . . .
xxiv
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
209
209
209
209
209
209
209
209
209
210
210
210
210
210
210
210
211
211
211
211
211
211
211
211
212
212
212
212
212
212
212
212
212
212
213
213
213
213
213
213
213
213
214
214
214
214
214
214
214
214
214
214
215
215
215
215
Library . . . . .
C Syntax . . . .
Description . . .
Parameters . . .
Errors . . . . .
Related Information
glLogicOp Subroutine
Purpose . . . .
Library . . . . .
C Syntax . . . .
Description . . .
Parameters . . .
Notes . . . . .
Errors . . . . .
Associated Gets .
Files . . . . . .
Related Information
glMap1 Subroutine .
Purpose . . . .
Library . . . . .
C Syntax . . . .
Description . . .
Parameters . . .
Notes . . . . .
Errors . . . . .
Associated Gets .
Files . . . . . .
Related Information
glMap2 Subroutine .
Purpose . . . .
Library . . . . .
C Syntax . . . .
Description . . .
Parameters . . .
Notes . . . . .
Errors . . . . .
Associated Gets .
Files . . . . . .
Related Information
glMapGrid Subroutine
Purpose . . . .
Library . . . . .
C Syntax . . . .
Description . . .
Parameters . . .
Errors . . . . .
Associated Gets .
Files . . . . . .
Related Information
glMaterial Subroutine.
Purpose . . . .
Library . . . . .
C Syntax . . . .
Description . . .
Parameters . . .
Notes . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
215
215
215
215
216
216
216
216
216
216
216
217
217
217
217
217
218
218
218
218
218
218
220
220
221
221
221
221
221
221
221
222
222
225
225
225
225
226
226
226
226
226
226
227
227
227
227
228
228
228
228
228
228
228
229
230
xxv
Errors . . . . . . . . . . . . .
Associated Gets . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
glMatrixMode Subroutine . . . . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Associated Gets . . . . . . . . .
Errors . . . . . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
glMultiDrawArraysEXT Subroutine . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Notes . . . . . . . . . . . . .
Errors . . . . . . . . . . . . .
Related Information . . . . . . . .
glMultiDrawElementsEXT Subroutine . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Notes . . . . . . . . . . . . .
Errors . . . . . . . . . . . . .
Associated Gets . . . . . . . . .
Related Information . . . . . . . .
glMultiModeDrawArraysIBM Subroutine . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Notes . . . . . . . . . . . . .
Error Codes . . . . . . . . . . .
Related Information . . . . . . . .
glMultiModeDrawElementsIBM Subroutine .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Notes . . . . . . . . . . . . .
Errors . . . . . . . . . . . . .
Related Information . . . . . . . .
glMultiTexCoordARB Subroutine . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
xxvi
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
230
230
230
230
230
230
230
230
231
231
231
231
231
231
231
231
231
231
232
232
232
232
232
233
233
233
233
233
233
233
234
234
234
234
234
234
234
234
234
235
235
235
235
235
235
235
235
236
236
236
236
236
236
236
237
238
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glMultMatrix Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glMultTransposeMatrixARB Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glNewList or glEndList Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Associated Gets . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glNormal Subroutine . . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Associated Gets . . . . . . .
Related Information . . . . . .
glNormalPointer Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Related Information . . . . . .
glNormalPointerEXT Subroutine. . .
Purpose . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
238
239
239
239
239
239
239
239
239
239
240
240
240
240
240
240
240
241
241
241
241
241
241
241
241
241
241
242
242
242
242
242
243
243
243
243
243
243
243
244
244
244
244
244
244
244
244
245
245
245
245
246
246
246
246
246
xxvii
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
File . . . . . . . . . . .
Related Information . . . . .
glNormalPointerListIBM Subroutine
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glNormalVertexSUN Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glOrtho Subroutine . . . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glPassThrough Subroutine. . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glPixelMap Subroutine . . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Errors . . . . . . . . . .
xxviii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
246
246
246
247
247
247
247
248
248
248
248
248
248
248
249
249
249
249
249
250
250
250
250
250
250
250
251
251
251
251
251
251
251
252
252
252
252
252
253
253
253
253
253
253
253
253
253
253
253
254
254
254
254
254
255
255
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glPixelStore Subroutine . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glPixelTransfer Subroutine .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glPixelZoom Subroutine. .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Parameters . . . . .
Description . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glPointSize Subroutine . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Notes . . . . . . .
Parameters . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glPolygonMode Subroutine
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Description . . . . .
Parameters . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Examples . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
256
256
256
256
256
256
257
257
261
261
261
261
262
262
262
262
262
262
262
265
265
265
265
266
266
266
266
266
266
266
266
267
267
267
267
267
267
267
267
267
268
268
268
268
269
269
269
269
269
269
269
269
269
270
270
270
xxix
Files . . . . . . . . . . . .
Related Information . . . . . .
glPolygonOffset Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Related Information . . . . . .
glPolygonOffsetEXT Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
File . . . . . . . . . . . .
Related Information . . . . . .
glPolygonStipple Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Associated Gets . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glPrioritizeTextures Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Parameters . . . . . . . . .
Description . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
Related Information . . . . . .
glPrioritizeTexturesEXT Subroutine .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Parameters . . . . . . . . .
Description . . . . . . . . .
Notes . . . . . . . . . . .
Errors . . . . . . . . . . .
Associated Gets . . . . . . .
File . . . . . . . . . . . .
Related Information . . . . . .
glPushAttrib or glPopAttrib Subroutine
Purpose . . . . . . . . . .
xxx
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
270
270
270
270
270
270
270
271
271
271
271
271
271
271
271
271
271
271
272
272
272
272
272
272
272
272
272
272
273
273
273
273
273
273
273
273
273
273
274
274
274
274
274
274
274
274
275
275
275
275
275
275
276
276
276
276
Library . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . .
Description . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . .
Files . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . .
glPushClientAttrib or glPopClientAttrib Subroutine
Purpose . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . .
Description . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . .
Related Information . . . . . . . . . .
glPushMatrix or glPopMatrix Subroutine . . . .
Purpose . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . .
Description . . . . . . . . . . . . .
Error Codes . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . .
Files . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . .
glPushName or glPopName Subroutine . . . .
Purpose . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . .
Description . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . .
Error Codes . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . .
glRasterPos Subroutine. . . . . . . . . .
Purpose . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . .
Description . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . . .
Files . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . .
glReadBuffer Subroutine . . . . . . . . .
Purpose . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . .
Description . . . . . . . . . . . . .
Error Codes . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
276
276
276
276
279
279
279
279
280
280
280
280
280
280
280
280
281
281
281
281
281
281
281
281
282
282
282
282
282
282
282
283
283
283
283
283
283
283
283
283
284
284
285
285
286
286
286
286
286
286
286
286
287
287
287
287
xxxi
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glReadPixels Subroutine .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Parameters . . . . .
Description . . . . .
Notes . . . . . . .
Error Codes . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
glRect Subroutine . . . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Parameters . . . . .
Description . . . . .
Errors . . . . . . .
Files . . . . . . . .
Related Information . .
glRenderMode Subroutine .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Parameters . . . . .
Description . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Return Values . . . .
Files . . . . . . . .
Related Information . .
glRotate Subroutine . . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Parameters . . . . .
Description . . . . .
Associated Gets . . .
Errors . . . . . . .
Files . . . . . . . .
Related Information . .
glScale Subroutine . . .
Purpose . . . . . .
Library . . . . . . .
C Syntax . . . . . .
Parameters . . . . .
Description . . . . .
Notes . . . . . . .
Errors . . . . . . .
Associated Gets . . .
Files . . . . . . . .
Related Information . .
xxxii
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
287
287
287
288
288
288
288
288
288
293
293
293
294
294
294
294
294
294
295
295
295
295
295
295
295
295
295
295
296
296
296
297
297
297
297
297
297
297
297
297
297
298
298
298
298
298
298
298
298
299
299
299
299
299
300
300
glScissor Subroutine . . . . . . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Parameters . . . . . . . . . . .
Description . . . . . . . . . . .
Errors . . . . . . . . . . . . .
Associated Gets . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
glSecondaryColorEXT Subroutine . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Files . . . . . . . . . . . . . .
glSecondaryColorPointerEXT Subroutine .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
glSecondaryColorPointerListIBM Subroutine
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
Notes . . . . . . . . . . . . .
Error Codes . . . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
glSelectBuffer Subroutine . . . . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Parameters . . . . . . . . . . .
Description . . . . . . . . . . .
Notes . . . . . . . . . . . . .
Errors . . . . . . . . . . . . .
Associated Gets . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
glShadeModel Subroutine . . . . . . .
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Parameters . . . . . . . . . . .
Description . . . . . . . . . . .
Errors . . . . . . . . . . . . .
Associated Gets . . . . . . . . .
Files . . . . . . . . . . . . . .
Related Information . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
300
300
300
300
300
300
300
301
301
301
301
301
301
301
302
302
302
302
302
302
302
303
303
303
303
304
304
304
304
304
304
305
305
306
306
306
306
306
306
306
306
307
307
307
307
307
308
308
308
308
308
308
308
308
309
309
xxxiii
glStencilFunc Subroutine . . . . . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Description . . . . . . . . . . . .
Notes . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
glStencilMask Subroutine . . . . . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Description . . . . . . . . . . . .
Errors . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
glStencilOp Subroutine . . . . . . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Description . . . . . . . . . . . .
Notes . . . . . . . . . . . . . .
Errors . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
glTexCoord Subroutine . . . . . . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Description . . . . . . . . . . . .
Notes . . . . . . . . . . . . . .
Associated Gets . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
glTexCoordColorNormalVertexSUN Subroutine
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Notes . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
glTexCoordColorVertexSUN Subroutine . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
xxxiv
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
309
309
309
309
309
309
310
310
310
310
311
311
311
311
311
311
311
311
311
311
311
312
312
312
312
312
312
313
313
313
313
313
314
314
314
314
315
315
316
316
316
316
316
316
316
316
317
317
318
318
318
318
318
318
318
319
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glTexCoordNormalVertexSUN Subroutine
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glTexCoordPointer Subroutine . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information . . . . . . .
glTexCoordPointerEXT Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Parameters . . . . . . . . . .
Description . . . . . . . . . .
Notes . . . . . . . . . . . .
Errors . . . . . . . . . . . .
Associated Gets . . . . . . . .
File . . . . . . . . . . . . .
Related Information . . . . . . .
glTexCoordPointerListIBM Subroutine .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Error Codes . . . . . . . . . .
Associated Gets . . . . . . . .
Related Information . . . . . . .
glTexCoordVertexSUN Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Notes . . . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glTexEnv Subroutine . . . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
319
319
319
319
319
319
319
320
320
320
320
320
320
321
321
321
321
321
321
321
322
322
322
322
322
322
322
322
323
323
323
324
324
324
324
324
324
324
324
325
325
326
326
326
326
326
326
326
326
327
327
327
327
327
327
327
xxxv
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Notes . . . . . . . .
Error Codes . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glTexGen Subroutine . . . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Error Codes . . . . . .
Associated Gets . . . .
Files . . . . . . . . .
Related Information . . .
glTexImage1D Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Related Information . . .
glTexImage2D Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Related Information . . .
glTexImage3D Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
Associated Gets . . . .
Related Information . . .
glTexImage3DEXT Subroutine
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Parameters . . . . . .
Description . . . . . .
Notes . . . . . . . .
Errors . . . . . . . .
xxxvi
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
327
328
329
332
332
332
333
333
333
333
333
333
333
334
336
336
336
336
336
336
336
336
337
337
341
341
342
342
342
342
342
342
343
343
347
347
348
348
348
348
348
348
348
349
353
353
353
353
354
354
354
354
354
355
357
358
Associated Gets . . . . . .
Related Information . . . . .
glTexParameter Subroutine . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glTexSubImage1D Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glTexSubImage1DEXT Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
File . . . . . . . . . . .
Related Information . . . . .
glTexSubImage2D Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glTexSubImage2DEXT Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
File . . . . . . . . . . .
Related Information . . . . .
glTexSubImage3D Subroutine . .
Purpose . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
358
358
359
359
359
359
359
360
362
362
362
362
362
362
362
363
363
363
367
367
368
368
368
368
368
368
368
369
369
369
370
370
370
370
370
370
370
370
371
375
375
376
376
376
376
376
376
377
377
377
377
378
378
378
378
378
xxxvii
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glTexSubImage3DEXT Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glTranslate Subroutine . . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glUnLockArraysEXT Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Errors . . . . . . . . . .
Related Information . . . . .
glVertex Subroutine . . . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glVertexPointer Subroutine . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glVertexPointerEXT Subroutine . .
Purpose . . . . . . . . .
xxxviii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
378
378
379
379
383
383
384
384
384
384
384
384
384
385
385
385
386
386
386
386
386
386
386
386
387
387
387
387
387
387
388
388
388
388
388
388
388
388
388
389
390
390
390
390
390
390
390
390
390
391
391
391
391
391
392
392
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Notes . . . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
File . . . . . . . . . . .
Related Information . . . . .
glVertexPointerListIBM Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . . .
Associated Gets . . . . . .
Related Information . . . . .
glViewport Subroutine . . . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Parameters . . . . . . . .
Description . . . . . . . .
Errors . . . . . . . . . .
Associated Gets . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glVisibilityBufferIBM Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glVisibilityThresholdIBM Subroutine
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
392
392
392
392
392
393
393
393
393
394
394
394
394
394
394
395
395
395
395
395
395
396
396
396
396
396
396
396
396
396
396
397
397
397
397
398
398
398
398
398
398
398
398
398
398
398
399
399
Chapter 2. OpenGL Utility (GLU) Library.
gluBeginCurve or gluEndCurve Subroutine.
Purpose . . . . . . . . . . . .
Library . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . .
Description . . . . . . . . . . .
Parameters . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
401
402
402
402
402
403
403
Contents
xxxix
Examples . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
gluBeginPolygon or gluEndPolygon Subroutine
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Notes . . . . . . . . . . . . . .
Examples . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
gluBeginSurface or gluEndSurface Subroutine
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Examples . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
gluBeginTrim or gluEndTrim Subroutine . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Examples . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
gluBuild1DMipmapLevels Subroutine . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
Notes . . . . . . . . . . . . . .
Error Codes . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
gluBuild1DMipmaps Subroutine . . . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
Parameters . . . . . . . . . . . .
NOTES. . . . . . . . . . . . . .
ERRORS . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . .
Related Information . . . . . . . . .
gluBuild2DMipmapLevels Subroutine . . . .
Purpose . . . . . . . . . . . . .
Library . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . .
Description . . . . . . . . . . . .
xl
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
403
403
403
403
403
403
403
403
404
404
404
404
404
404
404
404
404
405
405
405
405
405
405
405
405
405
406
406
406
407
407
407
407
407
407
407
407
409
409
410
410
410
410
410
410
410
411
413
414
414
414
414
414
414
414
414
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluBuild2DMipmaps Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluBuild3DMipmapLevels Subroutine .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluBuild3DMipmaps Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluCheckExtension Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluCylinder Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluDeleteNurbsRenderer Subroutine .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
415
417
417
418
418
418
418
418
418
418
419
421
421
422
422
422
422
422
422
422
423
425
425
426
426
426
426
426
426
426
427
429
429
430
430
430
430
430
430
431
431
431
431
431
431
431
431
431
431
432
432
432
432
432
432
432
Contents
xli
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluDeleteQuadric Subroutine . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluDeleteTess Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluDisk Subroutine . . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluErrorString Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluGetNurbsProperty Subroutine
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluGetString Subroutine . . .
Purpose . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Error Codes . . . . . . .
Related Information . . . .
gluGetTessProperty . . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
xlii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
432
432
433
433
433
433
433
433
433
433
433
433
433
433
433
433
434
434
434
434
434
434
434
434
434
435
435
435
435
435
435
435
435
435
436
436
436
436
436
436
436
436
436
437
437
437
437
437
437
437
437
438
438
438
438
438
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Related Information . . . . . .
gluLoadSamplingMatrices Subroutine.
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluLookAt Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNewNurbsRenderer Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNewQuadric Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNewTess Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNextContour Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Examples . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNurbsCallback Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
438
438
438
438
438
438
438
439
439
439
439
439
439
439
439
439
440
440
440
440
440
440
440
441
441
441
441
441
441
441
441
441
441
441
441
441
442
442
442
442
442
442
442
442
442
442
443
443
443
443
443
443
443
444
444
446
xliii
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNurbsCallbackData Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNurbsCallbackDataEXT Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNurbsCurve Subroutine. . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Examples . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNurbsProperty Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluNurbsSurface Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Examples . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluOrtho2D Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
gluPartialDisk Subroutine . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
xliv
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
446
446
446
446
447
447
447
447
447
447
447
447
447
447
447
447
448
448
448
448
448
448
448
448
449
449
449
449
449
449
449
449
452
452
452
453
453
453
453
453
453
453
454
454
454
454
454
454
454
454
455
455
455
455
455
455
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluPerspective Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluPickMatrix Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Examples . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluProject Subroutine . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Return Values . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluPwlCurve Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluQuadricCallback Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
gluQuadricDrawStyle Subroutine
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
455
455
456
456
456
456
456
456
456
456
457
457
457
457
457
457
457
458
458
458
458
458
459
459
459
459
459
459
459
460
460
460
460
460
460
460
460
460
461
461
461
461
461
461
461
461
461
461
461
461
462
462
462
462
462
462
xlv
gluQuadricNormals Subroutine . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
gluQuadricOrientation Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
gluQuadricTexture Subroutine . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
gluScaleImage Subroutine . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Return Values . . . . . . . . .
Error Codes . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
gluSphere Subroutine . . . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
gluTessBeginContour, gluTessEndContour
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Related Information . . . . . . .
gluTessBeginPolygon Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Examples . . . . . . . . . . .
xlvi
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
462
462
462
462
463
463
463
463
463
463
463
463
463
464
464
464
464
464
464
464
464
464
464
464
465
465
465
465
465
465
467
467
467
467
467
467
467
467
467
468
468
468
468
468
468
468
468
468
469
469
469
469
469
469
469
469
Related Information . . .
gluTessCallback Subroutine .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Examples . . . . . . .
Files . . . . . . . . .
Related Information . . .
gluTessEndPolygon Subroutine
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Examples . . . . . . .
Related Information . . .
gluTessNormal Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Related Information . . .
gluTessProperty Subroutine .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Related Information . . .
gluTessVertex Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Files . . . . . . . . .
Examples . . . . . . .
Notes . . . . . . . .
Related Information . . .
gluUnProject Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
Parameters . . . . . .
Return Values . . . . .
Files . . . . . . . . .
Related Information . . .
gluUnProject4 Subroutine . .
Purpose . . . . . . .
Library . . . . . . . .
C Syntax . . . . . . .
Description . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
470
470
470
470
470
470
473
473
474
474
474
474
474
474
474
474
474
475
475
475
475
475
475
476
476
476
476
476
476
476
478
478
478
478
478
478
478
478
478
479
479
479
479
479
479
479
480
480
480
480
480
480
480
481
481
481
xlvii
Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481
Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482
Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482
Chapter 3. OpenGL in the AIXwindows (GLX) Environment
Related Information . . . . . . . . . . . . . . . .
How to Render into an X Drawable . . . . . . . . . .
Procedure. . . . . . . . . . . . . . . . . . .
Example . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . .
OpenGL in the AIXwindows environment (GLX) Subroutines .
glXChooseFBConfig Subroutine. . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . . . .
Return Values . . . . . . . . . . . . . . . . .
Examples . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . .
glXChooseVisual Subroutine . . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . . . .
Return Values . . . . . . . . . . . . . . . . .
Examples . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . .
glXCopyContext Subroutine . . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . . . .
Error Codes . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . .
glXCreateContext Subroutine. . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . . . .
Error Codes . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . .
glXCreateGLXPixmap Subroutine . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . .
xlviii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
483
483
483
483
484
486
486
487
487
487
488
488
490
490
490
490
490
491
491
491
491
491
491
493
493
494
494
494
494
494
494
494
495
495
495
495
495
496
496
496
496
496
496
496
497
497
497
497
497
497
497
497
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glXCreateNewContext Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Notes . . . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glXCreatePbuffer Subroutine . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glXCreatePixmap Subroutine . . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glXCreateWindow Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glXDestroyContext Subroutine . .
Purpose . . . . . . . . .
Library . . . . . . . . . .
C Syntax . . . . . . . . .
Description . . . . . . . .
Parameters . . . . . . . .
Error Codes . . . . . . . .
Files . . . . . . . . . . .
Related Information . . . . .
glXDestroyGLXPixmap Subroutine .
Purpose . . . . . . . . .
Library . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
498
498
498
498
498
498
498
499
499
499
499
499
499
500
500
500
500
500
500
500
500
500
501
501
502
502
502
502
502
502
502
502
503
503
503
503
503
503
503
503
503
504
504
504
504
504
504
504
504
504
505
505
505
505
505
505
xlix
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXDestroyPbuffer Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXDestroyPixmap Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXDestroyWindow Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXFreeContextEXT Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Errors . . . . . . . . .
Related Information . . . .
glXGetClientString Subroutine .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Related Information . . . .
glXGetConfig Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
l
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
505
505
505
505
505
506
506
506
506
506
506
506
506
506
506
506
506
507
507
507
507
507
507
507
507
507
507
507
507
508
508
508
508
508
508
508
508
508
508
508
509
509
509
509
509
509
509
509
510
510
510
510
510
510
512
512
Return Values . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glXGetContextIDEXT Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Errors . . . . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glXGetCurrentContext Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Return Values . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glXGetCurrentDisplay Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Notes . . . . . . . . . . . .
Related Information . . . . . . .
glXGetCurrentDrawable Subroutine . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Return Values . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glXGetCurrentReadDrawable Subroutine
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Return Values . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glXGetFBConfigAttrib Subroutine . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
Description . . . . . . . . . .
Parameters . . . . . . . . . .
Return Values . . . . . . . . .
Files . . . . . . . . . . . . .
Related Information . . . . . . .
glXGetFBConfigs Subroutine . . . . .
Purpose . . . . . . . . . . .
Library . . . . . . . . . . . .
C Syntax . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Contents
513
513
513
513
513
513
513
513
513
513
514
514
514
514
514
514
514
514
514
514
515
515
515
515
515
515
515
515
515
515
515
515
515
516
516
516
516
516
516
516
516
516
516
517
517
517
517
517
520
520
520
520
520
520
521
521
li
Description . . . . . . . . .
Parameters . . . . . . . . .
Return Values . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXGetProcAddressARB Subroutine .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Return Values . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXGetSelectedEvent Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXGetVisualFromFBConfig Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Notes . . . . . . . . . . .
Return Values . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXImportContextEXT Subroutine . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXIsDirect Subroutine . . . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Return Values . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXMakeContextCurrent Subroutine .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
lii
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
521
521
521
521
521
521
521
521
521
522
522
522
522
522
523
523
523
523
523
523
523
523
523
523
523
523
524
524
524
524
524
524
524
524
524
524
524
525
525
525
525
525
525
525
525
526
526
526
526
526
526
526
526
526
526
526
Description . . . . . . . . .
Parameters . . . . . . . . .
Return Values . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXMakeCurrent Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Return Values . . . . . . . .
Notes . . . . . . . . . . .
Error Codes . . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXQueryContext Subroutine . . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Related Information . . . . . .
glXQueryContextInfoEXT Subroutine .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Related Information . . . . . .
glXQueryDrawable Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Parameters . . . . . . . . .
Errors . . . . . . . . . . .
Related Information . . . . . .
glXQueryExtension Subroutine . . .
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
Description . . . . . . . . .
Notes . . . . . . . . . . .
Parameters . . . . . . . . .
Return Values . . . . . . . .
Files . . . . . . . . . . . .
Related Information . . . . . .
glXQueryExtensionsString Subroutine
Purpose . . . . . . . . . .
Library . . . . . . . . . . .
C Syntax . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
527
527
527
527
528
528
528
528
528
528
528
528
529
529
529
529
530
530
530
530
530
530
530
530
531
531
531
531
531
531
531
531
531
531
532
532
532
532
532
532
532
533
533
533
533
533
533
533
533
533
533
534
534
534
534
534
Contents
liii
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Related Information . . . .
glXQueryServerString Subroutine
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXQueryVersion Subroutine . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Return Values . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXSelectEvent Subroutine . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXSwapBuffers Subroutine . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Notes . . . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXUseXFont Subroutine . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Parameters . . . . . . .
Error Codes . . . . . . .
Files . . . . . . . . . .
Related Information . . . .
glXWaitGL Subroutine . . . .
Purpose . . . . . . . .
Library . . . . . . . . .
C Syntax . . . . . . . .
Description . . . . . . .
Notes . . . . . . . . .
liv
OpenGL 2.1 Reference Manual
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
534
534
534
534
534
534
534
535
535
535
535
535
535
535
535
535
536
536
536
536
536
536
536
536
536
536
537
538
538
538
538
538
538
538
538
539
539
539
539
539
539
539
539
539
540
540
540
540
540
540
541
541
541
541
541
541
Files . . . . . .
Related Information
glXWaitX Subroutine .
Purpose . . . .
Library . . . . .
C Syntax . . . .
Description . . .
Notes . . . . .
Error Codes . . .
Files . . . . . .
Related Information
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
541
541
541
541
541
541
542
542
542
542
542
Chapter 4. OpenGL Drawing Widgets and Related Functions
GLwCreateMDrawingArea Function . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . . .
GLwDrawingArea or GLwMDrawingArea Widget. . . . . . .
Purpose . . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . .
New Resources . . . . . . . . . . . . . . . . .
Inherited Resources . . . . . . . . . . . . . . . .
Callback Information . . . . . . . . . . . . . . . .
Translations . . . . . . . . . . . . . . . . . . .
Action Routines. . . . . . . . . . . . . . . . . .
Initialization . . . . . . . . . . . . . . . . . . .
Notes . . . . . . . . . . . . . . . . . . . . .
Examples . . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . . .
GLwDrawingAreaMakeCurrent Function . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . . .
GLwDrawingAreaSwapBuffers Function . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . . .
Library . . . . . . . . . . . . . . . . . . . . .
C Syntax . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . .
Parameters . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . . .
Related Information . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
543
543
543
543
543
543
543
543
544
544
544
544
544
544
545
548
548
548
549
549
549
549
551
551
551
551
551
551
551
551
551
552
552
552
552
552
552
552
552
552
Appendix. Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555
Contents
lv
lvi
OpenGL 2.1 Reference Manual
About This Book
OpenGL Programmer’s Reference provides reference information on the OpenGL application programming
interface (API).
This publication documents the functional interface of:
v OpenGL 1.2 (first introduced in AIX 4.3.2)
v GLX 1.3 (first introduced in AIX 4.3.2)
v GLU 1.3 (first introduced in AIX 4.3.3)
It also documents several OpenGL extensions supported on this operating system.
Applications/users should query OpenGL to determine if the extension is supported
(glXQueryExtensionsString, glGetString, and gluGetString) prior to making extension specific OpenGL,
GLX, or GLU calls.
Further information is also avaiable in /usr/lpp/OpenGL/README on your installed operating system.
Who Should Use This Book
This book is intended for programmers with C programming knowledge who want to develop 3D
applications.
Highlighting
The following highlighting conventions are used in this book:
Bold
Italics
Monospace
Identifies commands, subroutines, keywords, files,
structures, directories, and other items whose names are
predefined by the system. Also identifies graphical objects
such as buttons, labels, and icons that the user selects.
Identifies parameters whose actual names or values are to
be supplied by the user.
Identifies examples of specific data values, examples of
text similar to what you might see displayed, examples of
portions of program code similar to what you might write
as a programmer, messages from the system, or
information you should actually type.
ISO 9000
ISO 9000 registered quality systems were used in the development and manufacturing of this product.
Related Publications
The following books contain information about or related to OpenGL Programmer’s Reference:
v AIX 5L for POWER-based Systems OpenGL 2.1 Reference Manual
v AIX 5L Version 5.1 General Programming Concepts: Writing and Debugging Programs
v GL3.2 Version 4.1 for AIX: Programming Concepts (POWER-based Systems Only)
v GL3.2 for AIX: Graphics Library (GL) Technical Reference (POWER-based Systems Only)
© Copyright IBM Corp. 1994, 2000
lvii
Trademarks
The following terms are trademarks of International Business Machines Corporation in the United States,
other countries, or both:
v AIXwindows
UNIX is a registered trademark of The Open Group in the United States and other countries.
Other company, product, or service names may be the trademarks or service marks of others.
lviii
OpenGL 2.1 Reference Manual
Chapter 1. OpenGL Subroutines
Following is a list of the basic OpenGL subroutines and the purpose of each.
A
glAccum
glActiveTextureARB
glAlphaFunc
glAreTexturesResident
glAreTexturesResidentEXT
glArrayElement
glArrayElementEXT
B
glBegin or glEnd
glBindTexture
glBindTextureEXT
glBitmap
glBlendColor
glBlendColorEXT
glBlendEquation
glBlendEquationEXT
glBlendFunc
glBlendFuncSeparateEXT
C
glCallList
glCallLists
glClear
glClearAccum
glClearColor
glClearDepth
glClearIndex
glClearStencil
glClientActiveTextureARB
glClipBoundingBoxIBM or glClipBoundingSphereIBM or
glClipBoundingVerticesIBM
glClipPlane
glColor
glColorMask
glColorMaterial
glColorNormalVertexSUN
glColorPointer
glColorPointerEXT
glColorPointerListIBM
glColorSubTable
glColorTable
glColorTableParameter
glColorVertexSUN
© Copyright IBM Corp. 1994, 2000
Operates on the accumulation buffer.
Specifies which texture unit is active.
Specifies the alpha test function.
Determines if textures are loaded in texture memory.
Determines if textures are loaded in texture memory.
Renders a vertex using the specified vertex array
element.
Renders a vertex using the specified vertex array
element.
Delimits the vertices of a primitive or group of like
primitives.
Binds a named texture to a texturing target.
Binds a named texture to a texturing target.
Draws a bitmap.
Sets the blend color.
Sets the blend color.
Specifies the RGB color blend equation.
Specifies the RGB color blend equation.
Specifies pixel arithmetic.
Specifies separate RGB and Alpha blend factors.
Executes a display list.
Executes a list of display lists.
Clears buffers within the viewport.
Specifies clear values for the accumulation buffer.
Specifies clear values for the color buffers.
Specifies the clear value for the depth buffer.
Specifies the clear value for the color index buffers.
Specifies the clear value for the stencil buffer.
Specifies which texture unit is active.
Determines whether the specified object is trivially
accepted, trivially rejected, or clipped by the current set
of clipping planes.
Specifies a plane against which all geometry is clipped.
Sets the current color.
Enables and disables the writing of frame buffer color
components.
Causes a material color to track the current color.
Specifies a color, a normal and a vertex in one call.
Defines an array of colors.
Defines an array of colors.
Defines a list of color arrays.
Defines a contiguous subset of a color lookup table.
Defines a color lookup table.
Specifies attributes to be used when loading a color
table.
Specifies a color and a vertex in one call.
1
glCopyColorSubTable
glCopyColorTable
glCopyPixels
glCopyTexImage1D
glCopyTexImage2D
glCopyTexSubImage1D
glCopyTexSubImage2D
glCopyTexSubImage3D
glCopyTexSubImage3DEXT
glCullFace
D
glDeleteLists
glDeleteTextures
glDeleteTexturesEXT
glDepthFunc
glDepthMask
glDepthRange
glDisable
glDisableClientState
glDrawArrays
glDrawArraysEXT
glDrawBuffer
glDrawElements
glDrawPixels
glDrawRangeElements
E
glEdgeFlag
glEdgeFlagPointer
glEdgeFlagPointerEXT
glEdgeFlagPointerListIBM
glEnable or glDisable
glEnableClientState orglDisableClientState
glEnd
Loads a subset of a color lookup table from the current
GL_READ_BUFFER.
Load a color lookup table from the current
GL_READ_BUFFER.
Copies pixels in the frame buffer.
Defines a one-dimensional (1D) texture image.
Defines a two-dimensional (2D) texture image.
Copies a one-dimensional (1D) texture subimage.
Copies a two-dimensional (2D) texture subimage.
Copies a three-dimensional (3D) texture subimage.
Copies a three-dimensional (3D) texture subimage.
Specifies whether frontfacing or backfacing facets may
be culled.
Deletes a contiguous group of display lists.
Deletes named textures.
Deletes named textures.
Specifies the function used for depth buffer
comparisons.
Enables or disables writing into the depth buffer.
Specifies the mapping of z values from normalized
device coordinates to window coordinates.
Tests whether a capability is enabled.
Disables an array.
Renders primitives from array data.
Renders primitives from array data.
Specifies which color buffers are to be used for drawing.
Renders primitives from array data.
Writes a block of pixels to the frame buffer.
Renders primitives from array data.
glEvalPoint
Marks edges as either boundary or nonboundary.
Defines an array of edge flags.
Defines an array of edge flags.
Defines a list of edge flag arrays.
Tests whether a capability is enabled.
Enables or disables an array.
Delimits the vertices of a primitive or group of like
primitives.
Evaluates enabled one-dimensional (1D) and
two-dimensional (2D) maps.
Computes a one-dimensional (1D) or two-dimensional
(2D) grid of points or lines.
Generates and evaluates a single point in a mesh.
F
glFeedbackBuffer
glFinish
glFlush
glFog
glFogCoordEXT
glFogCoordPointerEXT
glFogCoordPointerListIBM
glFrontFace
Controls the feedback mode.
Blocks until all GL execution is complete.
Forces the running of GL subroutines in finite time.
Specifies fog parameters.
Specifies a Fog Coordinate.
Specifies an array of fog coordinates.
Defines a list of arrays of fog coordinates.
Defines frontfacing and backfacing polygons.
glEvalCoord
glEvalMesh
2
OpenGL 2.1 Reference Manual
glFrustum
G
glGenLists
glGenTextures
glGenTexturesEXT
glGet
glGetClipPlane
glGetColorTable
glGetColorTableParameter
glGetError
glGetLight
glGetMap
glGetMaterial
glGetPixelMap
glGetPointerv
glGetPointervEXT
glGetPolygonStipple
glGetString
glGetTexEnv
glGetTexGen
glGetTexImage
glGetTexLevelParameter
Multiplies the current matrix by a perspective matrix.
glGetTexParameter
Generates a contiguous set of empty display lists.
Generate texture names.
Generates texture names.
Returns the value or values of a selected parameter.
Returns the coefficients of the clipping plane.
Returns a color lookup table to the user.
Returns attributes used when loading a color table.
Returns error information.
Returns light source parameter values.
Returns evaluator parameters.
Returns material parameters.
Returns the specified pixel map.
Returns the address of the specified pointer.
Returns the address of a vertex data array.
Returns the polygonstipple pattern.
Returns a string describing the current GL connection.
Returns texture environment parameters.
Returns texture coordinate generation parameters.
Returns a texture image.
Returns texture parameter levels for a specific level of
detail.
Returns texture parameter values.
H
glHint
Specifies implementation-specific hints.
I
glIndex
glIndexMask
glIndexPointer
glIndexPointerEXT
glIndexPointerListIBM
glInitNames
glInterleavedArrays
glIsEnabled
glIsList
glIsTexture
glIsTextureEXT
L
glLight
glLightModel
glLineStipple
glLineWidth
glListBase
glLoadIdentity
glLoadMatrix
glLoadName
glLoadNamedMatrixIBM
Sets the current color index.
Controls the writing of individual bits in the color index
buffers.
Defines an array of color indexes.
Defines an array of color indexes.
Defines a list of color index arrays.
Initializes the name stack.
Simultaneously specifies and enables several
interleaved arrays.
Tests whether a capability is enabled.
Tests for display list existence.
Determines if a name corresponds to a texture.
Determines if a name corresponds to a texture.
Sets light source parameters.
Sets the lighting model parameters.
Specifies the line stipple pattern.
Specifies the width of rasterized lines.
Sets the display-list base for the glCallLists subroutine.
Replaces the current matrix with the identity matrix.
Replaces the current matrix with an arbitrary matrix.
Loads a name onto the name stack.
Loads a pre-defined matrix into the top of the named
matrix stack.
Chapter 1. OpenGL Subroutines
3
glLoadTransposeMatrixARB
glLockArraysEXT
glLogicOp
M
glMap1
glMap2
glMapGrid
glMaterial
glMatrixMode
glMultiDrawArraysEXT
glMultiDrawElementsEXT
glMultiModeDrawArraysIBM
glMultiModeDrawElementsIBM
glMultiTexCoordARB
glMultMatrix
glMultTransposeMatrixARB
Loads a matrix in row-major order, rather than
column-major order.
Locks the currently enabled vertex arrays.
Specifies a logical pixel operation for color index
rendering.
Defines a one-dimensional (1D) evaluator.
Defines a two-dimensional (2D) evaluator.
Defines a one-dimensional (1D) or two-dimensional (2D)
mesh.
Specifies material parameters for the lighting model.
Specifies the current matrix.
Renders multiple primitives from array data.
Renders multiple primitives from array data.
Renders primitives of multiple primitive types from array
data.
Renders primitives of multiple primitive types from array
data.
Sets the current texture coordinates.
Multiplies the current matrix by an arbitrary matrix.
Multiplies the current matrix by a matrix specified in
row-major order, rather than column-major order.
N
glNewList
glNormal
glNormalPointer
glNormalPointerEXT
glNormalPointerListIBM
glNormalVertexSUN
Creates or replaces a display list.
Sets the current normal vector.
Defines an array of normals.
Defines an array of normals.
Defines a list of normal arrays.
Specifies a normal and a vertex in one call.
O
glOrtho
Multiplies the current matrix by an orthographic matrix.
P
glPassThrough
glPixelMap
glPixelStore
glPixelTransfer
glPixelZoom
glPointSize
glPolygonMode
glPolygonOffset
glPolygonOffsetEXT
glPolygonStipple
glPrioritizeTextures
glPrioritizeTexturesEXT
glPushAttrib or glPopAttrib
glPushClientAttrib or glPopClientAttrib
glPushMatrix or glPopMatrix
glPushName or glPopName
Places a marker in the feedback buffer.
Sets up pixel transfer maps.
Sets pixel storage modes.
Sets pixel transfer modes.
Specifies the pixel zoom factors.
Specifies the diameter of rasterized points.
Selects a polygon rasterization mode.
Sets the scale and bias used to calculate depth values.
Sets the scale and bias used to calculate z values.
Sets the polygon stippling pattern.
Sets texture residence priority.
Sets texture residence priority.
Pushes and pops the attribute stack.
Pushes and pops the attribute stack.
Pushes and pops the current matrix stack.
Pushes and pops the name stack.
R
glRasterPos
glReadBuffer
Specifies the raster position for pixel operations.
Selects a color buffer source for pixels.
4
OpenGL 2.1 Reference Manual
glReadPixels
glRect
glRenderMode
glRotate
S
glScale
glScissor
glSecondaryColorEXT
glSecondaryColorPointerEXT
glSecondaryColorPointerListIBM
glSelectBuffer
glShadeModel
glStencilFunc
glStencilMask
glStencilOp
T
glTexCoord
glTexCoordColorNormalVertexSUN
Reads a block of pixels from the frame buffer.
Draws a rectangle.
Sets rasterization mode.
Multiplies the current matrix by a rotation matrix.
Multiplies the current matrix by a general scaling matrix.
Defines the scissor box.
Specifies an RGB color used by the Color Sum stage.
Specifies an array of secondary colors.
Defines a list of arrays of secondary colors.
Establishes a buffer for selection mode values.
Selects flat or smooth shading.
Sets function and reference values for stencil testing.
Controls the writing of individual bits in the stencil
planes.
Sets stencil test actions.
glTexCoordPointer
glTexCoordPointerEXT
glTexCoordPointerListIBM
glTexCoordVertexSUN
glTexEnv
glTexGen
glTexImage1D
glTexImage2D
glTexImage3D
glTexImage3DEXT
glTexParameter
glTexSubImage1D
glTexSubImage1DEXT
glTexSubImage2D
glTexSubImage2DEXT
glTexSubImage3D
glTexSubImage3DEXT
glTranslate
Sets the current texture coordinates.
Specifies a texture coordinate, a color, a normal and a
vertex in one call.
Specifies a texture coordinate, a color, and a vertex in
one call.
Specifies a texture coordinate, a normal and a vertex in
one call.
Defines an array of texture coordinates.
Defines an array of texture coordinates.
Defines a list of texture coordinate arrays.
Specifies a texture coordinate and a vertex in one call.
Sets texture environment parameters.
Controls the generation of texture coordinates.
Specifies a one-dimensional (1D) texture image.
Specifies a two-dimensional (2D) texture image.
Specifies a three-dimensional (3D) texture image.
Specifies a three-dimensional (3D) texture image.
Sets texture parameters.
Specifies a one-dimensional (1D) texture subimage.
Specifies a one-dimensional (1D) texture subimage.
Specifies a two-dimensional (2D) texture subimage.
Specifies a two-dimensional (2D) texture subimage.
Specifies a three-dimensional (3D) texture subimage.
Specifies a three-dimensional (3D) texture subimage.
Multiplies the current matrix by a translation matrix.
U
glUnLockArraysEXT
Unlocks the currently enabled vertex arrays.
glTexCoordColorVertexSUN
glTexCoordNormalVertexSUN
V
glVertex
glVertexPointer
glVertexPointerEXT
glVertexPointerListIBM
glViewport
glVisibilityBufferIBM
Specifies a vertex.
Defines an array of vertex data.
Defines an array of vertex data.
Defines a list of vertex arrays.
Sets the viewport.
Specifies the array in which visibility calculation results
are stored.
Chapter 1. OpenGL Subroutines
5
glVisibilityThresholdIBM
Specifies the number of visible fragments rendered
before a visibility hit is registered.
glAccum Subroutine
Purpose
Operates on the accumulation buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glAccum(GLenum
GLfloat
Operation,
Value)
Description
The accumulation buffer is an extended-range color buffer. Images are not rendered into it. Rather, images
rendered into one of the color buffers are added to the contents of the accumulation buffer after rendering.
Effects such as antialiasing (of points, lines, and polygons), motion-blur, and depth of field can be created
by accumulating images generated with different transformation matrices.
Each pixel in the accumulation buffer consists of red, green, blue, and alpha (RGBA) values. The number
of bits per component in the accumulation buffer depends on the implementation. You can examine this
number by calling glGetInteger four times, with arguments GL_ACCUM_RED_BITS,
GL_ACCUM_GREEN_BITS, GL_ACCUM_BLUE_BITS, and GL_ACCUM_ALPHA_BITS, respectively.
(See the glGet subroutine for more information on glGetInteger.) Regardless of the number of bits per
component, however, the range of values stored by each component is [-1,1]. The accumulation buffer
pixels are mapped 1-to-1 with frame buffer pixels.
The glAccum subroutine operates on the accumulation buffer. The first argument, Operation, is a symbolic
constant that selects an accumulation buffer operation. The second argument, Value, is a floating-point
value to be used in that operation. Five operations are specified: GL_LOAD, GL_ACCUM, GL_ADD,
GL_MULT, and GL_RETURN.
All accumulation buffer operations are limited to the area of the current scissor box and are applied
identically to the RGBA components of each pixel. The contents of an accumulation buffer pixel
component are undefined if the glAccum operation results in a value outside the range [-1,1].
The operations are:
GL_ACCUM
GL_LOAD
GL_ADD
GL_MULT
6
Obtains RGBA values from the buffer currently selected for reading. (See glReadBuffer.) Each
component value is divided by 2n-1, where n is the number of bits allocated to each color
component in the currently selected buffer. The result is a floating-point value in the range [0,1],
which is multiplied by value and added to the corresponding pixel component in the accumulation
buffer, thereby updating the accumulation buffer.
Functions similarly to GL_ACCUM, except that the current value in the accumulation buffer is not
used in the calculation of the new value. That is, the RGBA values from the currently selected
buffer are divided by 2n-1, multiplied by Value, and then stored in the corresponding accumulation
buffer cell, overwriting the current value.
Adds Value to each R, G, B, and A in the accumulation buffer.
Multiplies each RGBA in the accumulation buffer by Value and returns the scaled component to its
corresponding accumulation buffer location.
OpenGL 2.1 Reference Manual
GL_RETURN
Transfers accumulation buffer values to the color buffer or buffers currently selected for writing.
Each RGBA component is multiplied by Value, then multiplied by 2n-1, clamped to the range [0,
2n-1] and stored in the corresponding display buffer cell. The only fragment operations that are
applied to this transfer are pixel ownership, scissor, dithering, and color writemasks.
The accumulation buffer is cleared by specifying R, G, B, A values to set it to with the glClearAccum
directive, and then issuing a glClear subroutine with the accumulation buffer enabled.
Parameters
Operation
Value
Specifies the accumulation buffer operation. Symbolic constants GL_LOAD, GL_ACCUM,
GL_MULT, GL_ADD, and GL_RETURN are accepted.
Specifies a floating-point value used in the accumulation buffer operation. The Operation parameter
determines how Value is used.
Notes
All glAccum operations update only those pixels within the current scissor box.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Operation is set to an unaccepted value.
There is no accumulation buffer.
The glAccum subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glAccum subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_ACCUM_RED_BITS
glGet with argument GL_ACCUM_GREEN_BITS
glGet with argument GL_ACCUM_BLUE_BITS
glGet with argument GL_ACCUM_ALPHA_BITS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glBlendFunc subroutine, glClear subroutine, glClearAccum
subroutine, glCopyPixels subroutine, glLogicOp subroutine, glPixelStore subroutine, glPixelTransfer
subroutine, glReadBuffer subroutine, glReadPixels subroutine, glScissor subroutine, glStencilOp
subroutine.
Chapter 1. OpenGL Subroutines
7
glActiveTextureARB Subroutine
Purpose
Specify which texture unit is active.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glActiveTextureARB(GLenum
texture)
Description
glActiveTextureARB selects which texture unit subsequent texture state calls will affect. The number of
texture units an implementation supports is implementation dependent, but must be at least two. The
texture parameter must be one of GL_TEXTUREi_ARB, where 0 <= i <
GL_MAX_TEXTURE_UNITS_ARB. The initial value is GL_TEXTURE0_ARB.
Parameters
texture
specifies which texture unit to make active.
Notes
Vertex arrays are client-side GL resources, which are selected by the glClientActiveTextureARB routine.
If the GL_ARB_multitexture extension is NOT present, then the number of texture units supported by the
implementation is one, not two, as described above.
The following OpenGL subroutines will be routed to different texture units based on this call:
v glEnable (GL_TEXTURE_GEN_*)
v
v
v
v
v
v
glDisable (GL_TEXTURE_GEN_*)
glTexGen*
glTexEnv*
glTexImage*
glTexSubImage*
glCopyTexImage*
v glCopyTexSubImage*
v glBindTexture
Errors
GL_INVALID_OPERATION
is generated if texture is not one of the accepted values.
Files
/usr/include/GL/gl.h
8
OpenGL 2.1 Reference Manual
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glEnableClientState or glDisableClientState subroutine, the glMultiTexCoordARB subroutine, the
glTexCoordPointer.
glAlphaFunc Subroutine
Purpose
Specifies the alpha test function.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glAlphaFunc(GLenum Function,
GLclampf Reference)
Description
The alpha test discards fragments conditional on the outcome of a comparison between the incoming
fragment’s alpha value and a constant reference value. The glAlphaFunc subroutine specifies the
reference and comparison function. The comparison is performed only if alpha testing is enabled. (See
glEnable or glDisable of GL_ALPHA_TEST.)
The Function and Reference parameters specify the conditions under which the pixel is drawn. The
incoming alpha value is compared to the Reference parameter using the function specified by Function. If
the comparison passes, the incoming fragment is drawn, conditional on subsequent stencil and
depth-buffer tests. If the comparison fails, no change is made to the frame buffer at that pixel location.
The comparison functions are:
GL_NEVER
GL_LESS
GL_EQUAL
GL_LEQUAL
GL_GREATER
GL_NOTEQUAL
GL_GEQUAL
GL_ALWAYS
Never passes.
Passes if the incoming
Passes if the incoming
Passes if the incoming
Passes if the incoming
Passes if the incoming
Passes if the incoming
Always passes.
alpha
alpha
alpha
alpha
alpha
alpha
value
value
value
value
value
value
is
is
is
is
is
is
less than the reference value.
equal to the reference value.
less than or equal to the reference value.
greater than the reference value.
not equal to the reference value.
greater than or equal to the reference value.
The glAlphaFunc subroutine operates on all pixel write operations, including those resulting from the scan
conversion of points, lines, polygons, and bitmaps, and those resulting from pixel draw and copy
operations. The glAlphaFunc subroutine does not affect screen clear operations.
Parameters
Function
Reference
Specifies the alpha comparison function. Symbolic constants GL_NEVER, GL_LESS, GL_EQUAL,
GL_LEQUAL, GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, and GL_ALWAYS are accepted.
The default function is GL_ALWAYS.
Specifies the reference value to which incoming alpha values are compared. This value is clamped
to the range 0 (zero) through 1 (one), where 0 represents the lowest possible alpha value, and 1
the highest possible value. The default reference is 0.
Chapter 1. OpenGL Subroutines
9
Notes
Alpha testing is done only in RGBA mode.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Function is set to an unaccepted value.
The glAlphaFunc subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glAlphaFunc subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_ALPHA_TEST_FUNC
glGet with argument GL_ALPHA_TEST_REF
glIsEnabled with argument GL_ALPHA_TEST.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glBlendFunc subroutine, glClear subroutine, glDepthfunc subroutine,
glEnable or glDisable subroutine, glStencilFunc subroutine.
glAreTexturesResident Subroutine
Purpose
Determines if textures are loaded in texture memory.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLboolean glAreTexturesResident(GLsizei
const GLuint * textures,
GLboolean * residences)
n,
Description
On machines with a limited amount of texture memory, OpenGL establishes a “working set” of textures that
are resident in texture memory. These textures may be bound to a texture target much more efficiently
than textures that are not resident.
The glAreTexturesResident subroutine queries the texture residence status of the n textures named by
the elements of textures. If all the named textures are resident, glAreTexturesResident returns GL_TRUE
and the contents of residences are undisturbed. If not all the named textures are resident,
10
OpenGL 2.1 Reference Manual
glAreTexturesResident returns GL_FALSE and detailed status is returned in the n elements of
residences. If an element of residences is GL_TRUE, then the texture named by the corresponding
element of textures is resident.
The residence status of a single bound texture may also be queried by calling glGetTexParameter with
the target argument set to the target to which the texture is bound, and the parameter name argument set
to GL_TEXTURE_RESIDENT. This is the only way that the residence status of a default texture can be
queried.
The glAreTexturesResident subroutine is not included in display lists.
Parameters
n
textures
residences
Specifies the number of textures to be queried.
Specifies an array containing the names of the textures to be queried.
Specifies an array in which the texture residence status is returned. The residence status of a
texture named by an element of textures is returned in the corresponding element of residences.
Notes
The glAreTexturesResident subroutine is available only if the GL version is 1.1 or greater.
The glAreTexturesResident subroutine returns the residency status of the textures at the time of
invocation. It does not guarantee that the textures will remain resident at any other time.
If textures live in virtual memory (there is no texture memory) they are considered always resident.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_VALUE is generated if any element in textures is zero or does not name a texture. In that
case, the function returns GL_FALSE and the contents of residences is indeterminate.
GL_INVALID_OPERATION is generated if glAreTexturesResident is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexParameter with parameter name GL_TEXTURE_RESIDENT retrieves the residence status of a
currently-bound texture.
Related Information
The glBindTexture subroutine, glPrioritizeTextures subroutine, glTexImage1D subroutine,
glTexImage2D subroutine, glTexParameter subroutine.
glAreTexturesResidentEXT Subroutine
Purpose
Renders a vertex using the specified vertex array element.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
11
C Syntax
GLboolean glAreTexturesResidentEXT(GLsizei
const GLuint * textures,
GLboolean
* residences)
n,
Description
On machines with a limited amount of texture memory, OpenGL establishes a “working set” of textures that
are resident in texture memory. These textures may be bound to a texture target much more efficiently
than textures that are not resident.
The glAreTexturesResidentEXT subroutine queries the texture residence status of the n textures named
by the elements of textures. If all the named textures are resident, glAreTexturesResidentEXT returns
GL_TRUE and the contents of residences are undisturbed. If not all the named textures are resident,
glAreTexturesResidentEXT returns GL_FALSE and detailed status is returned in the n elements of
residences. If an element of residences is GL_TRUE, then the texture named by the corresponding
element of textures is resident.
The residence status of a single bound texture may also be queried by calling glGetTexParameter with
the target argument set to the target to which the texture is bound, and the parameter name argument set
to GL_TEXTURE_RESIDENT_EXT. This is the only way that the residence status of a default texture can
be queried.
The glAreTexturesResidentEXT subroutine is not included in display lists.
Parameters
n
textures
residences
Specifies the number of textures to be queried.
Specifies an array containing the names of the textures to be queried.
Specifies an array in which the texture residence status is returned. The residence status of a
texture named by an element of textures is returned in the corresponding element of residences.
Notes
The glAreTexturesResidentEXT subroutine is part of the EXT_texture_object extension, not part of the
core GL command set. If GL_EXT_texture_object is included in the string returned by glGetString (when
called with argument GL_EXTENSIONS), extension EXT_texture_object is supported by the connection.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_VALUE is generated if any element in textures is zero or does not name a texture.
GL_INVALID_OPERATION is generated if glAreTexturesResidentEXT is executed between the
execution of glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexParameter with parameter name GL_TEXTURE_RESIDENT_EXT retrieves the residence status
of a currently-bound texture.
Files
/usr/include/GL/glext.h
12
OpenGL 2.1 Reference Manual
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBindTextureEXT subroutine, glPrioritizeTexturesEXT subroutine, glTexImage1D subroutine,
glTexImage2D subroutine, glTexParameter subroutine.
glArrayElement Subroutine
Purpose
Renders a vertex using the specified vertex array element.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glArrayElement(GLint
i)
Description
The glArrayElement commands are used within glBegin/glEnd pairs to specify vertex and attribute data
for point, line, and polygon primitives. If GL_VERTEX_ARRAY is enabled when glArrayElement is called,
a single vertex is drawn, using vertex and attribute data taken from location i of the enabled arrays. If
GL_VERTEX_ARRAY is not enabled, no drawing occurs but the attributes correspoinding to the enabled
arrays are modified.
Use glArrayElement to construct primitives by indexing vertex data, rather than by streaming through
arrays of data in first-to-last order. Because each call specifies only a single vertex, it is possible to
explicitly specify per- primitive attributes, such as a single normal per individual triangle.
Changes made to array data between the execution of glBegin and the corresponding execution of glEnd
may affect calls to glArrayElement that are made within the same glBegin/glEnd period in non-sequential
ways. That is, a call to glArrayElement that precedes a change to array data may access the changed
data, and a call that follows a change to array data may access original data.
Parameters
i
Specifies an index into the enabled vertex data arrays.
Notes
The glArrayElement subroutine is available only if the GL version is 1.1 or greater.
The glArrayElement subroutine is included in display lists. If glArrayElement is entered into a display list,
the necessary array data (determined by the array pointers and enables) is also entered into the display
list. Because the array pointers and enables are client side state, their values affect display lists when the
lists are created, not when the lists are executed.
Related Information
The glClientActiveTextureARB subroutine, glColorPointer subroutine, glDrawArrays subroutine,
glEdgeFlagPointer subroutine, glGetPointerv subroutine, glIndexPointer subroutine,
glInterleavedArrays subroutine, glNormalPointer subroutine, glTexCoordPointer subroutine,
glVertexPointer subroutine.
Chapter 1. OpenGL Subroutines
13
glArrayElementEXT Subroutine
Purpose
Specifies the array elements used to render a vertex.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glArrayElementEXT(GLint i )
Description
The glArrayElementEXT commands are used within glBegin/glEnd pairs to specify vertex and attribute
data for point, line and polygon primitives. When glArrayElementEXT is called, a single vertex is drawn,
using vertex and attribute data taken from location i of the enabled arrays.
Use glArrayElementEXT to construct primitives by indexing vertex data, rather than by streaming through
arrays of data in first-to-last order. Because each call specifies only a single vertex, it is possible to
explicitly specify perprimitive attributes, such as a single normal per individual triangle.
Parameters
i
Specifies an index in the enabled arrays.
Notes
The glArrayElementEXT subroutine may be included in display lists. If glArrayElementEXT is entered
into a display list, the necessary array data (determined by the array pointers and enables) is also entered
into the display list. Because the array pointers and enables are client side state, their values affect display
lists when the lists are created, not when the lists are executed.
Static array data may be read and cached by the implementation at any time. If static array elements are
modified and the arrays are not respecified, the results of any subsequent calls to glArrayElementEXT
are undefined.
The glArrayElementEXT subroutine executes even if GL_VERTEX_ARRAY_EXT is not enabled. No
drawing occurs in this case, but the attributes corresponding to enabled arrays are modified.
Although it is not an error to respecify an array between the execution of glBegin and the corresponding
execution of glEnd, the result of such respecification is undefined.
The glArrayElementEXT subroutine is part of the _extname(EXT_vertex_array) extension, not part of the
core GL command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString,
when called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
File
/usr/include/GL/glext.h
14
OpenGL 2.1 Reference Manual
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glClientActiveTextureARB subroutine, glColorPointerEXT subroutine, glDrawArraysEXT
subroutine, glEdgeFlagPointerEXT subroutine, glGetPointervEXT subroutine, glIndexPointerEXT
subroutine, glInterleavedArrays subrou glNormalPointerEXT subroutine, glTexCoordPointerEXT
subroutine, glVertexPointerEXT subroutine.
glBegin or glEnd Subroutine
Purpose
Delimits the vertices of a primitive or group of like primitives.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBegin(GLenum
mode)
void glEnd(void)
Description
The glBegin and glEnd subroutines delimit the vertices that define a primitive or group of like primitives.
The glBegin subroutine accepts a single argument that specifies which of 10 ways the vertices will be
interpreted. Taking n as an integer count starting at 1 (one), and N as the total number of vertices
specified, the interpretations are:
GL_POINTS
GL_LINES
GL_LINE_STRIP
GL_LINE_LOOP
GL_TRIANGLES
GL_TRIANGLE_STRIP
GL_TRIANGLE_FAN
GL_QUADS
GL_QUAD_STRIP
GL_POLYGON
Treats each vertex as a single point. Vertex n defines point n. N points are drawn.
Treats each pair of vertices as an independent line segment. Vertices 2n-1 and 2n
define line n. N/2 lines are drawn.
Draws a connected group of line segments from the first vertex to the last. Vertices
n and n+1 define line n. N-1 lines are drawn.
Draws a connected group of line segments from the first vertex to the last, then
back to the first. Vertices n and n+1 define line n. The last line, however, is defined
by vertices N and 1. N lines are drawn.
Treats each triplet of vertices as an independent triangle. Vertices 3n-2, 3n-1, and
3n define triangle n. N/3 triangles are drawn.
Draws a connected group of triangles. One triangle is defined for each vertex
presented after the first two vertices. For odd n, vertices n, n+1, and n+2 define
triangle n. For even n, vertices n+1, n, and n+2 define triangle n. N-2 triangles are
drawn.
Draws a connected group of triangles. One triangle is defined for each vertex
presented after the first two vertices. Vertices 1, n+1, and n+2 define triangle n. N-2
triangles are drawn.
Treats each group of four vertices as an independent quadrilateral. Vertices 4n-3,
4n-2, 4n-1, and 4n define quadrilateral n. N/4 quadrilaterals are drawn.
Draws a connected group of quadrilaterals. One quadrilateral is defined for each
pair of vertices presented after the first pair. Vertices 2n-1, 2n, 2n+2, and 2n+1
define quadrilateral n. N/2-1 quadrilaterals are drawn. Note that the order in which
vertices are used to construct a quadrilateral from strip data is different from that
used with independent data.
Draws a single, convex polygon. Vertices 1 through N define this polygon.
Only a subset of GL subroutines can be used between the glBegin and glEnd subroutines. The
subroutines are: glVertex, glColor, glIndex, glNormal, glTexCoord, glEvalCoord, glEvalPoint,
glMaterial, and glEdgeFlag. Also, it is acceptable to use glCallList or glCallLists to execute display lists
Chapter 1. OpenGL Subroutines
15
that include only the preceding subroutines. If any other GL subroutine is called between the glBegin and
glEnd subroutines, the error flag is set and the subroutine is ignored.
Regardless of the value chosen for mode, there is no limit to the number of vertices that can be defined
between the glBegin and glEnd subroutines. Lines, triangles, quadrilaterals, and polygons that are
incompletely specified are not drawn. Incomplete specification results when either too few vertices are
provided to specify even a single primitive or when an incorrect multiple of vertices is specified. The
incomplete primitive is ignored; the rest are drawn.
The minimum specification of vertices for each primitive is as follows: 1 for a point, 2 for a line, 3 for a
triangle, 4 for a quadrilateral, and 3 for a polygon. Modes that require a certain multiple of vertices are:
GL_LINES (2), GL_TRIANGLES (3), GL_QUADS (4), and GL_QUAD_STRIP (2).
Parameters
mode
Specifies the primitive or primitives that will be created from vertices presented between glBegin and the
subsequent glEnd. Ten symbolic constants are accepted: GL_POINTS, GL_LINES, GL_LINE_STRIP,
GL_LINE_LOOP, GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_QUADS,
GL_QUAD_STRIP, and GL_POLYGON.
Errors
INVALID_ENUM
GL_INVALID_OPERATION
Indicates that mode is set to an unaccepted value.
Indicates that a subroutine other than glVertex, glColor, glIndex, glNormal,
glTexCoord, glEvalCoord, glEvalPoint, glMaterial, glEdgeFlag, glCallList,
or glCallLists subroutine is called between glBegin and the corresponding
glEnd.
Indicates that glEnd is called before the corresponding glBegin is called.
GL_INVALID_OPERATION
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glArrayElement subroutine, glArrayElementEXT subroutine, glColor subroutine, glCallList
subroutine, glCallLists subroutine, glEdgeFlag subroutine, glEvalCoord subroutine, glEvalPoint
subroutine, glIndex subroutine, glMaterial subroutine, glNormal subroutine, glTexCoord subroutine,
glVertex subroutine.
glBindTexture Subroutine
Purpose
Binds a named texture to a texturing target.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBindTexture(GLenum
GLuint texture)
16
target,
OpenGL 2.1 Reference Manual
Description
The glBindTexture subroutine lets you create or use a named texture. Calling glBindTexture with target
set to GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, or GL_TEXTURE_3D_EXT and texture
set to the name of the new texture binds the texture name to the target. When a texture is bound to a
target, the previous binding for that target is automatically broken.
Texture names are unsigned integers. The value zero is reserved to represent the default texture for each
texture target. Texture names and the corresponding texture contents are local to the shared display-list
space (see glXCreateContext) of the current GL rendering context; two rendering contexts share texture
names only if they also share display lists.
You can use glGenTextures to generate a set of new texture names.
When a texture is first bound, it assumes the dimensionality of its target: A texture first bound to
GL_TEXTURE_1D becomes one-dimensional (1D), a texture first bound to GL_TEXTURE_2D becomes
two-dimensional (2D), a texture first bound to GL_TEXTURE_3D becomes three-dimensional (3D), a
texture first bound to GL_TEXTURE_3D_EXT becomes three-dimensional (3D). The state of a (1D)
texture immediately after it is first bound is equivalent to the state of the default GL_TEXTURE_1D at GL
initialization, and similarly for 2D and 3D textures.
While a texture is bound, GL operations on the target to which it is bound affect the bound texture, and
queries of the target to which it is bound return state from the bound texture. If texture mapping of the
dimensionality of the target to which a texture is bound is active, the bound texture is used. In effect, the
texture targets become aliases for the textures currently bound to them, and the texture name zero refers
to the default textures that were bound to them at initialization.
A texture binding created with glBindTexture remains active until a different texture is bound to the same
target, or until the bound texture is deleted with glDeleteTextures.
Once created, a named texture may be rebound to the target of the matching dimensionality as often as
needed. It is usually much faster to use glBindTexture to bind an existing named texture to one of the
texture targets than it is to reload the texture image using glTexImage1D or glTexImage2D. For additional
control over performance, use glPrioritizeTextures.
The glBindTexture subroutine is included in display lists.
Parameters
target
texture
Specifies the target to which the texture is bound. Must be either GL_TEXTURE_1D,
GL_TEXTURE_2D, GL_TEXTURE_3D, or GL_TEXTURE_3D_EXT (EXT_texture3D).
Specifies the name of a texture.
Errors
GL_INVALID_ENUM is generated if target is not one of the allowable values.
GL_INVALID_OPERATION is generated if texture has a dimensionality which doesn’t match that of target.
GL_INVALID_OPERATION is generated if glBindTexture is executed between the execution of glBegin
and the corresponding execution of glEnd.
Associated Gets
glGet with argument GL_TEXTURE_1D_BINDING
glGet with argument GL_TEXTURE_2D_BINDING
Chapter 1. OpenGL Subroutines
17
glGet with argument GL_TEXTURE_3D_BINDING
glGet with argument GL_TEXTURE_3D_BINDING_EXT
Related Information
The glAreTexturesResident subroutine, glDeleteTextures subroutine, glGenTextures subroutine, glGet
subroutine, glGetTexParameter subroutine, glIsTexture subroutine, glPrioritizeTextures subroutine,
glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3DEXT subroutine, glTexParameter
subroutine.
glBindTextureEXT Subroutine
Purpose
Binds a named texture to a texturing target.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBindTextureEXT(GLenum
GLuint texture)
target,
Description
glBindTextureEXT is part of the EXT_texture_object extension. This extension makes it possible to use
named 1-, 2-dimensional textures in addition to the usual OpenGL texture targets designated by
GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D_EXT, etc.
Texture names are unsigned integers. The value zero is reserved to represent the default texture for each
texture target. Texture names and the corresponding texture contents are local to the shared display-list
space (see glXCreateContext) of the current OpenGL rendering context; two rendering contexts will share
texture names only if they also share display lists.
To create a named texture, simply bind a previously-unused texture name to one of the texture targets
listed above. This can be accomplished by calling glBindTextureEXT with target set to the appropriate
texture target, and texture set to the name of the new texture. When a texture is bound to a target, the
previous binding for that target is automatically broken.
Note that glGenTexturesEXT may be used to generate a set of fresh texture names.
When a texture is first bound, it assumes the dimensionality of its target: A texture first bound to
GL_TEXTURE_1D becomes one-dimensional (1D), a texture first bound to GL_TEXTURE_2D becomes
two-dimensional (2D), a texture first bound to GL_TEXTURE_3D_EXT becomes three-dimensional (3D).
The state of a (1D) texture immediately after it is first bound is equivalent to the state of the default
GL_TEXTURE_1D at GL initialization, and similarly for 2D and 3D textures.
While a texture is bound, GL operations on the target towhich it is bound affect the bound texture, and
queries of the target to which it is bound return state from the bound texture. If texture mapping of the
dimensionality of the target to which a texture is bound is active, the bound texture is used. In effect, the
texture targets become aliases for the textures currently bound to them, and the texture name zero refers
to the default textures that were bound to them at initialization.
A texture binding created with glBindTextureEXT remains active until a different texture is bound to the
same target, or until the bound texture is deleted with glDeleteTexturesEXT.
18
OpenGL 2.1 Reference Manual
Once created, a named texture may be re-bound to the appropriate target as often as needed. It is usually
much faster to bind an existing named texture to one of the texture targets using glBindTextureEXT than
it is to reload the texture image using glTexImage*. For additional control over performance, consider
using glPrioritizeTexturesEXT.
glBindTextureEXT is included in display lists.
Parameters
target
texture
The target to which the texture will be bound. Must be one of GL_TEXTURE_1D, GL_TEXTURE_2D,
or GL_TEXTURE_3D_EXT (EXT_texture3D).
The name of a texture.
Notes
glBindTextureEXT is part of the EXT_texture_object extension, not part of the core GL command set. If
GL_EXT_texture_object is included in the string returned by glGetString, when called with argument
GL_EXTENSIONS, extension EXT_texture_object is supported by the connection.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Generated if target is not one of the allowable values.
Generated if texture has a dimensionality and it doesn’t match that of target.
Generated if glBindTextureEXT is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGet with argument GL_TEXTURE_1D_BINDING_EXT
glGet with argument GL_TEXTURE_2D_BINDING_EXT
glGet with argument GL_TEXTURE_3D_BINDING_EXT
Files
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glDeleteTexturesEXT subroutine, glGenTexturesEXT subroutine, glGet subroutine,
glGetTexParameter subroutine, glIsTexture subroutine, glTexImage1D subroutine, glTexImage2D
subroutine, glTexImage3DEXT subroutine, glTexParameter subroutine.
glBitmap Subroutine
Purpose
Draws a bitmap.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
19
C Syntax
void glBitmap(GLsizei Width,
GLsizei Height,
GLfloat xOrigin,
GLfloat yOrigin,
GLfloat xMove,
GLfloat yMove,
const GLubyte * Bitmap)
Description
A bitmap is a binary image. When drawn, the bitmap is positioned relative to the current raster position,
and frame buffer pixels corresponding to 1’s in the bitmap are written using the current raster color or
index. Frame buffer pixels corresponding to 0’s in the bitmap are not modified.
The glBitmap subroutine takes seven arguments. The first pair of arguments specify the width and height
of the bitmap image. The second pair of arguments specify the location of the bitmap origin relative to the
lower left corner of the bitmap image. The final pair of arguments specify x and y offsets to be added to
the current raster position after the bitmap has been drawn. The final argument is a pointer to the bitmap
image itself.
The bitmap image is interpreted like image data for the glDrawPixels subroutine, with Width and Height
corresponding to the width and height arguments of that subroutine, and with Type set to GL_BITMAP and
Format set to GL_COLOR_INDEX. Modes specified using the glPixelStore subroutine affect the
interpretation of bitmap image data; modes specified using the glPixelTransfer subroutine do not.
If the current raster position is not valid, the glBitmap subroutine is ignored. Otherwise, the lower left
corner of the bitmap image is positioned at the following window coordinates:
xw =
yw =
[xr - xo]
[yr - yo]
where ( xr, yr ) is the raster position, and ( xo, yo ) is the bitmap origin.
Fragments are then generated for each pixel corresponding to a 1 in the bitmap image. These fragments
are generated using the current raster z coordinate, color or color index, and current raster texture
coordinates. They are then treated just as if they had been generated by a point, line, or polygon,
including texture mapping, fogging, and all per-fragment operations such as alpha and depth testing.
After the bitmap has been drawn, the x and y coordinates of the current raster position are offset by
xMove and yMove. No change is made to the z coordinate of the current raster position, or to the current
raster color, index, or texture coordinates.
Parameters
Width
Height
xOrigin
yOrigin
xMove
yMove
Bitmap
20
Specifies the pixel width of the bitmap image.
Specifies the pixel height of the bitmap image.
Specifies the location of the x origin in the bitmap image. The x origin is measured from the lower left
corner of the bitmap, with right and up being the positive axes.
Specifies the location of the y origin in the bitmap image. The y origin is measured from the lower left
corner of the bitmap, with right and up being the positive axes.
Specifies the x offset to be added to the current raster position after the bitmap is drawn.
Specifies the y offset to be added to the current raster position after the bitmap is drawn.
Specifies the address of the bitmap image.
OpenGL 2.1 Reference Manual
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
Either Width or Height is negative.
The glBitmap subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glBitmap subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_RASTER_POSITION
glGet with argument GL_CURRENT_RASTER_COLOR
glGet with argument GL_CURRENT_RASTER_INDEX
glGet with argument GL_CURRENT_RASTER_TEXTURE_COORDS
glGet with argument GL_CURRENT_RASTER_POSITION_VALID.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glDrawPixels subroutine, glPixelStore subroutine, glPixelTransfer
subroutine, glRasterPos subroutine.
glBlendColor Subroutine
Purpose
Sets the blend color. This subroutine is part of OpenGL 1.2 ARB Imaging subset extension.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBlendColor(GLclampf
GLclampf
GLclampf
GLclampf
red,
green,
blue,
alpha)
Description
The GL_BLEND_COLOR may be used to calculate the source and destination blending factors. See
glBlendFunc for a complete description of the blending operations. Initially the GL_BLEND_COLOR is set
to (0, 0, 0, 0).
Chapter 1. OpenGL Subroutines
21
Parameters
red, green, blue, alpha
Specify the components of GL_BLEND_COLOR.
Notes
The glBlendColor subroutine is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_OPERATION
The glBlendColor is called between a call to glBegin and the corresponding
call to glEnd.
Associated Gets
glGet with argument GL_BLEND_COLOR.
Related Information
The glBlendFunc subroutine, glGetString subroutine.
glBlendColorEXT Subroutine
Purpose
Sets the blend color. This subroutine is part of OpenGL 1.2 ARB Imaging subset extension.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBlendColorEXT(GLclampf red,
GLclampf green,
GLclampf blue,
GLclampf alpha)
Description
The GL_BLEND_COLOR_EXT may be used to calculate the source and destination blending factors. See
glBlendFunc for a complete description of the blending operations. Initially the GL_BLEND_COLOR_EXT
is set to (0, 0, 0, 0).
Parameters
red, green, blue, alpha
Specify the components of GL_BLEND_COLOR_EXT.
Notes
The glBlendColorEXT subroutine is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_OPERATION
22
OpenGL 2.1 Reference Manual
The glBlendColorEXT is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
glGet with argument GL_BLEND_COLOR_EXT.
Related Information
The glBlendFunc subroutine, glGetString subroutine.
glBlendEquation Subroutine
Purpose
Specifies the RGB color blend equation. This subroutine is part of the OpenGL 1.2 ARB Imaging subset.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBlendEquation(GLenum
mode)
Description
Blending combines corresponding source and destination color components according to the blending
operation specified by the mode. The blend equations are:
GL_FUNC_ADD
GL_FUNC_SUBTRACT
GL_FUNC_REVERSE_SUBTRACT
GL_LOGIC_OP
GL_MIN
GL_MAX
min(Cs*sf + Cd*df, 1)
max(Cs*sf - Cd*df, 0)
max(Cd*df - Cs*sf, 0)
Cs Lop Cd
min(Cs, Cd)
max(Cs, Cd)
where Cs and Cd are the source and destination color components, respectively; sf and df are the source
and destination blending factors are specified by glBlendFunc; Lop is one of the 16 bitwise operators
specified by glLogicOp.
Parameters
mode
Specifies how source and destination RGBA color components are combined. The symbolic constants
GL_FUNC_ADD, GL_MIN, GL_MAX, GL_FUNC_SUBTRACT, GL_REVERSE_SUBTRACT are accepted.
The initial mode is GL_FUNC_ADD.
Notes
The mode GL_LOGIC_OP is part of the EXT_blend_logic_op extension, not part of the core GL command
set. If GL_EXT_blend_logic_op is included in the string returned by glGetString, when called with
argument GL_EXTENSIONS, extension EXT_blend_logic_op is supported by the connection.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
The mode parameter is not an accepted or supported value.
The glBlendEquation is called between a call to glBegin and the
corresponding call to glEnd.
Chapter 1. OpenGL Subroutines
23
Associated Gets
glGet with argument GL_BLEND_EQUATION.
Related Information
The glBlendFunc subroutine, glEnable or glDisable subroutine, glGet subroutine, glLogicOp subroutine.
glBlendEquationEXT Subroutine
Purpose
Specifies the RGB color blend equation.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBlendEquationEXT(GLenum
mode)
Description
Blending combines corresponding source and destination color components according to the blending
operation specified by the mode. The blend equations are:
GL_FUNC_ADD_EXT
GL_FUNC_SUBTRACT_EXT
GL_FUNC_REVERSE_SUBTRACT_EXT
GL_LOGIC_OP
GL_MIN_EXT
GL_MAX_EXT
min(Cs*sf + Cd*df, 1)
max(Cs*sf - Cd*df, 0)
max(Cd*df - Cs*sf, 0)
Cs Lop Cd
min(Cs, Cd)
max(Cs, Cd)
where Cs and Cd are the source and destination color components, respectively; sf and df are the source
and destination blending factors are specified by glBlendFunc; Lop is one of the 16 bitwise operators
specified by glLogicOp.
Parameters
mode
Specifies how source and destination RGBA color components are combined. The symbolic constants
GL_FUNC_ADD_EXT, GL_MIN_EXT, GL_MAX_EXT, GL_FUNC_SUBTRACT_EXT,
GL_REVERSE_SUBTRACT_EXT are accepted. The initial mode is GL_FUNC_ADD_EXT.
Notes
The modes GL_FUNC_SUBTRACT_EXT and GL_FUNC_REVERSE_SUBTRACT_EXT are part of the
EXT_blend_subtract extension, not part of the core GL command set. If GL_EXT_blend_subtract is
included in the string returned by glGetString, when called with argument GL_EXTENSIONS, extension
EXT_blend_subtract is supported by the connection.
The mode GL_LOGIC_OP is part of the EXT_blend_logic_op extension, not part of the core GL command
set. If GL_EXT_blend_logic_op is included in the string returned by glGetString, when called with
argument GL_EXTENSIONS, extension EXT_blend_logic_op is supported by the connection.
24
OpenGL 2.1 Reference Manual
The modes GL_MIN_EXT and GL_MAX_EXT are part of the EXT_blend_minmax extension, not part of
the core GL command set. If GL_EXT_blend_minmax is included in the string returned by glGetString,
when called with argument GL_EXTENSIONS, extension EXT_blend_minmax is supported by the
connection.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
The mode parameter is not an accepted or supported value.
The glBlendEquation is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
glGet with argument GL_BLEND_EQUATION_EXT.
Related Information
The glBegin subroutine, glBlendFunc subroutine, glEnable or glDisable subroutine, glGet subroutine,
glGetString subroutine, glLogicOp subroutine.
glBlendFunc Subroutine
Purpose
Specifies pixel arithmetic.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glBlendFunc(GLenum SourceFactor,
GLenum DestinationFactor)
Description
In RGB mode, pixels can be drawn using a function that blends the incoming (source) red, green, blue,
and alpha (RGBA) values with the RGBA values that are already in the frame buffer (the destination
values). By default, blending is disabled. Use the glEnable and glDisable subroutines with argument
GL_BLEND to enable and disable blending.
When blending is enabled, glBlendFunc and glBlendEquationEXT determine the blending operation.
SourceFactor and DestinationFactor specify the scaling rules used for scaling the source and destination
color components, respectively. Each rule defines four scale factors, one each for red, green, blue, and
alpha. The rules are described in the table below.
In the table and in subsequent equations, source color components are referred to as:
(Rs, Gs, Bs, As)
Destination color components are referred to as:
(Rd, Gd, Bd, Ad)
Constant color components are referred to as:
(Rc, Gc, Bc, Ac)
They are understood to have integer values between 0 (zero) and:
Chapter 1. OpenGL Subroutines
25
(kR, kG, kB, kA)
where
(kc = 2mc - 1)
(m R, m G, m B, m A)
represents the number of RGBA bit planes.
Source scale factors are referred to as:
(s R, s G, s B, s A)
Destination scale factors are referred to as:
(d R, d G, d B, d A)
The scale factors:
(fR, fG, fB, fA)
represent either source or destination factors. All scale factors have the range [0,1].
Parameter
(fR, fG, fB, fA)
GL_ZERO
(0, 0, 0, 0 )
GL_ONE
(1, 1, 1, 1 )
GL_SRC_COLOR
(Rs/kR, Gs/kG, Bs/kB, As/kA)
GL_ONE_MINUS_SRC_COLOR
(1, 1, 1, 1 ) - (Rs/kR, Gs/kG, Bs/kB, As/kA)
GL_DST_COLOR
(Rd/kR, Gd/kG, Bd/kB, Ad/kA)
GL_ONE_MINUS_DST_COLOR
(1, 1, 1, 1 ) - (Rd/kR, Gd/kG, Bd/kB, Ad/kA)
GL_SRC_ALPHA
(As/kA, As/kA, As/kA, As/kA)
GL_ONE_MINUS_SRC_ALPHA
(1, 1, 1, 1 ) - (As/kA, As/kA, As/kA, As/kA)
GL_DST_ALPHA
(Ad/kA, Ad/kA, Ad/kA, Ad/kA)
GL_ONE_MINUS_DST_ALPHA
(1, 1, 1, 1 ) - (Ad/kA, Ad/kA, Ad/kA, Ad/kA)
GL_CONSTANT_COLOR
(Rc/kR, Gc/kG, Bc/kB, Ac/kA)
GL_ONE_MINUS_CONSTANT_COLOR
(1, 1, 1, 1 ) - (Rc/kR, Gc/kG, Bc/kB, Ac/kA)
GL_CONSTANT_ALPHA
(Ac/kA, Ac/kA, Ac/kA, Ac/kA)
GL_ONE_MINUS_CONSTANT_ALPHA
(1, 1, 1, 1 ) - (Ac/kA, Ac/kA, Ac/kA, Ac/kA)
GL_SRC_ALPHA_SATURATE
(i, i, i, 1)
i = min (As, kA - Ad )/kA
To determine the blended RGBA values of a pixel when drawing in RGB mode, the system uses the
following equations:
Rd
Gd
Bd
Ad
=
=
=
=
min
min
min
min
(kR,
(kG,
(kB,
(kA,
RssR
GssG
BssB
AssA
+
+
+
+
RddR)
GddG)
BddB)
AddA)
Blending combines corresponding source and destination color components according to the blending
operation specified by GL_BLEND_EQUATION_EXT. The blending operations are:
GL_BLEND_EQUATION_EXT
Binary Operation
GL_FUNC_ADD_EXT
min(Cs x sC+Cd x dC,kC)
26
OpenGL 2.1 Reference Manual
GL_BLEND_EQUATION_EXT
Binary Operation
GL_FUNC_SUBTRACT_EXT
max(Cs x sC-Cd x dC,0)
GL_FUNC_REVERSE_SUBTRACT_EXT
max(Cd x dC-Cs x sC,0)
GL_LOGIC_OP
Cs Lop Cd
GL_MIN_EXT
min(Cs, Cd)
GL_MAX_EXT
max(Cs, Cd)
where C is the relevant color component (R, G, B, or A), Cs and Cd are the source and destination color
components, respectively, sC and sD are the source and destination scale factors, respectively, and Lop is
one of 16 bitwise operators specified by glLogicOp.
Despite the apparent precision of the preceding equations, blending arithmetic is not exactly specified,
because blending operates with imprecise integer color values. However, a blend factor that should be
equal to 1 is guaranteed not to modify its multiplicand, and a blend factor equal to 0 reduces its
multiplicand to 0. Thus, for example, when SourceFactor is GL_SRC_ALPHA, DestinationFactor is
GL_ONE_MINUS_SRC_ALPHA, and As is equal to kA, the equations reduce to simple replacement:
Rd
Gd
Rd
Ad
=
=
=
=
Rs
Gs
Bs
As
Parameters
SourceFactor
DestinationFactor
Specifies how the RGBA source-blending factors are computed. Thirteen symbolic
constants are accepted: GL_ZERO, GL_ONE, GL_DST_COLOR,
GL_ONE_MINUS_DST_COLOR, GL_SRC_ALPHA,
GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA,
GL_ONE_MINUS_DST_ALPHA, GL_CONSTANT_COLOR,
GL_CONSTANT_COLOR_EXT, GL_ONE_MINUS_CONSTANT_COLOR,
GL_ONE_MINUS_CONSTANT_COLOR_EXT, GL_CONSTANT_ALPHA,
GL_CONSTANT_ALPHA_EXT, GL_ONE_MINUS_CONSTANT_ALPHA,
GL_ONE_MINUS_CONSTANT_ALPHA_EXT, and GL_SRC_ALPHA_SATURATE.
These symbolic constants are defined in the Description section. The initial value is
GL_ONE.
Specifies how the RGBA destination-blending factors are computed. Twelve
symbolic constants are accepted: GL_ZERO, GL_ONE, GL_SRC_COLOR,
GL_ONE_MINUS_SRC_COLOR, GL_SRC_ALPHA,
GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA ,
GL_ONE_MINUS_DST_ALPHA, GL_CONSTANT_COLOR,
GL_CONSTANT_COLOR_EXT, GL_ONE_MINUS_CONSTANT_COLOR,
GL_ONE_MINUS_CONSTANT_COLOR_EXT, GL_CONSTANT_ALPHA,
GL_CONSTANT_ALPHA_EXT, GL_ONE_MINUS_CONSTANT_ALPHA, and
GL_ONE_MINUS_CONSTANT_ALPHA_EXT. These symbolic constants are
defined in the Description section. The initial value is GL_ZERO.
Notes
Incoming (source) alpha is correctly thought of as a material opacity, ranging from 1.0 (KA), representing
complete opacity, to 0.0 (0), representing complete transparency.
When more than one color buffer is enabled for drawing, blending is done separately for each enabled
buffer, using for destination color the contents of that buffer. (See the glDrawBuffer subroutine.)
Blending affects only RGB rendering. It is ignored by color index renderers.
Chapter 1. OpenGL Subroutines
27
The Source and destination factors GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR,
GL_CONSTANT_ALPHA, GL_ONE_MINUS_CONSTANT_ALPHA, and their _EXT versions are only valid
if the ARB imaging subset is supported and/or the Blend Color extension.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either SourceFactor or DestinationFactor is set to an unaccepted value.
The glBlendFunc subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glBlendFunc subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_BLEND_SRC, GL_BLEND_DST, GL_LOGIC_OP_MODE, or
GL_BLEND_EQUATION_EXT.
glIsEnabled with argument GL_BLEND
Examples
Transparency is best implemented using a blend function (GL_SRC_ALPHA,
GL_ONE_MINUS_SRC_ALPHA) with primitives sorted from farthest to nearest. Note that this
transparency calculation does not require the presence of alpha bit planes in the frame buffer.
The blend function operation (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) is also useful for
rendering antialiased points and lines in arbitrary order.
Polygon antialiasing is optimized using a blend function (GL_SRC_ALPHA_SATURATE, GL_ONE) with
polygons sorted from nearest to farthest. (See the glEnable or glDisable subroutine and the
GL_POLYGON_SMOOTH argument for information on polygon antialiasing.) Destination alpha bit planes,
which must be present for this blend function to operate correctly, store the accumulated coverage.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glAlphaFunc subroutine, glBegin or glEnd subroutine, glClear subroutine, glDrawBuffer subroutine,
glEnable or Disable ubroutine, glLogicOp subroutine, glStencilFunc subroutine.
glBlendFuncSeparateEXT Subroutine
Purpose
Specifies separate RGB and Alpha blend factors.
Library
OpenGL C bindings library: (libGL.a)
28
OpenGL 2.1 Reference Manual
C Syntax
void glBlendFuncSeparateEXT(enum sfactorRGB,
enum dfactorRGB,
enum sfactorAlpha,
enum dfactorAlpha)
Description
Blending capability is extended by this function. It allows independent specification of the RGB and alpha
blend factors for blend operations that require source and destination blend factors. It is not always
desired that the blending used for RGB is also applied to alpha.
The accepted values for sfactorRGB and sfactorAlpha are:
GL_ZERO
GL_ONE
GL_DST_COLOR
GL_ONE_MINUS_DST_COLOR
GL_SRC_ALPHA
GL_ONE_MINUS_SRC_ALPHA
GL_DST_ALPHA
GL_ONE_MINUS_DST_ALPHA
GL_CONSTANT_COLOR (_EXT)
GL_ONE_MINUS_CONSTANT_COLOR (_EXT)
GL_CONSTANT_ALPHA (_EXT)
GL_ONE_MINUS_CONSTANT_ALPHA (_EXT)
GL_SRC_ALPHA_SATURATE
The accepted values for sfactorRGB and sfactorAlpha are:
GL_ZERO
GL_ONE
GL_SRC_COLOR
GL_ONE_MINUS_SRC_COLOR
GL_SRC_ALPHA
GL_ONE_MINUS_SRC_ALPHA
GL_DST_ALPHA
GL_ONE_MINUS_DST_ALPHA
GL_CONSTANT_COLOR (_EXT)
GL_ONE_MINUS_CONSTANT_COLOR (_EXT)
GL_CONSTANT_ALPHA (_EXT)
GL_ONE_MINUS_CONSTANT_ALPHA (_EXT)
GL_SRC_ALPHA_SATURATE
For further information on the mathematical function of each of these accepted values, see glBlendFunc.
Chapter 1. OpenGL Subroutines
29
Parameters
sfactorRGB
sfactorAlpha
dfactorRGB
dfactorAlpha
is
is
is
is
the
the
the
the
source blend factor for the RGB components.
source blend factor for the Alpha component.
destination blend factor for the RGB components.
destination blend factor for the Alpha component.
Notes
This subroutine is only valid if the EXT_blend_func_separate extension is defined.
GL_CONSTANT_COLOR (_EXT), GL_ONE_MINUS_CONTANT_COLOR (_EXT),
GL_CONSTANT_ALPHA (_EXT), and GL_ONE_MINUS_CONSTANT_ALPHA (_EXT) are only valid if the
GL_EXT_blend_color extension is defined.
The (_EXT) at the end of these values above indicates that the enum can be specified with or without the
_EXT suffix, and behaves identically in both cases.
Error Codes
GL_INVALID_ENUM
is generated if any of sfactorRGB, dfactorRGB,
sfactorAlpha, or dfactorAlpha are not accepted values.
is generated if glBlendFuncSeparateEXT is executed
between the execution of glBegin and the corresponding
execution of glEnd.
GL_INVALID_OPERATION
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBlendFunc sunbroutine.
glCallList Subroutine
Purpose
Executes a display list.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCallList(GLuint
List)
Description
The glCallList subroutine causes the named display list to be executed. The subroutines saved in the
display list are executed in order, just as if they were called without using a display list. If List has not been
defined as a display list, glCallList is ignored.
30
OpenGL 2.1 Reference Manual
The glCallList subroutine may appear inside a display list. To avoid the possibility of infinite recursion
resulting from display lists calling one another, an implementation-dependent limit is placed on the the
nesting level of display lists during display list execution. This limit is at least 64.
GL state is not saved and restored across a call to glCallList. Thus, changes made to GL state during the
execution of a display list will remain after execution of the display list is completed. Use the glPushAttrib,
glPopAttrib, PushMatrix, and glPopMatrix subroutines to preserve GL state across glCallList calls.
Parameters
List
Specifies the integer name of the display list to be executed.
Notes
Display lists can be executed between a call to glBegin and the corresponding call to glEnd, as long as
the display list includes only commands that are allowed in this interval.
Associated Gets
The associated get for the glCallList subroutine is as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MAX_LIST_NESTING
glIsList.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallLists subroutine, glDeleteLists subroutine, glGenLists
subroutine, glNewList subroutine, glPushAttrib or glPopAttrib subroutine, glPushMatrix or glPopMatrix
subroutine.
glCallLists Subroutine
Purpose
Executes a list of display lists.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCallLists(GLsizei Number,
GLenum Type,
const GLvoid * Lists)
Chapter 1. OpenGL Subroutines
31
Description
The glCallLists subroutine causes each display list in the list of names passed as lists to be executed. As
a result, the commands saved in each display list are executed in order, just as if they were called without
using a display list. Names of display lists that have not been defined are ignored.
The glCallLists subroutine provides an efficient means for executing display lists. The Number parameter
allows lists with various name formats to be accepted. The formats are:
GL_BYTE
GL_UNSIGNED_BYTE
GL_SHORT
GL_UNSIGNED_SHORT
GL_INT
GL_UNSIGNED_INT
GL_FLOAT
GL_2_BYTES
GL_3_BYTES
GL_4_BYTES
Lists is treated as an array of signed bytes, each in the range -128 through 127.
Lists is treated as an array of unsigned bytes, each in the range 0 through 255.
Lists is treated as an array of signed 2-byte integers, each in the range -32,768
through 32,767.
Lists is treated as an array of unsigned 2-byte integers, each in the range 0 through
65,535.
Lists is treated as an array of signed 4-byte integers.
Lists is treated as an array of unsigned 4-byte integers.
Lists is treated as an array of 4-byte floating-point values.
Lists is treated as an array of unsigned bytes. Each pair of bytes specifies a single
display list name. The value of the pair is computed as 256 times the unsigned
value of the first byte plus the unsigned value of the second byte.
Lists is treated as an array of unsigned bytes. Each triplet of bytes specifies a
single display list name. The value of the triplet is computed as 65,536 times the
unsigned value of the first byte, plus 256 times the unsigned value of the second
byte, plus the unsigned value of the third byte.
Lists is treated as an array of unsigned bytes. Each quadruplet of bytes specifies a
single display list name. The value of the quadruplet is computed as 16,777,216
times the unsigned value of the first byte, plus 65,536 times the unsigned value of
the second byte, plus 256 times the unsigned value of the third byte, plus the
unsigned value of the fourth byte.
The list of display list names is not null-terminated. Rather, the Number parameter specifies how many
names are to be taken from Lists.
An additional level of indirection is made available with the glListBase subroutine, which specifies a
signed offset that is added to each display list name specified in Lists before that display list is executed.
The glCallLists subroutine can appear inside a display list. To avoid the possibility of infinite recursion
resulting from display lists calling one another, an implementation-dependent limit is placed on the the
nesting level of display lists during display list execution. This limit must be at least 64.
GL state is not saved and restored across a call to glCallLists. Thus, changes made to GL state during
the execution of the display lists remain after execution is completed. Use the glPushAttrib, glPopAttrib,
glPushMatrix, and glPopMatrix subroutines to preserve GL state across glCallLists calls.
Parameters
Number
Type
Lists
32
Specifies the number of display lists to be executed.
Specifies the type of values in lists. Symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT,
GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, GL_2_BYTES, GL_3_BYTES,
and GL_4_BYTES are accepted.
Specifies the address of an array of name offsets in the display list. The pointer type is void because the
offsets can be bytes, shorts, ints, or floats, depending on the value of Type.
OpenGL 2.1 Reference Manual
Notes
Display lists can be executed between a call to glBegin and the corresponding call to glEnd, as long as
the display list includes only commands that are allowed in this interval.
Associated Gets
Associated gets for the glCallLists subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_LIST_BASE
glGet with argument GL_MAX_LIST_NESTING
glIsList.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallList subroutine, glDeleteLists subroutine, glGenLists
subroutine, glListBase subroutine, glNewList subroutine, glPushAttrib or glPopAttrib subroutine,
glPushMatrix or glPopMatrix subroutine.
glClear Subroutine
Purpose
Clears buffers to preset values.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glClear(GLbitfield
Mask)
Description
The glClear subroutine sets the bit plane area of the viewport to values previously selected by
glClearColor, glClearIndex, glClearDepth, glClearStencil and glClearAccum. Multiple color buffers can
be cleared simultaneously by selecting more than one buffer at a time using glDrawBuffer.
The pixel ownership test, the scissor test, dithering and the buffer writemasks affect the operation of
glClear. The scissor box bounds the cleared region. Alpha function, blend function, logical operation,
stenciling, texture mapping, and z-buffering are ignored by glClear.
The glClear subroutine takes a single argument that is the bitwise OR of several values indicating which
buffer is to be cleared.
The values are:
GL_COLOR_BUFFER_BIT
GL_DEPTH_BUFFER_BIT
Indicates the buffers currently enabled for color writing.
Indicates the depth buffer.
Chapter 1. OpenGL Subroutines
33
GL_ACCUM_BUFFER_BIT
GL_STENCIL_BUFFER_BIT
Indicates the accumulation buffer.
Indicates the stencil buffer.
The value to which each buffer is cleared depends on the setting of the clear value for that buffer.
glGet with argument GL_COLOR_CLEAR_VALUE
glGet with argument GL_STENCIL_CLEAR_VALUE.
Parameters
Mask
Bitwise OR of masks that indicate the buffers to be cleared. The four masks are GL_COLOR_BUFFER_BIT,
GL_DEPTH_BUFFER_BIT, GL_ACCUM_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.
Notes
If a buffer is not present, then a glClear directed at that buffer has no effect.
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
A bit other than the four defined bits is set in Mask.
The glClear subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClear subroutine are as follows. (See the glGet subroutine for more information.)
glGet with argument GL_ACCUM_CLEAR_VALUE
glGet with argument GL_DEPTH_CLEAR_VALUE
glGet with argument GL_INDEX_CLEAR_VALUE
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClearAccum subroutine, glClearColor subroutine, glClearDepth
subroutine, glClearIndex subroutine, glClearStencil subroutine, glDrawBuffer subroutine, glScissor
subroutine.
glClearAccum Subroutine
Purpose
Specifies clear values for the accumulation buffer.
Library
OpenGL C bindings library: libGL.a
34
OpenGL 2.1 Reference Manual
C Syntax
void glClearAccum(GLfloat
GLfloat Green,
GLfloat Blue,
GLfloat Alpha)
Red,
Description
The glClearAccum subroutine specifies the red, green, blue, and alpha values used by the glClear
subroutine to clear the accumulation buffer. Values specified by glClearAccum are clamped to the range
[-1,1].
Parameters
Red
Green
Blue
Alpha
Specifies
Specifies
Specifies
Specifies
the
the
the
the
red value used when the accumulation buffer is cleared. The default value is 0 (zero).
green value used when the accumulation buffer is cleared. The default value is 0.
blue value used when the accumulation buffer is cleared. The default value is 0.
alpha value used when the accumulation buffer is cleared. The default value is 0.
Errors
GL_INVALID_OPERATION
The glClearAccum subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClearAccum subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_ACCUM_CLEAR_VALUE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClear subroutine.
glClearColor Subroutine
Purpose
Specifies clear values for the color buffers.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
35
C Syntax
void glClearColor(GLclampf
GLclampf Green,
GLclampf
Blue,
GLclampf
Alpha)
Red,
Description
The glClearColor subroutine specifies the red, green, blue, and alpha values used by the glClear
subroutine to clear the color buffers. Values specified by glClearColor are clamped to the range [0,1].
Parameters
Red
Green
Blue
Alpha
Specifies
Specifies
Specifies
Specifies
the
the
the
the
red value used when the color buffer is cleared. The default value is 0 (zero).
green value used when the color buffer is cleared. The default value is 0.
blue value used when the color buffer is cleared. The default value is 0.
alpha value used when the color buffer is cleared. The default value is 0.
Errors
GL_INVALID_OPERATION
The glClearColor subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClearColor subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_COLOR_CLEAR_VALUE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClear subroutine.
glClearDepth Subroutine
Purpose
Specifies the clear value for the depth buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glClearDepth(GLclampd
36
OpenGL 2.1 Reference Manual
Depth)
Description
The glClearDepth subroutine specifies the depth value used by the glClear subroutine to clear the depth
buffer. Values specified by glClearDepth are clamped to the range [0,1].
Parameters
Depth
Specifies the depth value used when the depth buffer is cleared. The default value is 0 (zero).
Errors
GL_INVALID_OPERATION
The glClearDepth subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClearDepth subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_DEPTH_CLEAR_VALUE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClear subroutine.
glClearIndex Subroutine
Purpose
Specifies the clear value for the color index buffers.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glClearIndex(GLfloat
Clear)
Description
The glClearIndex subroutine specifies the index used by glClear to clear the color index buffers. The
Clear parameter is not clamped. Rather, Clear is converted to a fixed-point value with unspecified
precision to the right of the binary point. The integer part of this value is then masked with 2m -1, where m
is the number of bits in a color index stored in the frame buffer.
Parameters
Clear
Specifies the index used when the color index buffers are cleared. The default value is 0 (zero).
Chapter 1. OpenGL Subroutines
37
Errors
GL_INVALID_OPERATION
The glClearIndex subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClearIndex subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_INDEX_CLEAR_VALUE
glGet with argument GL_INDEX_BITS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClear subroutine.
glClearStencil Subroutine
Purpose
Specifies the clear value for the stencil buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glClearStencil(GLint
Stencil)
Description
The glClearStencil subroutine specifies the index used by glClear to clear the stencil buffer. The Stencil
parameter is masked with 2m - 1, where m is the number of bits in the stencil buffer.
Parameters
Stencil
Specifies the index used when the stencil buffer is cleared. The default value is 0 (zero).
Errors
GL_INVALID_OPERATION
Indicates that glClearStencil is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClearStencil subroutine are as follows. (See the glGet subroutine for more
information.)
38
OpenGL 2.1 Reference Manual
glGet with argument GL_STENCIL_CLEAR_VALUE
glGet with argument GL_STENCIL_BITS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClear subroutine.
glClientActiveTextureARB Subroutine
Purpose
Specify which texture unit is active.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glClientActiveTextureARB(GLenum
texture)
Description
glClientActiveTextureARB selects which texture unit’s client state parameters will be modified by
glTexCoordPointer, and enabled or disabled with glEnableClientState or glDisableClientState,
respectively, when called with a parameter of GL_TEXTURE_COORD_ARRAY. The number of texture
units an implementation supports is implementation dependent, but must be at least two. The texture
parameter must be one of GL_TEXTUREi_ARB, where 0 <= i < GL_MAX_TEXTURE_UNITS_ARB. The
initial value is GL_TEXTURE0_ARB.
Parameters
texture
specifies which texture unit to make active.
Notes
If the GL_ARB_multitexture extension is NOT present, then the number of texture units supported by the
implementation is one, not two, as described above.
The following OpenGL subroutines will be routed to different texture units based on this call:
v glEnableClientState (GL_TEXTURE_COORD_ARRAY)
v glDisableClientState (GL_TEXTURE_COORD_ARRAY)
v glInterleavedArrays
v glTexCoordPointer
v glTexCoordPointerEXT
v glTexCoordPointerListIBM
Subroutine glClientActiveTextureARB is supported only if GL_ARB_multitexture is included in the string
returned by glGetString when called with the argument GL_EXTENSIONS.
Chapter 1. OpenGL Subroutines
39
Error Codes
GL_INVALID_OPERATION
is generated if texture is not one of the accepted values.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glActiveTextureARB subroutine, the glEnableClientState or glDisableClientState subroutine, the
glMultiTexCoordARB subroutine, the glTexCoordPointer subroutine.
glClipBoundingBoxIBM or glClipBoundingSphereIBM or
glClipBoundingVerticesIBM Subroutine
Purpose
Determine whether the specified object is trivially accepted, trivially rejected, or clipped by the current set
of clipping planes.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
GLenum glClipBoundingBoxIBM (GLfloat
GLfloat
GLfloat
GLfloat
GLfloat
GLfloat
xmin,
ymin,
zmin,
xmax,
ymax,
zmax)
GLenum glClipBoundingSphereIBM (GLfloat
GLfloat
GLfloat
GLfloat
x,
y,
z,
radius)
GLenum glClipBoundingVerticesIBM (GLint size,
GLenum type,
GLsizei stride,
GLsizei count,
GLvoid *data)
Description
These three new functions can be used by applications to determine if a complex object is fully outside,
inside, or both outside and inside the clip volume (ie, view volume plus any enabled clipping planes). The
complex object is generally defined by a simplified representation of the object. This extension provides for
3 different simplified object variants - a bounding box, a bounding sphere, and a set of bounding vertices.
These functions can not be inserted within a display list. If called while a display list is open, they are
executed immediately.
40
OpenGL 2.1 Reference Manual
An enable is also provided so that applications can directly update the clip volume hint without having to
make a separate OpenGL function call.
See GL_UPDATE_CLIP_VOLUME_HINT under glEnable.
All functions return the results of the clip check. These results include:
GL_REJECT_IBM
GL_ACCEPT_IBM
GL_CLIP_IBM
Indicates that the bounding object is trivially rejected.
Rendering the object will result in nothing being rendered.
Indicates that the bounding object is trivially accepted.
Rendering the object should be entirely within the viewport
and can be rendering without clipping.
Indicates that the bounding object is not trivially accepted
or rejected. Implementations that don’t support clip
checking for all rendering enviroments can return
CLIP_IBM for those unsupported environments.
Parameters
xmin,ymin,zmin
xmax,ymax,zmax
x,y,z
radius
size
type
stride
count
data
Specifies the minimum x,y and z modeling coordinates of
the bounding box.
Specifies the maximum x,y and z modeling coordinates of
the bounding box.
Specifies the center of the bounding sphere in modeling
coordinates.
Specifies the radius of the bounding sphere in modeling
coordinates.
Specifies the number of coordinate components per
vertex; must be 2, 3 or 4.
Specifies the data type for the data parameter. Symbolic
constants GL_SHORT, GL_INT, GL_FLOAT, and
GL_DOUBLE are accepted.
Specifies the byte offset between consecutive vertexes. If
stride is 0, the vertices are understood to be tightly
packed in the array.
Specifies the number of vertices pointed to by the data
parameter.
Specifies a pointer to the first coordinate of the vertex list.
Notes
These three functions are only available if the GL_IBM_clip_check extension is present.
Error Codes
GL_INVALID_value
GL_INVALID_ENUM
GL_INVALID_value
is generated if size is not 2, 3, or 4.
is generated if type is not one of the acceptable values.
is generated if count is negative.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Chapter 1. OpenGL Subroutines
41
glClipPlane Subroutine
Purpose
Specifies a plane against which all geometry is clipped.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glClipPlane(GLenum Plane,
const GLdouble * Equation)
By default, all clipping planes are defined as (0,0,0,0) in eye coordinates and are disabled.
Parameters
Plane
Equation
Specifies which clipping plane is being positioned. Symbolic names of the form GL_CLIP_PLANEi,
where i is an integer between 0 and GL_MAX_CLIP_PLANES-1, are accepted.
Specifies the address of an array of four double-precision floating-point values. These values are
interpreted as a plane equation.
Description
Geometry is always clipped against the boundaries of a six-plane frustum in x, y, and z. The glClipPlane
subroutine allows the specification of additional planes, not necessarily perpendicular to the x, y, or z axes,
against which all geometry is clipped. Up to GL_MAX_CLIP_PLANES planes can be specified, where
GL_MAX_CLIP_PLANES is at least 6 in all implementations. Because the resulting clipping region is the
intersection of the defined half-spaces, it is always convex.
The glClipPlane subroutine specifies a half-space using a four-component plane equation. When
glClipPlane is called, Equation is transformed by the inverse of the modelview matrix and stored in the
resulting eye coordinates. Subsequent changes to the modelview matrix have no effect on the stored
plane equation components. If the dot product of the eye coordinates of a vertex with the stored plane
equation components is positive or 0 (zero), the vertex is in with respect to that clipping plane. Otherwise it
is out.
Clipping planes are enabled and disabled with glEnable and glDisable, called with the argument
GL_CLIP_PLANEi, where i is the plane number.
Notes
It is always the case that GL_CLIP_PLANEi = GL_CLIP_PLANE0 + i.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Plane is set to an unaccepted value.
The glClipPlane subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glClipPlane subroutine are as follows. (See the glGet subroutine for more
information.)
42
OpenGL 2.1 Reference Manual
glGetClipPlane
glIsEnabled
Enabled with argument GL_CLIP_PLANEi.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL
Related Information
The glBegin or glEnd subroutine, glEnable or glDisable subroutine.
glColor Subroutine
Purpose
Sets the current color.
Library
OpenGL C bindings library: libGL.a
C Syntax
glColor3b, glColor3d, glColor3f, glColor3i, glColor3s,
glColor3ub, glColor3ui, glColor3us, glColor4b, glColor4d,
glColor4f, glColor4i,glColor4s, glColor4ub, glColor4ui,
glColor4us, glColor3bv, glColor3dv, glColor3fv, glColor3iv,
glColor3sv, glColor3ubv, glColor3uiv, glColor3usv, glColor4bv,
glColor4dv, glColor4fv, glColor4iv, glColor4sv, glColor4ubv,
glColor4uiv, glColor4usv
-set the current color
void glColor3b
void glColor3b(GLbyte
GLbyte Green,
GLbyte Blue)
Red,
void glColor3d(GLdouble
GLdouble Green,
GLdouble Blue)
void glColor3f(GLfloat
GLfloat Green,
GLfloat Blue)
void glColor3i(GLint
GLint Green,
GLint Blue)
void glColor3s(GLshort
GLshort Green,
GLshort Blue)
Red,
Red,
Red,
Red,
Chapter 1. OpenGL Subroutines
43
void glColor3ub(GLubyte
GLubyte Green,
GLubyte Blue)
Red,
void glColor3ui(GLuint
GLuint Green,
GLuint Blue)
Red,
void glColor3us(GLshort
GLshort Green,
GLshort Blue)
void glColor4b(GLbyte
GLbyte Green,
GLbyte Blue,
GLbyte Alpha)
Red,
Red,
void glColor4d(GLdouble
GLdouble Green,
GLdouble Blue,
GLdouble Alpha)
void glColor4f(GLfloat
GLfloat Green,
GLfloat Blue,
GLfloat Alpha)
void glColor4i(GLint
GLint Green,
GLint Blue,
GLint Alpha)
Red,
Red,
Red,
void glColor4s(GLshort
GLshort Green,
GLshort Blue,
GLshort Alpha)
Red,
void glColor4ub(GLubyte
GLubyte Green,
GLubyte Blue,
GLubyte Alpha)
Red,
void glColor4ui (GLuint
GLuint Green,
GLuint Blue,
GLuint Alpha)
Red,
void glColor4us(GLshort
GLshort Green,
GLshort Blue,
GLshort Alpha)
Red,
void glColor3bv(const GLbyte * Variable)
void glColor3dv(const GLdouble * Variable)
44
OpenGL 2.1 Reference Manual
void glColor3fv(const GLfloat * Variable)
void glColor3iv(const GLint * Variable)
void glColor3sv(const GLshort * Variable)
void glColor3ubv(const GLubyte * Variable)
void glColor3uiv(const GLuint * Variable)
void glColor3usv(const GLushort * Variable)
void glColor4bv(const GLbyte * Variable)
void glColor4dv(const GLdouble * Variable)
void glColor4fv(const GLfloat * Variable)
void glColor4iv(const GLint * Variable)
void glColor4sv(const GLshort * Variable)
void glColor4ubv(const GLubyte * Variable)
void glColor4uiv(const GLuint * Variable)
void glColorusv(const GLushort * Variable)
Description
The Graphics Library stores both a current single-valued color index and a current four-valued red, green,
blue, alpha (RGBA) color. The glColor subroutine sets a new four-valued RGBA color. The glColor
subroutine has two major variants: glColor3 and glColor4. glColor3 variants specify new red, green, and
blue values explicitly, and set the current alpha value to 1.0 implicitly. glColor4 variants specify all four
color components explicitly.
glColor3b, glColor4b, glColor3s, glColor4s, glColor3i, and glColor4i take 3 or 4 unsigned byte, short,
or long integers as arguments. When v is appended to the name, the color subroutines can take a pointer
to an array of such values.
Current color values are stored in floating-point format, with unspecified mantissa and exponent sizes.
Unsigned integer color components, when specified, are linearly mapped to floating-point values such that
the largest representable value maps to 1.0 (full intensity), and 0 (zero) maps to 0.0 (zero intensity).
Signed integer color components, when specified, are linearly mapped to floating-point values such that
the most positive representable value maps to 1.0, and the most negative representable value maps to
-1.0. Floating-point values are mapped directly.
Neither floating-point nor signed integer specified values are clamped to the range [0,1] before updating
the current color. However, color components are clamped to this range before they are interpolated or
written into a color buffer.
Parameters
Red
Green
Blue
Specifies a red value for the current color. The initial value is 1 (one).
Specifies a green value for the current color. The initial value is 1 (one).
Specifies a blue value for the current color. The initial value is 1 (one).
Chapter 1. OpenGL Subroutines
45
Alpha
Variable
Specifies a new alpha value for the current color. Included only in the four-argument glColor
subroutine. The initial value is 1 (one).
Specifies a pointer to an array that contains red, green, blue, and (sometimes) alpha values.
Notes
The current color can be updated at any time. In particular, glColor can be called between a call to
glBegin and the corresponding call to glEnd.
Associated Gets
Associated gets for the glColor subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_COLOR.
glGet with argument GL_RGBA_MODE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin subroutine, glColorPointer subroutine, glColorPointerEXT subroutine, glEnd subroutine,
glIndex subroutine.
glColorMask Subroutine
Purpose
Enables and disables the writing of frame buffer color components.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glColorMask(GLboolean
GLboolean Green,
GLboolean Blue,
GLboolean Alpha)
Red,
Description
The glColorMask subroutine specifies whether the individual color components in the frame buffer can or
cannot be written. If the Red parameter is GL_FALSE, for example, no change is made to the red
component of any pixel in any of the color buffers, regardless of the drawing operation attempted.
Changes to individual bits of components cannot be controlled. Rather, changes are either enabled or
disabled for entire color components.
46
OpenGL 2.1 Reference Manual
Parameters
Red
Green
Blue
Alpha
Specifies whether red can or cannot be written into the frame buffer. The default value is True, indicating
that the red color component can be written.
Specifies whether green can or cannot be written into the frame buffer. The default value is True, indicating
that the green color component can be written.
Specifies whether blue can or cannot be written into the frame buffer. The default value is True, indicating
that the blue color component can be written.
Specifies whether alpha can or cannot be written into the frame buffer. The default value is True, indicating
that the alpha color component can be written.
Errors
GL_INVALID_OPERATION
The glColorMask subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glColorMask subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_COLOR_WRITEMASK
glGet with argument GL_RGBA_MODE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColor subroutine, glDepthMask subroutine, glIndex subroutine,
glIndexMask subroutine, glStencilMask subroutine.
glColorMaterial Subroutine
Purpose
Causes a material color to track the current color.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glColorMaterial(GLenum
GLenum mode)
face,
Description
The glColorMaterial subroutine specifies which material parameters track the current color. When
GL_COLOR_MATERIAL is enabled, the material parameter or parameters specified by mode, of the
Chapter 1. OpenGL Subroutines
47
material or materials specified by face, track the current color at all times. GL_COLOR_MATERIAL is
enabled and disabled using the subroutines glEnable and glDisable, called with GL_COLOR_MATERIAL
as their argument. By default it is disabled.
Parameters
face
Specifies whether front, back, or both front and back material parameters should track the current color.
Accepted values are GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK. The default value is
GL_FRONT_AND_BACK.
Specifies which of several material parameters will track the current color. Accepted values are
GL_EMISSION, GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, and GL_AMBIENT_AND_DIFFUSE. The
default value is GL_AMBIENT_AND_DIFFUSE.
mode
Notes
The glColorMaterial subroutine allows a subset of material parameters to be changed for each vertex
using only the glColor subroutine, without calling glMaterial. If only such a subset of parameters is to be
specified for each vertex, the use of the glColorMaterial subroutine is preferred over calling glMaterial.
Calling glDrawElements may leave the current color indeterminate. If glColorMaterial is enabled while
the current color is indeterminate, the lighting material state specified by face and mode is also
indeterminate.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
face or mode is set to an unaccepted value.
The glColorMaterial subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glColorMaterial subroutine are as follows. (See the glGet subroutine for more
information.)
glIsEnabled with argument GL_COLOR_MATERIAL
glGet with argument GL_COLOR_MATERIAL_PARAMETER
glGet with argument GL_COLOR_MATERIAL_FACE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColor subroutine, glEnable or glDisable subroutine, glLight
subroutine, glLightModel subroutine, glMaterial subroutine.
glColorNormalVertexSUN Subroutine
Purpose
Specifies a color, a normal and a vertex in one call.
48
OpenGL 2.1 Reference Manual
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glColor4fNormal3fVertex3fSUN (GLfloat r,
GLfloat g,
GLfloat b,
GLfloat a,
GLfloat nx,
GLfloat ny,
GLfloat nz,
GLfloat x,
GLfloat y,
GLfloat z)
void glColor4fNormal3fVertex3fvSUN (const GLfloat
const GLfloat
const GLfloat
*c,
*n,
*v)
Description
This subroutine can be used as a replacement for the following calls:
glColor();
glNormal();
glVertex();
For example, glColor4fNormal3fVertex3fvSUN replaces the following calls:
glColor4f();
glNormal3f();
glVertex3fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
r, g, b, a
c
nx, ny, nz
n
x, y, z
v
specifies r, g, b, and a components of the color for this
vertex.
specifies a pointer to an array of the four components r, g,
b, and a.
specifies x, y, and z coordinates of the normal vector for
this vertex.
specifies a pointer to an array of the three elements nx, ny
and nz.
specifies the x, y, and z coordinates of a vertex. Not all
parameters are present in all forms of the command.
specifies a pointer to an array of the three elements x, y,
and z.
Notes
Calling glColorNormalVertexSUN outside of a glBegin/glEnd subroutine pair results in undefined
behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
Chapter 1. OpenGL Subroutines
49
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
glColorPointer Subroutine
Purpose
Defines an array of colors.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glColorPointer( GLint
GLenum type,
GLsizei stride,
const GLvoid * pointer)
size,
Description
The glColorPointer subroutine specifies the location and data format of an array of color components to
use when rendering. The size parameter specifies the number of components per color, and must be 3 or
4. The type parameter specifies the data type of each color component and stride gives the byte stride
from one color to the next allowing vertices and attributes to be packed into a single array or stored in
separate arrays. (Single-array storage may be more efficient on some implementations; see
glInterleavedArrays).
When a color array is specified, size, type, stride, and pointer are saved as client side state.
To enable and disable the color array, call glEnableClientState and glDisableClientState with the
argument GL_COLOR_ARRAY. If enabled, the color array is used when glDrawArrays, glDrawElements
or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Color array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
50
Specifies the number of components per color. It must be 3 or 4. The initial value is 4.
OpenGL 2.1 Reference Manual
type
stride
pointer
Specifies the data type of each color component in the array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Specifies the byte offset between consecutive colors. If stride is zero (the initial value), the colors are
understood to be tightly packed in the array. The initial value is 0.
Specifies a pointer to the first component of the first color element in the array. The initial value is 0
(NULL pointer).
Notes
The glColorPointer subroutine is available only if the GL version is 1.1 or greater.
The color array is initially disabled and it won’t be accessed when glArrayElement, glDrawElements, or
glDrawArrays is called.
Execution of glColorPointer is not allowed between glBegin and the corresponding glEnd, but an error
may or may not be generated. If an error is not generated, the operation is undefined.
The glColorPointer subroutine is typically implemented on the client side with no protocol.
Since the color array parameters are client side state, they are not saved or restored by glPushAttrib and
glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
The glColorPointer commands are not included in display lists.
Error Codes
GL_INVALID_VALUE is generated if size is not 3 or 4.
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride is negative.
Associated Gets
glIsEnabled with argument GL_COLOR_ARRAY.
glGet with argument GL_COLOR_ARRAY_SIZE.
glGet with argument GL_COLOR_ARRAY_TYPE.
glGet with argument GL_COLOR_ARRAY_STRIDE.
glGetPointerv with argument GL_COLOR_ARRAY_POINTER.
Related Information
The glArrayElement subroutine, glColorPointerListIBM subroutine, glDrawArrays subroutine,
glDrawElements subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv
subroutine, glIndexPointer subroutine, glInterleavedArrays subroutine, glNormalPointer subroutine,
glPopClientAttrib subroutine, glPushClientAttrib subroutine, glTexCoordPointer subroutine,
glVertexPointer subroutine.
Chapter 1. OpenGL Subroutines
51
glColorPointerEXT Subroutine
Purpose
Defines an array of colors.
Library
OpenGL and OpenGL C bindings library: libGL.a
C Syntax
void glColorPointerEXT(GLint size,
GLenum type,
GLsizei stride,
GLsizei count,
const GLvoid *pointer)
Description
The glColorPointerEXT subroutine specifies the location and data format of an array of color components
to use when rendering. size specifies the number of components per color, and must be 3 or 4. The type
parameter specifies the data type of each color component and stride gives the byte stride from one color
to the next allowing vertexes and attributes to be packed into a single array or stored in separate arrays.
(Single-array storage may be more efficient on some implementations). The count parameter indicates the
number of array elements (counting from the first) that are static. Static elements may be modified by the
application, but once they are modified, the application must explicitly respecify the array before using it for
any rendering. When a color array is specified, size, type, stride, count and pointer are saved as
client-side state, and static array elements may be cached by the implementation.
The color array is enabled and disabled using glEnable and glDisable with the argument
GL_COLOR_ARRAY_EXT. If enabled, the color array is used when glDrawArraysEXT or
glArrayElementEXT is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Color array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
Specifies the number of components per color. It must be
3 or 4.
Specifies the data type of each color component in the
array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT,
GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE_EXT, are accepted.
Specifies the byte offset between consecutive colors. If
stride is zero the colors are understood to be tightly
packed in the array.
Specifies the number of colors, counting from the first, that
are static.
type
stride
count
52
OpenGL 2.1 Reference Manual
pointer
Specifies a pointer to the first component of the first color
element in the array.
Notes
Non-static array elements are not accessed until glArrayElementEXT or glDrawArraysEXT is executed.
By default the color array is disabled and it won’t be accessed when glArrayElementEXT or
glDrawArraysEXT is called.
Although, it is not an error to call glColorPointerEXT between the execution of glBegin and the
corresponding execution of glEnd, the results are undefined.
glColorPointerEXT will typically be implemented on the client side with no protocol.
Since the color array parameters are client side state, they are not saved or restored by glPushAttrib and
glPopAttrib.
glColorPointerEXT commands are not entered into display lists.
glColorPointerEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Errors
GL_INVALID_VALUE is generated if size is not 3 or 4.
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride or count is negative.
Associated Gets
glIsEnabled with argument GL_COLOR_ARRAY_EXT.
glGet with argument GL_COLOR_ARRAY_SIZE_EXT.
glGet with argument GL_COLOR_ARRAY_TYPE_EXT.
glGet with argument GL_COLOR_ARRAY_STRIDE_EXT.
glGet with argument GL_COLOR_ARRAY_COUNT_EXT.
glGetPointervEXT with argument GL_COLOR_ARRAY_POINTER_EXT.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElement subroutine, glDrawArraysEXT subroutine, glEdgeFlagPointerEXT subroutine,
glGetPointervEXT subroutine, glIndexPointerEXT subroutine, glNormalPointerEXT subroutine,
glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.
Chapter 1. OpenGL Subroutines
53
glColorPointerListIBM Subroutine
Purpose
Defines a list of color arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glColorPointerListIBM ( GLint
GLenum type,
GLint stride,
const GLvoid ** pointer,
GLint ptrstride)
size,
Description
The glColorPointerListIBM subroutine specifies the location and data format of a list of arrays of color
components to use when rendering. The size parameter specifies the number of components per color,
and must be 3 or 4. The type parameter specifies the data type of each color component. The stride
parameter gives the byte stride from one color to the next allowing vertices and attributes to be packed
into a single array or stored in separate arrays. (Single-array storage may be more efficient on some
implementations; see glInterleavedArrays). The ptrstride parameter specifies the byte stride from one
pointer to the next in the pointer array.
When a color array is specified, size, type, stride, pointer and ptrstride are saved as client side state.
A stride value of 0 does not specify a ″tightly packed″ array as it does in glColorPointer. Instead, it
causes the first array element of each array to be used for each vertex. Also, a negative value can be
used for stride, which allows the user to move through each array in reverse order.
To enable and disable the color arrays, call glEnableClientState and glDisableClientState with the
argument GL_COLOR_ARRAY. The color array is initially disabled. When enabled, the color arrays are
used when glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, glDrawArrays, glDrawElements or glArrayElement is called. The last
three calls in this list will only use the first array (the one pointed at by pointer[0]). See the descriptions of
these routines for more information on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Color array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
type
54
Specifies the number of components per color. It must be 3 or 4. The initial value is 4.
Specifies the data type of each color component in the array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
OpenGL 2.1 Reference Manual
stride
pointer
ptrstride
Specifies the byte offset between consecutive colors. The initial value is 0.
Specifies a list of color arrays. The initial value is 0 (NULL pointer).
Specifies the byte stride between successive pointers in the pointer array. The initial value is 0.
Notes
The glColorPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists extension is
supported.
Execution of glColorPointerListIBM is not allowed between glBegin and the corresponding glEnd, but an
error may or may not be generated. If an error is not generated, the operation is undefined.
The glColorPointerListIBM subroutine is typically implemented on the client side.
Since the color array parameters are client side state, they are not saved or restored by glPushAttrib and
glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glColorPointerListIBM call is encountered while compiling a display list, the information it
contains does NOT contribute to the display list, but is used to update the immediate context instead.
The glColorPointer call and the glColorPointerListIBM call share the same state variables. A
glColorPointer call will reset the color list state to indicate that there is only one color list, so that any and
all lists specified by a previous glColorPointerListIBM call will be lost, not just the first list that it specified.
Error Codes
GL_INVALID_VALUE is generated if size is not 3 or 4.
GL_INVALID_ENUM is generated if type is not an accepted value.
Associated Gets
glIsEnabled with argument GL_COLOR_ARRAY.
glGetPointerv with argument GL_COLOR_ARRAY_LIST_IBM.
glGet with argument GL_COLOR_ARRAY_LIST_STRIDE_IBM.
glGet with argument GL_COLOR_ARRAY_SIZE.
glGet with argument GL_COLOR_ARRAY_STRIDE.
glGet with argument GL_COLOR_ARRAY_TYPE.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine,
glIndexPointer subroutine, glInterleavedArrays subroutine, glMultiDrawArraysEXT subroutine,
glMultiDrawElementsEXT subroutine, glMultiModeDrawArraysIBM subroutine,
glMultiModeDrawElementsIBM subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
Chapter 1. OpenGL Subroutines
55
glColorSubTable Subroutine
Purpose
Define a contiguous subset of a color lookup table.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glColorTable(GLenum target,
GLsizei start,
GLsizei count,
GLenum format,
GLenum type,
const GLvoid *data)
void glColorTableEXT(GLenum target,
GLsizei start,
GLsizei count,
GLenum format,
GLenum type,
const GLvoid *data)
Description
glColorSubTable is used to respecify a contiguous portion of a color table previously defined using
glColorTable. The pixels reference by data replace the portion of the existing table from indices start to
start + count - 1, inclusive. This region may not include any entries outside the range of the color table as
it was originally specified. It is not an error to specify a subtable with width of 0, but such a specification
has no effect.
Parameters
target
start
count
format
type
data
must be GL_TEXTURE_COLOR_TABLE_EXT.
is the starting index of the portion of the color table to be replaced.
is the number of table entries to replace.
is the format of the pixel data in data. The allowable values are GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, GL_BGR, GL_RGBA and
GL_BGRA.
is the type of the pixel data in table. The allowable values are GL_UNSIGNED_BYTE, GL_BYTE,
GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
is a pointer to a one-dimensional array of pixel data that is processed to replace the specified region
of the color table.
Notes
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably. GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
56
OpenGL 2.1 Reference Manual
Error Codes
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_OPERATION
is generated if target is not one of the allowable values.
is generated if start + count > width, where width is the
width of the previously defined color table.
is generated if format is not one of the allowable values.
is generated if type is not one of the allowable values.
is generated if glColorSubTable is executed between the
execution of glBegin and the corresponding execution of
glEnd.
Associated Gets
Associated gets for the glColorSubTable subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with arguement glGetColorTableParameter.
glGet with arguement glGetColorTable.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glColorTable subroutine, the glColorTableParameter subroutine, the glCopyColorTable subroutine,
the glCopyColorSubTable subroutine, the glGetColorTable subroutine.
glColorTable Subroutine
Purpose
Define a color lookup table.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glColorTable(GLenum target,
GLenum internalformat,
GLsizei width,
GLenum format,
GLenum type,
const GLvoid *table)
void glColorTableSGI(GLenum target,
GLenum internalformat,
GLsizei width,
GLenum format,
GLenum type,
const GLvoid *table)
Chapter 1. OpenGL Subroutines
57
Description
glColorTable may be used in two ways: to test the actual size and color resolution of a lookup table given
a particular set of parameters, or to load the contents of a color lookup table. Use the targets
GL_PROXY_* for the first case and the other targets for the second case.
If target is GL_TEXTURE_COLOR_TABLE_EXT, glColorTable builds a color lookup table from an array
of pixels. The pixel array specified by width, format, type, and table is extracted from memory and
processed just as if glDrawPixels were called, but processing stops after the final expansion to RGBA is
completed.
The four scale parameters and the four bias parameters that are defined for the table are then used to
scale and bias the R, G, B, and A components of each pixel. (Use glColorTableParameter to set these
scale and bias parameters).
Next, the R, G, B, and A values are clamped to the range [0, 1]. Each pixel is then converted to the
internal format specified by internalformat. This conversion simply maps the component values of the pixel
(R, G, B, and A) to the values included in the internal format (red, green, blue, alpha, and intensity). The
mapping is as follows:
Internal Format
Red
Green
GL_ALPHA
GL_LUMINANCE
GL_LUMINANCE_ALPHA
GL_INTENSITY
GL_RGB
R
GL_RGBA
R
Blue
Alpha
A
A
G
G
B
B
Luminance
R
R
Intensity
R
A
Finally, the red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are
stored in the color table. They form a one-dimensional table with indices in the range [0, width-1].
If target is GL_PROXY_TEXTURE_COLOR_TABLE_EXT, glColorTable recomputes and stores the
values of the proxy color table’s state variables GL_COLOR_TABLE_FORMAT,
GL_COLOR_TABLE_WIDTH, GL_COLOR_TABLE_RED_SIZE, GL_COLOR_TABLE_GREEN_SIZE,
GL_COLOR_TABLE_BLUE_SIZE, GL_COLOR_TABLE_ALPHA_SIZE,
GL_COLOR_TABLE_LUMINANCE_SIZE, and GL_COLOR_TABLE_INTENSITY_SIZE. There is no effect
on the image or state of any actual color table. If the specified color table is too large to be supported,
then all the proxy state variables listed above are set to zero. Otherwise, the color table could be
supported by glColorTable using the corresponding non-proxy target, and the proxy state variable are set
as if that target were being defined.
The proxy state variables can be retrieved by calling glGetColorTableParameter with a target of
GL_PROXY_*. This allows the application to decide what the resulting color table attributes would be.
If a color table is enabled, and its width is non-zero, then its contents are used to replace a subset of the
components of each RGBA pixel group, based on the internal format of the table.
Each pixel group has color components (R, G, B, A) that are in the range [0.0, 1.0]. The color components
are rescaled to the size of the color lookup table to form an index. Then a subset of the components
based on the internal format of the table are replaced by the table entry specified by that index. If the color
components and contents of the table are represented as follows:
Representation
r
g
b
a
L[i]
58
Meaning
Table index computed from R
Table index computed from G
Table index computed from B
Table index computed from A
Luminance value at table index i
OpenGL 2.1 Reference Manual
I[i]
R[i]
G[i]
B[i]
A[i]
Intensity value at table index i
Red value at table index i
Green value at table index i
Blue value at table index i
Alpha value at table index i
then the result of color table lookup is as follows:
Table Internal Format
Resulting Color Components
R
G
B
A
GL_ALPHA
GL_LUMINANCE
GL_LUMINANCE_ALPHA
GL_INTENSITY
GL_RGB
GL_RGBA
R
L[r]
L[r]
I[r]
R[r]
R[r]
G
L[g]
L[g]
I[g]
G[g]
G[g]
B
L[b]
L[b]
I[b]
B[b]
B[b]
A[a]
A
A[a]
I[a]
A
A[a]
Parameters
target
internalformat
width
format
must be GL_TEXTURE_COLOR_TABLE_EXT or
GL_PROXY_TEXTURE_COLOR_TABLE_EXT.
is the internal format of the color table. The allowable
values are GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4,
GL_ALPHA8, GL_ALPHA12, GL_ALPHA16,
GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8, GL_LUMINANCE12,
GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4,
GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8,
GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12,
GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12,
GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4,
GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4,
GL_RGB5_A1, GL_RGB8, GL_RGB10_A2,
GL_RGBA12, and GL_RGB16.
is the number of entries in the color lookup table specified
by table.
is the format of the pixel data in table. The allowable
values are GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_LUMINANCE,
GL_LUMINANCE_ALPHA, GL_RGB, GL_BGR,
GL_RGBA, GL_BGRA, GL_422_EXT,
GL_422_REV_EXT, GL_422_AVERAGE_EXT, and
GL_422_REV_AVERAGE_EXT.
Chapter 1. OpenGL Subroutines
59
type
is the type of the pixel data in table. The allowable values
are GL_UNSIGNED_BYTE, GL_BYTE,
GL_UNSIGNED_SHORT, GL_SHORT,
GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and
GL_UNSIGNED_INT_2_10_10_10_REV.
is pointer to a one-dimensional array of pixel data that is
processed to build the color table.
table
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably. GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_VALUE
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_TABLE_TOO_LARGE
GL_INVALID_OPERATION
is generated if target is not one of the allowable values.
is generated if internalformat is not one of the allowable
values.
is generated if width is less than zero.
is generated if target is set to
GL_TEXTURE_COLOR_TABLE_EXT and width is not a
power of two.
is generated if format is not one of the allowable values.
is generated if type is not one of the allowable values.
is generated if the requested color table is too large to be
supported by the implementation, and target is not a
GL_PROXY_* target.
is generated if glColorTable is executed between the
execution of glBegin and the corresponding execution of
glEnd.
Associated Gets
Associated gets for the glColorTable subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with arguement glGetColorTableParameter.
glGet with arguement glGetColorTable.
60
OpenGL 2.1 Reference Manual
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glColorSubTable subroutine, the glColorTableParameter subroutine, the glCopyColorTable
subroutine, the glCopyColorSubTable subroutine, the glGetColorTable subroutine.
glColorTableParameter Subroutine
Purpose
Specify attributes to be used when loading a color table.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glColorTableParameterfv(GLenum target,
GLenum pname,
const GLfloat *params)
void glColorTableParameteriv(GLenum target,
GLenum pname,
const GLint *params)
void glColorTableParameterfvSGI(GLenum target,
GLenum pname,
const GLfloat *params)
void glColorTableParameterivSGI(GLenum target,
GLenum pname,
const GLint *params)
Description
glColorTableParameter is used to specify the scale factors and bias terms applied to color components
when they are loaded into a color table. target indicates which color table the scale or bias terms apply to.
If pname is set to GL_COLOR_TABLE_SCALE, then the four values pointed to by params will be stored
as the red, green, blue and alpha scale factors, in that order.
If pname is set to GL_COLOR_TABLE_BIAS, then the four values pointed to by params will be stored as
the red, green, blue and alpha bias terms, in that order.
Parameters
target
pname
is the target color table and must be
GL_TEXTURE_COLOR_TABLE_EXT.
is the symbolic name of a texture color lookup table
parameter. Must be GL_COLOR_TABLE_SCALE or
GL_COLOR_TABLE_BIAS.
Chapter 1. OpenGL Subroutines
61
params
is a pointer to an array where the values of the
paramaters are stored.
Notes
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably.
GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_OPERATION
is generated if target is not one of the allowable values.
is generated if pname is not one of the allowable values.
is generated if glColorTable is executed between the
execution of glBegin and the corresponding execution of
glEnd.
Associated Gets
Associated gets for the glColorTableParameter subroutine are as follows. (See the glGet subroutine for
more information.)
glGet with arguement glGetColorTableParameter.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glPixelTransfer subroutine, the glColorTable subroutine.
glColorVertexSUN Subroutine
Purpose
Specifies a color and a vertex in one call.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glColor3fVertex3fSUN (GLfloat r,
GLfloat g,
GLfloat b,
GLfloat x,
GLfloat y,
GLfloat z)
void glColor3fVertex3fvSUN (const GLfloat
const GLfloat
void glColor4ubVertex2fSUN (GLubyte r,
62
OpenGL 2.1 Reference Manual
*c,
*v)
GLubyte g,
GLubyte b,
GLubyte a,
GLfloat x,
GLfloat y)
void glColor4ubVertex2fvSUN (const GLubyte *c,
const GLfloat *v)
void glColor4ubVertex3fSUN (GLubyte r,
GLubyte g,
GLubyte b,
GLubyte a,
GLfloat x,
GLfloat y,
GLfloat z)
void glColor4ubVertex3fvSUN (const GLubyte *c,
const GLfloat *v)
Description
This subroutine can be used as a replacement for the following calls:
glColor();
glVertex();
For example, glColor4ubVertex3fvSUN replaces the following calls:
glColor4ub();
glVertex3fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
x, y, z
v
r, g, b, a
c
Specifies the x, y, and z coordinates of a vertex. Not all
parameters are present in all forms of the command.
Specifies a pointer to an array of two, or three elements.
The elements of a two-element array are x and y. The
elements of a three-element array are x, y, and z.
Specifies the red, green, blue, and alpha components of a
color. Not all parameters are present in all forms of the
command.
Specifies a pointer to an array of three or four elements.
The elements of a three-element array are r, g, and b.
The elements of a four-element array are r, g, b, and a.
Notes
Calling glColorVertexSUN outside of a glBegin/glEnd subroutine pair results in undefined behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Chapter 1. OpenGL Subroutines
63
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
glCopyColorSubTable Subroutine
Purpose
Load a subset of a color lookup table from the current GL_READ_BUFFER.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glCopyColorSubTable(GLenum target,
GLsizei start,
GLint x,
GLint y,
GLsizei width)
void glCopyColorSubTableSGI(GLenum target,
GLsizei start,
GLint x,
GLint y,
GLsizei width)
Description
glCopyColorSubTable is used to respecify a contiguous portion of a color table previously defined using
glColorTable. The pixels copied from the framebuffer replace the portion of the existing table from indices
start to start + x - 1, inclusive. This region may not include any entries outside the range of the color table
as it was originally specified. It is not an error to specify a subtexture with width of 0, but such a
specification has no effect.
Parameters
target
start
Must be GL_TEXTURE_COLOR_TABLE_EXT.
is the starting index of the portion of the color table to be
replaced.
is the window coordinates of the left end of the row of
pixels to be copied.
is the width of the pixel rectangle.
x, y
width
Notes
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably. GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
Error Codes
GL_INVALID_ENUM
GL_INVALID_VALUE
64
OpenGL 2.1 Reference Manual
is generated if target is not one of the allowable values.
is generated if width is less than zero.
GL_INVALID_OPERATION
is generated if glCopyColorSubTable is executed
between the execution of glBegin and the corresponding
execution of glEnd.
Associated Gets
Associated gets for the glColorTable subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with arguement glGetColorTableParameter.
glGet with arguement glGetColorTable.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glColorSubTable subroutine, the glColorTableParameter subroutine, the glCopyColorTable
subroutine, the glGetColorTable subroutine.
glCopyColorTable Subroutine
Purpose
Load a color lookup table from the current GL_READ_BUFFER.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glCopyColorTable(GLenum target,
GLenum internalformat,
GLint x,
GLint y,
GLsizei width)
void glCopyColorTableSGI(GLenum target,
GLenum internalformat,
GLint x,
GLint y,
GLsizei width)
Description
glCopyColorTable loads a color table with pixels from the current GL_READ_BUFFER (rather than from
main memory, as is the case for glColorTable).
The screen-aligned pixel rectangle with lower-left corner at (x, y) having width width and height 1 is loaded
into the color table. If any pixels within this region are outside the window that is associated with the GL
context, the values obtained for those pixels are undefined
The pixels in the rectangle are processed just as if glReadPixels were called, with internalformat set to
RGBA, but processing stops after the final conversion to RGBA.
Chapter 1. OpenGL Subroutines
65
The four scale parameters and the four bias parameters that are defined for the table are then used to
scale and bias the R, G, B, and A components of each pixel. (Use glColorTableParameter to set these
scale and bias parameters).
Next, the R, G, B, and A values are clamped to the range [0, 1]. Each pixel is then converted to the
internal format specified by internalformat. This conversion simply maps the component values of the pixel
(R, G, B, and A) to the values included in the internal format (red, green, blue, alpha, and intensity). The
mapping is as follows:
Internal Format
Red
Green
GL_ALPHA
GL_LUMINANCE
GL_LUMINANCE_ALPHA
GL_INTENSITY
GL_RGB
R
GL_RGBA
R
Blue
Alpha
A
A
G
G
B
B
Luminance
R
R
Intensity
R
A
Finally, the red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are
stored in the color table. They form a one-dimensional table with indices in the range [0, width-1].
Parameters
target
internalformat
width
x
y
table
Must be GL_TEXTURE_COLOR_TABLE_EXT or
GL_PROXY_TEXTURE_COLOR_TABLE_EXT.
is the internal format of the color table. The allowable
values are: GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4,
GL_ALPHA8, GL_ALPHA12, GL_ALPHA16,
GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8, GL_LUMINANCE12,
GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4,
GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8,
GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12,
GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY12, GL_INTENSITY16,
GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5,
GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16,
GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1,
GL_RGB8, GL_RGB10_A2, GL_RGBA12, and
GL_RGB16.
The width of the pixel rectangle.
is the x coordinate of the lower-left corner of the pixel
rectangle to be transferred to the color table.
is the y coordinate of the lower-left corner of the pixel
rectangle to be transferred to the color table.
is a pointer to a one-dimensional array of pixel data that is
processed to build the color table.
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably. GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
66
OpenGL 2.1 Reference Manual
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
is generated if target is not one of the allowable values.
is generated if internalformat is not one of the allowable
values.
is generated if width is less than zero.
is generated if the requested color table is too large to be
supported by the implementation.
is generated if glCopyColorTable is executed between
the execution of glBegin and the corresponding execution
of glEnd.
GL_INVALID_VALUE
GL_TABLE_TOO_LARGE
GL_INVALID_OPERATION
Associated Gets
Associated gets for the glColorTable subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with arguement glGetColorTableParameter.
glGet with arguement glGetColorTable.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glColorTable subroutine, the glColorTableParameter subroutine, the glCopyColorSubTable
subroutine, the ReadPixels subroutine, the glGetColorTable subroutine.
glCopyPixels Subroutine
Purpose
Copies pixels in the frame buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyPixels(GLint
GLint yCoordinate,
GLsizei Width,
GLsizei Height,
GLenum Type)
xCoordinate,
Description
The glCopyPixels subroutine copies a screen-aligned rectangle of pixels from the specified frame buffer
location to a region relative to the current raster position. Its operation is well defined only if the entire pixel
source region is within the exposed portion of the window. Results of copies from outside the window, or
from regions of the window that are not exposed, are hardware-dependent and undefined.
Chapter 1. OpenGL Subroutines
67
The x and y parameters specify the window coordinates of the lower left corner of the rectangular region
to be copied. The Width and Height parameters specify the dimensions of the rectangular region to be
copied. Both Width and Height must be nonnegative numbers.
Several parameters control the processing of the pixel data while it is being copied. These parameters are
set with three subroutines: glPixelTransfer, glPixelMap, and glPixelZoom. This article describes the
effects on glCopyPixels of most, but not all, of the parameters specified by these three subroutines.
The glCopyPixels subroutine copies values from each pixel with lower left corner at (x + i, y + j) for 0 <= i
<Width and 0 <= j <Height. This pixel is said to be the ith pixel in the jth row. Pixels are copied in row
order from the lowest to the highest row, left to right in each row.
The Type parameter specifies whether color, depth, or stencil data is to be copied. The details of the
transfer for each data type are as follows.
GL_COLOR
Indices or red, green, blue, alpha (RGBA) colors are read from the buffer currently specified as
the read source buffer. (See the glReadBuffer subroutine.) If the GL is in color index mode, each
index that is read from this buffer is converted to a fixed-point format with an unspecified number
of bits to the right of the binary point. Each index is then shifted left by GL_INDEX_SHIFT bits
and added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift is to the right. In
either case, 0 (zero) bits fill otherwise unspecified bit locations in the result. If GL_MAP_COLOR
is True, the index is replaced with the value that it references in lookup table
GL_PIXEL_MAP_I_TO_I. Whether the lookup replacement of the index is done or not, the
integer part of the index is then ANDed with 2b -1, where b is the number of bits in a color index
buffer.
If the GL is in RGBA mode, the red, green, blue, and alpha components of each pixel that is read
are converted to an internal floating-point format with unspecified precision. The conversion maps
the largest representable component value to 1.0, and component value 0 to 0.0. The resulting
floating-point color values are then multiplied by GL_c_SCALE and added to GL_c_BIAS, where
c is RED, GREEN, BLUE, and ALPHA for the respective color components. The results are
clamped to the range [0,1]. If GL_MAP_COLOR is True, each color component is scaled by the
size of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value that it references
in that table. c is R, G, B, or A, respectively.
GL_DEPTH
The resulting indices or RGBA colors are then converted to fragments by attaching the current
raster position z coordinate and texture coordinates to each pixel, then assigning window
coordinates (xr + i , yr + j), where (xr, yr) is the current raster position, and the pixel was the ith
pixel in the jth row. These pixel fragments are then treated just like the fragments generated by
rasterizing points, lines, or polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
Depth values are read from the depth buffer and converted directly to an internal floating-point
format with unspecified precision. The resulting floating-point depth value is then multiplied by
GL_DEPTH_SCALE and added to GL_DEPTH_BIAS. The result is clamped to the range [0,1].
The resulting depth components are then converted to fragments by attaching the current raster
position color or color index and texture coordinates to each pixel, then assigning window
coordinates (xr + i , yr + j), where (xr, yr) is the current raster position, and the pixel was the ith
pixel in the jth row. These pixel fragments are then treated just like the fragments generated by
rasterizing points, lines, or polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
68
OpenGL 2.1 Reference Manual
GL_STENCIL
Stencil indices are read from the stencil buffer and converted to an internal fixed-point format with
an unspecified number of bits to the right of the binary point. Each fixed-point index is then
shifted left by GL_INDEX_SHIFT bits and added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is
negative, the shift is to the right. In either case, 0 bits fill otherwise unspecified bit locations in the
result. If GL_MAP_STENCIL is True, the index is replaced with the value that it references in the
lookup table GL_PIXEL_MAP_S_TO_S. Whether the lookup replacement of the index is done or
not, the integer part of the index is then ANDed with 2b -1, where b is the number of bits in the
stencil buffer. The resulting stencil indices are then written to the stencil buffer such that the index
read from the ith location of the jth row is written to location (xr + i, yr + j), where (xr, yr) is the
current raster position. Only the pixel ownership test, the scissor test, and the stencil writemask
affect these writes.
The rasterization described thus far assumes pixel zoom factors of 1.0. If glPixelZoom is used to change
the x and y pixel zoom factors, pixels are converted to fragments as follows. If (xr, yr) is the current raster
position, and a given pixel is in the ith location in the jth row of the source pixel rectangle, fragments are
generated for pixels whose centers are in the rectangle with corners at
Unmapped format: variant of paragraph
(xr + zoomx i, yr + zoomy j)
Unmapped format: variant of paragraph
and
Unmapped format: variant of paragraph
(xr + zoomx (i + 1), yr + zoomy ( j + 1 )),
where zoom x is the value of GL_ZOOM_X and zoomy is the value of GL_ZOOM_Y.
Parameters
xCoordinate
yCoordinate
Width
Height
Type
Specifies the x window coordinate of the lower left corner of the rectangular region of pixels to
be copied.
Specifies the y window coordinate of the lower left corner of the rectangular region of pixels to
be copied.
Specifies the width of the rectangular region of pixels to be copied. This parameter does not
accept a negative value.
Specifies the height of the rectangular region of pixels to be copied. This parameter does not
accept a negative value.
Specifies whether color values, depth values, or stencil values are to be copied. Symbolic
constants GL_COLOR, GL_DEPTH, and GL_STENCIL are accepted.
Notes
Modes specified by glPixelStore have no effect on the operation of glCopyPixels.
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_OPERATION
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Type is not an accepted value.
Either Width or Height is negative.
Type is GL_DEPTH and there is no depth buffer.
Type is GL_STENCIL and there is no stencil buffer.
The glCopyPixels subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Chapter 1. OpenGL Subroutines
69
Associated Gets
Associated gets for the glCopyPixels subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_RASTER_POSITION.
glGet with argument GL_CURRENT_RASTER_POSITION_VALID.
Examples
To copy the color pixel in the lower left corner of the window to the current raster position, enter the
following:
glCopyPixels(0, 0, 1, 1, GL_COLOR);
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glDepthFunc subroutine, glDrawBuffer subroutine, glDrawPixels
subroutine, glPixelMap subroutine, glPixelTransfer subroutine, glPixelZoom subroutine, glRasterPos
subroutine, glReadBuffer subroutine, glReadPixels subroutine, glStencilFunc subroutine.
glCopyTexImage1D Subroutine
Purpose
Defines a one-dimensional (1D) texture image.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyTexImage1D(GLenum target,
GLint level,
GLenum internalFormat,
GLint xCoordinate,
GLint yCoordinate,
GLsizei width,
GLint border)
Description
The glCopyTexImage1D subroutine defines a one dimensional texture image with pixels from the current
GL_READ_BUFFER.
The screen aligned pixel row with left corner at (x,y) and with a length of width + 2 * border defines the
texture array at the mipmap level specified by level. IIternalFormat specifies the internal format of the
texture array.
The pixels in the row are processed exactly as if glCopyPixels had been called, but the process stops
just before final conversion. At this point all pixel component values are clamped to the range [0, 1] and
then converted to the texture’s internal format for storage in the texel array.
70
OpenGL 2.1 Reference Manual
Pixel ordering is such that lower x screen coordinates correspond to lower texture coordinates.
If any of the pixels within the specified row of the current GL_READ_BUFFER are outside the window
associated with the current rendering context, then the values obtained for those pixels are undefined.
Parameters
target
level
internalFormat
xCoordinate
yCoordinate
width
border
Specifies the target texture. Must be GL_TEXTURE_1D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth
mipmap reduction image.
Specifies the internal format of the texture. Must be one of the following symbolic
constants: GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12,
GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8,
GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB,
GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
Specifies the x window coordinate of the lower left corner of the row of pixels to be
copied.
Specifies the y window coordinate of the lower left corner of the row of pixels to be
copied.
Specifies the width of the texture image. Must be 0 or 2**n + 2*border for some integer n.
The height of the texture image is 1.
Specifies the width of the border. Must be either 0 or 1.
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
The glCopyTexImage1D subroutine is available only if the GL version is 1.1 or greater.
1, 2, 3, or 4 are not accepted values for internalFormat.
An image with zero width indicates a null texture.
Errors
GL_INVALID_ENUM is generated if target is not one of the allowable values.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value
of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_VALUE is generated if width is less than zero, greater than 2 + GL_MAX_TEXTURE_SIZE,
or if width cannot be represented as 2**k+ 2 * border for some integer k.
GL_INVALID_VALUE is generated if width is less than zero or greater than 2 +
GL_MAX_TEXTURE_SIZE, or if it cannot be represented as 2**n + 2 * border for some integer value of n.
Chapter 1. OpenGL Subroutines
71
GL_INVALID_OPERATION is generated if glCopyTexImage1D is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D
Related Information
The glCopyTexImage2D subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage1D
subroutine, glTexParameter subroutine.
glCopyTexImage2D Subroutine
Purpose
Defines a two-dimensional (2D) texture image.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyTexImage2D(GLenum target,
GLint
level,
GLenum
internalFormat,
GLint
xCoordinate,
GLint
yCoordinate,
GLsizei
width,
GLsizei
height,
GLint
border)
Description
The glCopyTexImage2D subroutine defines a two-dimensional texture image with pixels from the current
GL_READ_BUFFER.
The screen aligned pixel rectangle with lower left corner at (x, y) and with a width of width + 2 * border
and height height + 2 * border defines the texture array at the mipmap level specified by level.
internalFormat specifies the internal format of the texture array.
The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process
stops just before final conversion. At this point all pixel component values are clamped to the range
[0.0,1.0] and then converted to the texture’s internal format for storage in the texel array.
Pixel ordering is such that lower x and y screen coordinates correspond to lower s and t texture
coordinates.
If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the
window associated with the current rendering context, then the values obtained for those pixels are
undefined.
72
OpenGL 2.1 Reference Manual
Parameters
target
level
internalFormat
xCoordinate
yCoordinate
width
height
border
Specifies the target texture. Must be GL_TEXTURE_2D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth
mipmap reduction image.
Specifies the internal format of the texture. Must be one of the following symbolic
constants: GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12,
GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8,
GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB,
GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
Specifies the x window coordinate of the lower left corner of the row of pixels to be
copied.
Specifies the y window coordinate of the lower left corner of the row of pixels to be
copied.
Specifies the width of the texture image. Must be 0 or 2**n + 2*border for some integer n.
The height of the texture image is 1.
Specifies the height of the texture image. Must be 0 or 2**m + 2*border for some integer
m.
Specifies the width of the border. Must be either 0 or 1.
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
The glCopyTexImage2D subroutine is available only if the GL version is 1.1 or greater.
1, 2, 3, or 4 are not accepted values for internalFormat.
An image with height or width of 0 indicates a NULL texture.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value
of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if width or height is less than zero, greater than 2 +
GL_MAX_TEXTURE_SIZE, or if width or height cannot be represented as 2**k + 2 * border for some
integer k.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_VALUE is generated if internalFormat is not one of the allowable values.
GL_INVALID_OPERATION is generated if glCopyTexImage2D is executed between the execution of
glBegin and the corresponding execution of glEnd.
Chapter 1. OpenGL Subroutines
73
Associated Gets
glGetTexImage.
glIsEnabled with argument GL_TEXTURE_2D.
Related Information
The glCopyPixels subroutine, glCopyTexImage1D subroutine, glPixelStore subroutine, glPixelTransfer
subroutine, glTexEnv subroutine, glTexImage2D subroutine, glTexParameter subroutine.
glCopyTexSubImage1D Subroutine
Purpose
Copies a one-dimensional (1D) texture subimage.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyTexSubImage1D(GLenum
GLint level,
GLint xoffset,
GLint xCoordinate,
GLint yCoordinate,
GLsizei width)
target,
Description
The glCopyTexSubImage1D subroutine replaces a portion of a one dimensional texture image with pixels
from the current GL_READ_BUFFER (rather than from main memory, as is the case for
glTexSubImage1D).
The screen aligned pixel row with left corner at (x, y), and with length width replaces the portion of the
texture array with x indices xoffset through xoffset + width - 1, inclusive. The destination in the texture
array may not include any texels outside the texture array as it was originally specified.
The pixels in the row are processed exactly as if glCopyPixels had been called, but the process stops
just before final conversion. At this point all pixel component values are clamped to the range [0, 1] and
then converted to the texture’s internal format for storage in the texel array.
It is not an error to specify a subtexture with zero width, but such a specification has no effect. If any of
the pixels within the specified row of the current GL_READ_BUFFER are outside the read window
associated with the current rendering context, then the values obtained for those pixels are undefined.
No change is made to the internalFormat, width, or border parameters of the specified texture array or to
texel values outside the specified subregion.
Parameters
target
level
xoffset
xCoordinate
74
Specifies the target texture. Must be GL_TEXTURE_1D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
reduction image.
Specifies the texel offset within the texture array.
Specifies the x window coordinate of the lower left corner of the row of pixels to be copied.
OpenGL 2.1 Reference Manual
yCoordinate
width
Specifies the y window coordinate of the lower left corner of the row of pixels to be copied.
Specifies the width of the texture image subimage.
Notes
The glCopyTexSubImage1D subroutine is available only if the GL version is 1.1 or greater.
Texturing has no effect in color index mode.
The glPixelTransfer mode affects texture images in exactly the way they affect glDrawPixels.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_1D.
GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous
glTexImage1D operation.
GL_INVALID_VALUE is generated if width is less than zero.
GL_INVALID_VALUE may be generated if level>log2 max, where max is the returned value of
GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if y < -b or if width < -b, where b is the border width of the texture
array.
GL_INVALID_VALUE is generated if xoffset < -b, or (xoffset + width) > (w-b). Where w is the
GL_TEXTURE_WIDTH, and b is the GL_TEXTURE_BORDER of the texture image being modified. Note
that w includes twice the border width.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D.
Related Information
The glCopyTexSubImage2D subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage1D
subroutine, glTexSubImage1D subroutine, glTexParameter subroutine,
glCopyTexSubImage2D Subroutine
Purpose
Copies a two-dimensional (2D) texture subimage.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyTexSubImage2D(GLenum
GLint level,
GLint xoffset,
GLint yoffset,
target,
Chapter 1. OpenGL Subroutines
75
GLint xCoordinate,
GLint yCoordinate,
GLsizei width,
GLsizei height)
Description
The glCopyTexSubImage2D subroutine replaces a portion of a two dimensional texture image with pixels
from the current GL_READ_BUFFER (rather than from main memory, as is the case for
glTexSubImage2D).
The screen aligned pixel rectangle with lower left corner at (x, y) and with width width and height height
replaces the portion of the texture array with x indices xoffset through xoffset + width - 1, inclusive, and y
indices yoffset through yoffset + height - 1, inclusive, at the mipmap level specified by level.
The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process
stops just before final conversion. At this point all pixel component values are clamped to the range [0, 1]
and then converted to the texture’s internal format for storage in the texel array.
The destination rectangle in the texture array may not include any texels outside the texture array as it
was originally specified. It is not an error to specify a subtexture with zero width or height, but such a
specification has no effect.
If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the read
window associated with the current rendering context, then the values obtained for those pixels are
undefined.
No change is made to the internalformat, width, height, or border parameters of the specified texture array
or to texel values outside the specified subregion.
Parameters
target
level
xoffset
yoffset
xCoordinate
yCoordinate
width
height
Specifies the target texture. Must be GL_TEXTURE_2D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
reduction image.
Specifies a texel offset in the x direction within the texture array.
Specifies a texel offset in the y direction within the texture array.
Specifies the x window coordinate of the lower left corner of the row of pixels to be copied.
Specifies the y window coordinate of the lower left corner of the row of pixels to be copied.
Specifies the width of the texture image subimage.
Specifies the height of the texture subimage.
Notes
The glCopyTexSubImage2D subroutine is available only if the GL version is 1.1 or greater.
Texturing has no effect in color index mode.
The glPixelTransfer mode affects texture images in exactly the way they affect glDrawPixels.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.
GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous
glTexImage2D operation.
76
OpenGL 2.1 Reference Manual
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value
of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if x < -b or if y < -b, where b is the border width of the texture array.
GL_INVALID_VALUE is generated if xoffset < -b, (xoffset + width) > (w - b), yoffset < -b, or (yoffset +
height) > (h - b). Where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, and b is the
GL_TEXTURE_BORDER of the texture image being modified. Note that w and h include twice the border
width.
GL_INVALID_OPERATION is generated if glCopyTexSubImage2D is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_2D
Related Information
The glCopyTexImage2D subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage2D
subroutine, glTexParameter subroutine.
glCopyTexSubImage3D Subroutine
Purpose
Copies a three-dimensional (3D) texture subimage. This subroutine is only supported on OpenGL 1.2 and
later.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyTexSubImage3D (GLenum target,
GLint level,
GLint xoffset,
GLint yoffset,
GLint zoffset,
GLint x,
GLint y,
GLsizei width,
GLsizei height)
Description
The glCopyTexSubImage3D subroutine replaces a rectangular portion of a three-dimensional texture
image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for
glTexSubImage3D).
Chapter 1. OpenGL Subroutines
77
The screen-aligned pixel rectangle with lower-left corner at (x, y) and with width width and height height
replaces the portion of the texture array with x indices xoffset through xoffset + width - 1, inclusive, and y
indices yoffset through yoffset + height - 1, inclusive, at the mipmap level specified by level.
The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process
stops just before final conversion. At this point all pixel component values are clamped to the range [0, 1]
and then converted to the texture’s internal format for storage in the texel array.
The destination rectangle in the texture array may not include any texels outside the texture array as it
was originally specified. It is not an error to specify a subtexture with zero width or height, but such a
specification has no effect.
If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the read
window associated with the current rendering context, then the values obtained for those pixels are
undefined.
No change is made to the internalformat, width, height, depth, or border parameters of the specified
texture array or to texel values outside the specified subregion.
Parameters
target
level
xoffset
yoffset
zoffset
x, y
width
height
Specifies the target texture. Must be GL_TEXTURE_3D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
reduction image.
Specifies a texel offset in the x direction within the texture array.
Specifies a texel offset in the y direction within the texture array.
Specifies a texel offset in the z direction within the texture array.
Specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
Specifies the width of the texture subimage.
Specifies the height of the texture subimage.
Notes
Texturing has no effect in color index mode.
The glPixelTransfer mode affects texture images in exactly the way they affect glDrawPixels.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D.
GL_INVALID_OPERATION is generated if texture array has not been defined by a previous
glTexImage3D operation.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value
of GL_MAX_3D_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if x < -b or if y < -b, where b is the border width of the texture array.
GL_INVALID_VALUE is generated if xoffset < -b, (xoffset + width) > (w - b), yoffset < -b, (yoffset + height)
> (h - b), zoffset < -b, or (zoffset + depth) > (d - b). Where w is the GL_TEXTURE_WIDTH, h is the
GL_TEXTURE_HEIGHT, d is the GL_TEXTURE_DEPTH, and b is the GL_TEXTURE_BORDER of the
texture image being modified. Note that w, h, and d include twice the border width.
78
OpenGL 2.1 Reference Manual
GL_INVALID_OPERATION is generated if glCopyTexSubImage3D is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D.
Related Information
The glDrawPixels subroutine, glFog subroutine, glPixelStore subroutine, glPixelTransfer subroutine,
glTexEnv subroutine, glTexGen subroutine, glTexImage3D subroutine, glTexParameter subroutine.
glCopyTexSubImage3DEXT Subroutine
Purpose
Copies a three-dimensional (3D) texture subimage.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCopyTexSubImage3DEXT(GLenum
GLint level,
GLint xoffset,
GLint yoffset,
GLint zoffset,
GLint x,
GLint y,
GLsizei width,
GLsizei height)
target,
Description
The glCopyTexSubImage3DEXT subroutine replaces a rectangular portion of a three-dimensional texture
image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for
glTexSubImage3DEXT).
The screen-aligned pixel rectangle with lower-left corner at (x, y) and with width width and height height
replaces the portion of the texture array with x indices xoffset through xoffset + width - 1, inclusive, and y
indices yoffset through yoffset + height - 1, inclusive, at the mipmap level specified by level.
The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process
stops just before final conversion. At this point all pixel component values are clamped to the range [0, 1]
and then converted to the texture’s internal format for storage in the texel array.
The destination rectangle in the texture array may not include any texels outside the texture array as it
was originally specified. It is not an error to specify a subtexture with zero width or height, but such a
specification has no effect.
If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the read
window associated with the current rendering context, then the values obtained for those pixels are
undefined.
Chapter 1. OpenGL Subroutines
79
No change is made to the internalformat, width, height, depth, or border parameters of the specified
texture array or to texel values outside the specified subregion.
Parameters
target
level
xoffset
yoffset
zoffset
x, y
width
height
Specifies the target texture. Must be GL_TEXTURE_3D_EXT.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
reduction image.
Specifies a texel offset in the x direction within the texture array.
Specifies a texel offset in the y direction within the texture array.
Specifies a texel offset in the z direction within the texture array.
Specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
Specifies the width of the texture subimage.
Specifies the height of the texture subimage.
Notes
The glCopyTexSubImage3DEXT subroutine is available only if the EXT_texture_3d extension is
supported.
Texturing has no effect in color index mode.
The glPixelTransfer mode affects texture images in exactly the way they affect glDrawPixels.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D_EXT.
GL_INVALID_OPERATION is generated if texture array has not been defined by a previous
glTexImage3D operation.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value
of GL_MAX_3D_TEXTURE_SIZE_EXT.
GL_INVALID_VALUE is generated if x < -b or if y < -b, where b is the border width of the texture array.
GL_INVALID_VALUE is generated if xoffset < -b, (xoffset + width) > (w - b), yoffset < -b, (yoffset + height)
> (h - b), zoffset < -b, or (zoffset + depth) > (d - b). Where w is the GL_TEXTURE_WIDTH, h is the
GL_TEXTURE_HEIGHT, d is the GL_TEXTURE_DEPTH_EXT, and b is the GL_TEXTURE_BORDER of
the texture image being modified. Note that w, h, and d include twice the border width.
GL_INVALID_OPERATION is generated if glCopyTexSubImage3DEXT is executed between the
execution of glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D_EXT.
Related Information
The glDrawPixels subroutine, glFog subroutine, glPixelStore subroutine, glPixelTransfer subroutine,
glTexEnv subroutine, glTexGen subroutine, glTexImage3DEXT subroutine, glTexParameter subroutine.
80
OpenGL 2.1 Reference Manual
glCullFace Subroutine
Purpose
Specifies whether frontfacing or backfacing facets may be culled.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glCullFace(GLenum
mode)
Parameters
mode
Specifies whether frontfacint or backfacing facets are candidates for culling. Symbolic constants GL_FRONT,
GL_BACK, and GL_FRONT_AND_BACK are accepted. The initial value is GL_BACK.
Description
The glCullFace subroutine specifies whether frontfacing or backfacing facets are culled (as specified by
the mode parameter) when facet culling is enabled. Facet culling is enabled and disabled using the
glEnable and glDisable subroutines with the argument GL_CULL_FACE. Facets include triangles,
quadrilaterals, polygons, and rectangles.
The glFrontFace subroutine specifies which of the clockwise and counterclockwise facets are frontfacing
and backfacing.
Notes
If mode is GL_FRONT_AND_BACK, no facets are drawn, but other primitives such as points and lines
are drawn.
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_OPERATION is generated if glCullFace is executed between the execution of glBegin and
the corresponding execution of glEnd.
Associated Gets
glIsEnabled with argument GL_CULL_FACE.
glGet with argument GL_CULL_FACE_MODE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glEnable or glDisable subroutine, glFrontFace subroutine.
Chapter 1. OpenGL Subroutines
81
glDeleteLists Subroutine
Purpose
Deletes a contiguous group of display lists.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDeleteLists(GLunint
GLsizei Range)
List,
Description
The glDeleteLists subroutine causes a contiguous group of display lists to be deleted. The List parameter
is the name of the first display list to be deleted, and the Range parameter is the number of display lists to
be deleted. All display lists d with List <= d <= List + Range - 1 are deleted.
All storage locations allocated to the specified display lists are freed, and the names are available for
reuse at a later time. Names within the range that do not have an associated display list are ignored. If
Range is 0 (zero), nothing happens.
Parameters
List
Range
Specifies the integer name of the first display list to delete.
Specifies the number of display lists to delete.
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
Range is negative.
The glDeleteLists subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallList subroutine, glCallLists subroutine, glGenLists subroutine,
glIsList subroutine, glNewList subroutine.
glDeleteTextures Subroutine
Purpose
Deletes named textures.
Library
OpenGL C bindings library: libGL.a
82
OpenGL 2.1 Reference Manual
C Syntax
void glDeleteTextures(GLsizei
const GLuint *textures)
n,
Parameters
n
textures
Specifies the number of textures to be deleted
Specifies an array of textures to be deleted.
Description
The glDeleteTextures subroutine deletes n textures named by the elements of the array textures. After a
texture is deleted, it has no contents or dimensionality, and its name is free for reuse (for example by
glGenTextures). If a texture that is currently bound is deleted, the binding reverts to 0 (the default
texture).
The glDeleteTextures subroutine silently ignores zeros and names that do not correspond to existing
textures.
Notes
The glDeleteTextures subroutine is available only if the GL version is 1.1 or greater.
The glDeleteTextures subroutine is not included in display lists.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glDeleteTextures is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glIsTexture
Related Information
The glAreTexturesResident subroutine, glBindTexture subroutine, glGenTextures subroutine, glGet
subroutine, glGetTexParameter subroutine, glPrioritizeTextures subroutine, glTexImage1D subroutine,
glTexImage2D subroutine, glTexParameter subroutine.
glDeleteTexturesEXT Subroutine
Purpose
Deletes named textures.
Library
OpenGL and OpenGL C bindings library: libGL.a
C Syntax
void glDeleteTexturesEXT(GLsizei
const GLuint *textures)
n,
Chapter 1. OpenGL Subroutines
83
Description
glDeleteTexturesEXT deletes n textures named by the elements of the array textures. After a texture is
deleted, it has no contents or dimensionality, and its name is free for reuse (by glGenTexturesEXT, for
example). If a texture that is currently bound is deleted, the binding reverts to zero (the default texture).
glDeleteTexturesEXT silently ignores zeros and names that do not correspond to existing textures.
glDeleteTexturesEXT is not included in display lists.
Parameters
n
textures
The number of textures to be deleted.
An array in which each element is the name of a texture to be deleted.
Notes
glDeleteTexturesEXT is part of the EXT_texture_object extension, not part of the core GL command set.
If GL_EXT_texture_object is included in the string returned by glGetString, when called with argument
GL_EXTENSIONS, extension EXT_texture_object is supported by the connection.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glDeleteTexturesEXT is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glIsTextureEXT
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBindTextureEXT subroutine, glGenTexturesEXT subroutine, glGet subroutine, glGetTexParameter
subroutine, glTexParameter subroutine, glTexSubImage1D subroutine, glTexSubImage2D subroutine,
glTexSubImage3DEXT subroutine.
glDepthFunc Subroutine
Purpose
Specifies the function used for depth buffer comparisons.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDepthFunc(GLenum
84
function)
OpenGL 2.1 Reference Manual
Description
The glDepthFunc subroutine specifies the function used to compare each incoming pixel z value with the
z value present in the depth buffer. The comparison is performed only if depth testing is enabled. (See
glEnable and glDisable of GL_DEPTH_TEST.)
The function parameter specifies the conditions under which the pixel will be drawn. The comparison
functions are as follows:
GL_NEVER
GL_LESS
GL_EQUAL
GL_LEQUAL
GL_GREATER
GL_NOTEQUAL
GL_GEQUAL
GL_ALWAYS
Never passes.
Passes if the incoming
Passes if the incoming
Passes if the incoming
Passes if the incoming
Passes if the incoming
Passes if the incoming
Always passes.
z
z
z
z
z
z
value
value
value
value
value
value
is
is
is
is
is
is
less than the stored z value.
equal to the stored z value.
less than or equal to the stored z value.
greater than the stored z value.
not equal to the stored z value.
greater than or equal to the stored z value.
The default value of function is GL_LESS. Initially, depth testing is disabled.
Parameters
function
Specifies the depth comparison function. Symbolic constants GL_NEVER, GL_LESS, GL_EQUAL,
GL_LEQUAL, GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, and GL_ALWAYS are accepted. The
default function is GL_LESS.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
function is not an accepted value.
The glDepthFunc subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glDepthFunc subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_DEPTH_FUNC
glIsEnabled with argument GL_DEPTH_TEST.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glDepthRange subroutine, glEnable or glDisable subroutine, glGet
subroutine, glPolygonOffset subroutine, glPolygonOffsetEXT subroutine.
Chapter 1. OpenGL Subroutines
85
glDepthMask Subroutine
Purpose
Enables or disables writing into the depth buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDepthMask(GLboolean
Flag)
Description
The glDepthMask subroutine specifies whether the depth buffer is enabled for writing. If the Flag
parameter is zero (0), depth buffer writing is disabled. Otherwise, it is enabled. Initially, depth buffer writing
is enabled.
Parameters
Flag
Specifies whether the depth buffer is enabled for writing. If Flag is 0, depth buffer writing is disabled.
Otherwise, it is enabled. Initially, depth buffer writing is enabled.
Errors
GL_INVALID_OPERATION
The glDepthMask subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glDepthMask subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_DEPTH_WRITEMASK.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColorMask subroutine, glDepthFunc subroutine, glDepthRange
subroutine, glIndexMask subroutine, glStencilMask subroutine.
glDepthRange Subroutine
Purpose
Specifies the mapping of z values from normalized device coordinates to window coordinates.
Library
OpenGL C bindings library: libGL.a
86
OpenGL 2.1 Reference Manual
C Syntax
void glDepthRange(GLclampd
GLclampd far)
near,
Description
After clipping and division by w, z coordinates range from -1.0 to 1.0, corresponding to the near and far
clipping planes. The glDepthRange subroutine specifies a linear mapping of the normalized z coordinates
in this range to window z coordinates. Regardless of the actual depth buffer implementation, window
coordinate depth values are treated as though they range from 0.0 through 1.0 (like color components).
Thus, the values accepted by glDepthRange are both clamped to this range before they are accepted.
The default mapping of 0,1 maps the near plane to 0 (zero) and the far plane to 1 (one). With this
mapping, the depth buffer range is fully utilized.
Parameters
near
far
Specifies the mapping of the near clipping plane to window coordinates. The default value is 0.
Specifies the mapping of the far clipping plane to window coordinates. The default value is 1.
Notes
It is not necessary that near be less than far. Reverse mappings such as 1,0 are acceptable.
Errors
GL_INVALID_OPERATION
The glDepthRange subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glDepthRange subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_DEPTH_RANGE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glDepthFunc subroutine, glPolygonOffset subroutine,
glPolygonOffsetEXT subroutine, glViewport subroutine.
glDrawArrays Subroutine
Purpose
Renders primitives from array data.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
87
C Syntax
void glDrawArrays(GLenum
GLint first,
GLsizei count)
mode,
Description
The glDrawArrays subroutine lets you specify multiple geometric primitives with very few subroutine calls.
Instead of calling a GL procedure to pass each individual vertex, normal, texture coordinate, edge flage, or
color, you can prespecify separate arrays of vertexes, normals, and colors and use them to construct a
sequence of primitives with a single call to glDrawArrays.
When glDrawArrays is called, it uses count sequential elements from each enabled array to construct a
sequence of geometric primitives, beginning with element first. The mode parameter specifies what kind of
primitives are constructed, and how the array elements construct these primitives. If GL_VERTEX_ARRAY
is not enabled, no geometric primitives are generated.
Vertex attributes that are modified by glDrawArrays have an unspecified value after glDrawArrays
returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after
glDrawArrays executes. Attributes that are not modified remain well defined.
Parameters
mode
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Specifies the starting index in the enabled arrays.
Specifies the number of indices to be rendered.
first
count
Notes
The glDrawArrays subroutine is available only if the GL version is 1.1 or greater.
The glDrawArrays subroutine is included in display lists. If glDrawArrays is entered into a display list, the
necessary array data (determined by the array pointers and enables) is also entered into the display list.
Because the array pointers and enables are client side state, their values affect display lists when the lists
are created, not when the lists are executed.
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative.
GL_INVALID_OPERATION is generated if glDrawArrays is executed between the execution of glBegin
and the corresponding glEnd.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawElements subroutine,
glEdgeFlagPointer subroutine, glGetPointerv subroutine, glIndexPointer subroutine,
glInterleavedArrays subroutine, glNormalPointer subroutine, glTexCoordPointer subroutine,
glVertexPointer subroutine.
88
OpenGL 2.1 Reference Manual
glDrawArraysEXT Subroutine
Purpose
Renders primitives from array data.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDrawArraysEXT(GLenum
GLint first,
GLsizei count)
mode,
Description
glDrawArraysEXT makes it possible to specify multiple geometric primitives with very few subroutine
calls. Instead of calling an OpenGL procedure to pass each individual vertex, normal, or color, separate
arrays of vertexes, normals, and colors can be prespecified, and used to define a sequence of primitives
(all of the same type) with a single call to glDrawArraysEXT.
When glDrawArraysEXT is called, count sequential elements from each enabled array are used to
construct a sequence of geometric primitives, beginning with element first. mode specifies what kind of
primitives are constructed, and how the array elements are used to construct these primitives. If
GL_VERTEX_ARRAY_EXT is not enabled, no geometric primitives are generated.
Vertex attributes that are modified by glDrawArraysEXT have an unspecified value after
glDrawArraysEXT returns. For example, if GL_COLOR_ARRAY_EXT is enabled, the value of the current
color is undefined after glDrawArraysEXT executes. Attributes that aren’t modified remain well defined.
Operation of glDrawArraysEXT is atomic with respect to error generation. If an error is generated, no
other operations take place.
Parameters
mode
first
count
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Specifies the starting index in the enabled arrays.
Specifies the number of indices which should be rendered.
Notes
glDrawArraysEXT may be included in display lists. If glDrawArraysEXT is entered into a display list, the
necessary array data (determined by the array pointers and enables) is also entered into the display list.
Because the array pointers and enables are client side state, their values affect display lists when the lists
are created, not when the lists are executed.
Static array data may be read and cached by the implementation at any time. If static array elements are
modified and the arrays are not respecified, the results of any subsequent calls to glDrawArraysEXT are
undefined.
Although it is not an error to respecify an array between the execution of glBegin and the corresponding
execution of glEnd, the result of such respecification is undefined.
Chapter 1. OpenGL Subroutines
89
glDrawArraysEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative.
GL_INVALID_OPERATION is generated if glDrawArraysEXT is called between the execution of glBegin
and the corresponding execution of glEnd.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glEdgeFlagPointerEXT subroutine,
glGetPointervEXT subroutine, glIndexPointerEXT subroutine, glNormalPointerEXT subroutine,
glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.
glDrawBuffer Subroutine
Purpose
Specifies which color buffers are to be used for drawing.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDrawBuffer(GLenum
Mode)
Description
When colors are written to the frame buffer, they are written into the color buffers specified by the
glDrawBuffer subroutine. The specifications are:
GL_NONE
GL_FRONT_LEFT
GL_FRONT_RIGHT
GL_BACK_LEFT
GL_BACK_RIGHT
GL_FRONT
GL_BACK
GL_LEFT
GL_RIGHT
90
OpenGL 2.1 Reference Manual
No color buffers are written.
Only the front left color buffer is written.
Only the front right color buffer is written.
Only the back left color buffer is written.
Only the back right color buffer is written.
Only the front left and front right color buffers are written. If there is no front right
color buffer, only the front left color buffer is written.
Only the back left and back right color buffers are written. If there is no back right
color buffer, only the back left color buffer is written.
Only the front left and back left color buffers are written. If there is no back left color
buffer, only the front left color buffer is written.
Only the front right and back right color buffers are written. If there is no back right
color buffer, only the front right color buffer is written.
GL_FRONT_AND_BACK
GL_AUXi
All the front and the back color buffers (front left, front right, back left, back right)
are written. If there are no back color buffers, only the front left and front right color
buffers are written. If there are no right color buffers, only the front left and back left
color buffers are written. If there are no right or back color buffers, only the front left
color buffer is written.
Only auxiliary color buffer i is written.
If more than one color buffer is selected for drawing, blending or logical operations are computed and
applied independently for each color buffer and may produce different results in each buffer.
Monoscopic contexts include only left buffers, while stereoscopic contexts include both left and right
buffers. Likewise, single-buffered contexts include only front buffers, while double-buffered contexts include
both front and back buffers. The context is selected at GL initialization.
Parameters
Mode
Specifies up to four color buffers to be drawn into. Symbolic constants GL_NONE, GL_FRONT_LEFT,
GL_FRONT_RIGHT, GL_BACK_LEFT, GL_BACK_RIGHT, GL_FRONT, GL_BACK, GL_LEFT, GL_RIGHT,
GL_FRONT_AND_BACK, and GL_AUXi, where i is between 0 and GL_AUX_BUFFERS - 1, are accepted.
(GL_AUX_BUFFERS is not the upper limit; use glGet to query the number of available aux buffers.) The
default value is GL_FRONT for single buffered contexts, and GL_BACK for double buffered contexts.
Notes
It is always the case that GL_AUXi = GL_AUX0 + i.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Mode is not an accepted value.
None of the buffers indicated by Mode exists.
The glDrawBuffer subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glDrawBuffer subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_DRAW_BUFFER
glGet with argument GL_AUX_BUFFERS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glBlendFunc subroutine, glColorMask subroutine, glIndexMask
subroutine, glLogicOp subroutine, glReadBuffer subroutine.
Chapter 1. OpenGL Subroutines
91
glDrawElements Subroutine
Purpose
Renders primitives from array data.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDrawElements (GLenum mode,
GLsizei count,
GLenum type,
const GLvoid *indices)
Description
The glDrawElements subroutine lets you specify multiple geometric primitives with very few subroutine
calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate, edge
flage, or color, you can prespecify separate arrays of vertexes, normals, and so on and use them to
construct a sequence of primitives with a single call to glDrawElements.
When glDrawElements is called, it uses count sequential elements from an enabled array, starting at
indices to construct a sequence of geometric primitives. mode specifies what kind of primitives are
constructed and how the array elements construct these primitives. If GL_VERTEX_ARRAY is not
enabled, no geometric primitives are generated.
Vertex attributes that are modified by glDrawElements have an unspecified value after glDrawElements
returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after
glDrawElements executes. Attributes that are not modified maintain their previous values.
Notes
The glDrawElements subroutine is available only if the GL version is 1.1 or greater.
The glDrawElements subroutine is included in display lists. If glDrawElements is entered into a display
list, the necessary array data (determined by the array pointers and enables) is also entered into the
display list. Because the array pointers and enables are client side state, their values affect display lists
when the lists are created, not when the lists are executed.
Parameters
mode
count
type
indices
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Specifies the number of elements to be rendered.
Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE,
GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
Specifies a pointer to the location where the indices are stored.
Errors
GL_INVALID_ENUM is generated ifmode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative.
92
OpenGL 2.1 Reference Manual
GL_INVALID_OPERATION is generated if glDrawElements is executed between the execution of
glBegin and the corresponding glEnd.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine,
glEdgeFlagPointer subroutine, glGetPointerv subroutine, glIndexPointer subroutine,
glInterleavedArrays subroutine, glNormalPointer subroutine, glTexCoordPointer subroutine,
glVertexPointer subroutine.
glDrawPixels Subroutine
Purpose
Writes a block of pixels to the frame buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDrawPixels(GLsizei Width,
GLsizei Height,
GLenum Format,
GLenum Type,
const GLvoid * Pixels)
Description
The glDrawPixels subroutine reads pixel data from memory and writes it into the frame buffer relative to
the current raster position. Use glRasterPos to set the current raster position, and use glGet with
argument GL_CURRENT_RASTER_POSITION to query the raster position.
A number of parameters define the encoding of pixel data in memory and control the processing of the
pixel data before it is placed in the frame buffer. These parameters are set with four subroutines:
glPixelStore, glPixelTransfer, glPixelMap, and glPixelZoom. This article describes the effects on
glDrawPixels of many, but not all, of the parameters specified by these four subroutines.
Data is read from the Pixels parameter as a sequence of signed or unsigned bytes, signed or unsigned
shorts, signed or unsigned integers, or single-precision floating-point values, depending on Type. Each of
these bytes, shorts, integers, or floating-point values is interpreted as one color or depth component, or
one index, depending on Format. Indices are always treated individually. Color components are treated as
groups of one, two, three, or four values, again based on Format. Both individual indices and groups of
components are referred to as pixels. If Type is GL_BITMAP, the data must be unsigned bytes, and
Format must be either GL_COLOR_INDEX or GL_STENCIL_INDEX. Each unsigned byte is treated as
eight 1-bit pixels, with bit ordering determined by GL_UNPACK_LSB_FIRST. (See glPixelStore.)
Width multiplied by Height pixels are read from memory, starting at location Pixels. By default these pixels
are taken from adjacent memory locations, except that after every Width pixels are read, the read pointer
is advanced to the next 4-byte boundary. The 4-byte row alignment is specified by glPixelStore with
argument GL_UNPACK_ALIGNMENT, and it can be set to 1, 2, 4, or 8 bytes. Other pixel store
parameters specify different read pointer advancements, both before the first pixel is read, and after all
Width pixels are read. Refer to the glPixelStore subroutine for details on these options.
The Width multiplied by Height pixels that are read from memory are each operated on in the same way,
based on the values of several parameters specified by glPixelTransfer and glPixelMap. The details of
these operations, as well as the target buffer into which the pixels will be drawn, are specific to the format
Chapter 1. OpenGL Subroutines
93
of the pixels, as specified by Format. Format can assume one of the following 18 symbolic values:
GL_COLOR_INDEX
Each pixel is a single value, a color index. It is converted to fixed point,
with an unspecified number of bits to the right of the binary point,
regardless of the memory data type. Floating-point values convert to true
fixed-point values. Signed and unsigned integer data is converted with all
fraction bits set to 0 (zero). Bitmap data converts to either 0.0 or 1.0.
Each fixed-point index is then shifted left by GL_INDEX_SHIFT bits and
added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift
is to the right. In either case, 0 bits fill otherwise unspecified bit locations
in the result.
If the GL is in red, green, blue, alpha (RGBA) mode, the resulting index is
converted to an RGBA pixel using the GL_PIXEL_MAP_I_TO_R,
GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A tables. If the GL is in color index mode and
GL_MAP_COLOR is True, the index is replaced with the value that it
references in the lookup table GL_PIXEL_MAP_I_TO_I. Whether the
lookup replacement of the index is done or not, the integer part of the
index is then ANDed with 2b -1, where b is the number of bits in a color
index buffer.
GL_STENCIL_INDEX
The resulting indices or RGBA colors are then converted to fragments by
attaching the current raster position z coordinate and texture coordinates
to each pixel, then assigning x and y window coordinates to the nth
fragment such that xn = xr + n mod Width and yn = yr + [n/Width], where
(xr, yr) is the current raster position. These pixel fragments are then
treated just like the fragments generated by rasterizing points, lines, or
polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
Each pixel is a single value, a stencil index. It is converted to fixed point,
with an unspecified number of bits to the right of the binary point,
regardless of the memory data type. Floating-point values convert to true
fixed-point values. Signed and unsigned integer data is converted with all
fraction bits set to 0. Bitmap data converts to either 0.0 or 1.0.
Each fixed-point index is then shifted left by GL_INDEX_SHIFT bits and
added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift
is to the right. In either case, 0 bits fill otherwise unspecified bit locations
in the result. If GL_MAP_STENCIL is True, the index is replaced with the
value that it references in the lookup table GL_PIXEL_MAP_S_TO_S.
Whether the lookup replacement of the index is done or not, the integer
part of the index is then ANDed with 2b -1, where b is the number of bits
in the stencil buffer. The resulting stencil indices are then written to the
stencil buffer such that the nth index is written to location xn = xr + n mod
Width and yn = yr + [n/Width], where (xr, yr) is the current raster position.
Only the pixel ownership test, the scissor test, and the stencil writemask
affect these write operations.
94
OpenGL 2.1 Reference Manual
GL_DEPTH_COMPONENT
GL_RGBA
Each pixel is a single depth component. Floating-point data is converted
directly to an internal floating-point format with unspecified precision.
Signed integer data is mapped linearly to the internal floating-point format
such that the most positive representable integer value maps to 1.0, and
the most negative representable value maps to -1.0. Unsigned integer
data is mapped similarly: the largest integer value maps to 1.0, and 0
maps to 0.0. The resulting floating-point depth value is then multiplied by
GL_DEPTH_SCALE and added to GL_DEPTH_BIAS. The result is
clamped to the range [0,1].
The resulting depth components are then converted to fragments by
attaching the current raster position color or color index and texture
coordinates to each pixel, then assigning x and y window coordinates to
the nth fragment such that xn = xr + n mod Width and yn = yr +
[n/Width], where (xr, yr) is the current raster position. These pixel
fragments are then treated just like the fragments generated by rasterizing
points, lines, or polygons. Texture mapping, fog, and all the fragment
operations are applied before the fragments are written to the frame
buffer.
Each pixel is a four-component group, red first, followed by green,
followed by blue, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is RED,
GREEN, BLUE, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is R, G, B, or A, respectively.
The resulting RGBA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
Chapter 1. OpenGL Subroutines
95
GL_BGRA
Each pixel is a four-component group, blue first, followed by green,
followed by red, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is BLUE,
GREEN, RED, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is B, G, R, or A, respectively.
GL_ABGR_EXT
The resulting BGRA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
Each pixel is a four-component group: for GL_RGBA, the red component
is first, followed by green, followed by blue, followed by alpha: for
GL_BGRA, the blue component is first, followed by green, followed by
red, followed by alpha: for GL_ABGR_EXT the order is alpha, blue,
green, and then red. Floating-point values are converted directly to an
internal floatingpoint format with unspecified precision. Signed integer
values are mapped linearly to the internal floating-point format such that
the most positive representable integer value maps to 1.0, and the most
negative representable value maps to -1.0. Unsigned integer data is
mapped similarly: the largest integer value maps to 1.0, and zero maps to
0.0. The resulting floating-point color values are then multiplied by
GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN,
BLUE, and ALPHA for the respective color components. The results are
clamped to the range [0,1].
If GL_MAP_COLOR is true, each color component is scaled by the size
of lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value that
it references in that table. c is R, G, B, or A, respectively.
The resulting RGBA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that
xn = xr + n mod width
yn = yr + |
GL_RED
96
OpenGL 2.1 Reference Manual
n
bwidthc
where (xr,yr) is the current raster position. These pixel fragments are then
treated just like the fragments generated by rasterizing points, lines, or
polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
Each pixel is a single red component. This component is converted to the
internal floating-point format in the same way as the red component of an
RGBA pixel is, then it is converted to an RGBA pixel with green and blue
set to 0.0, and alpha set to 1.0. After this conversion, the pixel is treated
just as if it had been sent in as an RGBA pixel.
GL_GREEN
GL_BLUE
GL_ALPHA
GL_RGB
GL_BGR
GL_LUMINANCE
GL_LUMINANCE_ALPHA
GL_422_EXT
Each pixel is a single green component. This component is converted to
the internal floating-point format in the same way as the green component
of an RGBA pixel is, then it is converted to an RGBA pixel with red and
blue set to 0.0, and alpha set to 1.0. After this conversion, the pixel is
treated just as if it had been sent in as an RGBA pixel.
Each pixel is a single blue component. This component is converted to
the internal floating-point format in the same way as the blue component
of an RGBA pixel is, then it is converted to an RGBA pixel with red and
green set to 0.0, and alpha set to 1.0. After this conversion, the pixel is
treated just as if it had been sent in as an RGBA pixel.
Each pixel is a single alpha component. This component is converted to
the internal floating-point format in the same way as the alpha component
of an RGBA pixel is, then it is converted to an RGBA pixel with red,
green, and blue set to 0.0. After this conversion, the pixel is treated just
as if it had been sent in as an RGBA pixel.
Each pixel is a three-component group, red first, followed by green,
followed by blue. Each component is converted to the internal
floating-point format in the same way as the red, green, and blue
components of an RGBA pixel are. The color triple is converted to an
RGBA pixel with alpha set to 1.0. After this conversion, the pixel is treated
just as if it had been sent in as an RGBA pixel.
Each pixel is a three-component group, blue first, followed by green,
followed by red. Each component is converted to the internal floating-point
format in the same way as the blue, green, and red components of an
BGRA pixel are. The color triple is converted to an BGRA pixel with alpha
set to 1.0. After this conversion, the pixel is treated just as if it had been
sent in as an BGRA pixel.
Each pixel is a single luminance component. This component is converted
to the internal floating-point format in the same way as the red component
of an RGBA pixel is, then it is converted to an RGBA pixel with red,
green, and blue set to the converted luminance value, and alpha set to
1.0. After this conversion, the pixel is treated just as if it had been sent in
as an RGBA pixel.
Each pixel is a two-component group, luminance first, followed by alpha.
The two components are converted to the internal floating-point format in
the same way as the red component of an RGBA pixel is, then they are
converted to an RGBA pixel with red, green, and blue set to the converted
luminance value, and alpha set to the converted alpha value. After this
conversion, the pixel is treated just as if it had been sent in as an RGBA
pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. The Cb for each even pixel is used as the Cb value for that pixel
and its neighbor to the right. The Cr in each odd pixel is used as the Cr
value for that pixel and its neighbor to the left. (If the width of the image is
odd, then the colors will be undefined in the rightmost column.) Through
the use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
Chapter 1. OpenGL Subroutines
97
GL_422_REV_EXT
GL_422_AVERAGE_EXT
GL_422_REV_AVERAGE_EXT
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. The Cb for each even pixel is used as the Cb value for that pixel and
its neighbor to the right. The Cr in each odd pixel is used as the Cr value
for that pixel and its neighbor to the left. (If the width of the image is odd,
then the colors will be undefined in the rightmost column.) Through the
use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. Each even pixel gets its Cb from itself, and its Cr from its neighbor
to the right. Each odd pixel gets its Cb from the average of its left and
right neighbor, and its Cr from the average of itself and its neighbor two to
the right. (If the width of the image is odd, then the colors will be
undefined in the rightmost column. If the neighbors to the right are not
present for a given fragment, we use GL_422_EXT to compute that
fragment.) Through the use of the color matrix, Y then assumes the role
of red, Cb becomes green and Cr becomes blue. After this conversion,
the pixel is treated just as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. Each even pixel gets its Cb from itself, and its Cr from its neighbor to
the right. Each odd pixel gets its Cb from the average of its left and right
neighbor, and its Cr from the average of itself and its neighbor two to the
right. (If the width of the image is odd, then the colors will be undefined in
the rightmost column. If the neighbors to the right are not present for a
given fragment, we use GL_422_REV_EXT to compute that fragment.)
Through the use of the color matrix, Y then assumes the role of red, Cb
becomes green and Cr becomes blue. After this convers ion, the pixel is
treated just as if it had been sent in as an RGB pixel.
The following table summarizes the meaning of the valid constants for the Type parameter:
Type
GL_UNSIGNED_BYTE
GL_BYTE
GL_BITMAP
GL_UNSIGNED_SHORT
GL_SHORT
GL_UNSIGNED_INT
GL_INT
GL_FLOAT
GL_UNSIGNED_BYTE_3_3_2
GL_UNSIGNED_BYTE_2_3_3_REV
GL_UNSIGNED_SHORT_5_6_5
98
OpenGL 2.1 Reference Manual
Corresponding Type
Unsigned 8-bit integer
Signed 8-bit integer
Single bits in unsigned 8-bit integers
Unsigned 16-bit integer
Signed 16-bit integer
Unsigned 32-bit integer
32-bit integer
Single-precision floating-point
Unsigned 8-bit integer
Unsigned 8-bit integer
Unsigned 16-bit integer
GL_UNSIGNED_SHORT_5_6_5_REV
GL_UNSIGNED_SHORT_4_4_4_4
GL_UNSIGNED_SHORT_4_4_4_4_REV
GL_UNSIGNED_SHORT_5_5_5_1
GL_UNSIGNED_SHORT_1_5_5_5_REV
GL_UNSIGNED_INT_8_8_8_8
GL_UNSIGNED_INT_8_8_8_8_REV
GL_UNSIGNED_INT_10_10_10_2
GL_UNSIGNED_INT_2_10_10_10_REV
Unsigned
Unsigned
Unsigned
Unsigned
Unsigned
Unsigned
Unsigned
Unsigned
Unsigned
16-bit
16-bit
16-bit
16-bit
16-bit
32-bit
32-bit
32-bit
32-bit
integer
integer
integer
integer
integer
integer
integer
integer
integer
The rasterization described thus far assumed pixel zoom factors of 1.0. If glPixelZoom is used to change
the x and y pixel zoom factors, pixels are converted to fragments as follows. If (xr, yr) is the current raster
position, and a given pixel is in the nth column and mth row of the pixel rectangle, fragments are
generated for pixels whose centers are in the rectangle with corners at (xr + zoomx n, yr + zoomy m) and
(xr + zoomx (n + 1), yr + zoomy (m + 1 )), where zoomx is the value of GL_ZOOM_X and zoomy is the
value of GL_ZOOM_Y.
Parameters
Width
Height
Format
Type
Pixels
Specifies the width of the pixel rectangle that will be written into the frame buffer.
Specifies the height of the pixel rectangle that will be written into the frame buffer.
Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX, GL_STENCIL_INDEX,
GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA,
GL_BGR, GL_BGRA, GL_ABGR_EXT, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_422_EXT,
GL_422_REV_EXT, GL_422_AVERAGE_EXT, and GL_422_REV_AVERAGE_EXT are accepted.
Specifies the data type for Pixels. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP,
GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
GL_UNSIGNED_INT_2_10_10_10_REV, are accepted.
Specifies a pointer to the pixel data.
Notes
Format of GL_ABGR_EXT is part of the _extname (EXT_abgr) extension, not part of the core GL
command set.
Packed pixel types and BGR/BGRA formats are only supported in OpenGL 1.2 or later.
Errors
GL_INVALID_VALUE
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Either Width or Height is negative.
Format or Type is not one of the accepted values.
Format is GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB,
GL_RGBA, GL_AGBR_EXT, GL_LUMINANCE, GL_LUMINANCE_ALPHA,
and the GL is in color index mode.
Type is GL_BITMAP and Format is not either GL_COLOR_INDEX or
GL_STENCIL_INDEX.
Format is GL_STENCIL_INDEX and there is no stencil buffer.
The glDrawPixels subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Chapter 1. OpenGL Subroutines
99
Associated Gets
Associated gets for the glDrawPixels subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_RASTER_POSITION
glGet with argument GL_CURRENT_RASTER_POSITION_VALID.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glAlphaFunc subroutine, glBegin or glEnd subroutine, glBlendFunc subroutine, glCopyPixels
subroutine, glDepthFunc subroutine, glLogicOp subroutine, glPixelMap subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glPixelZoom subroutine, glRasterPos subroutine, glReadPixels
subroutine, glScissor subroutine, glStencilFunc subroutine.
glDrawRangeElements Subroutine
Purpose
Renders primitives from array data. This subrotuine is only supported on OpenGL 1.2 and later.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glDrawRangeElements(GLenum mode,
GLuint start,
GLuint end,
GLsizei count,
GLenum type,
const GLvoid *indices)
Description
The glDrawRangeElements subroutine lets you specify multiple geometric primitives with very few
subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate,
edge flage, or color, you can prespecify separate arrays of vertexes, normals, and so on and use them to
construct a sequence of primitives with a single call to glDrawRangeElements.
When glDrawRangeElements is called, it uses count sequential elements from indices to construct a
sequence of geometric primitives. GLuint start and GLuint end specify the values between which all
values in the array indices must lie. GLenum mode specifies what kind of primitives are constructed and
how the array elements construct these primitives. If GL_VERTEX_ARRAY is not enabled, no geometric
primitives are generated.
The recommended maximum amounts of vertex and index data can be determined by calling GetIntegerv
with the symbolic constants MAX_ELEMENTS_VERTICES and MAX_ELEMENTS_INDICES. If
end-start+1 is greater than the value of MAX_ELEMENTS_VERTICES,or if count is greater than the value
100
OpenGL 2.1 Reference Manual
of MAX_ELEMENTS_INDICES, then the call may operate at reduced performance. There is no
requirement that all vertices in the range [start,end] be referenced. However, the implementation may
partially process unused vertices, reducing performance from what could be achieved with an optimal
index set.
Vertex attributes that are modified by glDrawRangeElements have an unspecified value after
glDrawRangeElements returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current
color is undefined after glDrawRangeElements executes. Attributes that are not modified remain well
defined.
Parameters
mode
start
end
count
type
indices
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Specifies the start value in indices. Must be less than the end value in indices.
Specifies the end value in indices. Must be greater than the start value in indices.
Specifies the number of elements to be rendered.
Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE,
GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
Specifies a pointer to the location where the indices are stored.
Notes
The glDrawRangeElements subroutine is available only if the GL version is 1.1 or greater.
The glDrawRangeElements subroutine is included in display lists. If glDrawRangeElements is entered
into a display list, the necessary array data (determined by the array pointers and enables) is also entered
into the display list. Because the array pointers and enables are client side state, their values affect display
lists when the lists are created, not when the lists are executed.
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative or the end value is less than the start value.
GL_INVALID_OPERATION is generated if glDrawRangeElements is executed between the execution of
glBegin and the corresponding glEnd.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine,
glEdgeFlagPointer subroutine, glGetPointerv subroutine, glIndexPointer subroutine, glNormalPointer
subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glEdgeFlag Subroutine
Purpose
Marks edges as either boundary or nonboundary.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
101
C Syntax
void glEdgeFlag(GLboolean
Flag)
void glEdgeFlagv(const GLboolean
*Flagv)
Description
Each vertex of a polygon, separate triangle, or separate quadrilateral specified between glBegin and
glEnd is marked as the start of either a boundary or nonboundary edge. If the current edge flag is True
when the vertex is specified, the vertex is marked as the start of a boundary edge. Otherwise, the vertex is
marked as the start of a nonboundary edge. glEdgeFlag sets the edge flag to True if the Flag parameter
is nonzero; otherwise, the edge flag is set to False.
The vertices of connected triangles and connected quadrilaterals are always marked as a boundary,
regardless of the value of the edge flag.
Boundary and nonboundary edge flags on vertices are significant only if GL_POLYGON_MODE is set to
GL_POINT or GL_LINE. See glPolygonMode.
Initially, the edge flag bit is True.
Parameters
Flag
Flagv
Specifies the current edge flag value, either True or False.
Specifies a pointer to an array that contains a single Boolean element (either True or False). Replaces the
current edge flag value.
Notes
The current edge flag can be updated at any time. In particular, glEdgeFlag can be called between a call
to glBegin and the corresponding call to glEnd.
Associated Gets
Associated gets for the glEdgeFlag subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_EDGE_FLAG.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin subroutine, glEdgeFlagPointer subroutine, glEdgeFlagPointerEXT subroutine, glEnd
subroutine, glPolygonMode subroutine.
glEdgeFlagPointer Subroutine
Purpose
Defines an array of edge flags.
102
OpenGL 2.1 Reference Manual
Library
OpenGL C bindings library: libGL.a
C Syntax
void glEdgeFlagPointer( GLsizei
const GLvoid * pointer)
stride,
Description
The glEdgeFlagPointer subroutine specifies the location and data format of an array of Boolean edge
flags to use when rendering. The stride parameter gives the byte stride from one edge flag to the next
allowing vertices and attributes to be packed into a single array or stored in separate arrays. (Single array
storage may be more efficient on some implementations; see glInterleavedArrays.)
When an edge flag array is specified, stride and pointer are saved as client side state.
To enable and disable the edge flag array, call glEnableClientState and glDisableClientState with the
argument GL_EDGE_FLAG_ARRAY. If enabled, the edge flag array is used when glDrawArrays,
glDrawElements or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Edge Flag array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
stride
pointer
Specifies the byte offset between consecutive edge flags. If stride is zero (the initial value), the edge
flags are understood to be tightly packed in the array. The initial value is 0.
Specifies a pointer to the first edge flag in the array. The initial value is 0 (NULL pointer).
Notes
The glEdgeFlagPointer subroutine is available only if the GL version is 1.1 or greater.
The edge flag array is initially disabled and it won’t be accessed when glArrayElement, glDrawElements,
or glDrawArrays is called.
Execution of glEdgeFlagPointer is not allowed between glBegin and the corresponding glEnd, but an
error may or may not be generated. If an error is not generated, the operation is undefined.
The glEdgeFlagPointer subroutine is typically implemented on the client side with no protocol.
Since the edge flag array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
The glEdgeFlagPointer subroutine is not included in display lists.
Error Codes
GL_INVALID_ENUM is generated if stride is negative.
Chapter 1. OpenGL Subroutines
103
Associated Gets
glIsEnabled with argument GL_EDGE_FLAG_ARRAY
glGet with argument GL_EDGE_FLAG_ARRAY_STRIDE
glGetPointerv with argument GL_EDGE_FLAG_ARRAY_POINTER
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointerListIBM subroutine, glEnable subroutine, glGetPointerv subroutine,
glIndexPointer subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glEdgeFlagPointerEXT Subroutine
Purpose
Defines an array of edge flags.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glEdgeFlagPointerEXT(GLsizei
GLsizei count,
const GLboolean *pointer)
stride,
Description
glEdgeFlagPointerEXT specifies the location and data format of an array of boolean edge flags to use
when rendering. stride gives the byte stride from one edge flag to the next allowing vertexes and attributes
to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient
on some implementations.) count indicates the number of array elements (counting from the first) that are
static. Static elements may be modified by the application, but once they are modified, the application
must explicitly respecify the array before using it for any rendering. When an edge flag array is specified,
stride, count and pointer are saved as client-side state, and static array elements may be cached by the
implementation.
The edge flag array is enabled and disabled using glEnable and glDisable with the argument
GL_EDGE_FLAG_ARRAY_EXT. If enabled, the edge flag array is used when glDrawArraysEXT or
glArrayElementEXT is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Edge Flag array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
104
OpenGL 2.1 Reference Manual
Parameters
stride
count
pointer
Specifies the byte offset between consecutive edge flags. If stride is zero the edge flags are
understood to be tightly packed in the array.
Specifies the number of edge flags, counting from the first, that are static.
Specifies a pointer to the first edge flag in the array.
Notes
Non-static array elements are not accessed until glArrayElementEXT or glDrawArraysEXT is executed.
By default the edge flag array is disabled and it won’t be accessed when glArrayElementEXT or
glDrawArraysEXT is called.
Although, it is not an error to call glEdgeFlagPointerEXT between the execution of glBegin and the
corresponding execution of glEnd, the results are undefined.
glEdgeFlagPointerEXT will typically be implemented on the client side with no protocol.
Since the edge flag array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib.
glEdgeFlagPointerEXT commands are not entered into display lists.
glEdgeFlagPointerEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Errors
GL_INVALID_ENUM is generated if stride or count is negative.
Associated Gets
glIsEnabled with argument GL_EDGE_FLAG_ARRAY_EXT .
glGet with argument GL_EDGE_FLAG_ARRAY_STRIDE_EXT.
glGet with argument GL_EDGE_FLAG_ARRAY_COUNT_EXT.
glGetPointervEXT with argument GL_EDGE_FLAG_ARRAY_POINTER_EXT.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glDrawArraysEXT subroutine,
glGetPointervEXT subroutine, glIndexPointerEXT subroutine, glNormalPointerEXT subroutine,
glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.
Chapter 1. OpenGL Subroutines
105
glEdgeFlagPointerListIBM Subroutine
Purpose
Defines a list of edge flag arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glEdgeFlagPointerListIBM ( GLint
const GLboolean ** pointer,
GLint ptrstride)
stride,
Description
The glEdgeFlagPointerListIBM subroutine specifies the location and data format of a list of arrays of
edge flags to use when rendering. The stride parameter gives the byte stride from one edge flag to the
next allowing vertices and attributes to be packed into a single array or stored in separate arrays.
(Single-array storage may be more efficient on some implementations; see glInterleavedArrays). The
ptrstride parameter specifies the byte stride from one pointer to the next in the pointer array.
When an edge flag array is specified, stride, pointer and ptrstride are saved as client side state.
A stride value of 0 does not specify a ″tightly packed″ array as it does in glEdgeFlagPointer. Instead, it
causes the first array element of each array to be used for each vertex. Also, a negative value can be
used for stride, which allows the user to move through each array in reverse order.
To enable and disable the edge flag arrays, call glEnableClientState and glDisableClientState with the
argument GL_EDGE_FLAG_ARRAY. The edge flag array is initially disabled. When enabled, the edge
flag arrays are used when glMultiDrawArraysEXT, glMultiDrawElementsEXT,
glMultiModeDrawArraysIBM, glMultiModeDrawElementsIBM, glDrawArrays, glDrawElements or
glArrayElement is called. The last three calls in this list will only use the first array (the one pointed at by
pointer[0]). See the descriptions of these routines for more information on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Edge Flag array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
stride
pointer
ptrstride
Specifies the byte offset between consecutive edge flags. The initial value is 0.
Specifies a list of edge flag arrays. The initial value is 0 (NULL pointer).
Specifies the byte stride between successive pointers in the pointer array. The initial value is 0.
Notes
The glEdgeFlagPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists extension is
supported.
106
OpenGL 2.1 Reference Manual
Execution of glEdgeFlagPointerListIBM is not allowed between glBegin and the corresponding glEnd,
but an error may or may not be generated. If an error is not generated, the operation is undefined.
The glEdgeFlagPointerListIBM subroutine is typically implemented on the client side.
Since the edge flag array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glEdgeFlagPointerListIBM call is encountered while compiling a display list, the information it
contains does NOT contribute to the display list, but is used to update the immediate context instead.
The glEdgeFlagPointer call and the glEdgeFlagPointerListIBM call share the same state variables. A
glEdgeFlagPointer call will reset the edge flag list state to indicate that there is only one edge flag list, so
that any and all lists specified by a previous glEdgeFlagPointerListIBM call will be lost, not just the first
list that it specified.
Error Codes
None.
Associated Gets
glIsEnabled with argument GL_EDGE_FLAG_ARRAY.
glGetPointerv with argument GL_EDGE_FLAG_ARRAY_LIST_IBM.
glGet with argument GL_EDGE_FLAG_ARRAY_LIST_STRIDE_IBM.
glGet with argument GL_EDGE_FLAG_ARRAY_STRIDE.
Related Information
The glArrayElement subroutine, glEdgeFlagPointer subroutine, glDrawArrays subroutine,
glDrawElements subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv
subroutine, glIndexPointer subroutine, glInterleavedArrays subroutine, glMultiDrawArraysEXT
subroutine, glMultiDrawElementsEXT subroutine, glMultiModeDrawArraysIBM subroutine,
glMultiModeDrawElementsIBM subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glEnable or glDisable Subroutine
Purpose
Enables or disables a GL capability.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glEnable(GLenum capability)
void glDisable(GLenum capability)
Description
glEnable and glDisable enable and disable various capabilities. Use glIsEnable or glGet to determine
the current setting of any capability. Both glEnable and glDisable take a single argument, capability,
which may assume one of the following values:
Chapter 1. OpenGL Subroutines
107
GL_ALPHA_TEST
GL_AUTO_NORMAL
GL_BLEND
GL_CLIP_PLANEi
GL_COLOR_ARRAY_EXT
GL_COLOR_LOGIC_OP
GL_COLOR_MATERIAL
GL_COLOR_SUM_EXT
GL_CULL_FACE
GL_CULL_VERTEX_IBM
GL_DEPTH_TEST
GL_DITHER
GL_EDGE_FLAG_ARRAY_EXT
108
OpenGL 2.1 Reference Manual
If enabled, do alpha testing. (See glAlphaFunc.)
If enabled, compute surface normal vectors analytically when
either GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4 is used
to generate vertices. (See glMap2.)
If enabled, blend the incoming red, green, blue, alpha (RGBA)
color values with the values in the color buffers. (See
glBlendFunc.)
If enabled, clip geometry against user-defined clipping plane i.
(See glClipPlane.)
If enabled, colors are taken from the color array when
glArrayElementEXT or glDrawArraysEXT is called. (See
glColorPointerEXT, glArrayElementEXT and
glDrawArraysEXT.)
If enabled, apply the currently selected logical operation to the
incoming color and color buffer values. The initial value is
GL_FALSE. (See glLogicOp.)
If enabled, have one or more material parameters track the
current color. (See glColorMaterial.)
If enabled, user may specify the RGB components of the
secondary color used in the Color Sum stage, instead of using the
default (0,0,0,0) color. This applies only in RGBA mode and when
LIGHTING is disabled. (See glSecondaryColorEXT.)
If enabled, cull polygons based on their winding in window
coordinates. (See glCullFace.)
If enabled, cull polygons based on their vertex normals. When
vertex culling is enabled, vertices are classified as front or back
facing according to the sign of the dot product between the
normal at the vertex and an eye direction vector from the vertex
toward the eye position. When (normal dot eye_direction) <= 0 the
vertex is classified as back facing. When (normal dot
eye_direction) > 0 the vertex is classified as front facing. Vertices
are culled when the face orientation determined by the dot
product is the same as the face specified by CullFace. When all
of the vertices of a polygon are culled, then the polygon may be
culled. Unlike GL_CULL_VERTEX_EXT, vertex culling using
GL_CULL_VERTEX_IBM does not necessarily result in polygons
being culled even if all of the vertices of the polygon are culled.
The eye direction is determined by transforming the column vector
(0, 0, 1) by the upper leftmost 3x3 matrix taken from the inverse
of the modelview matrix. The eye direction is undefined if the
modelview matrix is singular or nearly singular. This operation in
effect projects the z axis in eye coordinates back into object
space. If the projection matrix or DepthRange settings cause the z
axis in window coordinates to be misaligned with the z axis in eye
coordinates, this extension should not be used. Vertex culling is
performed independently of face culling. Polygons on the
silhouettes of objects may have both front and back facing
vertices. Since polygons are culled only if all of their vertices are
culled and are not necessarily culled by GL_CULL_VERTEX_IBM
even in that case, face culling may have to be used in addition to
vertex culling in order to correctly cull silhouette polygons.
If enabled, do depth comparisons and update the depth buffer.
(See glDepthFunc and glDepthRange.)
If enabled, dither color components or indices before they are
written to the color buffer.
If enabled, edge flags are taken from the edge flags array when
glArrayElementEXT or glDrawArraysEXT is called. (See
glEdgeFlagPointerEXT, glArrayElementEXT and
glDrawArraysEXT.)
GL_FOG
GL_INDEX_ARRAY_EXT
GL_LIGHTi
GL_LIGHTING
GL_LINE_SMOOTH
GL_LINE_STIPPLE
GL_LOGIC_OP
GL_MAP1_COLOR_4
GL_MAP1_INDEX
GL_MAP1_NORMAL
GL_MAP1_TEXTURE_COORD_1
GL_MAP1_TEXTURE_COORD_2
GL_MAP1_TEXTURE_COORD_3
GL_MAP1_TEXTURE_COORD_4
GL_MAP1_VERTEX_3
GL_MAP1_VERTEX_4
GL_MAP2_COLOR_4
GL_MAP2_INDEX
GL_MAP2_NORMAL
GL_MAP2_TEXTURE_COORD_1
GL_MAP2_TEXTURE_COORD_2
GL_MAP2_TEXTURE_COORD_3
GL_MAP2_TEXTURE_COORD_4
If enabled, blend a fog color into the post-texturing color. (See
glFog.)
If enabled, color indexes are taken from the color index array
when glArrayElementEXT or glDrawArraysEXT is called. (See
glIndexPointerEXT, glArrayElementEXT and
glDrawArraysEXT.)
If enabled, include light i in the evaluation of the lighting equation.
(See glLightModel and glLight.)
If enabled, use the current lighting parameters to compute the
vertex color or index. Otherwise, simply associate the current
color or index with each vertex. (See glMaterial, glLightModel,
and glLight.)
If enabled, draw lines with correct filtering. Otherwise, draw
aliased lines. (See glLineWidth.)
If enabled, use the current line stipple pattern when drawing lines.
(See glLineStipple.)
If enabled, apply the currently selected logical operation to the
incoming and color buffer indices. (See glLogicOp.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate RGBA values. (See glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate color indices. (See glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate normals. (See glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate s texture coordinates. (See glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate s and t texture coordinates. (See
glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate s, t, and r texture coordinates. (See
glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate s, t, r, and q texture coordinates. (See
glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate will generate x, y, and z vertex
coordinates. (See glMap1.)
If enabled, calls to glEvalCoord1, glEvalMesh1, and
glEvalPoint1 will generate homogeneous x, y, z, and w vertex
coordinates. (See glMap1.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate RGBA values. (See glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate color indices. (See glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate normals. (See glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate s texture coordinates. (See glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate s and t texture coordinates. (See
glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate s, t, and r texture coordinates. (See
glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate s, t, r, and q texture coordinates. (See
glMap2.)
Chapter 1. OpenGL Subroutines
109
GL_MAP2_VERTEX_3
GL_MAP2_VERTEX_4
GL_NORMAL_ARRAY_EXT
GL_NORMALIZE
GL_OCCLUSION_CULLING_HP
GL_POLYGON_OFFSET_EXT
GL_POLYGON_OFFSET_FILL
GL_POLYGON_OFFSET_LINE
GL_POLYGON_OFFSET_POINT
GL_POINT_SMOOTH
GL_POLYGON_SMOOTH
GL_POLYGON_STIPPLE
GL_RESCALE_NORMAL
GL_RESCALE_NORMAL_EXT
GL_SCISSOR_TEST
110
OpenGL 2.1 Reference Manual
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate will generate x, y, and z vertex
coordinates. (See glMap2.)
If enabled, calls to glEvalCoord2, glEvalMesh2, and
glEvalPoint2 will generate homogeneous x, y, z, and w vertex
coordinates. (See glMap2.)
If enabled, normals are taken from the normal array when
glArrayElementEXT or glDrawArraysEXT is called. (See
glNormalPointerEXT, glArrayElementEXT and
glDrawArraysEXT.)
If enabled, normal vectors specified with glNormal are scaled to
unit length after transformation. (See glNormal.)
If enabled, the occlusion testing described within extension
HP_occlusion_test is performed. This extension allows an
application to render some geometry and, at the completion of the
rendering, to determine if any of the geometry could or did modify
the depth buffer (in other words, a depth buffer test succeeded).
(See glGet with parameter
GL_OCCLUSION_TEST_RESULT_HP). Occlusion culling
operates independently of the current rendering state (in other
words, when occlusion culling is enabled, fragments are
generated and the depth and/or color buffer may be updated). To
prevent updating the depth/color buffers, the application must
disable updates to these buffers. As a side effect of calling glGet
with parameter GL_OCCLUSION_TEST_RESULT_HP, the
internal result state is cleared, and it is reset for a new bounding
box test.
If enabled, an offset is added to z values of a polygon’s fragments
before the depth comparison is performed. (See
glPolygonOffsetEXT.)
If enabled, and if the polygon is rendered in GL_FILL mode, an
offset is added to z values of a polygon’s fragments before the
depth comparison is performed. The initial value is GL_FALSE.
(See glPolygonOffset.)
If enabled, and if the polygon is rendered in GL_LINE mode, an
offset is added to z values of a polygon’s fragments before the
depth comparison is performed. The initial value is GL_FALSE.
(See glPolygonOffset.)
If enabled, an offset is added to z values of a polygon’s fragments
before the depth comparison is performed, if the polygon is
rendered in GL_POINT mode. The initial value is GL_FALSE.
(See glPolygonOffset.)
If enabled, draw points with proper filtering. Otherwise, draw
aliased points. (See glPointSize.)
If enabled, draw polygons with proper filtering. Otherwise, draw
aliased polygons. (See glPolygonMode.)
If enabled, use the current polygon stipple pattern when rendering
polygons. (See glPolygonStipple.)
If normal rescaling is enabled, a new operation is added to the
transformation of the normal vector into eye coordinates. The
normal vector is rescaled after it is multiplied by the inverse
modelview matrix and before it is normalized.
If normal rescaling is enabled, a new operation is added to the
transformation of the normal vector into eye coordinates. The
normal vector is rescaled after it is multiplied by the inverse
modelview matrix and before it is normalized.
If enabled, discard fragments that are outside the scissor
rectangle. (See glScissor.)
GL_STENCIL_TEST
GL_TEXTURE_1D
GL_TEXTURE_2D
GL_TEXTURE_3D
GL_TEXTURE_3D_EXT
GL_TEXTURE_COLOR_TABLE_EXT
GL_TEXTURE_COORD_ARRAY_EXT
GL_TEXTURE_GEN_Q
GL_TEXTURE_GEN_R
GL_TEXTURE_GEN_S
GL_TEXTURE_GEN_T
GL_UPDATE_CLIP_VOLUME_HINT
GL_VERTEX_ARRAY_EXT
If enabled, do stencil testing and update the stencil buffer. (See
glStencilFunc and glStencilOp.)
If enabled, one-dimensional texturing is performed (unless
two-dimensional texturing is also enabled). (See glTexImage1D.)
If enabled, two-dimensional texturing is performed. (See
glTexImage2D.)
If enabled, three-dimensional texturing is performed. (See
glTexImage3D.)
If enabled, three-dimensional texture mapping is performed. (See
glTexImage3DEXT.)
If enabled, a color lookup table is added to the texture
mechanism. (See glColorTable.)
If enabled, texture coordinates are taken from the texture
coordinates array when glArrayElementEXT or
glDrawArraysEXT is called. (See glTexCoordPointerEXT,
glArrayElementEXT and glDrawArraysEXT.)
If enabled, the q texture coordinate is computed using the texture
generation function defined with glTexGen. Otherwise the current
q texture coordinate is used. (See glTexGen.)
If enabled, the r texture coordinate is computed using the texture
generation function defined with glTexGen. Otherwise the current
r texture coordinate is used. (See glTexGen.)
If enabled, the s texture coordinate is computed using the texture
generation function defined with glTexGen. Otherwise the current
s texture coordinate is used. (See glTexGen.)
If enabled, the t texture coordinate is computed using the texture
generation function defined with glTexGen. Otherwise, the current
t texture coordinate is used. (See glTexGen.)
If enabled, calls to ClipBoundingBoxIBM,
ClipBoundingSphereIBM, and ClipBoundingVerticesIBM will
result in updates to the VOLUME_CLIPPING_HINT_EXT state. A
result of REJECT_IBM causes the hint to be set to DONT_CARE.
A result of CLIP_IBM causes the hint to be set to NICEST. A
result of ACCEPT_IBM causes the hint to be set to FASTEST. If
the EXT_clip_volume_hint extension is not supported, then the
UPDATE_CLIP_VOLUME_HINT enable state has no effect. (See
glClipBoundingBoxIBM, glClipBoundingSphereIBM, or
glClipBoundingVerticesIBM, )
If enabled, vertexes are taken from the vertex array when
glArrayElementEXT or glDrawArraysEXT is called. (See
glVertexPointerEXT, glArrayElementEXT and
glDrawArraysEXT.)
Parameters
capability
Specifies a symbolic constant indicating a GL capability. Initially, all are disabled except
GL_DITHER.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
capability is not an accepted value.
The glEnable subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Chapter 1. OpenGL Subroutines
111
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glAlphaFunc subroutine, glArrayElementEXT subroutine, glBegin or glEnd subroutine,
glBlendFunc subroutine, glClipPlane subroutine, glColorMaterial subroutine, glColorPointerEXT
subroutine, glCullFace subroutine, glDepthFunc subroutine, glDepthRange subroutine,
glDrawArraysEXT subroutine, glEdgeFlagPointerEXT subroutine, glFog subroutine, glIndexPointerEXT
subroutine, glIsEnabled subroutine, glLight subroutine, glLightModel subroutine, glLineStipple
subroutine, glLineWidth subroutine, and the glLogicOp subroutine.
The glMap1 subroutine, glMap2 subroutine, glMaterial subroutine, glNormal subroutine,
glNormalPointerEXT subroutine, glPointSize subroutine, glPolygonMode subroutine, glPolygonOffset
subroutine, glPolygonOffsetEXT subroutine, glPolygonStipple subroutine, glScissor subroutine,
glTexCoordPointerEXT subroutine, glTexGen subroutine, glTexImage1D subroutine, glTexImage2D
subroutine, and the glTexImage3DEXT subroutine.
glEnableClientState or glDisableClientState Subroutine
Purpose
Enables or disables an array.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glEnableClientState(GLenum
void glDisableClientState(GLenum
array)
array)
Description
The glEnableClientState subroutine lets you enable individual arrays, and glDisableClientState lets you
disable individual arrays.
Parameters
array
Specifies the array to enable or disable. Symbolic constraints GL_EDGE_FLAG_ARRAY,
GL_TEXTURE_COORD_ARRAY, GL_COLOR_ARRAY, GL_INDEX_ARRAY, GL_NORMAL_ARRAY,
GL_VERTEX_ARRAY, GL_FOG_COORDINATE_ARRAY_EXT, and
GL_SECONDARY_COLOR_ARRAY_EXT are accepted (for glEnableClientState).
Notes
The glEnableClientState and glDisableClientState subroutines are available only if the GL version is 1.1
or greater.
Errors
GL_INVALID_ENUM is generated if array is not an accepted value.
112
OpenGL 2.1 Reference Manual
The glEnableClientState subroutine is not allowed between the execution of glBegin and the
corresponding glEnd, but an error may or may not be generated. If no error is generated then the
behavior is undefined.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine,
glFogCoordEXT subroutine, glIndexPointer subroutine, glInterleavedArrays subroutine,
glNormalPointer subroutine, glSecondaryColorEXT subroutine, glTexCoordPointer subroutine,
glVertexPointer subroutine.
glEvalCoord Subroutine
Purpose
Evaluates enabled one-dimensional (1D) and two-dimensional (2D) maps.
Library
OpenGL C bindings library: libGL.a
C Syntax
glEvalCoord1d
void glEvalCoord1d(GLdouble
void glEvalCoord1f(GLfloat
void glEvalCoord2d(GLdouble
GLdouble
v)
void glEvalCoord2f(GLfloat
GLfloat
v)
u)
u)
u,
u,
glEvalCoord1dv
void glEvalCoord1dv(const GLdouble * u)
void glEvalCoord1fv(const GLfloat * u)
void glEvalCoord2dv(const GLdouble * u)
void glEvalCoord2fv(const GLfloat * u)
Description
The glEvalCoord1 subroutine evaluates enabled 1D maps at argument u. The glEvalCoord2 subroutine
does the same for 2D maps using two domain values, u and v. Maps are defined with glMap1 and
glMap2, and enabled and disabled with glEnable and glDisable.
When one of the glEvalCoord subroutines is issued, all currently enabled maps of the indicated
dimension are evaluated. Then, for each enabled map, it is as if the corresponding GL subroutine was
issued with the computed value. That is, if GL_MAP1_INDEX or GL_MAP2_INDEX is enabled, a glIndex
subroutine is simulated. If GL_MAP1_COLOR_4 or GL_MAP2_COLOR_4 is enabled, a glColor
subroutine is simulated. If GL_MAP1_NORMAL or GL_MAP2_NORMAL is enabled, a normal vector is
produced, and if any of GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2,
GL_MAP1_TEXTURE_COORD_3, GL_MAP1_TEXTURE_COORD_4, GL_MAP2_TEXTURE_COORD_1,
Chapter 1. OpenGL Subroutines
113
GL_MAP2_TEXTURE_COORD_2, GL_MAP2_TEXTURE_COORD_3, or
GL_MAP2_TEXTURE_COORD_4 is enabled, an appropriate glTexCoord subroutine is simulated.
The GL uses evaluated values instead of current values for those evaluations that are enabled, and
current values otherwise, for color, color index, normal, and texture coordinates. However, the evaluated
values do not update the current values. Thus if glVertex subroutines are interspersed with glEvalCoord
subroutines, the color, normal, and texture coordinates associated with the glVertex subroutines will not be
affected by the values generated by the glEvalCoord subroutines, but rather only by the most recent
glColor, glIndex, glNormal, and glTexCoord subroutines.
No subroutines are issued for maps that are not enabled. If more than one texture evaluation is enabled
for a particular dimension (for example, GL_MAP2_TEXTURE_COORD_1 and
GL_MAP2_TEXTURE_COORD_2), only the evaluation of the map that produces the larger number of
coordinates (in this case, GL_MAP2_TEXTURE_COORD_2) is carried out. GL_MAP1_VERTEX_4
overrides GL_MAP1_VERTEX_3, and GL_MAP2_VERTEX_4 overrides GL_MAP2_VERTEX_3 in the
same manner. If neither a three-component nor a four-component vertex map is enabled for the specified
dimension, the glEvalCoord subroutine is ignored.
If automatic normal generation is enabled by calling glEnable with argument GL_AUTO_NORMAL,
glEvalCoord2 generates surface normals analytically, regardless of the contents or enabling of the
GL_MAP2_NORMAL map. Let:
m = (delta p / delta u) (delta p / delta v)
Then the generated normal n is
n = m/||m||
If automatic normal generation is disabled, the corresponding normal map GL_MAP2_NORMAL, if
enabled, is used to produce a normal. If neither automatic normal generation nor a normal map is enabled,
no normal is generated for glEvalCoord2 subroutines.
Parameters
glEvalCoord1d
u
v
Specifies a value that is the domain coordinate u to the basis function defined in a previous glMap1 or glMap2
subroutine.
Specifies a value that is the domain coordinate v to the basis function defined in a previous glMap2
subroutine. This argument is not present in an glEvalCoord1 subroutine.
glEvalCoord1dv
u
Specifies a pointer to an array containing either one or two domain coordinates. The first coordinate is u. The
second coordinate is v, and is present only in glEvalCoord2 versions.
Associated Gets
Associated gets for the glEvalCoord subroutine are as follows. (See the glGet subroutine for more
information.)
glIsEnabled with argument GL_MAP1_VERTEX_3.
glIsEnabled with argument GL_MAP1_VERTEX_4.
glIsEnabled with argument GL_MAP1_INDEX.
114
OpenGL 2.1 Reference Manual
glIsEnabled with argument GL_MAP1_COLOR_4.
glIsEnabled with argument GL_MAP1_NORMAL.
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_1.
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_2.
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_3.
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_4.
glIsEnabled with argument GL_MAP2_VERTEX_3.
glIsEnabled with argument GL_MAP2_VERTEX_4.
glIsEnabled with argument GL_MAP2_INDEX.
glIsEnabled with argument GL_MAP2_COLOR_4.
glIsEnabled with argument GL_MAP2_NORMAL.
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_1.
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_2.
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_3.
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_4.
glIsEnabled with argument GL_AUTO_NORMAL.
glGetMap.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColor subroutine, glEnable or Disable subroutine, glEvalMesh
subroutine, glEvalPoint subroutine, glIndex subroutine, glMap1 subroutine, glMap2 subroutine,
glMapGrid subroutine, glNormal subroutine, glTexCoord subroutine, glVertex subroutine.
glEvalMesh Subroutine
Purpose
Computes a one-dimensional (1D) or two-dimensional (2D) grid of points or lines.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
115
C Syntax
void glEvalMesh1(GLenum
GLint i1,
GLint i2)
Mode,
void glEvalMesh2(GLenum
GLint i1,
GLint i2,
GLint j1,
GLint j2)
Mode,
Description
The glMapGrid and glEvalMesh subroutines are used in tandem to efficiently generate and evaluate a
series of evenly spaced map domain values. The glEvalMesh subroutine steps through the integer
domain of a 1D or 2D grid whose range is the domain of the evaluation maps specified by glMap1 and
glMap2. The Mode parameter determines whether the resulting vertices are connected as points, lines, or
filled polygons.
In the 1D case, glEvalMesh1, the mesh is generated as if the following code fragment was executed:
glBegin(Type);
for (i = i1; i <= i2; i += 1)
glEvalCoord1(i (DELTA u) + u1)
glEnd();
where DELTA u = (u2 - u1 )/n and n, u1, and u2 are the arguments to the most recent glMapGrid1
subroutine. Type is GL_POINTS if Mode is GL_POINT, or GL_LINES if Mode is GL_LINE. The one
absolute numeric requirement is that if i = n, the value computed from i (DELTA u) + u1 is exactly u2.
In the 2D case, glEvalMesh2, DELTA u = (u2 - u1)/n and DELTA v = (v2 - v1)/m, where n, u1, u2, m, v1,
and v2 are the arguments to the most recent glMapGrid2 subroutine. Then, if Mode is GL_FILL, the
glEvalMesh2 subroutine is equivalent to:
for (j = j1; j < j2; j += 1) {
glBegin(GL_QUAD_STRIP)
for (i= i1; i <= i2; i += 1) {
glEvalCoord2(i (DELTA u) + u1, j (DELTA v) + v1);
glEvalCoord2(i (DELTA u) + u1, (j+1) (DELTA v) +
v1);
}
glEnd();
}
If Mode is GL_LINE, a call to glEvalMesh2 is equivalent to:
for (j = j1; j <= j2; j += 1) {
glBegin(GL_LINE_STRIP)
for (i = i1; i <= i2; i += 1)
glEvalCoord2(i DELTA u + u1, j (DELTA v) + v1);
glEnd();
}
for (i = i1; i <= i2; i += 1) {
glBegin(GL_LINE_STRIP);
for (j = j1; j <= j1; j += 1)
glEvalCoord2(i (DELTA u + u1, j (DELTA v) + v1);
glEnd();
}
And finally, if Mode is GL_POINT, a call to glEvalMesh2 is equivalent to:
116
OpenGL 2.1 Reference Manual
glBegin(GL_POINTS);
for (j = j1; j <= j2; j += 1) {
for (i = i1; i <= i2; i += 1) {
glEvalCoord2(i (DELTA u) + u1, j (DELTA v) + v1):
}
}
glEnd();
In all three cases, the only absolute numeric requirements are that if i = n, the value computed from i
(DELTA u) + u1 is exactly u2, and if j = m, the value computed from j (DELTA v) + v1 is exactly v2.
Parameters
glEvalMesh1
Mode
i1
i2
Specifies whether to compute a 1D mesh of points or lines. Symbolic constants GL_POINT and GL_LINE
are accepted.
Specifies the first integer values for grid domain variable i.
Specifies the last integer values for grid domain variable i.
glEvalMesh2
Mode
i1
i2
j1
j2
Specifies whether to compute a 2D mesh of points, lines, or polygons. Symbolic constants GL_POINT,
GL_LINE, and GL_FILL are accepted.
Specifies the first integer values for grid domain variable i.
Specifies the last integer values for grid domain variable i.
Specifies the first integer values for grid domain variable j.
Specifies the last integer values for grid domain variable j.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Indicates that Mode is not an accepted value.
Indicates that glEvalMesh is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glEvalMesh subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MAP1_GRID_DOMAIN
glGet with argument GL_MAP2_GRID_DOMAIN
glGet with argument GL_MAP1_GRID_SEGMENTS
glGet with argument GL_MAP2_GRID_SEGMENTS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Chapter 1. OpenGL Subroutines
117
Related Information
The glBegin or glEnd subroutine, glEvalCoord subroutine, glEvalPoint subroutine, glMap1 subroutine,
glMap2 subroutine, glMapGrid subroutine.
glEvalPoint Subroutine
Purpose
Generates and evaluates a single point in a mesh.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glEvalPoint1(GLint
i)
void glEvalPoint2(GLint
GLint j)
i,
Description
The glMapGrid and glEvalMesh subroutines are used in tandem to efficiently generate and evaluate a
series of evenly spaced map domain values. glEvalPoint can be used to evaluate a single grid point in
the same grid space that is traversed by glEvalMesh. Calling glEvalPoint1 is equivalent to calling
EvalCoord1(i (DELTA u) + u1);
where DELTA u = (u2 - u1)/n and n, u1, and u2 are the arguments to the most recent glMapGrid1
subroutine. The one absolute numeric requirement is that if i = n, the value computed from i (DELTA u) +
u1 is exactly u2.
In the two-dimensional case, glEvalPoint2, let
DELTA u = (u2 - u1 )/n
DELTA v = (v2 - v1 )/m
where n, u1, u2, m, v1, and v2 are the arguments to the most recent glMapGrid2 subroutine. Then the
glEvalPoint2 subroutine is equivalent to calling:
EvalCoord2(i (DELTA u) + u1,
j (DELTA v) + v1)
The only absolute numeric requirements are that if i = n, the value computed from i (DELTA u) + u1 is
exactly u2, and if j = m, the value computed from j (DELTA v) + v1 is exactly v2.
Parameters
i
j
Specifies the integer value for grid domain variable i.
Specifies the integer value for grid domain variable j. (This parameter applies to glEvalPoint2 only.)
Associated Gets
Associated gets for the glEvalPoint subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MAP1_GRID_DOMAIN.
118
OpenGL 2.1 Reference Manual
glGet with argument GL_MAP2_GRID_DOMAIN.
glGet with argument GL_MAP1_GRID_SEGMENTS.
glGet with argument GL_MAP2_GRID_SEGMENTS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glEvalCoord subroutine, glEvalMesh subroutine, glMap1 subroutine, glMap2 subroutine, glMapGrid
subroutine.
glFeedbackBuffer Subroutine
Purpose
Controls the feedback mode.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glFeedbackBuffer(GLsizei
GLenum Type,
GLfloat * Buffer)
Size,
Description
The glFeedbackBuffer subroutine controls feedback. Feedback, like selection, is a GL mode. The mode is
selected by calling glRenderMode with GL_FEEDBACK. When the GL is in feedback mode, no pixels are
produced by rasterization. Instead, information about primitives that would have been rasterized is fed
back to the application using the GL.
The glFeedbackBuffer subroutine has three arguments:
v Buffer is a pointer to an array of floating point values into which feedback information is placed.
v Size indicates the size of the array.
v Type is a symbolic constant describing the information that is fed back for each vertex.
The glFeedbackBuffer subroutine must be issued before feedback mode is enabled (by calling
glRenderMode with argument GL_FEEDBACK). Setting GL_FEEDBACK without establishing the
feedback buffer, or calling glFeedbackBuffer while the GL is in feedback mode, results in an error.
The GL is taken out of feedback mode by calling glRenderMode with a parameter value other than
GL_FEEDBACK. When this is done while the GL is in feedback mode, glRenderMode returns the
number of entries placed in the feedback array. The returned value never exceeds Size. If the feedback
data requires more room than is available in Buffer, glRenderMode returns a negative value.
While in feedback mode, each primitive that would be rasterized generates a block of values that get
copied into the feedback array. If doing so would cause the number of entries to exceed the maximum, the
block is partially written so as to fill the array (if there is any room left at all), and an overflow flag is set.
Chapter 1. OpenGL Subroutines
119
Each block begins with a code indicating the primitive type, followed by values that describe the primitive’s
vertices and associated data. Entries are also written for bitmaps and pixel rectangles. Feedback occurs
after polygon culling and glPolyMode interpretation of polygons has taken place, so polygons that are
culled are not returned in the feedback buffer. It can also occur after polygons with more than three edges
are broken up into triangles, if the GL implementation renders polygons by performing this decomposition.
The glPassThrough subroutine can be used to insert a marker into the feedback buffer. (See
glPassThrough.)
Following is the grammar for the blocks of values written into the feedback buffer. Each primitive is
indicated with a unique identifying value followed by some number of vertices. Polygon entries include an
integer value indicating how many vertices follow. A vertex is fed back as some number of floating-point
values, as determined by Type. Colors are fed back as four values in red, green, blue, alpha (RGBA)
mode and one value in color index mode.
feedbackList
feedbackItem
point
lineSegment
polygon
polySpec
bitmap
pixelRectangle
passThru
vertex
2d
3d
3dColor
3dColorTexture
4dColorTexture
color
rgba
index
tex
->
->
->
->
->
->
->
->
->
->
->
->
->
->
->
->
->
->
->
feedbackItem feedbackList | feedbackItem
point | lineSegment | polygon | bitmap | pixelRectangle | passThru
GL_POINT_TOKEN vertex
GL_LINE_TOKEN vertex vertex | GL_LINE_RESET_TOKEN vertex vertex
GL_POLYGON_TOKEN n polySpec
polySpec vertex | vertex vertex vertex
GL_BITMAP_TOKEN vertex
GL_DRAW_PIXEL_TOKEN vertex | GL_COPY_PIXEL_TOKEN vertex
GL_PASS_THROUGH_TOKEN value
2d | 3d | 3dColor | 3dColorTexture | 4dColorTexture
value value
value value value
value value value color
value value value color tex
value value value value color tex
rgba | index
value value value value
value
value value value value
where value is a floating-point number, and n is a floating-point integer giving the number of vertices in the
polygon. GL_POINT_TOKEN, GL_LINE_TOKEN, GL_LINE_RESET_TOKEN, GL_POLYGON_TOKEN,
GL_BITMAP_TOKEN, GL_DRAW_PIXEL_TOKEN, GL_COPY_PIXEL_TOKEN and
GL_PASS_THROUGH_TOKEN are symbolic floating-point constants. GL_LINE_RESET_TOKEN is
returned whenever the line stipple pattern is reset. The data returned as a vertex depends on the feedback
Type.
The following table gives the correspondence between Type and the number of values per vertex. The
variable k is 1 in color index mode and 4 in RGBA mode.
Type
Coordinates
GL_2D
x, y
2
GL_3D
x, y, z
3
GL_3D_COLOR
x, y, z
k
GL_3D_COLOR_TEXTURE
x, y, z
k
4
7+k
GL_4D_COLOR_TEXTURE
x, y, z, w
k
4
8+k
120
OpenGL 2.1 Reference Manual
Color
Texture
Total Number
of Values
3+k
Feedback vertex coordinates are in window coordinates, except w, which is in clip coordinates. Feedback
colors are lighted, if lighting is enabled. Feedback texture coordinates are generated, if texture coordinate
generation is enabled. They are always transformed by the texture matrix.
Parameters
Size
Type
Buffer
Specifies the maximum number of values that can be written into Buffer.
Specifies a symbolic constant that describes the information that is returned for each vertex. GL_2D,
GL_3D, GL_3D_COLOR, GL_3D_COLOR_TEXTURE, and GL_4D_COLOR_TEXTURE are accepted.
Returns the feedback data.
Notes
The glFeedbackBuffer subroutine, when used in a display list, is not compiled into the display list but
rather is executed immediately.
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Type is not an accepted value.
Size is negative.
The glFeedbackBuffer subroutine is called while the render mode is
GL_FEEDBACK, or glRenderMode is called with argument GL_FEEDBACK
before glFeedbackBuffer is called at least once.
The glFeedbackBuffer subroutine is called between a call to glBegin and
the corresponding call to glEnd.
Associated Gets
Associated gets for the glFeedbackBuffer subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_RENDER_MODE.
glGetPointerv with argument GL_FEEDBACK_BUFFER_POINTER.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glGetPointerv subroutine, glLineStipple subroutine, glPassThrough
subroutine, glPolygonMode subroutine, glRenderMode subroutine, glSelectBuffer subroutine.
glFinish Subroutine
Purpose
Blocks until all GL execution is complete.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
121
C Syntax
void glFinish( void )
Description
The glFinish subroutine does not return until the effects of all previously called GL subroutines are
complete. Such effects include all changes to the GL state, all changes to the connection state, and all
changes to the frame buffer contents.
Notes
The glFinish subroutine requires a round-trip to the server.
Errors
GL_INVALID_OPERATION
The glFinish subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFlush subroutine, glWaitGL subroutine, glWaitX subroutine.
glFlush Subroutine
Purpose
Forces the running of GL subroutines in finite time.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glFlush( void )
Description
Different GL implementations buffer subroutines in several different locations, including network buffers and
the graphics accelerator itself. The glFlush subroutine empties all of these buffers, causing all issued
subroutines to be executed as quickly as they are accepted by the actual rendering engine. Though this
execution cannot be completed in any particular time period, it does complete in finite time.
Because any GL program might be executed over a network, or on an accelerator that buffers subroutines,
all programs should call glFlush whenever they must have all of their previously issued subroutines
completed. For example, call glFlush before waiting for user input that depends on the generated image.
Notes
The glFlush subroutine can return at any time. It does not wait until the execution of all previously issued
OpenGL commands is complete.
122
OpenGL 2.1 Reference Manual
Errors
GL_INVALID_OPERATION
The glFlush subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFinish subroutine.
glFog Subroutine
Purpose
Specifies fog parameters.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glFogf(GLenum ParameterName,
GLfloat ParameterValue)
void glFogi(GLenum ParameterName,
GLint ParameterValue)
void glFogfv(GLenum ParameterName,
const GLfloat * ParameterValues)
void glFogiv(GLenum ParameterName,
const GLint * ParameterValues)
Description
The glFog subroutine is enabled and disabled with glEnable and glDisable using the argument GL_FOG.
While enabled, fog affects rasterized geometry, bitmaps, and pixel blocks, but not buffer clear operations.
The glFog subroutine assigns the value or values in ParameterValues to the fog parameter specified by
ParameterName. The accepted values for ParameterName are:
GL_FOG_MODE
GL_FOG_DENSITY
ParameterValues is a single integer or floating-point value that
specifies the equation to be used to compute the fog blend
factor, f. Three symbolic constants are accepted:
GL_LINEAR, GL_EXP, and GL_EXP2. The equations
corresponding to these symbolic constants are defined in the
following sections. The default fog mode is GL_EXP.
ParameterValues is a single integer or floating-point value that
specifies Density, the fog density used in both exponential fog
equations. Only nonnegative densities are accepted. The
default fog density is 1.0.
Chapter 1. OpenGL Subroutines
123
GL_FOG_START
GL_FOG_END
GL_FOG_INDEX
GL_FOG_COLOR
GL_FOG_COORDINATE_SOURCE_EXT
ParameterValues is a single integer or floating-point value that
specifies Start, the near distance used in the linear fog
equation. The default near distance is 0.0.
ParameterValues is a single integer or floating-point value that
specifies End, the far distance used in the linear fog equation.
The default far distance is 1.0.
ParameterValues is a single integer or floating-point value that
specifies if, the fog color index. The default fog index is 0.0.
ParameterValues contains four integer or floating-point values
that specify Cf, the fog color. Integer values are mapped
linearly such that the most positive representable value maps
to 1.0, and the most negative representable value maps to
-1.0. Floating-point values are mapped directly. After
conversion, all color components are clamped to the range
[0,1]. The default fog color is (0,0,0,0).
ParameterValues is a single integer or floating point value that
specifies the source for the fog coordinates. Two symbolic
constants are accepted: GL_FOG_COORDINATE_EXT and
GL_FRAGMENT_DEPTH_EXT. Their use is described below.
The default fog coordinate source is
GL_FRAGMENT_DEPTH_EXT.
Fog blends a fog color with each rasterized pixel fragment’s post-texturing color using a blending factor f.
Factor f is computed in one of three ways, depending on the fog mode, using one of two values,
depending on the fog coordinate source. If the fog coordinate source is GL_FOG_COORDINATE_EXT
then z in the equations below comes from the current fog coordinate. Otherwise, it comes from the
fragment’s distance from the origin in eye coordinates.
The equation for GL_LINEAR fog is:
f =
end – z
end – start
Figure 1. Equation for GL_LINEAR Fog. This figure shows that f is equal to end–z / end–start.
The equation for GL_EXP fog is:
.
f = e (–density z)
Figure 2. Equation for GL_EXP Fog. This figure shows that f is equal to e(-density*z).
The equation for GL_EXP2 fog is:
124
OpenGL 2.1 Reference Manual
.
2
f = e (–density z)
Figure 3. Equation for GL_EXP2 Fog. This figure shows that f is equal to e(-density*z) to the power of two.
Regardless of the fog mode, f is clamped to the range [0,1] after it is computed. Then, if the GL is in red,
green, blue, alpha (RGBA) color mode, the fragment’s color, Cr, is replaced by the following:
Cr prime = fCr + (1 - f) Cf
In color index mode, the fragment’s color index, ir, is replaced by the following:
ir prime = ir + (1 - f) if
Parameters
glFogf and glFogi
ParameterName
ParameterValue
Specifies a single-valued fog parameter. GL_FOG_DENSITY, GL_FOG_END,
GL_FOG_INDEX, GL_FOG_MODE, GL_FOG_START, and
GL_FOG_COORDINATE_SOURCE_EXT are accepted.
Specifies the value to which ParameterName is set.
glFogfv and glFogiv
ParameterName
ParameterValues
Specifies a fog parameter. GL_FOG_COLOR, GL_FOG_DENSITY, GL_FOG_END,
GL_FOG_INDEX, GL_FOG_MODE, GL_FOG_START, and
GL_FOG_COORDINATE_SOURCE_EXT are accepted.
Specifies the value or values to be assigned to ParameterName. GL_FOG_COLOR
requires an array of four values. All other parameters accept an array containing only a
single value.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_VALUE
GL_INVALID_ENUM
ParameterName is not an accepted value.
The glFog subroutine is called between a call to glBegin and the
corresponding call to glEnd.
ParameterName is GL_FOG_DENSITY and ParameterValues is negative.
ParameterName is GL_FOG_COORDINATE_SOURCE_EXT and
ParameterValues is not one of the two permitted values.
Associated Gets
Associated gets for the glFog subroutine are as follows. (See the glGet subroutine for more information.)
glIsEnabled with argument GL_FOG.
glGet with argument GL_FOG_COLOR.
glGet with argument GL_FOG_INDEX.
glGet with argument GL_FOG_DENSITY.
Chapter 1. OpenGL Subroutines
125
glGet with argument GL_FOG_START.
glGet with argument GL_FOG_END.
glGet with argument GL_FOG_MODE.
glGet with argument GL_CURRENT_FOG_COORDINATE_EXT.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable or glDisable subroutine.
glFogCoordEXT Subroutine
Purpose
Specifies a Fog Coordinate.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void
void
void
void
glFogCoordfEXT(GLfloat coord)
glFogCoorddEXT(GLdouble coord)
glFogCoordfvEXT(GLfloat *Variable)
glFogCoorddvEXT(GLdouble *Variable)
Description
This extension allows specifying an explicit per-vertex fog coord to be used in fog computations, rather
than using a fragment depth-based fog equation.
Parameters
coord
Variable
specifies the fog coordinate, which is used in computing
the fogging effect, as described in glFog. This coordinate
is used in place of the distance in eye coordinates from
the origin to the fragment being fogged.
specifies a pointer to a one-element array containing a fog
coordinate.
Files
/usr/include/GL/gl.h
126
OpenGL 2.1 Reference Manual
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFog subroutine, the glFogCoordPointerEXT subroutine, the
glFogCoordPointerListIBM subroutine.
glFogCoordPointerEXT Subroutine
Purpose
Specifies an array of fog coordinates.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glFogCoordPointerEXT(GLenum type,
GLsizei stride,
const GLvoid *pointer)
Description
The glFogCoordPointerEXT extension specifies the location and data format of an array of fog
coordinates to use when rendering. The type parameter specifies the data type of each fog coordinate,
and stride gives the byte stride from one coordinate to the next allowing vertices and attributes to be
packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on
some implementations; see glInterleavedArrays).
When a fog coordinate array is specified, type, stride, and pointer are saved as client side state.
To enable and disable the fog coordinate array, call glEnableClientState and glDisableClientState with
the argument GL_FOG_COORDINATE_ARRAY_EXT. If enabled, the fog coordinate array is used when
glDrawArrays, glDrawElements or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Fog Coord array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
pointer
specifies the data type of each fog coordinate in the array.
Symbolic constants GL_FLOAT, or GL_DOUBLE are
accepted. The initial value is GL_FLOAT.
specifies the byte offset between consecutive fog
coordinates. If stride is zero (the initial value), the
coordinates are understood to be tightly packed in the
array. The initial value is 0.
specifies a pointer to the first component of the first fog
coordinate in the array. The initial value is 0 (NULL
pointer).
Chapter 1. OpenGL Subroutines
127
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElement subroutine, the glColorPointer subroutine, the glDrawArrays subroutine, the
glDrawElements subroutine, the glEdgeFlagPointer subroutine, the glEnable subroutine, the
glFogCoordPointerListIBM subroutine, the glGetPointerv subroutine, the glIndexPointer subroutine, the
glInterleavedArrays subroutine, the glNormalPointer subroutine, the glPushClientAttrib or
glPopClientAttrib subroutine, the glTexCoordPointer subroutine, the glVertexPointer subroutine.
glFogCoordPointerListIBM Subroutine
Purpose
Defines a list of arrays of fog coordinates.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glFogCoordPointerListIBM ( GLenum type,
GLint stride,
const GLvoid **pointer,
GLint ptrstride)
Description
The glFogCoordPointerListIBM subroutine specifies the location and data format of a list of arrays of fog
coordinates to use when rendering. The type parameter specifies the data type of each fog coordinate.
The stride parameter gives the byte stride from one coordinate to the next, allowing vertices and attributes
to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient
on some implementations; see glInterleavedArrays). The ptrstride parameter specifies the byte stride
from one pointer to the next in the pointer array.
When a fog coordinate array is specified, type, stride, pointer and ptrstride are saved as client side state.
A stride value of 0 does not specify a ″tightly packed″ array as it does in glFogCoordPointer. Instead, it
causes the first array element of each array to be used for each vertex. Also, a negative value can be
used for stride, which allows the user to move through each array in reverse order.
To enable and disable the fog coordinate arrays, call glEnableClientState and glDisableClientState with
the argument GL_COLOR_ARRAY. The fog coordinate array is initially disabled. When enabled, the fog
coordinate arrays are used when glMultiDrawArraysEXT, glMultiDrawElementsEXT,
glMultiModeDrawArraysIBM, glMultiModeDrawElementsIBM, glDrawArrays, glDrawElements or
glArrayElement is called. The last three calls in this list will only use the first array (the one pointed at by
pointer[0]). See the descriptions of these routines for more information on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
128
OpenGL 2.1 Reference Manual
If enabled, the Fog Coord array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
pointer
ptrstride
specifies the data type of each fog coordinate in the
arrays. Symbolic constants GL_FLOAT or GL_DOUBLE
are accepted. The initial value is GL_FLOAT.
specifies the byte offset between consecutive fog
coordinates. The initial value is 0.
specifies a list of fog coordinate arrays. The initial value is
0 (NULL pointer).
specifies the byte stride between successive pointers in
the pointer array. The initial value is 0.
Notes
The glFogCoordPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists extension
is supported.
Execution of glFogCoordPointerListIBM is not allowed between glBegin and the corresponding glEnd,
but an error may or may not be generated. If an error is not generated, the operation is undefined.
The glFogCoordPointerListIBM subroutine is typically implemented on the client side.
Since the fog coordinate array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glFogCoordPointerListIBM call is encountered while compiling a display list, the information it
contains does NOT contribute to the display list, but is used to update the immediate context instead.
The glFogCoordPointerEXT call and the glFogCoordPointerListIBM call share the same state variables.
A glFogCoordPointerEXT call will reset the fog coordinate list state to indicate that there is only one fog
coordinate list, so that any and all lists specified by a previous glFogCoordPointerListIBM call will be
lost, not just the first list that it specified.
Error Codes
GL_INVALID_ENUM
is generated if type is not an accepted value.
Associated Gets
Associated gets for the glFogCoordPointerListIBM subroutine are as follows. (See the glGet subroutine
for more information.)
glIsEnabled with argument GL_FOG_COORDINATE_ARRAY_EXT.
glGetPointerv with argument GL_FOG_COORDINATE_ARRAY_POINTER_EXT.
glGet with arguement GL_CURRENT_FOG_COORDINATE.
glGet with arguement GL_FOG_COORDINATE_ARRAY_TYPE_EXT.
glGet with arguement GL_FOG_COORDINATE_ARRAY_STRIDE_EXT.
Chapter 1. OpenGL Subroutines
129
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElement subroutine, the glColorPointer subroutine, the glDrawArrays subroutine, the
glDrawElements subroutine, the glEdgeFlagPointer subroutine, the glEnable subroutine, the
glFogCoordPointerEXT subroutine, the glGetPointerv subroutine, the glIndexPointer subroutine, the
glInterleavedArrays subroutine, the glMultiDrawArraysEXT subroutine, the glMultiDrawElementsEXT
subroutine, the glMultiModeDrawArraysIBM subroutine, the glMultiModeDrawElementsIBM subroutine,
the glNormalPointer subroutine, the glPushClientAttrib or glPopClientAttrib subroutine, the
glTexCoordPointer subroutine, the glVertexPointer subroutine.
glFrontFace Subroutine
Purpose
Defines frontfacing and backfacing polygons.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glFrontFace(GLenum
Mode)
Description
In a scene composed entirely of opaque closed surfaces, backfacing polygons are never visible.
Eliminating these invisible polygons speeds up the rendering of the image. Backface elimination is enabled
and disabled with glEnable and glDisable using argument GL_CULL_FACE.
The projection of a polygon to window coordinates is said to have clockwise winding if an imaginary object
following the path from its first vertex, its second vertex, and so on, to its last vertex, and finally back to its
first vertex, moves in a clockwise direction about the interior of the polygon. The polygon’s winding is said
to be counterclockwise if the imaginary object following the same path moves in a counterclockwise
direction about the interior of the polygon. The glFrontFace subroutine specifies whether polygons with
clockwise winding in window coordinates, or counterclockwise winding in window coordinates, are taken to
be frontfacing. Passing GL_CCW to the Mode parameter selects counterclockwise polygons as frontfacing;
GL_CW selects clockwise polygons as frontfacing. By default, counterclockwise polygons are taken to be
frontfacing.
Parameters
Mode
Specifies the orientation of frontfacing polygons. GL_CW and GL_CCW are accepted. The default value is
GL_CCW.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
130
OpenGL 2.1 Reference Manual
Mode is not an accepted value.
The glFrontFace subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glFrontFace subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_FRONT_FACE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glCullFace subroutine, glLightModel subroutine.
glFrustum Subroutine
Purpose
Multiplies the current matrix by a perspective matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glFrustum(GLdouble
GLdouble Right,
GLdouble Bottom,
GLdouble Top,
GLdouble Near,
GLdouble Far)
Left,
Description
The glFrustum subroutine describes a perspective matrix that produces a perspective projection.
The parameters (Left, Bottom, -Near) and (Right, Top, -Near) specify the points on the near clipping plane
that are mapped to the lower left and upper right corners of the window, respectively, assuming that the
eye is located at (0, 0, 0). -Far specifies the location of the far clipping plane. Both Near and Far must be
positive.
The corresponding matrix is:
Chapter 1. OpenGL Subroutines
131
2 Near
Right–Left
0
A
0
0
B
0
0
2 Near
Top–Bottom
0
C
D
0
0
–1
0
Figure 4. Perspective Projection Perspective Matrix. This diagram shows a matrix enclosed in brackets. The matrix
consists of four lines containing four characters each. The first line contains the following (from left to right): 2Near /
Right-Left, zero, A, zero. The second line contains the following (from left to right): zero, 2Near / Top-Bottom, B, zero.
The third line contains the following (from left to right): zero, zero, C, D. The fourth line contains the following (from left
to right): zero, zero, -1, zero.
where the following statements apply:
A=
Right+Left
Right–Left
B=
Top+Bottom
Top–Bottom
C=
Far+Near
Far–Near
D=
2 Far Near
Far–Near
Figure 5. Statements. This figure shows the equations used to find the values of A, B, C, and D in the matrix above. In
the first equation, A equals Right+Left / Right-Left. In the second equation, B equals Top+Bottom / Top-Bottom. In the
third equation, C equals Far+Near / Far-Near. In the fourth equation, D equals 2FarNear / Far-Near.
The current matrix is multiplied by this matrix with the result replacing the current matrix. That is, if M is
the current matrix and F is the frustum perspective matrix, M is replaced with MF.
Use glPushMatrix and glPopMatrix to save and restore the current matrix stack.
Parameters
Left
Right
Bottom
Top
Near
Far
Specifies
Specifies
Specifies
Specifies
Specifies
Specifies
a point on the left side of the clipping plane
a point on the right side of the clipping plane.
a point on the bottom of the clipping plane.
a point on the top of the clipping plane.
the location of the near clipping plane. This must be a positive value.
the location of the far clipping plane. This must be a positive value.
Notes
Depth buffer precision is affected by the values specified for Near and Far. The greater the ratio of Far to
Near is, the less effective the depth buffer will be at distinguishing between surfaces that are near each
other. If r = Far / Near, roughly log2r bits of depth buffer precision are lost. Because r approaches infinity
as Near approaches 0 (zero), Near must never be set to 0.
Errors
GL_INVALID_VALUE
132
OpenGL 2.1 Reference Manual
Either Near or Far is not positive.
GL_INVALID_OPERATION
The glFrustum subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glFrustum subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE.
glGet with argument GL_MODELVIEW_MATRIX.
glGet with argument GL_PROJECTION_MATRIX.
glGet with argument GL_TEXTURE_MATRIX.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glMatrixMode subroutine, glMultMatrix subroutine, glOrtho
subroutine, glPushMatrix or glPopMatrix subroutine, glViewport subroutine.
glGenLists Subroutine
Purpose
Generates a contiguous set of empty display lists.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLuint glGenLists(GLsizei
Range)
Description
The glGenLists subroutine has one argument, Range. It returns an integer n such that Range contiguous
empty display lists, named n, n+1, ..., n+Range-1, are created. If Range is 0 (zero), if there is no group of
Range contiguous names available, or if any error is generated, no display lists are generated, and 0 is
returned.
Parameters
Range
Specifies the number of contiguous empty display lists to be generated.
Errors
GL_INVALID_VALUE
Range is negative.
Chapter 1. OpenGL Subroutines
133
GL_INVALID_OPERATION
The glGenLists subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glGenLists subroutine are as follows. (See the glGet subroutine for more
information.)
glIsList.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallList subroutine, glCallLists subroutine, glDeleteLists subroutine,
glNewList subroutine.
glGenTextures Subroutine
Purpose
Generate texture names.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGenTextures(GLsizei
GLuint *textures)
n,
Parameters
n
textures
Specifies the number of texture names to be generated.
Specifies an array in which the generated texture names are stored.
Description
The glGenTextures subroutine returns n texture names in textures. There is no guarantee that the names
form a contiguous set of integers; however, it is guaranteed that none of the returned names was in use
immediately before the call to glGenTextures.
The generated textures have no dimensionality; they assume the dimensionality of the texture target to
which they are first bound (see glBindTexture).
Texture names returned by a call to glGenTextures are not returned by subsequent calls, unless they are
first deleted with glDeleteTextures.
The glGenTextures subroutine is not included in display lists.
134
OpenGL 2.1 Reference Manual
Notes
The glGenTextures subroutine is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glGenTextures is executed between the execution of glBegin
and the corresponding execution of glEnd.
Associated Gets
glIsTexture
Related Information
The glBindTexture subroutine, glDeleteTextures subroutine, glGet subroutine, glGetTexParameter
subroutine, glIsTexture subroutine, glTexImage1D subroutine, glTexImage2D subroutine,
glTexImage3DEXT subroutine, glTexParameter subroutine.
glGenTexturesEXT Subroutine
Purpose
Generates texture names.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGenTexturesEXT(GLsizei
GLuint * textures)
n,
Description
glGenTexturesEXT returns n texture names in textures. There is no guarantee that the names form a
contiguous set of integers; however, it is guaranteed that none of the returned names was in use
immediately before the call to glGenTexturesEXT.
The generated textures have no dimensionality; they assume the dimensionality of the texture target to
which they are first bound (see glBindTextureEXT).
Texture names returned by a call to glGenTexturesEXT will not be returned by subsequent calls, unless
they are first deleted with glDeleteTexturesEXT.
glGenTexturesEXT is not included in display lists.
Parameters
n
textures
The number of texture names to be generated.
An array in which the generated texture names are stored.
Chapter 1. OpenGL Subroutines
135
Notes
glGenTexturesEXT is part of the EXT_texture_object extension, not part of the core GL command set. If
GL_EXT_texture_object is included in the string returned by glGetString, when called with argument
GL_EXTENSIONS, extension EXT_texture_object is supported by the connection.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glGenTexturesEXT is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glIsTextureEXT.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBindTextureEXT subroutine, glDeleteTexturesEXT subroutine, glGet subroutine,
glGetTexParameter subroutine, glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3DEXT
subroutine, glTexParameter subroutine.
glGet Subroutine
Purpose
Returns the value or values of a selected parameter.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetBooleanv( GLenum ParameterName,
GLBoolean * ParameterValues)
void glGetDoublev(GLenum ParameterName,
GLdouble * ParameterValues )
void glGetFloatv(GLenum ParameterName,
GLfloat * ParameterValues)
void glGetIntegerv(GLenum ParameterName,
GLint ParameterValues)
Description
The four commands, glGetBooleanv, glGetDoublev, glGetFloatv, and glGetIntegerv, return values for
simple-state variables in GL. ParameterName is a symbolic constant indicating the state variable to be
returned, and ParameterValues is a pointer to an array of the indicated type in which to place the returned
data.
136
OpenGL 2.1 Reference Manual
Type conversion is performed if ParameterValues has a different type than the state variable value being
requested. If glGetBooleanv is called, a floating-point or integer value is converted to GL_FALSE if and
only if it is 0 (zero). Otherwise, it is converted to GL_TRUE. If glGetIntegerv is called, Boolean values are
returned as GL_TRUE or GL_FALSE, and most floating-point values are rounded to the nearest integer
value. Floating-point colors and normals, however, are returned with a linear mapping that maps 1.0 to the
most positive representable integer value, and -1.0 to the most negative representable integer value. If
either glGetFloatv or glGetDoublev is called, Boolean values are returned as GL_TRUE or GL_FALSE,
and integer values are converted to floating-point values.
The following symbolic constants are accepted by ParameterName:
GL_ACCUM_ALPHA_BITS
GL_ACCUM_BLUE_BITS
GL_ACCUM_CLEAR_VALUE
GL_ACCUM_GREEN_BITS
GL_ACCUM_RED_BITS
GL_ALIASED_LINE_WIDTH_RANGE
GL_ALIASED_POINT_SIZE_RANGE
GL_ALPHA_BIAS
GL_ALPHA_BITS
GL_ALPHA_SCALE
GL_ALPHA_TEST
GL_ALPHA_TEST_FUNC
ParameterValues returns one value, the
number of alpha bit planes in the accumulation
buffer.
ParameterValues returns one value, the
number of blue bit planes in the accumulation
buffer.
ParameterValues returns four values: the red,
green, blue, and alpha (RGBA) values used to
clear the accumulation buffer. Integer values, if
requested, are linearly mapped from the
internal floating-point representation such that
1.0 returns the most positive representable
integer value, and -1.0 returns the most
negative representable integer value. (See
glClearAccum.)
ParameterValues returns one value, the
number of green bit planes in the
accumulation buffer.
ParameterValues returns one value, the
number of red bit planes in the accumulation
buffer.
ParameterValues returns two values: the
smallest and largest supported widths for
aliased lines. (See glLineWidth.)
ParameterValues returns two values: the
smallest and largest supported sizes for
aliased points. (See glPointSize.)
ParameterValues returns one value, the alpha
bias factor used during pixel transfers. (See
glPixelTransfer.)
ParmeterValues returns one value, the number
of alpha bit planes in each color buffer.
ParameterValues returns one value, the alpha
scale factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns a single Boolean
value indicating whether alpha testing of
fragments is enabled. (See glAlphaFunc.)
ParameterValues returns one value, the
symbolic name of the alpha test function. (See
glAlphaFunc.)
Chapter 1. OpenGL Subroutines
137
GL_ALPHA_TEST_REF
GL_ARRAY_ELEMENT_LOCK_FIRST_EXT
GL_ARRAY_ELEMENT_LOCK_COUNT_EXT
GL_ATTRIB_STACK_DEPTH
GL_AUTO_NORMAL
GL_AUX_BUFFERS
GL_BLEND
GL_BLEND_DST
GL_BLEND_DST_ALPHA_EXT
GL_BLEND_DST_RGB_EXT
GL_BLEND_EQUATION_EXT
GL_BLEND_SRC
GL_BLEND_SRC_ALPHA_EXT
GL_BLEND_SRC_RGB_EXT
138
OpenGL 2.1 Reference Manual
ParameterValues returns one value, the
reference value for the alpha test. (See
glAlphaFunc.) An integer value, if requested,
is linearly mapped from the internal
floating-point representation such that 1.0
returns the most positive representable integer
value, and -1.0 returns the most negative
representable integer value.
ParameterValues returns one value, the first
element in the locked range. (See
glLockArraysEXT.) Requires extension
EXT_compiled_vertex_array.
ParameterValues returns one value, the count
of elements in the locked range. (See
glLockArraysEXT.) Requires extension
EXT_compiled_vertex_array.
ParameterValues returns one value, the depth
of the attribute stack. If the stack is empty, 0 is
returned. (See glPushAttrib.)
ParameterValues returns a single Boolean
value indicating whether two-dimensional (2D)
map evaluation automatically generates
surface normals. (See glMap2.)
ParameterValues returns one value, the
number of auxiliary color buffers.
ParameterValues returns a single Boolean
value indicating whether blending is enabled.
(See glBlendFunc.)
ParameterValues returns one value, the
symbolic constant identifying the destination
blend function. (See glBlendFunc.)
ParameterValues returns one value, the
symbolic constant identifying the destination
alpha separate blend function. (See
glBlendFuncSeparate.)
ParameterValues returns one value, the
symbolic constant identifying the destination
RGB separate blend function. (See
glBlendFuncSeparate.)
ParameterValues returns one value, a
symbolic constant indicating the blend
equation. (See glBlendEquationEXT.)
Requires at least one of the following
extensions: EXT_blend_minmax,
EXT_blend_color, EXT_blend_subtract,
EXT_blend_logic_op.
ParameterValues returns one value, the
symbolic constant identifying the source blend
function. (See glBlendFunc.)
ParameterValues returns one value, the
symbolic constant identifying the source alpha
separate blend function. (See
glBlendFuncSeparate.)
ParameterValues returns one value, the
symbolic constant identifying the source RGB
separate blend function. (See
glBlendFuncSeparate.)
GL_BLUE_BIAS
GL_BLUE_BITS
GL_CLIENT_ATTRIB_STACK_DEPTH
GL_BLUE_SCALE
GL_CLIP_PLANE
GL_COLOR_ARRAY
GL_COLOR_ARRAY_COUNT_EXT
GL_COLOR_ARRAY_EXT
GL_COLOR_ARRAY_LIST_STRIDE_IBM
GL_COLOR_ARRAY_SIZE
GL_COLOR_ARRAY_SIZE_EXT
GL_COLOR_ARRAY_STRIDE
GL_COLOR_ARRAY_STRIDE_EXT
GL_COLOR_ARRAY_TYPE
GL_COLOR_ARRAY_TYPE_EXT
ParameterValues returns one value, the blue
bias factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns one value, the
number of blue bit planes in each color buffer.
ParameterValues returns one value indicating
the depth of the attribute stack. The initial
value is 0. (See glPushClientAttrib.)
ParameterValues returns one value, the blue
scale factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns a single Boolean
value indicating whether the specified clipping
plane is enabled. (See glClipPlane.)
ParameterValues returns a single Boolean
value indicating whether the color array is
enabled. The initial value is GL_FALSE. (See
glColorPointer.)
ParameterName returns one value, the
number of colors in the color array, counting
from the first, that are static. (See
glColorPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns a single boolean
value, indicating whether the color array is
enabled. (See glColorPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns one value, the byte
stride between successive pointers to color
lists. The initial value is 0. (See
glColorPointerListIBM.) Requires extension
IBM_vertex_array_lists.
ParameterValues returns one value, the
number of components per color in the color
array. The initial value is 4. (See
glColorPointer.)
ParameterValues returns one value, the
number of components per color in the color
array. (See glColorPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns one value, the byte
offset between consecutive colors in the color
array. The initial value is 0. (See
glColorPointer.)
ParameterName returns one value, the byte
offset between consecutive colors in the color
array. (See glColorPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns one value, the data
type of each component in the color array. The
initial value is GL_FLOAT. (See
glColorPointer.)
ParameterValues returns one value, the data
type of each component in the color array.
(See glColorPointerEXT.) Requires extension
EXT_vertex_array.
Chapter 1. OpenGL Subroutines
139
GL_COLOR_CLEAR_VALUE
GL_COLOR_LOGIC_OP
GL_COLOR_MATERIAL
GL_COLOR_MATERIAL_FACE
GL_COLOR_MATERIAL_PARAMETER
GL_COLOR_MATRIX
GL_COLOR_SUM_EXT
GL_COLOR_WRITEMASK
GL_CULL_FACE
GL_CULL_FACE_MODE
GL_CURRENT_COLOR
GL_CURRENT_FOG_COORDINATE_EXT
GL_CURRENT_INDEX
140
OpenGL 2.1 Reference Manual
ParameterValues returns four values: the
RGBA values used to clear the color buffers.
Integer values, if requested, are linearly
mapped from the internal floating-point
representation such that 1.0 returns the most
positive representable integer value, and -1.0
returns the most negative representable
integer value. (See glClearColor.)
ParameterValues returns a single Boolean
value indicating whether a fragment’s color
values are merged into the framebuffer using
a logical operation. The initial value is
GL_FALSE. (See glLogicOp.)
ParameterValues returns a single Boolean
value indicating whether one or more material
parameters are tracking the current color. (See
glColorMaterial.)
ParameterValues returns one value, a
symbolic constant indicating which materials
have a parameter that is tracking the current
color. (See glColorMaterial.)
ParameterValues returns one value, a
symbolic constant indicating which material
parameters are tracking the current color. (See
glColorMaterial.)
ParameterValues returns 16 values: the color
matrix. (See glLoadNamedMatrixIBM.)
ParameterValues returns a single Boolean
value indicating whether the color sum stage
and secondary color handling is enabled. (See
glSecondaryColorEXT.)
ParameterValues returns four Boolean values:
the RGBA write enables for the color buffers.
(See glColorMask.)
ParameterValues returns a single Boolean
value indicating whether polygon culling is
enabled. (See glCullFace.)
ParameterValues returns one value, a
symbolic constant indicating which polygon
faces are to be culled. (See glCullFace.)
ParameterValues returns four values: the
RGBA values of the current color. Integer
values, if requested, are linearly mapped from
the internal floating-point representation such
that 1.0 returns the most positive
representable integer value, and -1.0 returns
the most negative representable integer value.
(See glColor.)
ParameterValues returns one value, the
current fog coordinate. (See
glFogCoordEXT.)
ParameterValues returns one value, the
current color index. (See glIndex.)
GL_CURRENT_NORMAL
GL_CURRENT_RASTER_COLOR
GL_CURRENT_RASTER_DISTANCE
GL_CURRENT_RASTER_INDEX
GL_CURRENT_RASTER_POSITION
GL_CURRENT_RASTER_TEXTURE_COORDS
GL_CURRENT_RASTER_POSITION_VALID
GL_CURRENT_SECONDARY_COLOR
GL_CURRENT_TEXTURE_COORDS
GL_DEPTH_BIAS
GL_DEPTH_BITS
GL_DEPTH_CLEAR_VALUE
GL_DEPTH_FUNC
ParameterValues returns three values: the x,
y, and z values of the current normal. Integer
values, if requested, are linearly mapped from
the internal floating-point representation such
that 1.0 returns the most positive
representable integer value, and -1.0 returns
the most negative representable integer value.
(See glNormal.)
ParameterValues returns four values: the
RGBA values of the current raster position.
Integer values, if requested, are linearly
mapped from the internal floating-point
representation such that 1.0 returns the most
positive representable integer value, and -1.0
returns the most negative representable
integer value. (See glRasterPos.)
ParameterValues returns one value, the
distance from the eye to the current raster
position. The initial value is 0. (See
glRasterPos.)
ParameterValues returns one value, the color
index of the current raster position. (See
glRasterPos.)
ParameterValues returns four values: the x, y,
z, and w components of the current raster
position. x, y, and z are in window
coordinates, w is in clip coordinates. (See
glRasterPos.)
ParameterValues returns four values: the s, t,
r, and q current raster texture coordinates.
(See glRasterPos and glTexCoord.)
ParameterValues returns a single Boolean
value indicating whether the current raster
position is valid. (See glRasterPos.)
ParameterValues returns a four values: the
RGBA values of the secondary color. (See
glSecondaryColorEXT.)
ParameterValues returns four values: the s, t,
r, and q current texture coordinates. (See
glTexCoord.)
ParameterValues returns one value, the depth
bias factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns one value, the
number of bit planes in the depth buffer.
ParameterValues returns one value, the value
that is used to clear the depth buffer. Integer
values, if requested, are linearly mapped from
the internal floating-point representation such
that 1.0 returns the most positive
representable integer value, and -1.0 returns
the most negative representable integer value.
(See glClearDepth.)
ParameterValues returns one value, the
symbolic constant that indicates the depth
comparison function. (See glDepthFunc.)
Chapter 1. OpenGL Subroutines
141
GL_DEPTH_RANGE
GL_DEPTH_SCALE
GL_DEPTH_TEST
GL_DEPTH_WRITEMASK
GL_DITHER
GL_DOUBLEBUFFER
GL_DRAW_BUFFER
GL_EDGE_FLAG
GL_EDGE_FLAG_ARRAY
GL_EDGE_FLAG_ARRAY_COUNT_EXT
GL_EDGE_FLAG_ARRAY_EXT
GL_EDGE_FLAG_LIST_STRIDE_IBM
GL_EDGE_FLAG_ARRAY_STRIDE
GL_EDGE_FLAG_ARRAY_STRIDE_EXT
142
OpenGL 2.1 Reference Manual
ParameterValues returns two values: the near
and far mapping limits for the depth buffer.
Integer values, if requested, are linearly
mapped from the internal floating-point
representation such that 1.0 returns the most
positive representable integer value, and -1.0
returns the most negative representable
integer value. (See glDepthRange.)
ParameterValues returns one value, the depth
scale factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns a single Boolean
value indicating whether depth testing of
fragments is enabled. (See glDepthFunc and
glDepthRange.)
ParameterValues returns a single Boolean
value indicating if the depth buffer is enabled
for writing. (See glDepthMask.)
ParameterValues returns a single Boolean
value indicating whether dithering of fragment
colors and indices is enabled.
ParameterValues returns a single Boolean
value indicating whether double buffering is
supported.
ParameterValues returns one value, a
symbolic constant indicating which buffers are
being drawn to. (See glDrawBuffer.)
ParameterValues returns a single Boolean
value indicating whether the current edge flag
is True or False. (See glEdgeFlag.)
ParameterValues returns a single Boolean
value indicating whether the edge flag array is
enabled. The initial value is GL_FALSE. (See
glEdgeFlagPointer.)
ParameterValues returns one value, the
number of edge flags in the edge flag array,
counting from the first, that are static. (See
glEdgeFlagPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns a single boolean
value, indicating whether the edge flag array is
enabled. (See glEdgeFlagPointerEXT.)
Requires extension EXT_vertex_array.
ParameterValues returns one value, the byte
stride between successive pointers to edge
flag lists. The initial value is 0. (See
glEdgeFlagPointerListIBM.) Requires
extension IBM_XXX.
ParameterValues returns one value, the byte
offset between consecutive edge flags in the
edge flag array. The initial value is 0. (See
glEdgeFlagPointer.)
ParameterValues returns one value, the byte
offset between consecutive edge flags in the
edge flag array. (See
glEdgeFlagPointerEXT.) Requires extension
EXT_vertex_array.
GL_FOG
GL_FOG_COLOR
GL_FOG_COORDINATE_ARRAY_TYPE_EXT
GL_FOG_COORDINATE_ARRAY_STRIDE_EXT
GL_FOG_DENSITY
GL_FOG_END
GL_FOG_HINT
GL_FOG_INDEX
GL_FOG_MODE
GL_FOG_START
GL_FRONT_FACE
GL_GREEN_BIAS
GL_GREEN_BITS
GL_GREEN_SCALE
GL_INDEX_ARRAY
GL_INDEX_ARRAY_COUNT_EXT
GL_INDEX_ARRAY_EXT
ParameterValues returns a single Boolean
value indicating whether fogging is enabled.
(See glFog.)
ParameterValues returns four values: the
RGBA components of the fog color. Integer
values, if requested, are linearly mapped from
the internal floating-point representation such
that 1.0 returns the most positive
representable integer value, and -1.0 returns
the most negative representable integer value.
(See glFog.)
ParameterValues returns one value, the fog
coordinate array type. (See
glFogCoordPointerEXT.)
ParameterValues returns one value, the fog
coordinate array stride. (See
glFogCoordPointerEXT.)
ParameterValues returns one value, the fog
density parameter. (See glFog.)
ParameterValues returns one value, the end
factor for the linear fog equation. (See glFog.)
ParameterValues returns one value, a
symbolic constant indicating the mode of the
fog hint. (See glHint.)
ParameterValues returns one value, the fog
color index. (See glFog.)
ParameterValues returns one value, a
symbolic constant indicating which fog
equation is selected. (See glFog.)
ParameterValues returns one value, the start
factor for the linear fog equation. (See glFog.)
ParameterValues returns one value, a
symbolic constant indicating whether clockwise
or counterclockwise polygon winding is treated
as frontfacing. (See glFrontFace.)
ParameterValues returns one value, the green
bias factor used during pixel transfers.
ParameterValues returns one value, the
number of green bit planes in each color
buffer.
ParameterValues returns one value, the green
scale factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns a single Boolean
value indicating whether the color index array
is enabled. The initial value is GL_FALSE.
(See glIndexPointer.)
ParameterValues returns one value, the
number of color indexes in the color index
array, counting from the first, that are static.
(See glIndexPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns a single boolean
value, indicating whether the color index array
is enabled. (See glIndexPointerEXT.)
Requires extension EXT_vertex_array.
Chapter 1. OpenGL Subroutines
143
GL_INDEX_ARRAY_LIST_STRIDE_IBM
GL_INDEX_ARRAY_STRIDE
GL_INDEX_ARRAY_STRIDE_EXT
GL_INDEX_ARRAY_TYPE
GL_INDEX_ARRAY_TYPE_EXT
GL_INDEX_BITS
GL_INDEX_CLEAR_VALUE
GL_INDEX_MODE
GL_INDEX_OFFSET
GL_INDEX_SHIFT
GL_INDEX_WRITEMASK
GL_LIGHT# (where ’#’ is 0...GL_MAXLIGHTS-1)
GL_LIGHTING
GL_LIGHT_MODEL_AMBIENT
144
OpenGL 2.1 Reference Manual
ParameterValues returns one value, the byte
stride between successive pointers to index
lists. The initial value is 0. (See
glIndexPointerListIBM.) Requires extension
IBM_vertex_array_lists.
ParameterValues returns one value, the byte
offset between consecutive color indexes in
the color index array. The initial value is 0.
(See glIndexPointer.)
ParameterValues returns one value, the byte
offset between consecutive color indexes in
the color index array. (See
glIndexPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns one value, the data
type of indexes in the color index array. The
initial value is GL_FLOAT. (See
glIndexPointer.)
ParameterValues returns one value, the data
type of indexes in the color index array. (See
glIndexPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns one value, the
number of bit planes in each color index
buffer.
ParameterValues returns one value, the color
index used to clear the color index buffers.
(See glClearIndex.)
ParameterValues returns a single Boolean
value indicating whether the GL is in color
index mode (True) or RGBA mode (False).
ParameterValues returns one value, the offset
added to color and stencil indices during pixel
transfers. (See glPixelTransfer.)
ParameterValues returns one value, the
amount that color and stencil indices are
shifted during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns one value, a mask
indicating which bit planes of each color index
buffer can be written. (See glIndexMask.)
ParameterValues returns a single Boolean
value indicating whether the specified light is
enabled. (See glLight and glLightModel.)
ParameterValues returns a single Boolean
value indicating whether lighting is enabled.
(See glLightModel.)
ParameterValues returns four values: the
RGBA components of the ambient intensity of
the entire scene. Integer values, if requested,
are linearly mapped from the internal
floating-point representation such that 1.0
returns the most positive representable integer
value, and -1.0 returns the most negative
representable integer value. (See
glLightModel.)
GL_LIGHT_MODEL_COLOR_CONTROL
GL_LIGHT_MODEL_LOCAL_VIEWER
GL_LIGHT_MODEL_TWO_SIDE
GL_LINE_SMOOTH
GL_LINE_SMOOTH_HINT
GL_LINE_STIPPLE
GL_LINE_STIPPLE_PATTERN
GL_LINE_STIPPLE_REPEAT
GL_LINE_WIDTH
GL_LINE_WIDTH_GRANULARITY
GL_LINE_WIDTH_RANGE
GL_LIST_BASE
GL_LIST_INDEX
GL_LIST_MODE
GL_LOGIC_OP
GL_LOGIC_OP_MODE
GL_MAP1_COLOR_4
ParameterValues can be
GL_SINGLE_COLOR or
GL_SPECULAR_COLOR.
GL_SINGLE_COLOR is the default value.
Depending upon the ParameterValues, the
lighting equations compute the two colors
differently. All computations are carried out in
eye coordinates. (See glLightModel.)
ParameterValues returns a single Boolean
value indicating whether specular reflection
calculations treat the viewer as being local to
the scene. (See glLightModel.)
ParameterValues returns a single Boolean
value indicating whether separate materials
are used to compute lighting for frontfacing
and backfacing polygons. (See glLightModel.)
ParameterValues returns a single Boolean
value indicating whether antialiasing of lines is
enabled. (See glLineWidth.)
ParameterValues returns one value, a
symbolic constant indicating the mode of the
line antialiasing hint. (See glHint).
ParameterValues returns a single Boolean
value indicating whether stippling of lines is
enabled. (See glLineStipple.)
ParameterValues returns one value, the 16-bit
line stipple pattern. (See glLineStipple.)
ParameterValues returns one value, the line
stipple repeat factor. (See glLineStipple.)
ParameterValues returns one value, the line
width as specified with glLineWidth.
ParameterValues returns one value, the width
difference between adjacent supported widths
for antialiased lines. (See glLineWidth.)
ParameterValues returns two values: the
smallest and largest supported widths for
antialiased lines. (See glLineWidth.)
ParameterValues returns one value, the base
offset added to all names in arrays presented
to glCallLists. (See glListBase.)
ParameterValues returns one value, the name
of the display list currently under construction.
If no display list is currently under
construction, 0 is returned. (See glNewList.)
ParameterValues returns one value, a
symbolic constant indicating the construction
mode of the display list currently being
constructed. (See glNewList.)
ParameterValues returns a single Boolean
value indicating whether fragment indexes are
merged into the frame buffer using a logical
operation. (See glLogicOp.)
ParameterValues returns one value, a
symbolic constant indicating the selected logic
operational mode. (See glLogicOp.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates colors. (See glMap1.)
Chapter 1. OpenGL Subroutines
145
GL_MAP1_GRID_DOMAIN
GL_MAP1_GRID_SEGMENTS
GL_MAP1_INDEX
GL_MAP1_NORMAL
GL_MAP1_TEXTURE_COORD_1
GL_MAP1_TEXTURE_COORD_2
GL_MAP1_TEXTURE_COORD_3
GL_MAP1_TEXTURE_COORD_4
GL_MAP1_VERTEX_3
GL_MAP1_VERTEX_4
GL_MAP2_COLOR_4
GL_MAP2_GRID_DOMAIN
GL_MAP2_GRID_SEGMENTS
GL_MAP2_INDEX
GL_MAP2_NORMAL
GL_MAP2_TEXTURE_COORD_1
GL_MAP2_TEXTURE_COORD_2
146
OpenGL 2.1 Reference Manual
ParameterValues returns two values: the
endpoints of the one-dimensional (1D) map’s
grid domain. (See glMapGrid.)
ParameterValues returns one value, the
number of partitions in the 1D map’s grid
domain. (See glMapGrid.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates color indices. (See glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates normals. (See glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates 1D texture coordinates. (See
glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates 2D texture coordinates. (See
glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates 3D texture coordinates. (See
glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates 4D texture coordinates. (See
glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates 3D vertex coordinates. (See
glMap1.)
ParameterValues returns a single Boolean
value indicating whether 1D evaluation
generates 4D vertex coordinates. (See
glMap1.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates colors. (See glMap2.)
ParameterValues returns four values: the
endpoints of the 2D map’s i and j grid
domains. (See glMapGrid.)
ParameterValues returns two values: the
number of partitions in the 2D map’s i and j
grid domains. (See glMapGrid.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates color indices. (See glMap2.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates normals. (See glMap2.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates 1D texture coordinates. (See
glMap2.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates 2D texture coordinates. (See
glMap2.)
GL_MAP2_TEXTURE_COORD_3
GL_MAP2_TEXTURE_COORD_4
GL_MAP2_VERTEX_3
GL_MAP2_VERTEX_4
GL_MAP_COLOR
GL_MAP_STENCIL
GL_MATRIX_MODE
GL_MAX_3D_TEXTURE_SIZE
GL_MAX_3D_TEXTURE_SIZE_EXT
GL_MAX_ATTRIB_STACK_DEPTH
GL_MAX_CLIENT_ATTRIB_STACK_DEPTH
GL_MAX_CLIP_PLANES
GL_MAX_ELEMENTS_INDICES
GL_MAX_ELEMENTS_VERTICES
GL_MAX_EVAL_ORDER
GL_MAX_LIGHTS
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates 3D texture coordinates. (See
glMap2.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates 4D texture coordinates. (See
glMap2.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates 3D vertex coordinates. (See
glMap2.)
ParameterValues returns a single Boolean
value indicating whether 2D evaluation
generates 4D vertex coordinates. (See
glMap2.)
ParameterValues returns a single Boolean
value indicating if colors and color indices are
to be replaced by table lookup during pixel
transfers. (See glPixelTransfer.)
ParameterValues returns a single Boolean
value indicating if stencil indices are to be
replaced by table lookup during pixel transfers.
(See glPixelTransfer.)
ParameterValues returns one value, a
symbolic constant indicating which matrix
stack is currently the target of all matrix
operations. (See glMatrixMode.)
ParameterValues returns one value, the
maximum width, height, or depth of any 3D
texture image (without borders). (See
glTexImage3DEXT.)
ParameterValues returns one value, a rough
estimate of the largest 3D texture that the GL
can handle. If the GL version is 1.2 or greater,
use GL_PROXY_TEXTURE_3D″ to determine
if a texture is too large. (See
glTexImage3DEXT.) Requires extension
EXT_texture3D.
ParameterValues returns one value, the
maximum supported depth of the attribute
stack. (See glPushAttrib.)
ParameterValues returns one value indicating
the maximum supported depth of the client
attribute stack. (See glPushClientAttrib.)
ParameterValues returns one value, the
maximum number of application-defined
clipping planes. (See glClipPlane.)
ParameterValues returns one value: the
maximum number of DrawRangeElements
vertices.
ParameterValues returns one value: the
maximum number of DrawRangeElements
vertices.
ParameterValues returns one value, the
maximum equation order supported by 1D and
2D evaluators. (See glMap1 and glMap2.)
ParameterValues returns one value, the
maximum number of lights. (See glLight.)
Chapter 1. OpenGL Subroutines
147
GL_MAX_LIST_NESTING
GL_MAX_MODELVIEW_STACK_DEPTH
GL_MAX_NAME_STACK_DEPTH
GL_MAX_PIXEL_MAP_TABLE
GL_MAX_PROJECTION_STACK_DEPTH
GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT
GL_MAX_TEXTURE_SIZE
GL_MAX_TEXTURE_STACK_DEPTH
GL_MAX_VIEWPORT_DIMS
GL_MAX_VISIBILITY_THRESHOLD_IBM
GL_MODELVIEW_MATRIX
GL_MODELVIEW_STACK_DEPTH
GL_NAME_STACK_DEPTH
GL_NORMAL_ARRAY
GL_NORMAL_ARRAY_COUNT_EXT
GL_NORMAL_ARRAY_EXT
148
OpenGL 2.1 Reference Manual
ParameterValues returns one value, the
maximum recursion depth allowed during
display list traversal. (See glCallList.)
ParameterValues returns one value, the
maximum supported depth of the modelview
matrix stack. (See glPushMatrix.)
ParameterValues returns one value, the
maximum supported depth of the selection
name stack. (See glPushName.)
ParameterValues returns one value, the
maximum supported size of a glPixelMap
lookup table. (See glPixelMap.)
ParameterValues returns one value, the
maximum supported depth of the projection
matrix stack. (See glPushMatrix.)
ParameterValues returns one value, the
maximum level of texture anisotropy supported
by this implementation. (See
glGetTexParameter.) Requires extension
EXT_texture_filter_anisotropic.
ParameterValues returns one value, the
maximum width or height of any texture image
(without borders). (See glTexImage1D and
glTexImage2D.)
ParameterValues returns one value, the
maximum supported depth of the texture
matrix stack. (See glPushMatrix.)
ParameterValues returns two values: the
maximum supported width and height of the
viewport. (See glViewport.)
ParameterValues returns one value: the
maximum permitted number of visible
fragments that will be discarded prior to
registering a visibility hit. (See
glVisibilityBufferIBM.) Requires extension
IBM_occlusion_cull.
ParameterValues returns 16 values: the
modelview matrix on the top of the modelview
matrix stack. (See glMatrixMode.)
ParameterValues returns one value, the
number of matrices on the modelview matrix
stack. (See glPushMatrix.)
ParameterValues returns one value, the
number of names on the selection name
stack. (See glPushMatrix.)
ParameterValues returns a single Boolean
value, indicating whether the normal array is
enabled. The initial value is GL_FALSE. (See
glNormalPointer.)
ParameterValues returns one value, the
number of normals in the normal array,
counting from the first, that are static. (See
glNormalPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns a single boolean
value, indicating whether the normal array is
enabled. (See glNormalPointerEXT.)
Requires extension EXT_vertex_array.
GL_NORMAL_ARRAY_LIST_STRIDE_IBM
GL_NORMAL_ARRAY_STRIDE
GL_NORMAL_ARRAY_STRIDE_EXT
GL_NORMAL_ARRAY_TYPE
GL_NORMAL_ARRAY_TYPE_EXT
GL_NORMALIZE
GL_OCCLUSION_TEST_HP
GL_OCCLUSION_TEST_RESULT_HP
GL_PACK_ALIGNMENT
GL_PACK_IMAGE_HEIGHT
GL_PACK_IMAGE_HEIGHT_EXT
GL_PACK_LSB_FIRST
GL_PACK_ROW_LENGTH
GL_PACK_SKIP_IMAGES
ParameterValues returns one value, the byte
stride between successive pointers to normal
lists. The initial value is 0. (See
glNormalPointerListIBM.) Requires extension
IBM_vertex_array_lists.
ParameterValues returns one value, the byte
offset between consecutive normals in the
normal array. The initial value is 0. (See
glNormalPointer.)
ParameterValues returns one value, the byte
offset between consecutive normals in the
normal array. (See glNormalPointerEXT.)
Requires extension EXT_vertex_array.
ParameterValues returns one value, the data
type of each coordinate in the normal array.
The initial value is GL_FLOAT. (See
glNormalPointer.)
ParameterValues returns one value, the data
type of each coordinate in the normal array.
(See glNormalPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns a single Boolean
value indicating whether normals are
automatically scaled to unit length after they
have been transformed to eye coordinates.
(See glNormal.)
ParameterValues returns a single Boolean
value indicating whether the occlusion test
HP_OCCLUSION_TEST is enabled. (See
glEnable.)
ParameterValues returns a single Boolean
value indicating whether the occlusion test
HP_OCCLUSION_TEST noted any fragments
successfully passing the depth test. (See
glEnable.)
ParameterValues returns one value, the byte
alignment used for writing pixel data to
memory. (See glPixelStore.)
ParameterValues returns one value, the
number of image rows used for writing 3D
pixel data to memory. (See glPixelStore.)
ParameterValues returns one value, the
number of image rows used for writing 3D
pixel data to memory. (See glPixelStore.)
Requires extension EXT_texture3D.
ParameterValues returns a single Boolean
value indicating whether single-bit pixels being
written to memory are written first to the least
significant bit of each unsigned byte. (See
glPixelStore.)
ParameterValues returns one value, the row
length used for writing pixel data to memory.
(See glPixelStore.)
ParameterValues returns one value, the
number of 2D images skipped before the first
pixel of a 3D image is written into memory.
(See glPixelStore.)
Chapter 1. OpenGL Subroutines
149
GL_PACK_SKIP_IMAGES_EXT
GL_PACK_SKIP_PIXELS
GL_PACK_SKIP_ROWS
GL_PACK_SWAP_BYTES
GL_PERSPECTIVE_CORRECTION_HINT
GL_PIXEL_MAP_A_TO_A_SIZE
GL_PIXEL_MAP_B_TO_B_SIZE
GL_PIXEL_MAP_G_TO_G_SIZE
GL_PIXEL_MAP_I_TO_A_SIZE
GL_PIXEL_MAP_I_TO_B_SIZE
GL_PIXEL_MAP_I_TO_G_SIZE
GL_PIXEL_MAP_I_TO_I_SIZE
GL_PIXEL_MAP_I_TO_R_SIZE
GL_PIXEL_MAP_R_TO_R_SIZE
GL_PIXEL_MAP_S_TO_S_SIZE
GL_POINT_SIZE
GL_POINT_SIZE_GRANULARITY
GL_POINT_SIZE_RANGE
150
OpenGL 2.1 Reference Manual
ParameterValues returns one value, the
number of 2D images skipped before the first
pixel of a 3D image is written into memory.
(See glPixelStore.) Requires extension
EXT_texture3D.
ParameterValues returns one value, the
number of pixel locations skipped before the
first pixel is written into memory. (See
glPixelStore.)
ParameterValues returns one value, the
number of rows of pixel locations skipped
before the first pixel is written into memory.
(See glPixelStore.)
ParameterValues returns a single Boolean
value indicating whether the bytes of 2-byte
and 4-byte pixel indices and components are
swapped before being written to memory. (See
glPixelStore.)
ParameterValues returns one value, a
symbolic constant indicating the mode of the
perspective correction hint. (See glHint.)
ParameterValues returns one value, the size
of the alpha-to-alpha pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the size
of the blue-to-blue pixel translation table. (See
glPixelMap.)
ParameterValues returns one value, the size
of the green-to-green pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the size
of the index-to-alpha pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the size
of the index-to-blue pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the size
of the index-to-green pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the size
of the index-to-index pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the size
of the index-to-red pixel translation table. (See
glPixelMap.)
ParameterValues returns one value, the size
of the red-to-red pixel translation table. (See
glPixelMap.)
ParameterValues returns one value, the size
of the stencil-to-stencil pixel translation table.
(See glPixelMap.)
ParameterValues returns one value, the point
size as specified by glPointSize.
ParameterValues returns one value, the size
difference between adjacent supported sizes
for antialiased points. (See glPointSize.)
ParameterValues returns two values: the
smallest and largest supported sizes for
antialiased points. (See glPointSize.)
GL_POINT_SMOOTH
GL_POINT_SMOOTH_HINT
GL_POLYGON_MODE
GL_POLYGON_OFFSET_BIAS_EXT
GL_POLYGON_OFFSET_EXT
GL_POLYGON_OFFSET_FACTOR
GL_POLYGON_OFFSET_FACTOR_EXT
GL_POLYGON_OFFSET_FILL
GL_POLYGON_OFFSET_LINE
GL_POLYGON_OFFSET_POINT
GL_POLYGON_OFFSET_UNITS
GL_POLYGON_SMOOTH
GL_POLYGON_SMOOTH_HINT
GL_POLYGON_STIPPLE
ParameterValues returns a single Boolean
value indicating whether antialiasing of points
is enabled. (See glPointSize.)
ParameterValues returns one value, a
symbolic constant indicating the mode of the
point antialiasing hint. (See glHint.)
ParameterValues returns two values: symbolic
constants indicating whether frontfacing and
backfacing polygons are rasterized as points,
lines, or filled polygons. (See
glPolygonMode.)
ParameterValues returns one value, the
constant which is added to the z value of each
fragment generated when a polygon is
rasterized. (See glPolygonOffsetEXT.)
Requires extension EXT_polygon_offset.
ParameterValues returns a single Boolean
value indicating whether polygon offest is
enabled. (See glPolygonOffsetEXT.)
Requires extension EXT_polygon_offset.
ParameterValues returns one value, the
scaling factor used to determine the variable
offset which is added to the depth value of
each fragment generated when a polygon is
rasterized. The initial value is 0.0. (See
glPolygonOffset.)
ParameterValues returns one value, the
scaling factor used to determine the variable
offset which is added to the z value of each
fragment generated when a polygon is
rasterized. (See glPolygonOffsetEXT.)
Requires extension EXT_polygon_offset.
ParameterValues returns a single Boolean
value indicating whether polygon offset is
enabled for polygons in fill mode. The initial
value is GL_FALSE. (See glPolygonOffset.)
ParameterValues returns a single Boolean
value indicating whether polygon offset is
enabled for polygons in line mode. The initial
value is GL_FALSE. (See glPolygonOffset.)
ParameterValues returns a single Boolean
value indicating whether polygon offset is
enabled for polygons in point mode. The initial
value is GL_FALSE. (See glPolygonOffset.)
ParameterValues returns one value, this value
is multiplied by an implementation-specific
value and then added to the z value of each
fragment generated when a polygon is
rasterized. The initial value is 0.0. (See
glPolygonOffset.)
ParameterValues returns a single Boolean
value indicating whether antialiasing of
polygons is enabled. (See glPolygonMode.)
ParameterValues returns one value, a
symbolic constant indicating the mode of the
polygon antialiasing hint. (See glHint.)
ParameterValues returns a single Boolean
value indicating whether stippling of polygons
is enabled. (See glPolygonStipple.)
Chapter 1. OpenGL Subroutines
151
GL_PROJECTION_MATRIX
GL_PROJECTION_STACK_DEPTH
GL_READ_BUFFER
GL_RED_BIAS
GL_RED_BITS
GL_RED_SCALE
GL_RENDER_MODE
GL_RGBA_MODE
GL_SCISSOR_BOX
GL_SCISSOR_TEST
GL_SHADE_MODEL
GL_SECONDARY_COLOR_ARRAY_SIZE_EXT
GL_SECONDARY_COLOR_ARRAY_STRIDE_EXT
GL_SECONDARY_COLOR_ARRAY_TYPE_EXT
GL_SMOOTH_LINE_WIDTH_GRANULARITY
GL_SMOOTH_LINE_WIDTH_RANGE
GL_SMOOTH_POINT_SIZE_GRANULARITY
152
OpenGL 2.1 Reference Manual
ParameterValues returns 16 values: the
projection matrix on the top of the projection
matrix stack. (See glMatrixMode.)
ParameterValues returns one value, the
number of matrices on the projection matrix
stack. (See glPushMatrix.)
ParameterValues returns one value, a
symbolic constant indicating which color buffer
is selected for reading. (See glReadPixels
and glAccum.)
ParameterValues returns one value, the red
bias factor used during pixel transfers.
ParameterValues returns one value, the
number of red bit planes in each color buffer.
ParameterValues returns one value, the red
scale factor used during pixel transfers. (See
glPixelTransfer.)
ParameterValues returns one value, a
symbolic constant indicating whether the GL is
in render, select, or feedback mode. (See
glRenderMode.)
ParameterValues returns a single Boolean
value indicating whether the GL is in RGBA
mode (True) or color index mode (False). (See
glColor.)
ParameterValues returns four values: the x
and y window coordinates of the scissor box,
followed by its width and height. (See
glScissor.)
ParameterValues returns a single Boolean
value indicating whether scissoring is enabled.
(See glScissor.)
ParameterValues returns one value, a
symbolic constant indicating whether the
shading mode is flat or smooth. (See
glShadeModel.)
ParameterValues returns one value, the
number of components in each entry of the
secondary color array, which will be either 3 or
4. (See glSecondaryColorPointerEXT.)
ParameterValues returns one value, the byte
offset between consecutive entries in the
secondary color array. (See
glSecondaryColorPointerEXT.)
ParameterValues returns one value, the data
type of each component in the secondary
color array. (See
glSecondaryColorPointerEXT.)
ParameterValues returns one value, the width
difference between adjacent supported widths
for antialiased lines. (See glLineWidth.)
ParameterValues returns two values: the
smallest and largest supported widths for
antialiased lines. (See glLineWidth.)
ParameterValues returns one value, the size
difference between adjacent supported sizes
for antialiased points. (See glPointSize.)
GL_SMOOTH_POINT_SIZE_RANGE
GL_STENCIL_BITS
GL_STENCIL_CLEAR_VALUE
GL_STENCIL_FAIL
GL_STENCIL_FUNC
GL_STENCIL_PASS_DEPTH_FAIL
GL_STENCIL_PASS_DEPTH_PASS
GL_STENCIL_REF
GL_STENCIL_TEST
GL_STENCIL_VALUE_MASK
GL_STENCIL_WRITEMASK
GL_STEREO
GL_SUBPIXEL_BITS
GL_TEXTURE_1D
GL_TEXTURE_2D
GL_TEXTURE_1D_BINDING
ParameterValues returns two values: the
smallest and largest supported sizes for
antialiased points. (See glPointSize.)
ParameterValues returns one value, the
number of bit planes in the stencil buffer.
ParameterValues returns one value, the index
to which the stencil bit planes are cleared.
(See glClearStencil.)
ParameterValues returns one value, a
symbolic constant indicating what action is
taken when the stencil test fails. (See
glStencilOp.)
ParameterValues returns one value, a
symbolic constant indicating what function is
used to compare the stencil reference value
with the stencil buffer value. (See
glStencilFunc.)
ParameterValues returns one value, a
symbolic constant indicating what action is
taken when the stencil test passes but the
depth test fails. (See glStencilOp.)
ParameterValues returns one value, a
symbolic constant indicating what action is
taken when the stencil test passes and the
depth test passes. (See glStencilOp.)
ParameterValues returns one value, the
reference value that is compared with the
contents of the stencil buffer. (See
glStencilFunc.)
ParameterValues returns a single Boolean
value indicating whether stencil testing of
fragments is enabled. (See glStencilFunc and
glStencilOp.)
ParameterValues returns one value, the mask
that is used to mask both the stencil reference
value and the stencil buffer value before they
are compared. (See glStencilFunc.)
ParameterValues returns one value, the mask
that controls writing of the stencil bit planes.
(See glStencilMask.)
ParameterValues returns a single Boolean
value indicating whether stereo buffers (left
and right) are supported.
ParameterValues returns one value, an
estimate of the number of bits of subpixel
resolution that are used to position rasterized
geometry in window coordinates.
ParameterValues returns a single Boolean
value indicating whether 1D texture mapping is
enabled. (See glTexImage1D.)
ParameterValues returns a single Boolean
value indicating whether 2D texture mapping is
enabled. (See glTexImage2D.)
ParameterValues returns a single value, the
name of the texture currently bound to the
target GL_TEXTURE_1D. The initial value is
0. (See glBindTexture.)
Chapter 1. OpenGL Subroutines
153
GL_TEXTURE_1D_BINDING_EXT
GL_TEXTURE_2D_BINDING
GL_TEXTURE_2D_BINDING_EXT
GL_TEXTURE_3D_BINDING_EXT
GL_TEXTURE_3D_EXT
GL_TEXTURE_COLOR_TABLE_EXT
GL_TEXTURE_COORD_ARRAY
GL_TEXTURE_COORD_ARRAY_COUNT_EXT
GL_TEXTURE_COORD_ARRAY_EXT
GL_TEXTURE_COORD_ARRAY_LIST_STRIDE_IBM
GL_TEXTURE_COORD_ARRAY_SIZE
GL_TEXTURE_COORD_ARRAY_SIZE_EXT
GL_TEXTURE_COORD_ARRAY_STRIDE
154
OpenGL 2.1 Reference Manual
ParameterValues returns a single value, the
name of the texture currently bound to the
target GL_TEXTURE_1D. (See
glBindTextureEXT.) Requires extension
EXT_texture_object.
ParameterValues returns a single value, the
name of the texture currently bound to the
target GL_TEXTURE_2D. The initial value is
0. (See glBindTexture.)
ParameterValues returns a single value, the
name of the texture currently bound to the
target GL_TEXTURE_2D. (See
glBindTextureEXT.) Requires extension
EXT_texture_object.
ParameterValues returns a single value, the
name of the texture currently bound to the
target GL_TEXTURE_3D_EXT. (See
glBindTexture.) Requires extension
EXT_texture_object.
ParameterValues returns a single Boolean
value indicating whether 3D texture mapping is
enabled. (See glTexImage3DEXT.) Requires
extension EXT_texture3D.
ParameterValues returns a single Boolean
value indicating whether the texture color table
is enabled. The initial value is GL_FALSE.
(See glColorTable.)
ParameterValues returns a single Boolean
value indicating whether the texture coordinate
array is enabled. The initial value is
GL_FALSE. (See glTexCoordPointer.)
ParameterValues returns one value, the
number of elements in the texture coordinate
array, counting from the first, that are static.
(See glTexCoordPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns a single boolean
value, indicating whether the texture
coordinate array is enabled. (See
glTexCoordPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns one value, the byte
stride between successive pointers to texture
coord lists. The initial value is 0. (See
glTexCoordPointerListIBM.) Requires
extension IBM_vertex_array_lists.
ParameterValues returns one value, the
number of coordinates per element in the
texture coordinate array. The initial value is 4.
(See glTexCoordPointer.)
ParameterValues returns one value, the
number of coordinates per element in the
texture coordinate array. (See
glTexCoordPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns one value, the byte
offset between consecutive elements in the
texture coordinate array. The initial value is 0.
(See glTexCoordPointer.)
GL_TEXTURE_COORD_ARRAY_STRIDE_EXT
GL_TEXTURE_COORD_ARRAY_TYPE
GL_TEXTURE_COORD_ARRAY_TYPE_EXT
GL_TEXTURE_ENV_COLOR
GL_TEXTURE_ENV_MODE
GL_TEXTURE_GEN_S
GL_TEXTURE_GEN_T
GL_TEXTURE_GEN_R
GL_TEXTURE_GEN_Q
GL_TEXTURE_MATRIX
GL_TEXTURE_STACK_DEPTH
GL_TRANSPOSE_COLOR_MATRIX_ARB
GL_TRANSPOSE_MODELVIEW_MATRIX_ARB
ParameterValues returns one value, the byte
offset between consecutive elements in the
texture coordinate array. (See
glTexCoordPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns one value, the data
type of the coordinates in the texture
coordinate array. The initial value is
GL_FLOAT. (See glTexCoordPointer.)
ParameterValues returns one value, the data
type of the coordinates in the texture
coordinate array. (See
glTexCoordPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns four values: the
RGBA values of the texture environment color.
Integer values, if requested, are linearly
mapped from the internal floating-point
representation such that 1.0 returns the most
positive representable integer value, and -1.0
returns the most negative representable
integer value. (See glTexEnv.)
ParameterValues returns one value, a
symbolic constant indicating what texture
environment function is currently selected.
(See glTexEnv.)
ParameterValues returns a single Boolean
value indicating whether automatic generation
of the S texture coordinate is enabled. (See
glTexGen.)
ParameterValues returns a single Boolean
value indicating whether automatic generation
of the T texture coordinate is enabled. (See
glTexGen.)
ParameterValues returns a single Boolean
value indicating whether automatic generation
of the R texture coordinate is enabled. (See
glTexGen.)
ParameterValues returns a single Boolean
value indicating whether automatic generation
of the Q texture coordinate is enabled. (See
glTexGen.)
ParameterValues returns 16 values: the
texture matrix on the top of the texture matrix
stack. (See glMatrixMode.)
ParameterValues returns one value, the
number of matrices on the texture matrix stack
. (See glPushMatrix.)
ParameterValues returns 16 values: the
transpose of the color matrix. (See
glLoadNamedMatrixIBM.) Requires extension
ARB_transpose_matrix.
ParameterValues returns 16 values: the
transpose of the modelview matrix on the top
of the modelview matrix stack. (See
glMatrixMode.) Requires extension
ARB_transpose_matrix.
Chapter 1. OpenGL Subroutines
155
GL_TRANSPOSE_PROJECTION_MATRIX_ARB
GL_TRANSPOSE_TEXTURE_MATRIX_ARB
GL_UNPACK_ALIGNMENT
GL_UNPACK_IMAGE_HEIGHT
GL_UNPACK_IMAGE_HEIGHT_EXT
GL_UNPACK_LSB_FIRST
GL_UNPACK_ROW_LENGTH
GL_UNPACK_SKIP_IMAGES
GL_UNPACK_SKIP_IMAGES_EXT
GL_UNPACK_SKIP_PIXELS
GL_UNPACK_SKIP_ROWS
GL_UNPACK_SWAP_BYTES
GL_UPDATE_CLIP_VOLUME_HINT
156
OpenGL 2.1 Reference Manual
ParameterValues returns 16 values: the
transpose of the projection matrix on the top of
the projection matrix stack. (See
glMatrixMode.) Requires extension
ARB_transpose_matrix.
ParameterValues returns 16 values: the
transpose of the texture matrix on the top of
the texture matrix stack. (See glMatrixMode.)
Requires extension ARB_transpose_matrix.
ParameterValues returns one value, the byte
alignment used for reading pixel data from
memory. (See glPixelStore.)
ParameterValues returns one value, the
number of image rows used for reading 3D
pixel data from memory. (See glPixelStore.)
ParameterValues returns one value, the
number of image rows used for reading 3D
pixel data from memory. (See glPixelStore.)
Requires extension EXT_texture3D.
ParameterValues returns a single Boolean
value indicating whether single-bit pixels being
read from memory are read first from the least
significant bit of each unsigned byte. (See
glPixelStore.)
ParameterValues returns one value, the row
length used for reading pixel data from
memory. (See glPixelStore.)
ParameterValues returns one value, the
number of 2D images skipped before the first
pixel of a 3D image is read from memory.
(See glPixelStore.)
ParameterValues returns one value, the
number of 2D images skipped before the first
pixel of a 3D image is read from memory.
(See glPixelStore.) Requires extension
EXT_texture3D.
ParameterValues returns one value, the
number of pixel locations skipped before the
first pixel is read from memory. (See
glPixelStore.)
ParameterValues returns one value, the
number of rows of pixel locations skipped
before the first pixel is read from memory.
(See glPixelStore.)
ParameterValues returns a single Boolean
value indicating whether the bytes of 2-byte
and 4-byte pixel indices and components are
swapped after being read from memory. (See
glPixelStore.)
ParameterValues returns a single Boolean
value indicating whether the automatic
updating of the Clip Volume Hint (through calls
to glClipBoundingBoxIBM,
glClipBoundingSphereIBM or
glClipBoundingVerticesIBM) is enabled.
(See glHint.) Requires extension
IBM_clip_check.
GL_VERTEX_ARRAY
GL_VERTEX_ARRAY_COUNT_EXT
GL_VERTEX_ARRAY_EXT
GL_VERTEX_ARRAY_LIST_STRIDE_IBM
GL_VERTEX_ARRAY_SIZE_EXT
GL_VERTEX_ARRAY_STRIDE
GL_VERTEX_ARRAY_STRIDE_EXT
GL_VERTEX_ARRAY_TYPE
GL_VERTEX_ARRAY_TYPE_EXT
GL_VIEWPORT
GL_VISIBILITY_BUFFER_SIZE_IBM
GL_VISIBILITY_THRESHOLD_IBM
GL_ZOOM_X
GL_ZOOM_Y
ParameterValues returns a single Boolean
value indicating whether the vertex array is
enabled. The initial value is GL_FALSE. (See
glVertexPointer.)
ParameterValues returns one value, the
number of vertices in the vertex array,
counting from the first, that are static. (See
glVertexPointerEXT.) Requires extension
EXT_vertex_array.
ParameterValues returns a single boolean
value, indicating whether the vertex array is
enabled. (See glVertexPointerEXT.)
ParameterValues returns one value, the byte
stride between successive pointers to vertex
lists. The initial value is 0. (See
glVertexPointerListIBM.) Requires extension
IBM_vertex_array_lists.
ParameterValues returns one value, the
number of coordinates per vertex in the vertex
array. (See glVertexPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns one value, the byte
offset between consecutive vertices in the
vertex array. The initial value is 0. (See
glVertexPointer.)
ParameterValues returns one value, the byte
offset between consecutive vertices in the
vertex array. (See glVertexPointerEXT.)
Requires extension EXT_vertex_array.
ParameterValues returns one value, the data
type of each coordinate in the vertex array.
The initial value is GL_FLOAT. (See
glVertexPointer.)
ParameterValues returns one value, the data
type of each coordinate in the vertex array.
(See glVertexPointerEXT.) Requires
extension EXT_vertex_array.
ParameterValues returns four values: the x
and y window coordinates of the viewport,
followed by its width and height. (See
glViewPort.)
ParameterValues returns one value: the
maximum number of values that can be stored
in the visibility array. (See
glVisibilityBufferIBM.) Requires extension
IBM_occlusion_cull.
ParameterValues returns one value: the
number of visible fragments that will be
discarded prior to registering a visibility hit.
(See glVisibilityThresholdIBM.) Requires
extension IBM_occlusion_cull.
ParameterValues returns one value, the x
pixel zoom factor. (See glPixelZoom.)
ParameterValues returns one value, the y
pixel zoom factor. (See glPixelZoom.)
Many of the Boolean parameters can also be queried more easily using glIsEnabled.
Chapter 1. OpenGL Subroutines
157
Parameters
ParameterName
ParameterValues
Specifies the parameter value to be returned. The symbolic constants listed in the
Description section are accepted.
Returns the value or values of the specified parameter.
Error Codes
GL_INVALID_ENUM
GL_INVALID_OPERATION
ParameterName is not an accepted value.
The glGet subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glGetClipPlane subroutine, glGetError subroutine, glGetLight subroutine, glGetMap subroutine,
glGetMaterial subroutine, glGetPixelMap subroutine, glGetPointerv subroutine, glGetPointervEXT
subroutine, glGetPolygonStipple subroutine, glGetString subroutine, glGetTexEnv subroutine,
glGetTexGen subroutine, glGetTexImage subroutine, glGetTexLevelParameter subroutine,
glGetTexParameter subroutine, glIsEnabled subroutine.
glGetClipPlane Subroutine
Purpose
Returns the coefficients of the clipping plane.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetClipPlane(GLenum Plane,
GLdouble * Equation)
Description
The glGetClipPlane subroutine returns in Equation the four coefficients of the plane equation for Plane.
Parameters
Plane
Equation
158
Specifies a clipping plane. The number of clipping planes depends on the implementation; however,
at least six clipping planes are supported. They are identified by symbolic names of the form
GL_CLIP_PLANEi where 0 < i < GL_MAX_CLIP_PLANES.
Returns four double-precision values that are the coefficients of the plane equation of Plane in eye
coordinates.
OpenGL 2.1 Reference Manual
Notes
It is always the case that GL_CLIP_PLANEi = GL_CLIP_PLANE0 + i.
If an error is generated, no change is made to the contents of Equation.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Plane is not an accepted value.
The glGetClipPlane subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glClipPlane subroutine.
glGetColorTable Subroutine
Purpose
Return a color lookup table to the user.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glGetColorTable(GLenum target,
GLenum format,
GLenum type,
const GLvoid *table)
void glGetColorTableSGI(GLenum target,
GLenum format,
GLenum type,
const GLvoid *table)
Description
glGetColorTable returns in table the contents of the color table specified by target. No pixel transfer
operations are performed, but pixel storage modes that are applicable to glReadPixels are performed.
Color components that are requested to be in the specified format, but which are not included in the
internal format of the color lookup table, are returned as zero. The assignments of the internal color
components to the components requested by format are:
Internal Component
red
green
blue
alpha
luminance
intensity
Resulting Component
red
green
blue
alpha
red
red
Chapter 1. OpenGL Subroutines
159
Parameters
target
format
Must be GL_TEXTURE_COLOR_TABLE_EXT.
is the format of the pixel data in table. The allowable
values are GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_LUMINANCE,
GL_LUMINANCE_ALPHA, GL_RGB, GL_BGR,
GL_RGBA, GL_BGRA, GL_422_EXT,
GL_422_REV_EXT, GL_422_AVERAGE_EXT, and
GL_422_REV_AVERAGE_EXT.
is the type of the pixel data in table. The allowable values
are GL_UNSIGNED_BYTE, GL_BYTE,
GL_UNSIGNED_SHORT, GL_SHORT,
GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and
GL_UNSIGNED_INT_2_10_10_10_REV.
is a pointer to a one-dimensional array of pixel data that
will be loaded with the contents of the color table.
type
table
Notes
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably.
GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
160
OpenGL 2.1 Reference Manual
is generated if target is not one of the allowable values.
is generated if format is not one of the allowable values.
is generated if type is not one of the allowable values.
is generated if type is one of
GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, or
GL_UNSIGNED_SHORT_5_6_5_REV, and format is not
GL_RGB.
is generated if type is one of
GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_SHORT_8_8_8_8,
GL_UNSIGNED_SHORT_8_8_8_8_REV,
GL_UNSIGNED_SHORT_10_10_10_2, or
GL_UNSIGNED_SHORT_2_10_10_10_REV, and format
is neigher GL_RGBA nor GL_BGRA.
GL_INVALID_OPERATION
is generated if glColorTable is executed between the
execution of glBegin and the corresponding execution of
glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glColorSubTable subroutine, the glColorTableParameter subroutine, the
glGetColorTableParameter subroutine.
glGetColorTableParameter Subroutine
Purpose
Returns attributes used when loading a color table.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glGetColorTableParameterfv(GLenum target,
GLenum pname,
const GLfloat *params)
void glGetColorTableParameteriv(GLenum target,
GLenum pname,
const GLint *params)
void glGetColorTableParameterfvSGI(GLenum target,
GLenum pname,
const GLfloat *params)
void glGetColorTableParameterivSGI(GLenum target,
GLenum pname,
const GLint *params)
Description
This subroutine returns parameters specific to color table target.
When pname is set to GL_COLOR_TABLE_SCALE or GL_COLOR_TABLE_BIAS,
glGetColorTableParameter returns the color table scale or bias parameters for the table specified by
target. For these queries, target must be set to GL_TEXTURE_COLOR_TABLE_EXT and params points
to an array of four elements, which receive the scale or bias factors for red, green, blue, and alpha, in that
order.
glGetColorTableParameter can also be used to retrieve the format and size parameters for a color table.
For thes queries, set target to any of the six targets listed above. The format and size parameters are set
by glColorTable.
The following table lists the format and size parameters that may be queried. For each symbolic constant
listed below for pname, params must point to an array of the given length, and will receive the values
indicated.
Chapter 1. OpenGL Subroutines
161
Parameter
N
Meaning
GL_COLOR_TABLE_FORMAT
GL_COLOR_TABLE_WIDTH
GL_COLOR_TABLE_RED_SIZE
GL_COLOR_TABLE_GREEN_SIZE
GL_COLOR_TABLE_BLUE_SIZE
GL_COLOR_TABLE_ALPHA_SIZE
GL_COLOR_TABLE_LUMINANCE_SIZE
GL_COLOR_TABLE_INTENSITY_SIZE
1
1
1
1
1
1
1
1
Internal format (e.g. GL_RGBA)
Number of elements in the table
Size of red component, in bits
Size of green component, in bits
Size of blue component, in bits
Size of alpha component, in bits
Size of luminance component, in bits
Size of intensity component, in bits
Parameters
target
is the target color table. Must be
GL_TEXTURE_COLOR_TABLE_EXT, or
GL_PROXY_TEXTURE_COLOR_TABLE_EXT.
is the symbolic name of a texture color lookup table
parameter. Must be one of GL_COLOR_TABLE_SCALE,
GL_COLOR_TABLE_BIAS,
GL_COLOR_TABLE_FORMAT,
GL_COLOR_TABLE_WIDTH,
GL_COLOR_TABLE_RED_SIZE,
GL_COLOR_TABLE_GREEN_SIZE,
GL_COLOR_TABLE_BLUE_SIZE,
GL_COLOR_TABLE_ALPHA_SIZE,
GL_COLOR_TABLE_LUMINANCE_SIZE, or
GL_COLOR_TABLE_INTENSITY_SIZE.
is a pointer to an array where the values of the
paramaters will be stored.
pname
params
Notes
GL_TEXTURE_COLOR_TABLE_SGI is an alias for GL_TEXTURE_COLOR_TABLE_EXT, and these
tokens may be used interchangeably. GL_PROXY_TEXTURE_COLOR_TABLE_SGI is an alias for
GL_PROXY_TEXTURE_COLOR_TABLE_EXT, and these tokens may be used interchangeably.
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_OPERATION
is generated if target is not one of the allowable values.
is generated if pname is not one of the allowable values.
is generated if glColorTableParameter is executed
between the execution of a glBegin and the
corresponding execution of glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glColorSubTable subroutine, the glColorTableParameter subroutine.
162
OpenGL 2.1 Reference Manual
glGetError Subroutine
Purpose
Returns error information.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLenum glGetError( void )
Description
The glGetError subroutine returns the value of the error flag. Each detectable error is assigned a numeric
code and symbolic name. When an error occurs, the error flag is set to the appropriate error code value.
No other errors are recorded until glGetError is called, the error code is returned, and the flag is reset to
GL_NO_ERROR. If a call to glGetError returns GL_NO_ERROR, there has been no detectable error
since the last call to glGetError, or since the GL was initialized.
To allow for distributed implementations, there may be several error flags. If any single error flag has
recorded an error, the value of that flag is returned, and that flag is reset to GL_NO_ERROR when
glGetError is called. If more than one flag has recorded an error, glGetError returns and clears an
arbitrary error flag value. Therefore, glGetError should always be called in a loop, until it returns
GL_NO_ERROR, if all error flags are to be reset.
Initially, all error flags are set to GL_NO_ERROR.
The currently defined errors are:
GL_NO_ERROR
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_OPERATION
GL_STACK_OVERFLOW
GL_STACK_UNDERFLOW
GL_OUT_OF_MEMORY
GL_TABLE_TOO_LARGE
No error has been recorded. The value of this symbolic constant is
guaranteed to be 0 (zero).
An unacceptable value is specified for an enumerated argument. The
offending command is ignored, having no side effect other than to set the
error flag.
A numeric argument is out of range. The offending command is ignored,
having no side effect other than to set the error flag.
The specified operation is not allowed in the current state. The offending
command is ignored, having no side effect other than to set the error flag.
This command would cause a stack overflow. The offending command is
ignored, having no side effect other than to set the error flag.
This command would cause a stack underflow. The offending command is
ignored, having no side effect other than to set the error flag.
There is not enough memory left to execute the command. The state of the
GL is undefined, except for the state of the error flags, after this error is
recorded.
The specified table is too large.
When an error flag is set, results of a GL operation are undefined only if GL_OUT_OF_MEMORY has
occurred. In all other cases, the command generating the error is ignored and has no effect on the GL
state or frame buffer contents.
Chapter 1. OpenGL Subroutines
163
Errors
GL_INVALID_OPERATION
The glGetError subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes fo OpenGL.
Related Information
The glBegin or glEnd subroutine.
glGetLight Subroutine
Purpose
Returns light source parameter values.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetLightfv(GLenum Light,
GLenum ParameterName,
GLfloat * ParameterValues)
void glGetLightiv(GLenum Light,
GLenum ParameterName,
GLint * ParameterValues)
Description
The glGetLight subroutine returns in ParameterValues the value or values of a light source parameter.
Light names the light and is a symbolic name of the form GL_LIGHTi for 0 < i < GL_MAX_LIGHTS, where
GL_MAX_LIGHTS is an implementation-dependent constant that is greater than or equal to 8.
ParameterName specifies one of 10 light source parameters, again by symbolic name.
The parameters are:
GL_AMBIENT
GL_DIFFUSE
164
OpenGL 2.1 Reference Manual
ParameterValues returns four integer or floating-point values
representing the ambient intensity of the light source. Integer values,
when requested, are linearly mapped from the internal floating-point
representation such that 1.0 maps to the most positive representable
integer value, and -1.0 maps to the most negative representable
integer value. If the internal value is outside the range [-1,1], the
corresponding integer return value is undefined.
ParameterValues returns four integer or floating-point values
representing the diffuse intensity of the light source. Integer values,
when requested, are linearly mapped from the internal floating-point
representation such that 1.0 maps to the most positive representable
integer value, and -1.0 maps to the most negative representable
integer value. If the internal value is outside the range [-1,1], the
corresponding integer return value is undefined.
GL_SPECULAR
GL_POSITION
GL_SPOT_DIRECTION
GL_SPOT_EXPONENT
GL_SPOT_CUTOFF
GL_CONSTANT_ATTENUATION
GL_LINEAR_ATTENUATION
GL_QUADRATIC_ATTENUATION
ParameterValues returns four integer or floating-point values
representing the specular intensity of the light source. Integer values,
when requested, are linearly mapped from the internal floating-point
representation such that 1.0 maps to the most positive representable
integer value, and -1.0 maps to the most negative representable
integer value. If the internal value is outside the range [-1,1], the
corresponding integer return value is undefined.
ParameterValues returns four integer or floating-point values
representing the position of the light source. Integer values, when
requested, are computed by rounding the internal floating-point values
to the nearest integer value. The returned values are those
maintained in eye coordinates. They will not be equal to the values
specified using glLight, unless the modelview matrix was identified at
the time glLight was called.
ParameterValues returns three integer or floating-point values
representing the direction of the light source. Integer values, when
requested, are computed by rounding the internal floating-point values
to the nearest integer value. The returned values are those
maintained in eye coordinates. They will not be equal to the values
specified using glLight, unless the modelview matrix was identity at
the time glLight was called. Although spot direction is normalized
before being used in the lighting equation, the returned values are the
transformed versions of the specified values prior to normalization.
ParameterValues returns a single integer or floating-point value
representing the spot exponent of the light. An integer value, when
requested, is computed by rounding the internal floating-point
representation to the nearest integer.
ParameterValues returns a single integer or floating-point value
representing the spot cutoff angle of the light. An integer value, when
requested, is computed by rounding the internal floating-point
representation to the nearest integer.
ParameterValues returns a single integer or floating-point value
representing the constant (not distance related) attenuation of the
light. An integer value, when requested, is computed by rounding the
internal floating point representation to the nearest integer.
ParameterValues returns a single integer or floating-point value
representing the linear attenuation of the light. An integer value, when
requested, is computed by rounding the internal floating-point
representation to the nearest integer.
ParameterValues returns a single integer or floating-point value
representing the quadratic attenuation of the light. An integer value,
when requested, is computed by rounding the internal floating-point
representation to the nearest integer.
Parameters
Light
ParameterName
ParameterValues
Specifies a light source. The number of possible lights depends on the implementation;
however, at least eight lights are supported. They are identified by symbolic names of
the form GL_LIGHTi where 0 < i < GL_MAX_LIGHTS.
Specifies a light source parameter for Light. Accepted symbolic names are
GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_POSITION,
GL_SPOT_DIRECTION, GL_SPOT_EXPONENT, GL_SPOT_CUTOFF,
GL_CONSTANT_ATTENUATION, GL_LINEAR_ATTENUATION, and
GL_QUADRATIC_ATTENUATION.
Returns the requested data.
Chapter 1. OpenGL Subroutines
165
Notes
It is always the case that GL_LIGHTi = GL_LIGHT0 + i.
If an error is generated, no change is made to the contents of ParameterValues.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either Light or ParameterName is not an accepted value.
The glGetLight subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glLight subroutine.
glGetMap Subroutine
Purpose
Returns evaluator parameters.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetMapdv(GLenum
GLenum Query,
GLdouble * v)
Target,
void glGetMapfv(GLenum
GLenum Query,
GLfloat * v)
Target,
void glGetMapiv(GLenum
GLenum Query,
GLint * v)
Target,
Description
The glMap1 and glMap2 subroutines define evaluators. The glGetMap subroutine returns evaluator
parameters. Target chooses a map, Query selects a specific parameter, and v points to storage where the
values are returned. (See the glMap1 and glMap2 subroutines for a description of the acceptable values
for the Target parameter.)
166
OpenGL 2.1 Reference Manual
Query can assume the following values:
GL_COEFF
GL_ORDER
GL_DOMAIN
v returns the control points for the evaluator function. One-dimensional (1D) evaluators return order
control points, and two-dimensional (2D) evaluators return uorder x vorder control points. Each
control point consists of 1, 2, 3, or 4 integer, single-precision floating-point, or double-precision
floating-point values, depending on the type of the evaluator. Two-dimensional control points are
returned in row major order, incrementing the uorder index quickly, and the vorder index after each
row. Integer values, when requested, are computed by rounding the internal floating-point values to
the nearest integer values.
v returns the order of the evaluator function. One-dimensional evaluators return a single value,
order. Two-dimensional evaluators return two values, uorder and vorder.
v returns the linear u and v mapping parameters. One-dimensional evaluators return two values, u1
and u2, as specified by glMap1. Two-dimensional evaluators return four values, u1, u2, v1, and v2,
as specified by glMap2. Integer values, when requested, are computed by rounding the internal
floating-point values to the nearest integer values.
Parameters
Target
Query
v
Specifies the symbolic name of a map. Accepted values are GL_MAP1_COLOR_4, GL_MAP1_INDEX,
GL_MAP1_NORMAL, GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2,
GL_MAP1_TEXTURE_COORD_3, GL_MAP1_TEXTURE_COORD_4, GL_MAP1_VERTEX_3,
GL_MAP1_VERTEX_4, GL_MAP2_COLOR_4, GL_MAP2_INDEX, GL_MAP2_NORMAL,
GL_MAP2_TEXTURE_COORD_1, GL_MAP2_TEXTURE_COORD_2,
GL_MAP2_TEXTURE_COORD_3, GL_MAP2_TEXTURE_COORD_4, GL_MAP2_VERTEX_3, and
GL_MAP2_VERTEX_4.
Specifies which parameter to return. Symbolic names GL_COEFF, GL_ORDER, and GL_DOMAIN are
accepted.
Returns the requested data.
Notes
If an error is generated, no change is made to the contents of v.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either Target or Query is not an accepted value.
The glGetMap subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEvalCoord subroutine, glMap1 subroutine, glMap2 subroutine.
glGetMaterial Subroutine
Purpose
Returns material parameters.
Chapter 1. OpenGL Subroutines
167
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetMaterialfv(GLenum Face,
GLenum ParameterName,
GLfloat * ParameterValues)
void glGetMaterialiv(GLenum Face,
GLenum ParameterName,
GLint * ParameterValues)
Description
The glGetMaterial subroutine returns in ParameterValues the value or values of parameter
ParameterName of material Face. Six parameters are defined:
GL_AMBIENT
GL_DIFFUSE
GL_SPECULAR
GL_EMISSION
GL_SHININESS
GL_COLOR_INDEXES
ParameterValues returns four integer or floating-point values representing the ambient
reflectance of the material. Integer values, when requested, are linearly mapped from
the internal floating-point representation such that 1.0 maps to the most positive
representable integer value, and -1.0 maps to the most negative representable
integer value. If the internal value is outside the range [-1,1], the corresponding
integer return value is undefined.
ParameterValues returns four integer or floating-point values representing the diffuse
reflectance of the material. Integer values, when requested, are linearly mapped from
the internal floating-point representation such that 1.0 maps to the most positive
representable integer value, and -1.0 maps to the most negative representable
integer value. If the internal value is outside the range [-1,1], the corresponding
integer return value is undefined.
ParameterValues returns four integer or floating-point values representing the
specular reflectance of the material. Integer values, when requested, are linearly
mapped from the internal floating-point representation such that 1.0 maps to the most
positive representable integer value, and -1.0 maps to the most negative
representable integer value. If the internal value is outside the range [-1,1], the
corresponding integer return value is undefined.
ParameterValues returns four integer or floating-point values representing the emitted
light intensity of the material. Integer values, when requested, are linearly mapped
from the internal floating-point representation such that 1.0 maps to the most positive
representable integer value, and -1.0 maps to the most negative representable
integer value. If the internal value is outside the range [-1,1], the corresponding
integer return value is undefined.
ParameterValues returns one integer or floating-point value representing the specular
exponent of the material. Integer values, when requested, are computed by rounding
the internal floating-point value to the nearest integer value.
ParameterValues returns three integer or floating-point values representing the
ambient, diffuse, and specular indices of the material. These indices are used only for
color index lighting. (The other parameters are all used only for red, green, blue, and
alpha lighting.) Integer values, when requested, are computed by rounding the
internal floating-point values to the nearest integer values.
Parameters
Face
ParameterName
168
Specifies which of the two materials is being queried. GL_FRONT or GL_BACK are
accepted, representing the front and back materials, respectively.
Specifies the material parameter to return. GL_AMBIENT, GL_DIFFUSE,
GL_SPECULAR, GL_EMISSION, GL_SHININESS, and GL_COLOR_INDEXES are
accepted.
OpenGL 2.1 Reference Manual
ParameterValues
Returns the requested data.
Notes
If an error is generated, no change is made to the contents of ParameterValues.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either Face or ParameterName is not an accepted value.
The glGetMaterial subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glMaterial subroutine.
glGetPixelMap Subroutine
Purpose
Returns the specified pixel map.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetPixelMapfv(GLenum
GLfloat *Values)
Map,
void glGetPixelMapuiv(GLenum
GLuint *Values)
Map,
void glGetPixelMapusv(GLenum
GLushort *Values)
Map,
Description
The glGetPixelMap subroutine returns in the Values parameter the contents of the pixel map specified by
the Map parameter. Pixel maps are used during the execution of glReadPixels, glDrawPixels,
glCopyPixels, glTexImage1D, and glTexImage2D to map color indices, stencil indices, color
components, and depth components to other values.
Unsigned integer values, if requested, are linearly mapped from the internal fixed- or floating-point
representation such that 1.0 maps to the largest representable integer value, and 0.0 maps to 0 (zero).
Returned unsigned integer values are undefined if the map value was not in the range [0,1].
To determine the required size of the Map parameter, call the glGet subroutine with the appropriate
symbolic constant.
Chapter 1. OpenGL Subroutines
169
Parameters
Map
Specifies the name of the pixel map to return. Accepted values are GL_PIXEL_MAP_I_TO_I,
GL_PIXEL_MAP_S_TO_S, GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G,
GL_PIXEL_MAP_I_TO_B, GL_PIXEL_MAP_I_TO_A, GL_PIXEL_MAP_R_TO_R,
GL_PIXEL_MAP_G_TO_G, GL_PIXEL_MAP_B_TO_B, and GL_PIXEL_MAP_A_TO_A.
Returns the pixel map contents.
Values
Notes
If an error is generated, no change is made to the contents of the Values parameter.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Map is not an accepted value.
The glGetPixelMap subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glGetPixelMap subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_PIXEL_MAP_I_TO_I_SIZE.
glGet with argument GL_PIXEL_MAP_S_TO_S_SIZE.
glGet with argument GL_PIXEL_MAP_I_TO_R_SIZE.
glGet with argument GL_PIXEL_MAP_I_TO_G_SIZE.
glGet with argument GL_PIXEL_MAP_I_TO_B_SIZE.
glGet with argument GL_PIXEL_MAP_I_TO_A_SIZE.
glGet with argument GL_PIXEL_MAP_R_TO_R_SIZE.
glGet with argument GL_PIXEL_MAP_G_TO_G_SIZE.
glGet with argument GL_PIXEL_MAP_B_TO_B_SIZE.
glGet with argument GL_PIXEL_MAP_A_TO_A_SIZE.
glGet with argument GL_MAX_PIXEL_MAP_TABLE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCopyPixels subroutine, glDrawPixels subroutine, glPixelMap
subroutine, glPixelTransfer subroutine, glReadPixels subroutine, glTexImage1D subroutine,
glTexImage2D subroutine.
170
OpenGL 2.1 Reference Manual
glGetPointerv Subroutine
Purpose
Returns the address of the specified pointer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetPointerv(GLenum
GLvoid* *params)
pname,
Description
The glGetPointerv subroutine returns pointer information. The pname parameter is a symbolic constant
indicating the pointer to be returned, and params is a pointer to a location in which to place the returned
data.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the various vertex arrays are used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
pname
Specifies the array or buffer pointer to be returned. The following symbolic constants are accepted:
v GL_COLOR_ARRAY_LIST_IBM
v GL_COLOR_ARRAY_POINTER
v GL_EDGE_FLAG_ARRAY_LIST_IBM
v GL_EDGE_FLAG_ARRAY_POINTER
v GL_FEEDBACK_BUFFER_POINTER
v GL_FOG_COORDINATE_ARRAY_LIST_IBM
v GL_FOG_COORDINATE_ARRAY_POINTER_EXT
v GL_INDEX_ARRAY_LIST_IBM
v GL_INDEX_ARRAY_POINTER
v GL_NORMAL_ARRAY_LIST_IBM
v GL_NORMAL_ARRAY_POINTER
v GL_SECONDARY_COLOR_ARRAY_LIST_IBM
v GL_SECONDARY_COLOR_ARRAY_POINTER
v GL_SELECTION_BUFFER_POINTER
v GL_TEXTURE_COORD_ARRAY_LIST_IBM
v GL_TEXTURE_COORD_ARRAY_POINTER
v GL_VERTEX_ARRAY_LIST_IBM
v GL_VERTEX_ARRAY_POINTER
params
v GL_VISIBILITY_BUFFER_POINTER_IBM
Returns the pointer value specified by pname.
Chapter 1. OpenGL Subroutines
171
Notes
The glGetPointerv subroutine is available only if the GL version is 1.1 or greater.
The ″*_ARRAY_LIST_IBM″ symbolic constants are only accepted if the IBM_vertex_array_list extension
is defined.
The *_ARRAY_LIST_IBM symbolic constants are only accepted if the IBM_vertex_array_list extension is
defined.
The ″GL_FOG_COORDINATE_*″ symbolic constants are only accepted if the EXT_fog_coord extension
is defined.
The ″GL_SECONDARY_COLOR_*″ symbolic constants are only accepted if the EXT_secondary_color
extension is defined.
The GL_VISIBILITY_BUFFER_POINTER_IBM symbolic constant is only accepted if the
IBM_occlusion_cull extension is supported.
The pointers are all client side state.
The initial value for each pointer is 0.
Error Codes
GL_INVALID_ENUM is generated if pname is not an accepted value.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glColorPointerListIBM subroutine,
glDrawArrays subroutine, glEdgeFlagPointer subroutine, glEdgeFlagPointerListIBM subroutine,
glFeedbackBuffer subroutine, glIndexPointer subroutine, glIndexPointerListIBM subroutine,
glNormalPointer subroutine, glNormalPointerListIBM subroutine, glSelectBuffer subroutine,
glTexCoordPointer subroutine, glTexCoordPointerListIBM subroutine, glVertexPointer subroutine,
glVertexPointerListIBM subroutine, glVisibilityBufferIBM subroutine.
glGetPointervEXT Subroutine
Purpose
Returns the address of a vertex data array.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetPointervEXT(GLenum
GLvoid **params)
pname,
Description
glGetPointervEXT returns array pointer information. pname is a symbolic constant indicating the array
pointer to be returned, and params is a pointer to a location in which to place the returned data.
172
OpenGL 2.1 Reference Manual
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the various vertex arrays are used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
pname
**params
Specifies the array pointer to be returned. Symbolic constants
GL_VERTEX_ARRAY_POINTER_EXT, GL_NORMAL_ARRAY_POINTER_EXT,
GL_COLOR_ARRAY_POINTER_EXT, GL_INDEX_ARRAY_POINTER_EXT,
GL_TEXTURE_COORD_ARRAY_POINTER_EXT, GL_EDGE_FLAG_ARRAY_POINTER_EXT, are
accepted.
returns the array pointer value specified by pname.
Notes
The array pointers are client side state.
glGetPointervEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Errors
GL_INVALID_ENUM is generated if pname is not an accepted value.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glDrawArraysEXT subroutine,
glEdgeFlagPointerEXT subroutine, glIndexPointerEXT subroutine, glNormalPointerEXT subroutine,
glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.
glGetPolygonStipple Subroutine
Purpose
Returns the polygon stipple pattern.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetPolygonStipple(GLubyte
*Mask)
Chapter 1. OpenGL Subroutines
173
Description
The glGetPolygonStipple subroutine returns to Mask a 32 x 32 polygon stipple pattern. The pattern is
packed into memory as if the following values were called:
v glReadPixels with both Height and Width equal to 32.
v Type is GL_BITMAP.
v Format is GL_COLOR_INDEX.
In addition, the pattern is packed into memory as if the stipple pattern was stored in an internal 32 x 32
color index buffer. Unlike glReadPixels, however, pixel transfer operations (shift, offset, pixel map) are not
applied to the returned stipple image.
Parameters
Mask
Returns the stipple pattern.
Notes
If an error is generated, no change is made to the contents of the Mask parameter.
Errors
GL_INVALID_OPERATION
The glGetPolygonStipple subroutine is called between a call to glBegin and
the corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glPixelStore subroutine, glPixelTransfer subroutine, glPolygonStipple
subroutine, glReadPixels subroutine.
glGetString Subroutine
Purpose
Returns a string describing the current GL connection.
Library
OpenGL C bindings library: libGL.a
C Syntax
const GLubyte * glGetString(GLenum
Parameter1)
Description
The glGetString subroutine returns a pointer to a static string describing some aspect of the current GL
connection. The Parameter1 parameter can be one of the following values:
174
OpenGL 2.1 Reference Manual
GL_VENDOR
GL_RENDERER
GL_VERSION
GL_EXTENSIONS
Returns the name of the company responsible for this GL implementation. This name does
not change from release to release.
Returns the name of the renderer. This name is typically specific to a particular
configuration of a hardware platform. It does not change from release to release.
Returns a version or release number.
Returns a space-separated list of supported extensions to GL.
Because GL does not include queries for the performance characteristics of an implementation, it is
expected that some applications will be written to recognize known platforms and will modify their GL
usage based on known performance characteristics of these platforms. Together, strings GL_VENDOR
and GL_RENDERER uniquely specify a platform, and do not change from release to release. These
strings should be used by such platform recognition algorithms.
The format and contents of the string that glGetString returns depend on the implementation, except that
extension names do not include space characters and are separated by space characters in the
GL_EXTENSIONS string, and all strings are null-terminated.
Parameters
Parameter1
Specifies a symbolic constant, one of GL_VENDOR, GL_RENDERER, GL_VERSION, or
GL_EXTENSIONS.
Notes
If an error is generated, glGetString returns 0 (zero).
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Parameter1 is not an accepted value.
The glGetString subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine.
glGetTexEnv Subroutine
Purpose
Returns texture environment parameters.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
175
C Syntax
void glGetTexEnvfv(GLenum Target,
GLenum ParameterName,
GLfloat *ParameterValues)
void glGetTexEnviv(GLenum Target,
GLenum ParameterName,
GLint *ParameterValues)
Description
The glGetTexEnv subroutine returns in the ParameterValues parameter selected values of a texture
environment that was specified with glTexEnv. The Target parameter specifies a texture environment.
Currently only the GL_TEXTURE_ENV texture environment is defined and supported.
ParameterName names a specific texture environment parameter. The parameters are:
GL_TEXTURE_ENV_MODE
GL_TEXTURE_ENV_COLOR
GL_COMBINE_RGB_EXT
GL_COMBINE_ALPHA_EXT
GL_SOURCE0_RGB_EXT
GL_SOURCE1_RGB_EXT
GL_SOURCE2_RGB_EXT
GL_SOURCE0_ALPHA_EXT
GL_SOURCE1_ALPHA_EXT
GL_SOURCE2_ALPHA_EXT
GL_OPERAND0_RGB_EXT
GL_OPERAND1_RGB_EXT
GL_OPERAND2_RGB_EXT
GL_OPERAND0_ALPHA_EXT
GL_OPERAND1_ALPHA_EXT
GL_OPERAND2_ALPHA_EXT
GL_RGB_SCALE_EXT
GL_ALPHA_SCALE
ParameterValues returns the single-valued texture environment mode, a
symbolic constant.
ParameterValues returns four integer or floating-point values that are the
texture environment color. Integer values, when requested, are linearly
mapped from the internal floating-point representation such that 1.0 maps to
the most positive representable integer, and -1.0 maps to the most negative
representable integer.
ParameterValues returns the currently defined function to be used when
blending texture RGB values in ″combine″ mode.
ParameterValues returns the currently defined function to be used when
blending texture Alpha values in ″combine″ mode.
ParameterValues returns the currently defined value used to determine the
source for RGB Operand 0.
ParameterValues returns the currently defined value used to determine the
source for RGB Operand 1.
ParameterValues returns the currently defined value used to determine the
source for RGB Operand 2.
ParameterValues returns the currently defined value used to determine the
source for Alpha Operand 0.
ParameterValues returns the currently defined value used to determine the
source for Alpha Operand 1.
ParameterValues returns the currently defined value used to determine the
source for Alpha Operand 2.
ParameterValues returns the currently defined RGB Operand 0.
ParameterValues returns the currently defined RGB Operand 1.
ParameterValues returns the currently defined RGB Operand 2.
ParameterValues returns the currently defined RGB Alpha 0.
ParameterValues returns the currently defined RGB Alpha 1.
ParameterValues returns the currently defined RGB Alpha 2.
ParameterValues returns the floating-point value which is used to do the
final scale on the RGB channels.
ParameterValues returns the floating-point number which is used to do the
final scale on the alpha channel.
Parameters
Target
176
Specifies a texture environment. Must be GL_TEXTURE_ENV.
OpenGL 2.1 Reference Manual
ParameterName
Specifies the symbolic name of a texture environment parameter. Accepted values are:
v GL_TEXTURE_ENV_MODE
v GL_TEXTURE_ENV_COLOR
v GL_COMBINE_RGB_EXT
v GL_COMBINE_ALPHA_EXT
v GL_SOURCE0_RGB_EXT
v GL_SOURCE1_RGB_EXT
v GL_SOURCE2_RGB_EXT
v GL_SOURCE0_ALPHA_EXT
v GL_SOURCE1_ALPHA_EXT
v GL_SOURCE2_ALPHA_EXT
v GL_OPERAND0_RGB_EXT
v GL_OPERAND1_RGB_EXT
v GL_OPERAND2_RGB_EXT
v GL_OPERAND0_ALPHA_EXT
v GL_OPERAND1_ALPHA_EXT
v GL_OPERAND2_ALPHA_EXT
v GL_RGB_SCALE_EXT
ParameterValues
v GL_ALPHA_SCALE
Returns the requested data.
Notes
If an error is generated, no change is made to the contents of ParameterValues.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either Target or ParameterName is not an accepted value.
The glGetTexEnv subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glTexEnv subroutine.
glGetTexGen Subroutine
Purpose
Returns texture coordinate generation parameters.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
177
C Syntax
void glGetTexGendv(GLenum Coordinate,
GLenum ParameterName,
GLdouble *ParameterValues)
void glGetTexGenfv(GLenum Coordinate,
GLenum ParameterName,
GLfloat *ParameterValues)
void glGetTexGeniv(GLenum Coordinate,
GLenum ParameterName,
GLint *ParameterValues)
Description
The glGetTexGen subroutine returns in ParameterValues selected parameters of a texture coordinate
generation function specified with glTexGen. Coordinate names one of the (s, t, r, q) texture coordinates,
using the symbolic constant GL_S, GL_T, GL_R, or GL_Q.
ParameterName specifies one of three symbolic names:
GL_TEXTURE_GEN_MODE
ParameterValues returns the single-valued texture generation function, a
symbolic constant.
ParameterValues returns the four plane equation coefficients that specify object
linear-coordinate generation. Integer values, when requested, are mapped
directly from the internal floating-point representation.
ParameterValues returns the four plane equation coefficients that specify eye
linear-coordinate generation. Integer values, when requested, are mapped
directly from the internal floating-point representation. The returned values are
those maintained in eye coordinates. They are not equal to the values specified
using glTexGen, unless the modelview matrix was identified at the time
glTexGen was called.
GL_OBJECT_PLANE
GL_EYE_PLANE
Parameters
Coordinate
ParameterName
ParameterValues
Specifies a texture coordinate. Must be GL_S, GL_T, GL_R, or GL_Q.
Specifies the symbolic name of the values to be returned. Must be either
GL_TEXTURE_GEN_MODE or the name of one of the texture generation plane
equations, either GL_OBJECT_PLANE or GL_EYE_PLANE.
Returns the requested data.
Notes
If an error is generated, no change is made to the contents of ParameterValues.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either Coordinate or ParameterName is not an accepted value.
The glGetTexGen subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
178
OpenGL 2.1 Reference Manual
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glTexGen subroutine.
glGetTexImage Subroutine
Purpose
Returns a texture image.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetTexImage(GLenum Target,
GLint Level,
GLenum Format,
GLenum Type,
GLvoid *Pixels)
Description
The glGetTexImage subroutine returns a texture image and places it in the Pixels parameter. Target
specifies whether the desired texture image is one specified by glTexImage1D (GL_TEXTURE_1D),
glTexImage2D (GL_TEXTURE_2D), glTexImage3D (GL_TEXTURE_3D), or by glTexImage3DEXT
(GL_TEXTURE_3D_EXT). Level specifies the level-of-detail number of the desired image. Format and
Type specify the format and type of the desired image array. (See the glTexImage1D and glDrawPixels
subroutines for a description of the acceptable values for the Format and Type parameters, respectively.)
Operation of glGetTexImage is best understood by considering the selected internal four-component
texture image to be a red, green, blue, alpha (RGBA) color buffer that is the size of the image. The
semantics of glGetTexImage are then identical to those of glReadPixels called with the same Format and
Type, with x and y set to 0 (zero), Width set to the width of the texture image (including the border if one
was specified), and Height set to 1 (one) for one-dimensional (1D) images, or to the height of the texture
image (including the border if one was specified) for two-dimensional (2D) images. Because the internal
texture image is an RGBA image, pixel formats GL_COLOR_INDEX, GL_STENCIL_INDEX, and
GL_DEPTH_COMPONENT are not accepted, and pixel type GL_BITMAP is not accepted.
If the selected texture image does not contain four components, the following mappings are applied:
v Single-component textures are treated as RGBA buffers with red set to the single-component value, and
green, blue, and alpha set to 0.
v Two-component textures are treated as RGBA buffers with red set to the value of component 0, alpha
set to the value of component 1, and green and blue set to 0.
v Three-component textures are treated as RGBA buffers with red set to component 0, green set to
component 1, blue set to component 2, and alpha set to 0.
To determine the required size of Pixels, use the glGetTexLevelParameter subroutine to ascertain the
dimensions of the internal texture image, then scale the required number of pixels by the storage required
for each pixel, based on Format and Type. Be sure to consider the pixel storage parameters, especially
GL_PACK_ALIGNMENT.
Notes
If an error is generated, no change is made to the contents of Pixels.
Chapter 1. OpenGL Subroutines
179
Format of GL_ABGR_EXT is part of the _extname (EXT_abgr) extension, not part of the core GL
command set.
Target of GL_TEXTURE_3D_EXT is part of the _extname (EXT_texture3D) extension, not part of the core
GL command set.
Parameters
Target
Specifies which texture is to be obtained. GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D,
and GL_TEXTURE_3D_EXT are accepted.
Specifies the level-of-detail number of the desired image. Level 0 is the base image level. Level n is the
nth mipmap reduction image.
Specifies a pixel format for the returned data. The supported formats are GL_RED, GL_GREEN,
GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_ABGR_EXT, GL_LUMINANCE, and
GL_LUMINANCE_ALPHA.
Specifies a pixel type for the returned data. The supported types are GL_UNSIGNED_BYTE, GL_BYTE,
GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, and GL_FLOAT.
Returns the texture image. Should be a pointer to an array of the type specified by the Type parameter.
Level
Format
Type
Pixels
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_OPERATION
Either Target, Format, or Type is not an accepted value.
Level is less than 0 or greater than log2max, where max is the returned value
of GL_MAX_TEXTURE_SIZE.
The glGetTexImage subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glGetTexImage subroutine are as follows. (See the glGet subroutine for more
information.)
glGetTexLevelParameter with argument GL_TEXTURE_WIDTH.
glGetTexLevelParameter with argument GL_TEXTURE_HEIGHT.
glGetTexLevelParameter with argument GL_TEXTURE_BORDER.
glGetTexLevelParameter with argument GL_TEXTURE_COMPONENTS.
glGet with arguments GL_PACK_ALIGNMENT and others.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glDrawPixels subroutine, glReadPixels subroutine, glTexImage1D
subroutine, glTexImage2D subroutine.
180
OpenGL 2.1 Reference Manual
glGetTexLevelParameter Subroutine
Purpose
Returns texture parameter values for a specific level of detail.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetTexLevelParameterfv(GLenum target,
GLint level,
GLenum pname,
GLfloat * params)
void glGetTexLevelParameteriv(GLenum target,
GLint level,
GLenum pname,
GLint *params)
Description
The glGetTexLevelParameter subroutine returns in params texture parameter values for a specific
level-of-detail value, specified as level. The target parameter defines the target texture, either
GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_3D_EXT,
GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_2D, GL_PROXY_TEXTURE_3D, or
GL_PROXY_TEXTURE_3D_EXT.
The GL_MAX_TEXTURE_SIZE parameter reports the largest square texture image which can be
accomodated with mipmaps and borders (but a long skinny texture, or a texture without mipmaps and
borders, may easily fit in texture memory). The proxy targets allow the user to more accurately query
whether the GL can accomodate a texture of a given configuration. If the texture cannot be accomodated,
the texture state variables (which may be queried with glGetTexLevelParameter) are set to 0. If the
texture can be accomodated the texture state values will be set as they would be set for a non-proxy
target.
The pname parameter specifies the texture parameter whose value or values will be returned.
The accepted parameter names are as follows:
GL_TEXTURE_ALPHA_SIZE
GL_TEXTURE_BLUE_SIZE
GL_TEXTURE_BORDER
GL_TEXTURE_DEPTH
The internal storage resolution of an individual alpha component.
The resolution chosen by the GL will be a close match for the
resolution requested by the user with the component argument of
glTexImage1D, glTexImage2D, or glTexImage3DEXT. The initial
value is 0.
The internal storage resolution of an individual blue component.
The resolution chosen by the GL will be a close match for the
resolution requested by the user with the component argument of
glTexImage1D, glTexImage2D, or glTexImage3DEXT. The initial
value is 0.
params returns a single value, the width in pixels of the border of
the texture image. The inital value is 0.
params returns a single value, the depth of the texture image.
This value includes the border of the texture image. The initial
value is 0.
Chapter 1. OpenGL Subroutines
181
GL_TEXTURE_DEPTH_EXT
GL_TEXTURE_GREEN_SIZE
GL_TEXTURE_HEIGHT
GL_TEXTURE_INTENSITY_SIZE
GL_TEXTURE_INTERNAL_FORMAT
GL_TEXTURE_LUMINANCE_SIZE
GL_TEXTURE_RED_SIZE
GL_TEXTURE_WIDTH
params returns a single value, the depth of the texture image.
This value includes the border of the texture image. The initial
value is 0.
The internal storage resolution of an individual green component.
The resolution chosen by the GL will be a close match for the
resolution requested by the user with the component argument of
glTexImage1D, glTexImage2D, or glTexImage3DEXT. The initial
value is 0.
params returns a single value, the height of the texture image.
This value includes the border of the texture image. The initial
value is 0.
The internal storage resolution of an individual component. The
resolution chosen by the GL will be a close match for the
resolution requested by the user with the component argument of
glTexImage1D or glTexImage2D. The initial value is 0.
params returns a single value, the requested internal format of the
texture image.
The internal storage resolution of an individual luminance
component. The resolution chosen by the GL will be a close
match for the resolution requested by the user with the
component argument of glTexImage1D, glTexImage2D, or
glTexImage3DEXT. The initial value is 0.
The internal storage resolution of an individual red component.
The resolution chosen by the GL will be a close match for the
resolution requested by the user with the component argument of
glTexImage1D, glTexImage2D, or glTexImage3DEXT. The initial
value is 0.
params returns a single value, the width of the texture image. This
value includes the border of the texture image. The initial value is
0.
Parameters
target
Specifies the symbolic name of the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D,
GL_TEXTURE_3D, GL_PROXY_TEXTURE_1D, or GL_PROXY_TEXTURE_2D,
GL_PROXY_TEXTURE_3D, GL_PROXY_TEXTURE_3D_EXT, GL_TEXTURE_3D_EXT.
Specifies the level-of-detail number of the desired image. Level 0 is the base image level. Level n is the
nth mipmap reduction image.
Specifies the symbolic name of a texture parameter. GL_TEXTURE_DEPTH,
GL_TEXTURE_DEPTH_EXT, GL_TEXTURE_WIDTH, GL_TEXTURE_HEIGHT,
GL_TEXTURE_INTERNAL_FORMAT, GL_TEXTURE_BORDER, GL_TEXTURE_RED_SIZE,
GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE,
GL_TEXTURE_LUMINANCE_SIZE, and GL_TEXTURE_INTENSITY_SIZE are accepted.
Returns the requested data.
level
pname
params
Notes
If an error is generated, no change is made to the contents of params.
The GL_TEXTURE_INTERNAL_FORMAT parameter is only available if the GL version is 1.1 or greater.
In version 1.0, use GL_TEXTURE_COMPONENTS instead.
Errors
GL_INVALID_ENUM is generated if target or pname is not an accepted value.
GL_INVALID_VALUE is generated if level is less than zero.
182
OpenGL 2.1 Reference Manual
GL_INVALID_VALUE may be generated if level is greater than log sub 2 max, where max is the returned
value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_OPERATION is generated if glGetTexLevelParameter is executed between the execution
of glBegin and the corresponding execution of glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glGetTexParameter subroutine, glTexImage1D subroutine, glTexImage2D subroutine,
glTexParameter subroutine.
glGetTexParameter Subroutine
Purpose
Returns texture parameter values.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glGetTexParameterfv(GLenum Target,
GLenum ParameterName,
GLfloat *ParameterValues)
void glGetTexParameteriv(GLenum Target,
GLenum ParameterName,
GLint *ParameterValues)
Description
The glGetTexParameter subroutine returns in ParameterValues the value or values of the texture
parameter specified as ParameterName. Target defines the target texture, either GL_TEXTURE_1D,
GL_TEXTURE_2D, GL_TEXTURE_3D, and GL_TEXTURE_3D_EXT (if the 3D texture extension is
supported). ParameterName accepts the same symbols as glTexParameter, with the same interpretations:
GL_TEXTURE_BASE_LEVEL
GL_TEXTURE_MAX_LEVEL
GL_TEXTURE_BORDER_COLOR
GL_TEXTURE_MAG_FILTER
GL_TEXTURE_MIN_FILTER
Specifies for the texture the base array level. Any non-negative integer
value is permissable. Supported in OpenGL 1.2 and later.
Specifies for the texture the maximum array level. Any non-negative
integer value is permissable. Supported in OpenGL 1.2 and later.
Returns four integer or floating-point numbers that comprise the red,
green, blue, alpha (RGBA) color of the texture border. Floating-point
values are returned in the range [0,1]. Integer values are returned as a
linear mapping of the internal floating-point representation such that 1.0
maps to the most positive representable integer and -1.0 maps to the
most negative representable integer.
Returns the single-valued texture magnification filter, a symbolic
constant.
Returns the single-valued texture minification filter, a symbolic constant.
Chapter 1. OpenGL Subroutines
183
GL_TEXTURE_MAX_LOD
Specifies for the texture the maximum level of detail of the image array.
Any floating-point value is permissable. Supported in OpenGL 1.2 and
later.
Specifies for the texture the minimum level of detail of the image array.
Any floating-point value is permissable. Supported in OpenGL 1.2 and
later.
GL_TEXTURE_MIN_LOD
GL_TEXTURE_PRIORITY (1.1 only)
GL_TEXTURE_PRIORITY_EXT
(EXT_texture_object)
GL_TEXTURE_RESIDENT (1.1 only)
GL_TEXTURE_RESIDENT_EXT
(EXT_texture_object)
GL_TEXTURE_WRAP_R
GL_TEXTURE_WRAP_R (3D Texture
Extension)
GL_TEXTURE_WRAP_S
GL_TEXTURE_WRAP_T
Returns the priority of the target texture (or the named texture bound to
it). The initial value is 1. See glPrioritizeTextures.
Returns the residence status of the target texture. If the value returned
in params is GL_TRUE, the texture is resident in texture memory. See
glAreTexturesResident.
Returns the single-valued wrapping function for texture coordinate r, a
symbolic constant.
Returns the single-valued wrapping function for texture coordinate r, a
symbolic constant.
Returns the single-valued wrapping function for texture coordinate s, a
symbolic constant.
Returns the single-valued wrapping function for texture coordinate t, a
symbolic constant.
Parameters
Target
ParameterName
ParameterValues
Specifies the symbolic name of the target texture. GL_TEXTURE_1D,
GL_TEXTURE_2D, GL_TEXTURE_3D, and GL_TEXTURE_3D_EXT (EXT_texture_3D)
are accepted.
Specifies the symbolic name of a texture parameter. GL_TEXTURE_BASE_LEVEL,
GL_TEXTURE_MAX_LEVEL, GL_TEXTURE_MAG_FILTER,
GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MAX_LOD, GL_TEXTURE_MIN_LOD,
GL_TEXTURE_PRIORITY, GL_TEXTURE_PRIORITY_EXT,
GL_TEXTURE_RESIDENT, GL_TEXTURE_RESIDENT_EXT,
GL_TEXTURE_WRAP_R, GL_TEXTURE_WRAP_R_EXT, GL_TEXTURE_WRAP_S,
GL_TEXTURE_WRAP_T, and GL_TEXTURE_BORDER_COLOR are accepted.
Returns the texture parameters.
Notes
If an error is generated, no change is made to the contents of ParameterValues.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Either Target or ParameterName is not an accepted value.
The glGetTexParameter subroutine is called between a call to glBegin and
the corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glTexParameter subroutine.
184
OpenGL 2.1 Reference Manual
glHint Subroutine
Purpose
Specifies implementation-specific hints.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glHint( GLenum
GLenum Mode)
Target,
Description
Certain aspects of GL behavior, when there is room for interpretation, can be controlled with hints. A hint is
specified with two arguments. Target is a symbolic constant indicating the behavior to be controlled, and
Mode is another symbolic constant indicating the desired behavior. Mode can be one of the following
three:
GL_FASTEST
GL_NICEST
GL_DONT_CARE
The most efficient option should be chosen.
The most correct or highest quality option should be chosen.
The client does not have a preference. This is the initial setting for all hints.
Though the implementation aspects that can be hinted are well-defined, the interpretation of the hints
depends on the implementation. The hint aspects that can be specified with Target, along with suggested
semantics, are:
GL_FOG_HINT
GL_LINE_SMOOTH_HINT
GL_PERSPECTIVE_CORRECTION_HINT
GL_POINT_SMOOTH_HINT
GL_POLYGON_SMOOTH_HINT
GL_SUBPIXEL_HINT_IBM
Indicates the accuracy of fog calculation. If per-pixel
fog calculation is not efficiently supported by the GL
implementation, hinting GL_DONT_CARE or
GL_FASTEST can result in per-vertex calculation of
fog effects.
Indicates the sampling quality of antialiased lines.
Hinting GL_NICEST can result in more pixel
fragments being generated during rasterization, if a
larger filter function is applied.
Indicates the quality of color and texture coordinate
interpolation. If perspective-corrected parameter
interpolation is not efficiently supported by the GL
implementation, hinting GL_DONT_CARE or
GL_FASTEST can result in simple linear interpolation
of colors and texture coordinates.
Indicates the sampling quality of antialiased points.
Hinting GL_NICEST can result in more pixel
fragments being generated during rasterization, if a
larger filter function is applied.
Indicates the sampling quality of antialiased polygons.
Hinting GL_NICEST can result in more pixel
fragments being generated during rasterization, if a
larger filter function is applied.
Indicates if primitives are rendered using subpixel
sampling techniques. Hinting GL_NICEST can result
in a greater accuracy of pixels turned on when a
primitive is rendered. GL_FASTEST and
GL_DONT_CARE may result in faster, non-subpixel
positioned, rendering of some primitives.
Chapter 1. OpenGL Subroutines
185
GL_CLIP_VOLUME_CLIPPING_HINT_EXT
GL_PIXEL_FILTER_HINT_IBM
Indicates whether clip volume clipping is desirable.
Hinting GL_NICEST can result in all clipping
calculations being performed, while GL_FASTEST can
suppress such clipping. GL_FASTEST should only be
used when the user is confident that no attempts to
render will occur outside the clip volume, for the
behavior of the GL library is undefined if any primitive
extends beyond the clip volume. If extension
IBM_clip_check is present and
GL_UPDATE_CLIP_VOLUME_HINT is enabled, this
hint can be automatically updated by calls to
glClipBoundingBoxIBM,
glClipBoundingVolumeIBM, or
glClipBoundingVerticesIBM. See these routines for
details. This hint is supported only if the
GL_EXT_clip_volume_hint extension is supported.
Indicates desired quality of pixel filtering when
rendering pixel images specified by glBitmap,
glCopyPixel, and glDrawPixel. Hinting GL_NICEST
should perform pixel filtering that provides the best
image quality, regardless of performance.
GL_FASTEST should perform pixel filtering that
provides the fastest possible pixel zoom regardless of
the image quality. GL_DONT_CARE should perform
point-sampled blits in accordance with the OpenGL
specification.
Parameters
Target
Specifies a symbolic constant indicating the behavior to be controlled. GL_FOG_HINT,
GL_LINE_SMOOTH_HINT, GL_PERSPECTIVE_CORRECTION_HINT, GL_POINT_SMOOTH_HINT,
GL_POLYGON_SMOOTH_HINT, GL_SUBPIXEL_HINT_IBM,
GL_CLIP_VOLUME_CLIPPING_HINT_EXT and GL_PIXEL_FILTER_HINT_IBM are accepted.
Specifies a symbolic constant indicating the desired behavior. GL_FASTEST, GL_NICEST, and
GL_DONT_CARE are accepted.
Mode
Notes
The interpretation of hints depends on the implementation. The glHint subroutine can be ignored.
GL_CLIP_VOLUME_CLIPPING_HINT_EXT is only valid if the GL_EXT_clip_volume_hint extension is
present.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_ENUM
Either Target or Mode is not an accepted value.
The glHint subroutine is called between a call to glBegin and the
corresponding call to glEnd.
The GL_PIXEL_FILTER_HINT_IBM parameter is used in an OpenGL
implementation that doesn’t support the GL_EXT_pixel_filter_hint extension.
Files
/usr/include/GL/gl.h
186
OpenGL 2.1 Reference Manual
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine.
glIndex Subroutine
Purpose
Sets the current color index.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glIndexd(GLdouble
Current)
void glIndexf(GLfloat Current)
void glIndexi(GLint Current)
void glIndexs(GLshort Current)
void glIndexdv(const GLdouble *Current)
void glIndexfv(const GLfloat *Current)
void glIndexiv(const GLint *Current)
void glIndexsv(const GLshort *Current)
void glIndexub(GLubyte Current)
void glIndexubv(const GLubyte *Current)
Description
The glIndex subroutine updates the current (single-valued) color index. It takes one argument, the new
value for the current color index.
The current index is stored as a floating-point value. Integer values are converted directly to floating-point
values, with no special mapping.
Index values outside the representable range of the color index buffer are not clamped. However, before
an index is dithered (if enabled) and written to the frame buffer, it is converted to fixed-point format. Any
bits in the integer portion of the resulting fixed-point value that do not correspond to bits in the frame buffer
are masked out.
Parameters
Current
In the case of glIndexd, glIndexf, glIndexi, glIndexs, and glIndexub this parameter specifies the new
value for the current color index.
In the case of glIndexdv, glIndexfv, glIndexiv, glIndexsv, and glIndexubv this parameter specifies a
pointer to a one-element array that contains the new value for the current color index.
Notes
The current index can be updated at any time. In particular, glIndex can be called between a call to
glBegin and the corresponding call to glEnd.
Chapter 1. OpenGL Subroutines
187
Associated Gets
Associated gets for the glIndex subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_INDEX.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin subroutine, glColor subroutine, glEnd subroutine, glIndexPointer subroutine,
glIndexPointerEXT subroutine.
glIndexMask Subroutine
Purpose
Controls the writing of individual bits in the color index buffers.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glIndexMask(GLuint
Mask)
Description
The glIndexMask subroutine controls the writing of individual bits in the color index buffers. The least
significant n bits of the Mask parameter, where n is the number of bits in a color index buffer, specify a
mask. Wherever a 1 (one) appears in the mask, the corresponding bit in the color index buffer (or buffers)
is made writable. Where a 0 (zero) appears, the bit is write-protected.
This mask is used only in color index mode, and it affects only the buffers currently selected for writing
(see glDrawBuffer). Initially, all bits are enabled for writing.
Parameters
Mask
Specifies a bit mask to enable and disable the writing of individual bits in the color index buffers. Initially, the
mask is all 1’s.
Errors
GL_INVALID_OPERATION
The glIndexMask subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glIndexMask subroutine are as follows. (See the glGet subroutine for more
information.)
188
OpenGL 2.1 Reference Manual
glGet with argument GL_INDEX_WRITEMASK.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColorMask subroutine, glDepthMask subroutine, glDrawBuffer
subroutine, glIndex subroutine, glStencilMask subroutine.
glIndexPointer Subroutine
Purpose
Defines an array of color indexes.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glIndexPointer( GLenum
GLsizei stride,
const GLvoid * pointer)
type,
Description
The glIndexPointer subroutine specifies the location and data format of an array of color indexes to use
when rendering. The type parameter specifies the data type of each color index and stride gives the byte
stride from one color index to the next allowing vertices and attributes to be packed into a single array or
stored in separate arrays. (Single array storage may be more efficient on some implementations; see
glInterleavedArrays.)
The parameters type, stride, and pointer are saved as client-side state.
The color index array is initially disabled. To enable and disable the array, call glEnableClientState and
glDisableClientState with the argument GL_INDEX_ARRAY. If enabled, the color index array is used
when glDrawArrays, glDrawElements or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Index array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
Specifies the data type of each color index in the array. Symbolic constants GL_UNSIGNED_BYTE,
GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Chapter 1. OpenGL Subroutines
189
stride
Specifies the byte offset between consecutive color indexes. If stride is zero (the initial value), the color
indexes are understood to be tightly packed in the array.
Specifies a pointer to the first index in the array. The initial value is 0 (NULL pointer).
pointer
Notes
The glIndexPointer subroutine is available only if the GL version is 1.1 or greater.
The color index array is initially disabled, and it won’t be accessed when glArrayElement,
glDrawElements or glDrawArrays is called.
Execution of glIndexPointer is not allowed between glBegin and the corresponding glEnd, but an error
may or may not be generated. If an error is not generated, the operation is undefined.
The glIndexPointer subroutine is typically implemented on the client side with no protocol.
Since the color index array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
The glIndexPointer subroutine is not included in display lists.
Errors
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride is negative.
Associated Gets
glIsEnabled with argument GL_INDEX_ARRAY
glGet with argument GL_INDEX_ARRAY_TYPE
glGet with argument GL_INDEX_ARRAY_STRIDE
glGetPointerv with argument GL_INDEX_ARRAY_POINTER
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine,
glIndexPointerListIBM subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glIndexPointerEXT Subroutine
Purpose
Defines an array of color indexes.
Library
OpenGL C bindings library: libGL.a
190
OpenGL 2.1 Reference Manual
C Syntax
void glIndexPointerEXT(GLenum
GLsizei stride,
GLsizei count,
const GLvoid *pointer)
type,
Description
The glIndexPointerEXT subroutine specifies the location and data format of an array of color indexes to
use when rendering. type specifies the data type of each color index and stride gives the byte stride from
one color index to the next allowing vertexes and attributes to be packed into a single array or stored in
separate arrays. (Single-array storage may be more efficient on some implementations.) count indicates
the number of array elements (counting from the first) that are static. Static elements may be modified by
the application, but once they are modified, the application must explicitly respecify the array before using
it for any rendering. When a color index array is specified, type, stride, count and pointer are saved as
client-side state, and static array elements may be cached by the implementation.
The color index array is enabled and disabled using glEnable and glDisable with the argument
GL_INDEX_ARRAY_EXT. If enabled, the color index array is used when glDrawArraysEXT or
glArrayElementEXT is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Index array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
count
pointer
Specifies the data type of each color index in the array. Symbolic constants GL_SHORT, GL_INT,
GL_FLOAT, or GL_DOUBLE_EXT, are accepted.
Specifies the byte offset between consecutive color indexes. If stride is zero the color indexes are
understood to be tightly packed in the array.
Specifies the number of indexes, counting from the first, that are static.
Specifies a pointer to the first index in the array.
Notes
Non-static array elements are not accessed until glArrayElementEXT or glDrawArraysEXT is executed.
By default the color index array is disabled and it won’t be accessed when glArrayElementEXT or
glDrawArraysEXT is called.
Although, it is not an error to call glIndexPointerEXT between the execution of glBegin and the
corresponding execution of glEnd, the results are undefined.
glIndexPointerEXT will typically be implemented on the client side with no protocol.
Since the color index array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib.
glIndexPointerEXT commands are not entered into display lists.
Chapter 1. OpenGL Subroutines
191
glIndexPointerEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Errors
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride or count is negative.
Associated Gets
glIsEnabled with argument GL_INDEX_ARRAY_EXT.
glGet with argument GL_INDEX_ARRAY_SIZE_EXT.
glGet with argument GL_INDEX_ARRAY_TYPE_EXT.
glGet with argument GL_INDEX_ARRAY_STRIDE_EXT.
glGet with argument GL_INDEX_ARRAY_COUNT_EXT.
glGetPointervEXT with argument GL_INDEX_ARRAY_POINTER_EXT.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glDrawArraysEXT subroutine,
glEdgeFlagPointerEXT subroutine, glGetPointervEXT subroutine, glNormalPointerEXT subroutine,
glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.
glIndexPointerListIBM Subroutine
Purpose
Defines a list of color index arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glIndexPointerListIBM( GLenum
GLint stride,
const GLvoid ** pointer,
GLint ptrstride)
type,
Description
The glIndexPointerListIBM subroutine specifies the location and data format of a list of arrays of color
indices to use when rendering. The type parameter specifies the data type of each color index. The stride
parameter gives the byte stride from one color index to the next allowing vertices and attributes to be
192
OpenGL 2.1 Reference Manual
packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on
some implementations; see glInterleavedArrays). The ptrstride parameter specifies the byte stride from
one pointer to the next in the pointer array.
When a color index array is specified, type, stride, pointer and ptrstride are saved as client side state.
A stride value of 0 does not specify a ″tightly packed″ array as it does in glIndexPointer. Instead, it
causes the first array element of each array to be used for each vertex. Also, a negative value can be
used for stride, which allows the user to move through each array in reverse order.
To enable and disable the color index arrays, call glEnableClientState and glDisableClientState with the
argument GL_INDEX_ARRAY. The color index array is initially disabled. When enabled, the color index
arrays are used when glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, glDrawArrays, glDrawElements or glArrayElement is called. The last
three calls in this list will only use the first array (the one pointed at by pointer[0]). See the descriptions of
these routines for more information on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Index array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
pointer
ptrstride
Specifies the data type of each color component in the array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Specifies the byte offset between consecutive color indices. The initial value is 0.
Specifies a list of color index arrays. The initial value is 0 (NULL pointer).
Specifies the byte stride between successive pointers in the pointer array. The initial value is 0.
Notes
The glIndexPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists extension is
supported.
Execution of glIndexPointerListIBM is not allowed between glBegin and the corresponding glEnd, but an
error may or may not be generated. If an error is not generated, the operation is undefined.
The glIndexPointerListIBM subroutine is typically implemented on the client side.
Since the color index array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glIndexPointerListIBM call is encountered while compiling a display list, the information it
contains does NOT contribute to the display list, but is used to update the immediate context instead.
The glIndexPointer call and the glIndexPointerListIBM call share the same state variables. A
glIndexPointer call will reset the color index list state to indicate that there is only one color index list, so
that any and all lists specified by a previous glIndexPointerListIBM call will be lost, not just the first list
that it specified.
Chapter 1. OpenGL Subroutines
193
Error Codes
GL_INVALID_ENUM is generated if type is not an accepted value.
Associated Gets
glIsEnabled with argument GL_INDEX_ARRAY.
glGetPointerv with argument GL_INDEX_ARRAY_LIST_IBM.
glGet with argument GL_INDEX_ARRAY_LIST_STRIDE_IBM.
glGet with argument GL_INDEX_ARRAY_STRIDE.
glGet with argument GL_INDEX_ARRAY_TYPE.
Related Information
The glArrayElement subroutine, glIndexPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine,
glIndexPointer subroutine, glInterleavedArrays subroutine, glMultiDrawArraysEXT subroutine,
glMultiDrawElementsEXT subroutine, glMultiModeDrawArraysIBM subroutine,
glMultiModeDrawElementsIBM subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glInitNames Subroutine
Purpose
Initializes the name stack.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glInitNames( void )
Description
The name stack is used during selection mode to allow sets of rendering commands to be uniquely
identified. It consists of an ordered set of unsigned integers. The glInitNames subroutine causes the name
stack to be initialized to its default empty state.
The name stack is always empty while the render mode is not GL_SELECT. Calls to the glInitNames
subroutine while the render mode is not GL_SELECT are ignored.
Errors
GL_INVALID_OPERATION
The glInitNames subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glInitNames subroutine are as follows. (See the glGet subroutine for more
information.)
194
OpenGL 2.1 Reference Manual
glGet with argument GL_NAME_STACK_DEPTH
glGet with argument GL_MAX_NAME_STACK_DEPTH.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glLoadName subroutine, glPushName subroutine, glRenderMode
subroutine, glSelectBuffer subroutine.
glInterleavedArrays Subroutine
Purpose
Simultaneously specifies and enables several interleaved arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glInterleavedArrays(GLenum
GLsizei stride,
const GLvoid *pointer)
format,
Description
The glInterleavedArrays subroutine lets you specify and enable individual color, normal, texture and
vertex arrays whose elements are part of a larger aggregate array element. For some implementations,
this is more efficient than specifying the arrays seperately.
If stride is zero then the aggregate element are stored consecutively, otherwise stride bytes occur between
aggregate array elements.
The format enumerant serves as a ’key’ describing the extraction of individual arrays from the aggregate
array. If format contains a T, then texture coordinates are extracted from the interleaved array. If C is
present, color values are extracted. If N is present, normal coordinates are extracted; Vertex coordinates
are always extracted.
The digits 2, 3, and 4 denote how many values are extracted. F indicates that values are extracted as
floating point values. Colors may also be extracted as 4 unsigned bytes if 4UB follows the C. If a color is
extracted as 4 unsigned bytes, the vertex array element which follows is located at the first possible
floating point aligned address.
Parameters
format
stride
Specifies the type of array to enable. Symbolic constants GL_V2F, GL_V3F, GL_C4UB_V2F,
GL_C4UB_V3F, GL_C3F_V3F, GL_N3F_V3F, GL_C4F_N3F_V3F, GL_T2F_V3F, GL_T4F_V4F,
GL_T2F_C4UB_V3F, GL_T2F_C3F_V3F, GL_T2F_N3F_V3F, GL_T2F_C4F_N3F_V3F, or
GL_T4F_C4F_N3F_V4F are accepted.
Specifies the offset in bytes between each aggregate array element.
Chapter 1. OpenGL Subroutines
195
Notes
The glInterleavedArrays subroutine is available only if the GL version is 1.1 or greater.
If glInterleavedArrays is called while compiling a display list, it is not compiled into the list, and it is
executed immediately.
Execution of glInterleavedArrays is not allowed between glBegin and the corresponding glEnd, but an
error may or may not be generated. If an error is not generated, the operation is undefined.
The glInterleavedArrays subroutine is typically implemented on the client side with no protocol.
Since the vertex array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
Errors
GL_INVALID_ENUM is generated if format is not an accepted value.
GL_INVALID_VALUE is generated if stride is negative.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointer subroutine, glEnableClientState subroutine, glGetPointerv subroutine,
glIndexPointer subroutine, glNormalPointer subroutine, PopClientAttrib subroutine, glPushClientAttrib
subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glIsEnabled Subroutine
Purpose
Tests whether a capability is enabled.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLboolean glIsEnabled (GLenum
Capability)
Description
The glIsEnabled subroutine returns GL_TRUE if the Capability parameter is an enabled capability and
returns GL_FALSE otherwise. The following capabilities are accepted for Capability:
GL_ALPHA_TEST
GL_AUTO_NORMAL
GL_BLEND
GL_CLIP_PLANEi
GL_COLOR_ARRAY
GL_COLOR_ARRAY_EXT
GL_COLOR_LOGIC_OP
GL_COLOR_MATERIAL
GL_COLOR_SUM_EXT
GL_CULL_FACE
GL_CULL_VERTEX_IBM
GL_DEPTH_TEST
196
OpenGL 2.1 Reference Manual
See
See
See
See
See
See
See
See
See
See
See
See
glAlphaFunc.
glEvalCoord.
glBlendFunc.
glClipPlane.
glColorPointer
glColorPointerEXT
glLogicOp.
glColorMaterial.
glSecondaryColorEXT.
glCullFace.
GL_CULL_VERTEX_IBM.
glDepthFunc and glDepthRange.
GL_DITHER
GL_EDGE_FLAG_ARRAY
GL_EDGE_FLAG_ARRAY_EXT
GL_FOG
GL_INDEX_ARRAY
GL_INDEX_ARRAY_EXT
GL_LIGHTi
GL_LIGHTING
GL_LINE_SMOOTH
GL_LINE_STIPPLE
GL_LOGIC_OP
GL_MAP1_COLOR_4
GL_MAP1_INDEX
GL_MAP1_NORMAL
GL_MAP1_TEXTURE_COORD_1
GL_MAP1_TEXTURE_COORD_2
GL_MAP1_TEXTURE_COORD_3
GL_MAP1_TEXTURE_COORD_4
GL_MAP1_VERTEX_3
GL_MAP1_VERTEX_4
GL_MAP2_COLOR_4
GL_MAP2_INDEX
GL_MAP2_NORMAL
GL_MAP2_TEXTURE_COORD_1
GL_MAP2_TEXTURE_COORD_2
GL_MAP2_TEXTURE_COORD_3
GL_MAP2_TEXTURE_COORD_4
GL_MAP2_VERTEX_3
GL_MAP2_VERTEX_4
GL_NORMAL_ARRAY
GL_NORMAL_ARRAY_EXT
GL_NORMALIZE
GL_OCCLUSION_CULLING_HP
GL_POINT_SMOOTH
GL_POLYGON_SMOOTH
GL_POLYGON_STIPPLE
GL_POLYGON_OFFSET_EXT
GL_POLYGON_OFFSET_FILL
GL_POLYGON_OFFSET_LINE
GL_POLYGON_OFFSET_POINT
GL_RESCALE_NORMAL_EXT
GL_SCISSOR_TEST
GL_STENCIL_TEST
GL_TEXTURE_1D
GL_TEXTURE_2D
GL_TEXTURE_3D_EXT
GL_TEXTURE_COLOR_TABLE_EXT
GL_TEXTURE_COORD_ARRAY
GL_VERTEX_ARRAY
GL_TEXTURE_COORD_ARRAY_EXT
GL_TEXTURE_GEN_Q
GL_TEXTURE_GEN_R
GL_TEXTURE_GEN_S
GL_TEXTURE_GEN_T
GL_UPDATE_CLIP_VOLUME_HINT
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
See
glEnable.
glEdgeFlagPointer.
glEdgeFlagPointerEXT
glFog.
glIndexPointer.
glIndexPointerEXT
glLightModel and glLight.
glMaterial, glLightModel, and glLight.
glLineWidth.
glLineStipple.
glLogicOp.
glMap1.
glMap1.
glMap1.
glMap1.
glMap1.
glMap1.
glMap1.
glMap1.
glMap1.
glMap2.
glMap2.
glMap2.
glMap2.
glMap2.
glMap2.
glMap2.
glMap2.
glMap2.
glNormalPointer.
glNormalPointerEXT
glNormal.
glEnable.
glPointSize.
glPolygonMode.
glPolygonStipple.
glPolygonOffsetEXT
glPolygonOffset.
glPolygonOffset.
glPolygonOffset.
glEnable.
glScissor.
glStencilFunc and glStencilOp.
glTexImage1D.
glTexImage2D.
glTexImage3DEXT
glColorTable.
glTexCoordPointer.
glVertexPointer.
glTexCoordPointerEXT
glTexGen.
glTexGen.
glTexGen.
glTexGen.
glHint.
Chapter 1. OpenGL Subroutines
197
GL_VERTEX_ARRAY_EXT
See glVertexPointerEXT.
Parameters
Capability
Specifies a symbolic constant indicating a GL capability.
Notes
If an error is generated, glIsEnabled returns 0 (zero).
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Capability is not an accepted value.
The glIsEnabled subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable subroutine.
glIsList Subroutine
Purpose
Tests for display list existence.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLboolean glIsList(GLuint
List)
Description
The glIsList subroutine returns GL_TRUE if the List parameter is the name of a display list and returns
GL_FALSE otherwise.
Parameters
List
Specifies a potential display-list name.
Errors
GL_INVALID_OPERATION
198
OpenGL 2.1 Reference Manual
The glIsList subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallList subroutine, glCallLists subroutine, glDeleteLists subroutine,
glGenLists subroutine, glNewList subroutine.
glIsTexture Subroutine
Purpose
Determines if a name corresponds to a texture.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLboolean glIsTexture(GLuint
texture)
Description
The glIsTexture subroutine returns GL_TRUE if texture is currently the name of a texture. If texture is
zero, or is a non-zero value that is not currently the name of a texture, or if an error occurs, glIsTexture
returns GL_FALSE.
The glIsTexture subroutine is not included in display lists.
Parameters
texture
Specifies a value which may be the name of a texture.
Notes
The glIsTexture subroutine is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_OPERATION is generated if glIsTexture is executed between the execution of glBegin and
the corresponding execution of glEnd.
Related Information
The glBindTexture subroutine, glDeleteTextures subroutine, glGenTextures subroutine, glGet
subroutine, glGetTexParameter subroutine, glTexImage1D subroutine, glTexImage2D subroutine,
glTexParameter subroutine.
glIsTextureEXT Subroutine
Purpose
Determines if a name corresponds to a texture.
Chapter 1. OpenGL Subroutines
199
Library
OpenGL C bindings library: libGL.a
C Syntax
GLboolean glIsTextureEXT( GLuint texture )
Description
glIsTextureEXT returns GL_TRUE if texture is currently the name of a texture. If texture is zero, or is a
non-zero value that is not currently the name of a texture, or if an error occurs, glIsTextureEXT returns
GL_FALSE.
glIsTextureEXT is not included in display lists.
Parameters
texture
A value which might be the name of a texture.
Notes
glIsTextureEXT is part of the EXT_texture_object extension, not part of the core GL command set. If
GL_EXT_texture_object is included in the string returned by glGetString, when called with argument
GL_EXTENSIONS, extension EXT_texture_object is supported by the connection.
Errors
GL_INVALID_OPERATION is generated if glIsTextureEXT is executed between the execution of glBegin
and the corresponding execution of glEnd.
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBindTextureEXT subroutine, glDeleteTexturesEXT subroutine, glGenTexturesEXT subroutine,
glGet subroutine, glGetTexParameter subroutine, glTexImage1D subroutine, glTexImage2D subroutine,
glTexParameter subroutine.
glLight Subroutine
Purpose
Sets light source parameters.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLightf(GLenum Light,
GLenum ParameterName,
GLfloat Parameter)
200
OpenGL 2.1 Reference Manual
void glLighti(GLenum Light,
GLenum ParameterName,
GLint Parameter)
void glLightfv(GLenum Light,
GLenum ParameterName,
const GLfloat * ParameterValues)
void glLightiv(GLenum Light,
GLenum ParameterName,
const GLint * ParameterValues)
Description
The glLight subroutine sets the values of individual light source parameters. Light names the light and is a
symbolic name of the form GL_LIGHTi, where 0 is less than or equal to i which is less than
GL_MAX_LIGHTS. ParameterName specifies one of 10 light source parameters, again by symbolic name.
ParameterValues is either a single value or a pointer to an array that contains the new values.
Lighting calculation is enabled and disabled using glEnable and glDisable with argument GL_LIGHTING.
When lighting is enabled, light sources that are enabled contribute to the lighting calculation. Light source i
is enabled and disabled using glEnable and glDisable with argument GL_LIGHTi.
The 10 light parameters are as follows:
GL_AMBIENT
GL_DIFFUSE
GL_SPECULAR
ParameterValues contains four integer or floating-point values that
specify the ambient red, green, blue, alpha (RGBA) intensity of the
light. Integer values are mapped linearly such that the most positive
representable value maps to 1.0, and the most negative representable
value maps to -1.0. Floating-point values are mapped directly. Neither
integer nor floating-point values are clamped. The default ambient
light intensity is (0.0, 0.0, 0.0, 1.0).
ParameterValues contains four integer or floating-point values that
specify the diffuse RGBA intensity of the light. Integer values are
mapped linearly such that the most positive representable value maps
to 1.0, and the most negative representable value maps to -1.0.
Floating-point values are mapped directly. Neither integer nor
floating-point values are clamped. The default diffuse intensity is (0.0,
0.0, 0.0, 1.0) for all lights other than light zero. The default diffuse
intensity of light zero is (1.0, 1.0, 1.0, 1.0).
ParameterValues contains four integer or floating-point values that
specify the specular RGBA intensity of the light. Integer values are
mapped linearly such that the most positive representable value maps
to 1.0, and the most negative representable value maps to -1.0.
Floating-point values are mapped directly. Neither integer nor
floating-point values are clamped. The default specular intensity is
(0.0, 0.0, 0.0, 1.0) for all lights other than light zero. The default
specular intensity of light zero is (1.0, 1.0, 1.0, 1.0).
Chapter 1. OpenGL Subroutines
201
GL_POSITION
GL_SPOT_DIRECTION
GL_SPOT_EXPONENT
GL_SPOT_CUTOFF
GL_CONSTANT_ATTENUATION,
GL_LINEAR_ATTENUATION, or
GL_QUADRATIC_ATTENUATION
202
OpenGL 2.1 Reference Manual
ParameterValues contains four integer or floating-point values that
specify the position of the light in homogeneous object coordinates.
Both integer and floating-point values are mapped directly. Neither
integer nor floating-point values are clamped.
The position is transformed by the modelview matrix when glLight is
called (just as if it were a point), and it is stored in eye coordinates. If
the w component of the position is 0.0, the light is treated as a
directional source. Diffuse and specular lighting calculations consider
the light’s direction, but not its actual position, and attenuation is
disabled. Otherwise, diffuse and specular lighting calculations are
based on the actual location of the light in eye coordinates, and
attenuation is enabled. The default position is (0,0,1,0); thus, the
default light source is directional, as well as parallel to and in the
direction of the -z axis.
ParameterValues contains three integer or floating-point values that
specify the direction of the light in homogeneous object coordinates.
Both integer and floating-point values are mapped directly. Neither
integer nor floating-point values are clamped.
The spot direction is transformed by the inverse of the modelview
matrix when glLight is called (just as if it were a normal), and it is
stored in eye coordinates. It is significant only when
GL_SPOT_CUTOFF is not 180, which it is by default. The default
direction is (0,0,-1).
ParameterValues is a single integer or floating-point value that
specifies the intensity distribution of the light. Integer and
floating-point values are mapped directly. Only values in the range
[0,128] are accepted.
Effective light intensity is attenuated by the cosine of the angle
between the direction of the light and the direction from the light to
the vertex being lighted, raised to the power of the spot exponent.
Thus, higher spot exponents result in a more focused light source,
regardless of the spot cutoff angle. (See the GL_SPOT_CUTOFF
description.) The default spot exponent is 0, resulting in uniform light
distribution.
ParameterValues is a single integer or floating-point value that
specifies the maximum spread angle of a light source. Integer and
floating-point values are mapped directly. Only values in the range
[0,90] and the special value 180 are accepted. If the angle between
the direction of the light and the direction from the light to the vertex
being lighted is greater than the spot cutoff angle, the light is
completely masked. Otherwise, its intensity is controlled by the spot
exponent and the attenuation factors. The default spot cutoff is 180,
resulting in uniform light distribution.
ParameterValues is a single integer or floating-point value that
specifies one of the three light attenuation factors. Integer and
floating-point values are mapped directly. Only nonnegative values are
accepted. If the light is positional, rather than directional, its intensity
is attenuated by the reciprocal of the sum of the constant factor, the
linear factor times the distance between the light and the vertex being
lighted, and the quadratic factor times the square of the same
distance. The default attenuation factors are (1,0,0), resulting in no
attenuation.
Parameters
Light
ParameterName
Parameter
ParameterValues
Specifies a light. The number of lights depends on the implementation, but at least
eight lights are supported. They are identified by symbolic names of the form
GL_LIGHTi where 0 is less than or equal to i which is less than GL_MAX_LIGHTS.
For glLightf, glLighti, and glLightv, this parameter specifies a single-valued light
source parameter for Light. GL_SPOT_EXPONENT, GL_SPOT_CUTOFF,
GL_CONSTANT_ATTENUATION, GL_LINEAR_ATTENUATION, and
GL_QUADRATIC_ATTENUATION are accepted.
For glLightfv and glLightiv, this parameter specifies a light source parameter for Light.
GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_POSITION,
GL_SPOT_DIRECTION, GL_SPOT_EXPONENT, GL_SPOT_CUTOFF,
GL_CONSTANT_ATTENUATION, GL_LINEAR_ATTENUATION, and
GL_QUADRATIC_ATTENUATION are accepted.
Specifies the value to which the parameter ParameterName of light source Light is set.
Specifies a pointer to the value or values to which the parameter ParameterName of
light source Light is set. This parameter is used only with glLightfv and glLightiv.
Notes
It is always the case that GL_LIGHTi = GL_LIGHT0 + i.
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_OPERATION
Either Light or ParameterName is not an accepted value.
A spot exponent value is specified outside the range [0,128], or spot cutoff is
specified outside the range [0,90] (except for the special value 180), or a
negative attenuation factor is specified.
The glLight subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLight subroutine are as follows. (See the glGet subroutine for more information.)
glGetLight
glIsEnabled with argument GL_LIGHTING.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColorMaterial subroutine, glEnable or glDisable subroutine,
glLightModel subroutine, glMaterial subroutine.
glLightModel Subroutine
Purpose
Sets the lighting model parameters.
Chapter 1. OpenGL Subroutines
203
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLightModelf(GLenum ParameterName,
GLfloat Parameter)
void glLightModeli(GLenum ParameterName,
GLint Parameter)
void glLightModelfv(GLenum ParameterName,
const GLfloat * ParameterValues)
void glLightModeliv(GLenum ParameterName,
const GLint * ParameterValues)
Description
The glLightModel subroutine sets the lighting model parameters. ParameterName names a parameter
and ParameterValues gives the new value. There are three lighting model parameters:
GL_LIGHT_MODEL_COLOR_CONTROL
GL_LIGHT_MODEL_AMBIENT
GL_LIGHT_MODEL_LOCAL_VIEWER
GL_LIGHT_MODEL_TWO_SIDE
204
OpenGL 2.1 Reference Manual
Lighting produces two colors at the vertex: a primary color
and a secondary color. The values of the two colors depend
on the light model color control. ParameterValues can be
GL_SINGLE_COLOR or GL_SPECULAR_COLOR.
GL_SINGLE_COLOR is the default value. Depending upon
the ParameterValues, the lighting equations compute the two
colors differently. All computations are carried out in eye
coordinates
ParameterValues contains four integer or floating-point values
that specify the ambient red, green, blue, alpha (RGBA)
intensity of the entire scene. Integer values are mapped
linearly such that the most positive representable value maps
to 1.0, and the most negative representable value maps to
-1.0. Floating-point values are mapped directly. Neither integer
nor floating-point values are clamped. The default ambient
scene intensity is (0.2, 0.2, 0.2, 1.0).
ParameterValues is a single integer or floating-point value that
specifies how specular reflection angles are computed. If
ParameterValues is 0 (or 0.0), specular reflections are
computed from the origin of the eye coordinate system.
Otherwise, reflection angles take the view direction to be
parallel to and in the direction of the -z axis, regardless of the
location of the vertex in eye coordinates. The default is False.
ParameterValues is a single integer or floating-point value that
specifies whether one-sided or two-sided lighting calculations
are done for polygons. It has no effect on the lighting
calculations for points, lines, or bitmaps. If ParameterValues is
0 (or 0.0), one-sided lighting is specified, and only the front
material parameters are used in the lighting equation.
Otherwise, two-sided lighting is specified. In this case, vertices
of backfacing polygons are lighted using the back material
parameters, and have their normals reversed before the
lighting equation is evaluated. Vertices of frontfacing polygons
are always lighted using the front material parameters, with no
change to their normals. The default is False.
In RGBA mode, the lighted color of a vertex is the sum of the material emission intensity, the product of
the material ambient reflectance and the lighting model full-scene ambient intensity, and the contribution of
each enabled light source. Each light source contributes the sum of three terms: ambient, diffuse, and
specular.
v The ambient light source contribution is the product of the material ambient reflectance and the light’s
ambient intensity.
v The diffuse light source contribution is the product of the material diffuse reflectance, the light’s diffuse
intensity, and the dot product of the vertex’s normal with the normalized vector from the vertex to the
light source.
v The specular light source contribution is the product of the material specular reflectance, the light’s
specular intensity, and the dot product of the normalized vertex-to-eye and vertex-to-light vectors, raised
to the power of the shininess of the material.
All three light source contributions are attenuated equally based on the distance from the vertex to the light
source and on light source direction, spread exponent, and spread cutoff angle. All dot products are
replaced with 0 (zero) if they are a negative value.
The alpha component of the resulting lighted color is set to the alpha value of the material diffuse
reflectance.
In color index mode, the value of the lighted index of a vertex ranges from the ambient to the specular
values passed to glMaterial using GL_COLOR_INDEXES. The extent to which the resulting index is
above ambient is determined by diffuse and specular coefficients, computed with a weighting of the lights’
colors (.30, .59, .11); the shininess of the material; and the same reflection and attenuation equations as in
the RGBA case.
Parameters
ParameterName
Parameter
ParameterValues
For glLightModelf and glLightModeli, this parameter specifies a single-valued lighting
model parameter. GL_LIGHT_MODEL_COLOR_CONTROL,
GL_LIGHT_MODEL_LOCAL_VIEWER, and GL_LIGHT_MODEL_TWO_SIDE are
accepted.
For glLightModelfv and glLightModeliv, this parameter specifies a lighting model
parameter. GL_LIGHT_MODEL_AMBIENT, GL_LIGHT_MODEL_COLOR_CONTROL,
GL_LIGHT_MODEL_LOCAL_VIEWER, and GL_LIGHT_MODEL_TWO_SIDE are
accepted.
Specifies the value to which ParameterName is set. This parameter applies only to
GL_LIGHT_MODEL_COLOR_CONTROL, glLightModelf, and glLightModeli.
Specifies a pointer to the value or values to which ParameterName is set. This
parameter applies only to glLightModelfv and glLightModeliv.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
ParameterName is not an accepted value.
The glLightModel subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLightModel subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_LIGHT_MODEL_AMBIENT.
Chapter 1. OpenGL Subroutines
205
glGet with argument GL_LIGHT_MODEL_LOCAL_VIEWER.
glGet with argument GL_LIGHT_MODEL_TWO_SIDE.
glIsEnabled with argument GL_LIGHTING.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable or glDisable subroutine, glLight subroutine, glMaterial
subroutine.
glLineStipple Subroutine
Purpose
Specifies the line stipple pattern.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLineStipple(GLint
GLushort Pattern)
Factor,
Description
Line stippling masks out certain fragments produced by rasterization; those fragments are not drawn. The
masking is achieved by using three parameters: the 16-bit line stipple pattern (the Pattern parameter), the
repeat count (the Factor parameter), and an integer stipple counter s.
Counter s is reset to 0 (zero) whenever the glBegin subroutine is called, and before each line segment of
a glBegin(GL_LINES)glEnd sequence is generated. It is incremented after each fragment of a unit width
aliased line segment is generated, or after each of the i fragments of an i width line segment are
generated. The i fragments associated with count s are masked out if
Pattern bit floor (s/Factor) mod 16
is 0, otherwise these fragments are sent to the frame buffer. Bit 0 of the Pattern parameter is the least
significant bit.
Antialiased lines are treated as a sequence of 1 times width rectangles for purposes of stippling.
Rectangle s is rasterized or not rasterized, based on the fragment rule described for aliased lines, counting
rectangles rather than groups of fragments.
Line stippling is enabled or disabled using the glEnable and glDisable subroutines with the
GL_LINE_STIPPLE argument. When enabled, the line stipple pattern is applied as described in the
preceding section. When disabled, it is as if the pattern were all 1s. Initially, line stippling is disabled.
206
OpenGL 2.1 Reference Manual
Parameters
Factor
Pattern
Specifies a multiplier for each bit in the line stipple pattern. If Factor is 3, for example, each bit in the
pattern is used three times before the next bit in the pattern is used. Factor is clamped to the range [1,
255] and defaults to 1.
Specifies a 16-bit integer whose bit pattern determines which fragments of a line is drawn when the
line is rasterized. Bit 0 is used first, and the default pattern is all 1s.
Errors
GL_INVALID_OPERATION
The glLineStipple subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLineStipple subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_LINE_STIPPLE_PATTERN
glGet with argument GL_LINE_STIPPLE_REPEAT
glIsEnabled with argument GL_LINE_STIPPLE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin subroutine, glEnable or Disable subroutine, glLineWidth subroutine, glPolygonStipple
subroutine.
glLineWidth Subroutine
Purpose
Specifies the width of rasterized lines.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLineWidth(GLfloat
Width)
Description
The glLineWidth subroutine specifies the rasterized width of both aliased and antialiased lines. Using a
line width other than 1.0 has different effects, depending on whether line antialiasing is enabled. Line
antialiasing is controlled by calling the glEnable and glDisable subroutines with the GL_LINE_SMOOTH
argument.
Chapter 1. OpenGL Subroutines
207
If line antialiasing is disabled, the actual width is determined by rounding the supplied width to the nearest
integer. (If the rounding results in the value 0 (zero), it is as if the line width were 1 (one).) If | DELTAx |
> | DELTAy |, i pixels are filled in each column that is rasterized, where i is the rounded value of Width.
Otherwise, i pixels are filled in each row that is rasterized.
If antialiasing is enabled, line rasterization produces a fragment for each pixel square that intersects the
region lying within the rectangle. The fragment has a width equal to the current line width, a length equal
to the actual length of the line, and is centered on the mathematical line segment. The coverage value for
each fragment is the window coordinate area of the intersection of the rectangular region with the
corresponding pixel square. This value is saved and used in the final rasterization step.
Not all widths can be supported when line antialiasing is enabled. If an unsupported width is requested,
the nearest supported width is used. Only width 1.0 is guaranteed to be supported; others depend on the
implementation. The range of supported widths and the size difference between supported widths within
the range can be queried by calling the glGet subroutine with the GL_LINE_WIDTH_RANGE and
GL_LINE_WIDTH_GRANULARITY arguments.
Parameters
Width
Specifies the width of rasterized lines. The default is 1.0.
Notes
The line width specified by glLineWidth is always returned when GL_LINE_WIDTH is queried. Clamping
and rounding for aliased and antialiased lines have no effect on the specified value.
Non-antialiased line width may be clamped to an implementation-dependent maximum. Although this
maximum cannot be queried, it must be no less than the maximum value for antialiased lines, rounded to
the nearest integer value.
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
Width is less than or equal to 0.
The glLineWidth subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLineWidth subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_LINE_WIDTH
glGet with argument GL_LINE_WIDTH_RANGE
glGet with argument GL_LINE_WIDTH_GRANULARITY
glIsEnabled with argument GL_LINE_SMOOTH.
Files
/usr/include/GL/gl.h
208
OpenGL 2.1 Reference Manual
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable or Disable subroutine.
glListBase Subroutine
Purpose
Sets the display-list base for the glCallLists subroutine.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glListBase(GLuint
Base)
Description
The glCallLists subroutine specifies an array of offsets. Display-list names are generated by adding the
Base parameter to each offset. Names that reference valid display lists are executed; the others are
ignored.
Parameters
Base
Specifies an integer offset that is added to glCallLists offsets to generate display-list names. Initial value is 0
(zero).
Errors
GL_INVALID_OPERATION
The glListBase subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glListBase subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_LIST_BASE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallLists subroutine.
glLoadIdentity Subroutine
Purpose
Replaces the current matrix with the identity matrix.
Chapter 1. OpenGL Subroutines
209
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLoadIdentity( void )
Description
The glLoadIdentity subroutine replaces the current matrix with the identity matrix. It is semantically
equivalent to calling the glLoadMatrix subroutine with the following identity matrix:
Figure 6. Identity Matrix. This diagram shows a matrix enclosed in brackets. The matrix consists of four lines
containing four characters each. The first line contains the following (from left to right): one, zero, zero, zero. The
second line contains the following (from left to right): zero, one, zero, zero. The third line contains the following (from
left to right): zero, zero, one, zero. The fourth line contains the following (from left to right): zero, zero, zero, one.
Calling glLoadIdentity is in some cases more efficient.
Errors
GL_INVALID_OPERATION
The glLoadIdentity subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLoadIdentity subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glLoadMatrix subroutine, glMatrixMode subroutine, glMultMatrix
subroutine, glPushMatrix subroutine.
210
OpenGL 2.1 Reference Manual
glLoadMatrix Subroutine
Purpose
Replaces the current matrix with an arbitrary matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLoadMatrixd(const GLdouble
void glLoadMatrixf(const GLfloat
*Matrix)
*Matrix)
Description
The glLoadMatrix subroutine replaces the current matrix with the one specified in the Matrix parameter.
The current matrix is the projection matrix, model view matrix, or texture matrix, determined by the current
matrix mode. (See the glMatrixMode subroutine for information on specifiying the current matrix.) The
Matrix parameter points to a 4 x 4 matrix of single- or double-precision floating-point values stored in
column-major order. That is, the matrix is stored as the following:
a0
a4
a8
a12
a1
a5
a9
a13
a2
a6
a10 a14
a3
a7
a11 a15
Figure 7. Stored Matrix. This diagram shows a matrix enclosed in brackets. The matrix consists of four lines containing
four characters each. The first line contains the following (from left to right): a subscript zero, a subscript four, a
subscript eight, a subscript twelve. The second line contains the following (from left to right): a subscript one, a
subscript five, a subscript nine, a subscript thirteen. The third line contains the following (from left to right): a subscript
two, a subscript six, a subscript ten, a subscript fourteen. The fourth line contains the following (from left to right): a
subscript three, a subscript seven, a subscript eleven, a subscript fifteen.
Parameters
Matrix
Specifies a pointer to 4 x 4 matrix stored in column-major order as 16 consecutive values.
Errors
GL_INVALID_OPERATION
The glLoadMatrix subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLoadMatrix subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
Chapter 1. OpenGL Subroutines
211
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glLoadIdentity subroutine, glMatrixMode subroutine, glMultMatrix
subroutine, glPushMatrix subroutine, glLoadTransposeMatrixARB subroutine.
glLoadName Subroutine
Purpose
Loads a name onto the name stack.
Library
OpenGL C bindings library: libGL.a
C Syntax
void LoadName(GLuint
Name)
Description
The name stack is used during selection mode to allow sets of rendering commands to be uniquely
identified. It consists of an ordered set of unsigned integers. The glLoadName subroutine causes the
Name parameter to replace the value on the top of the name stack, which is initially empty.
The name stack is always empty while the render mode is not GL_SELECT. Calls to glLoadName while
the render mode is not GL_SELECT are ignored.
Parameters
Name
Specifies a name that replaces the top value on the name stack.
Errors
GL_INVALID_OPERATION
GL_INVALID_OPERATION
The glLoadName subroutine is called while the name stack is empty.
The glLoadName subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLoadName subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_NAME_STACK_DEPTH.
glGet with argument GL_MAX_NAME_STACK_DEPTH.
212
OpenGL 2.1 Reference Manual
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glInitNames subroutine, glPushName subroutine, glRenderMode
subroutine, glSelectBuffer subroutine.
glLoadNamedMatrixIBM Subroutine
Purpose
Loads a pre-defined matrix into the top of the named matrix stack.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glLoadNamedMatrixIBM(GLenum
GLenum
matrix,
name)
Description
Using this subroutine, a predefined matrix can be loaded into any matrix stack, regardless of the current
matrix mode in use.
glLoadNamedMaxtrixIBM(matrix, GL_IDENTITY_MATRIX_IBM) is functionally equivalent to:
PushAttrib(GL_TRANSFORM_BIT);
MatrixMode(matrix);
LoadIdentity();
PopAttrib();
This subroutine does NOT change the current matrix mode.
Parameters
matrix
name
specifies which of the matrices to load. Acceptable values
are GL_COLOR, GL_TEXTURE, GL_MODELVIEW, and
GL_PROJECTION.
specifies the named matrix to load. Acceptable values and
their corresponding matrices are:
GL_IDENTITY_MATRIX_IBM 1.0 0.0 0.0 0.0
0.0 1.0 0.0 0.0
0.0 0.0 1.0 0.0
0.0 0.0 0.0 1.0
GL_YCRCB_TO_RGB_MATRIX_IBM 1.164 0.000 1.596 -0.874
1.164 -0.392 -0.813 0.532
1.164 2.017 0.000 1.000
0.000 0.000 0.000 1.000
GL_RGB_TO_YCRCB_MATRIX_IBM 0.257 0.504 0.098 0.063
-0.148 -0.291 0.439 0.502
0.439 -0.368 -0.071 0.502
0.000 0.000 0.000 1.000
Note that the second and third parameters above are only
valid if the GL_IBM_YCbCr extension is present.
Chapter 1. OpenGL Subroutines
213
Notes
This subroutine is only available if the GL_IBM_load_matrix extension is present.
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
is generated if matrix is not one of the acceptable values.
is generated if name is not one of the acceptable values.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
glLoadTransposeMatrixARB Subroutine
Purpose
Loads a matrix in row-major order, rather than column-major order.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glLoadTransposeMatrixfARB(const GLfloat *Matrix)
void glLoadTransposeMatrixdARB(const GLdouble *Matrix)
Description
The glLoadTransposeMatrixARB subroutine replaces the current matrix with the one specified in the
Matrix parameter. The current matrix is the projection matrix, model view matrix, or texture matrix,
determined by the current matrix mode. (See the glMatrixMode subroutine for information on specifiying
the current matrix.) The Matrix parameter points to a 4 x 4 matrix of single- or double-precision
floating-point values stored in row-major order. That is, the matrix is stored as the following:
/
|
|
\
a0
a4
a8
a12
a1
a5
a9
a13
a2
a6
a10
a14
a3
a7
a11
a15
\
|
|
/
Parameters
Matrix
is an array of 16 values, specified in row-major order.
Error Codes
GL_INVALID_OPERATION
214
OpenGL 2.1 Reference Manual
is generated if glLoadTransposeMatrixARB is executed
between the execution of glBegin and the corresponding
execution of glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glLoadMatrix subroutine, the glMatrixMode subroutine.
glLockArraysEXT Subroutine
Purpose
Locks the currently enabled vertex arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glLockArraysEXT (int
sizei count)
first,
Description
The currently enabled vertex arrays can be locked with the subroutine glLockArraysEXT. When the
vertex arrays are locked, the GL can compile the array data or the transformed results of array data
associated with the currently enabled vertex arrays. The vertex arrays are unlocked by the
glUnlockArraysEXT subroutine.
Between glLockArraysEXT and glUnlockArraysEXT the application should ensure that none of the array
data in the range of elements specified by first and count are changed. Changes to the array data
between the execution of glLockArraysEXT and glUnlockArraysEXT subroutines may affect calls to
DrawArrays, ArrayElement, or DrawElements subroutines in non-sequential ways.
While using a compiled vertex array, references to array elements by the subroutines DrawArrays,
ArrayElement, or DrawElements which are outside of the range specified by first and count are undefined.
This extension defines an interface which allows static vertex array data to be cached or pre-compiled for
more efficient rendering. This is useful for implementations which can cache the transformed results of
array data for reuse by several DrawArrays, ArrayElement, or DrawElements subroutines. It is also useful
for implementations which can transfer array data to fast memory for more efficient processing.
For example, rendering an M by N mesh of quadrilaterals can be accomplished by setting up vertex arrays
containing all of the vertexes in the mesh and issuing M DrawElements subroutines each of which operate
on 2 * N vertexes. Each DrawElements subroutine after the first will share N vertexes with the preceding
DrawElements subroutine. If the vertex array data is locked while the DrawElements subroutines are
executed, then OpenGL may be able to transform each of these shared vertexes just once.
Parameters
first
count
The first element in the locked range.
The number of elements to be contained in the locked range.
Chapter 1. OpenGL Subroutines
215
Errors
INVALID_VALUE
INVALID_OPERATION
First is less than or equal to zero.
The glLockArraysEXT subroutine is called between execution of
glLockArraysEXT and the corresponding execution of glUnlockArraysEXT.
The glLockArraysEXT subroutine is called between execution of Begin and the
corresponding execution of End.
INVALID_OPERATION
Related Information
The glUnlockArraysEXT subroutine.
glLogicOp Subroutine
Purpose
Specifies a logical pixel operation for color index rendering.
Library
OpenGL C bindings library: libGL.a
C Syntax
void LogicOp(GLenum
OperatorCode)
Description
The glLogicOp subroutine specifies a logical operation that, when enabled, is applied between the
incoming color and the color at the corresponding location in the frame buffer. The logical operation is
enabled or disabled with the glEnable and glDisable subroutines using the GL_LOGIC_OP symbolic
constant for color index mode or the GL_COLOR_LOGIC_OP for RGB mode.
The OperatorCode parameter specifies a symbolic constant chosen from the following list. In the
explanation of the logical operations, s represents the incoming color index and d represents the index in
the frame buffer. Standard C-language operators are used. As these bit-wise operators suggest, the logical
operation is applied independently to each bit pair of the source and destination indexes.
Operation
GL_CLEAR
GL_SET
GL_COPY
GL_COPY_INVERTED
GL_NOOP
GL_INVERT
GL_AND
GL_NAND
GL_OR
GL_NOR
GL_XOR
GL_EQUIV
GL_AND_REVERSE
GL_AND_INVERTED
GL_OR_REVERSE
GL_OR_INVERTED
216
Resulting Value
0
1
s
!s
d
!d
s&d
!(s & d)
s|d
!(s | d)
s|d
!(s | d)
s & !d
!s & d
s | !d
!s | d
OpenGL 2.1 Reference Manual
Parameters
OperatorCode
Specifies a symbolic constant that selects a logical operation. The following symbols are
accepted:
v GL_CLEAR
v GL_SET
v GL_COPY
v GL_COPY_INVERTED
v GL_NOOP
v GL_INVERT
v GL_AND
v GL_NAND
v GL_OR
v GL_NOR
v GL_XOR
v GL_EQUIV
v GL_AND_REVERSE
v GL_AND_INVERTED
v GL_OR_REVERSE
v GL_OR_INVERTED
Notes
When more than one color index buffer is enabled for drawing, logical operations are done separately for
each enabled buffer, using the contents of that buffer for the destination index. (See the glDrawBuffer
subroutine for information about specifying color buffers for drawing.)
The OperatorCode parameter must be one of the 16 accepted values. Other values result in an error.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
OperatorCode is not an accepted value.
The glLogicOp subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glLogicOp subroutine are as follows. (See the glGet subroutine for more
information.)
glEnable or glDisable with argument GL_COLOR_LOGIC_OP for RGB mode or GL_INDEX_LOGIC_OP
for color index mode.
glGet with argument GL_LOGIC_OP_MODE.
glIsEnabled with argument GL_LOGIC_OP.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Chapter 1. OpenGL Subroutines
217
Related Information
The glAlphaFunc subroutine, glBegin or glEnd subroutine, glBlendEquationEXT subroutine,
glBlendFunc subroutine, glDrawBuffer subroutine, glEnable or Disable subroutine, glStencilOp
subroutine.
glMap1 Subroutine
Purpose
Defines a 1-dimensional (1D) evaluator.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMap1d(GLenum Target,
GLdouble u1,
GLdouble u2,
GLint Stride,
GLint Order,
const GLdouble * Points)
void glMap1f(GLenum Target,
GLfloat u1,
GLfloat u2,
GLint Stride,
GLint Order,
const GLfloat * Points)
Description
Evaluators provide a way to use polynomial or rational polynomial mapping to produce vertices, normals,
texture coordinates, and colors. The values produced by an evaluator are sent to further stages of GL
processing just as if they had been presented using the glVertex, glNormal, glTexCoord, and glColor
subroutines, except that the generated values do not update the current normal, texture coordinates, or
color.
All polynomial or rational polynomial splines of any degree (up to the maximum degree supported by the
GL implementation) can be described using evaluators. These include almost all splines used in computer
graphics, such as B-splines, Bezier curves, and Hermite splines.
Evaluators define curves based on Bernstein polynomials. Define p(t) as the following:
Let p(t) = Bn0(t)R0 + Bn1(t)R1 + . . . + Bnn(t)Rn
where Ri is a control point and Bni(t) is the ith Bernstein polynomial of degree:
n (Order = n+1)
See the figure:
218
OpenGL 2.1 Reference Manual
n
k
n!
n
is the binomial coefficient given by
=
k
k! (n–k)!
Figure 8. Binomial Coefficient Equation. This figure shows that the binomial coefficient with original set of size n and
subset of size k is the binomial coefficient given by the following equation: the binomial coefficient with original set of
size n and subset of size k is equal to n! / k! (n-k)!.
See the figure:
00
1 and
n
1
k
Figure 9. Definition. This figure shows that zero to the power of zero is eqivalent to one and the binomial coefficient
with original set of size n and subset of size k is also eqivalent to one.
The glMap1 subroutine is used to define the basis and to specify what kind of values are produced. Once
defined, a map can be enabled and disabled by calling the glEnable and glDisable subroutines with the
map name, one of the nine predefined values for the Target parameter. The glEvalCoord1 subroutine
evaluates the 1D maps that are enabled. When glEvalCoord1 presents a value u, the Bernstein functions
are evaluated using t, as in the following figure:
u – u1
t=
u2 – u1
Figure 10. Value of t. This figure shows that t is equal to u-u1 / u2–u1.
The Target parameter specifies a symbolic constant that indicates what kind of control points are provided
in the Points parameter, and what output is generated when the map is evaluated. It can assume one of
the following nine predefined values:
GL_MAP1_VERTEX_3
GL_MAP1_VERTEX_4
GL_MAP1_INDEX
GL_MAP1_COLOR_4
Each control point is three floating-point values representing x, y, and z.
Internal glVertex3 subroutines are generated when the map is
evaluated.
Each control point is four floating-point values representing x, y, z, and
w. Internal glVertex4 subroutines are generated when the map is
evaluated.
Each control point is a single floating-point value representing a color
index. Internal glIndex subroutines are generated when the map is
evaluated. However, the current index is not updated with the value of
these glIndex subroutines.
Each control point is four floating-point values representing red, green,
blue, and alpha (RGBA). Internal glColor4 subroutines are generated
when the map is evaluated. However, the current color is not updated
with the value of these glColor4 subroutines.
Chapter 1. OpenGL Subroutines
219
GL_MAP1_NORMAL
GL_MAP1_TEXTURE_COORD_1
GL_MAP1_TEXTURE_COORD_2
GL_MAP1_TEXTURE_COORD_3
GL_MAP1_TEXTURE_COORD_4
Each control point is three floating-point values representing the x, y,
and z components of a normal vector. Internal glNormal subroutines
are generated when the map is evaluated. However, the current normal
is not updated with the value of these glNormal subroutines.
Each control point is a single floating-point value representing the s
texture coordinate. Internal glTexCoord1 subroutines are generated
when the map is evaluated. However, the current texture coordinates
are not updated with the value of these glTexCoord subroutines.
Each control point is two floating-point values representing the s and t
texture coordinates. Internal glTexCoord2 subroutines are generated
when the map is evaluated. However, the current texture coordinates
are not updated with the value of these glTexCoord subroutines.
Each control point is three floating-point values representing the s, t,
and r texture coordinates. Internal glTexCoord3 subroutines are
generated when the map is evaluated. However, the current texture
coordinates are not updated with the value of these glTexCoord
subroutines.
Each control point is four floating-point values representing the s, t, r
and q texture coordinates. Internal glTexCoord4 subroutines are
generated when the map is evaluated. However, the current texture
coordinates are not updated with the value of these glTexCoord
subroutines.
The Stride, Order, and Points parameters define the array addressing for accessing the control points.
Points is the location of the first control point, which occupies one, two, three, or four contiguous memory
locations, depending on which map is being defined. Order is the number of control points in the array.
Stride tells how many float or double locations to advance the internal memory pointer to reach the next
control point.
Parameters
Target
Specifies the values that are generated by the evaluator. The following symbolic constants are accepted:
v GL_MAP1_VERTEX_3
v GL_MAP1_VERTEX_4
v GL_MAP1_INDEX
v GL_MAP1_COLOR_4
v GL_MAP1_NORMAL
v GL_MAP1_TEXTURE_COORD_1
v GL_MAP1_TEXTURE_COORD_2
v GL_MAP1_TEXTURE_COORD_3
v GL_MAP1_TEXTURE_COORD_4
Specify a linear mapping of u, as presented to glEvalCoord1, to u1, the variable that is evaluated by the
equations specified by this subroutine.
Specifies the number of floats or doubles between the beginning of one control point and the beginning
of the next one in the data structure referenced in Points. This allows control points to be embedded in
arbitrary data structures. The only constraint is that the values for a particular control point must occupy
contiguous memory locations.
Specifies the number of control points. Must be positive.
Specifies a pointer to the array of control points.
u1, u2
Stride
Order
Points
Notes
As is the case with all GL subroutines that accept pointers to data, it is as if the contents of Points were
copied by glMap1 before it returned. Changes to the contents of Points have no effect after glMap1 is
called.
220
OpenGL 2.1 Reference Manual
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_VALUE
GL_INVALID_VALUE
GL_INVALID_OPERATION
Target is not an accepted value.
u1 is equal to u2.
Stride is less than the number of values in a control point.
Order is less than one or greater than GL_MAX_EVAL_ORDER.
The glMap1 subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glMap1 subroutine are as follows. (See the glGet subroutine for more information.)
glGetMap.
glGet with argument GL_MAX_EVAL_ORDER.
glIsEnabled with argument GL_MAP1_VERTEX_3.
glIsEnabled with argument GL_MAP1_VERTEX_4.
glIsEnabled with argument GL_MAP1_INDEX.
glIsEnabled with argument GL_MAP1_COLOR_4.
glIsEnabled with argument GL_MAP1_NORMAL.
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_1.
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_2
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_3
glIsEnabled with argument GL_MAP1_TEXTURE_COORD_4.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColor subroutine, glEnable or glDisable subroutine, glEvalCoord
subroutine, glEvalMesh subroutine, glEvalPoint subroutine, glGetMap subroutine, glIndex subroutine,
glMap2 subroutine, glMapGrid subroutine, glNormal subroutine, glTexCoord subroutine, glVertex
subroutine.
glMap2 Subroutine
Purpose
Defines a 2-dimensional (2D) evaluator.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
221
C Syntax
void glMap2d(GLenum Target,
GLdouble u1,
GLdouble u2,
GLint uStride,
GLint uOrder,
GLdouble v1,
GLdouble v2,
GLint vStride,
GLint vOrder,
const GLdouble * Points)
void glMap2f(GLenum Target,
GLfloat u1,
GLfloat u2,
GLint uStride,
GLint uOrder,
GLfloat v1,
GLfloat v2,
GLint vStride,
GLint vOrder,
const GLfloat * Points)
Description
Evaluators provide a way to use polynomial or rational polynomial mapping to produce vertices, normals,
texture coordinates, and colors. The values produced by an evaluator are sent on to further stages of GL
processing just as if they had been presented using the glVertex, glNormal, glTexCoord, and glColor
subroutines, except that the generated values do not update the current normal, texture coordinates, or
color.
All polynomial or rational polynomial splines of any degree (up to the maximum degree supported by the
GL implementation) can be described using evaluators. These include almost all surfaces used in
computer graphics, such as B-spline surfaces, non-uniform rational B-spline surfaces (NURBS), and Bezier
surfaces.
Evaluators define surfaces based on bivariate Bernstein polynomials. Define p(s, t) as follows:
Let p(s, t) = Bn0Bm0R00 + Bn1Bm0R01 + . . . + BnnBm0Rn0
+Bn0Bm1R01 + . . . + BnnBm1Rn1
.
.
.
+Bn0BmmR0m + . . . + BnnBmmRnm
where Rij is a control point, Bni (s) is the ith Bernstein polynomial of degree:
n (uOrder = n +1)
See the following figure:
222
OpenGL 2.1 Reference Manual
n
Bni (s) =
s i (1 – s) n – i
i
Figure 11. Value of Bni (s). This figure shows that Bni (s) is equal to [the binomial coefficient with original set of size n
and subset of size i] s to the power of i (1–s) to the power of n-i.
and Bmj (t) is the jth Bernstein polynomial of degree:
m (vOrder = m + 1)
See the following figure:
m
Bmj (t) =
t j (1 – t) m – j
j
Figure 12. Value of Bmj (t). This figure shows that Bmj (t) is equal to [the binomial coefficient with original set of size
m and subset of size j] t to the power of j (1–t) to the power of m-j.
See the following figure:
00
1 and
n
1
0
Figure 13. Definition. This figure shows that zero to the power of zero is eqivalent to one and the binomial coefficient
with original set of size n and subset of size zero is also eqivalent to one.
The glMap2 subroutine is used to define the basis and to specify what kind of values are produced. Once
defined, a map can be enabled and disabled by calling the glEnable and glDisable subroutines with the
map name, which is one of the nine predefined values for the Target parameter. When the glEvalCoord2
subroutine presents values u and v, the bivariate Bernstein polynomials are evaluated using s and t, as in
the following figure:
u – u1
s=
u2 – u1
v – v1
t=
v2 – v1
Figure 14. Value of s and t. This figure shows two equations. The first equation shows that s is equal to u–u1 / u2–u1.
The second equation shows that t is equal to v–v1 / v2–v1.
The Target parameter specifies a symbolic constant that indicates what kind of control points are provided
in the Points parameter, and what output is generated when the map is evaluated. It can assume one of
Chapter 1. OpenGL Subroutines
223
the following nine predefined values:
GL_MAP2_VERTEX_3
GL_MAP2_VERTEX_4
GL_MAP2_INDEX
GL_MAP2_COLOR_4
GL_MAP2_NORMAL
GL_MAP2_TEXTURE_COORD_1
GL_MAP2_TEXTURE_COORD_2
GL_MAP2_TEXTURE_COORD_3
GL_MAP2_TEXTURE_COORD_4
Each control point is three floating-point values representing x, y, and z.
Internal glVertex3 subroutines are generated when the map is
evaluated.
Each control point is four floating-point values representing x, y, z, and
w. Internal glVertex4 subroutines are generated when the map is
evaluated.
Each control point is a single floating-point value representing a color
index. Internal glIndex subroutines are generated when the map is
evaluated. However, the current index is not updated with the value of
these glIndex subroutines.
Each control point is four floating-point values representing red, green,
blue, and alpha. Internal glColor4 subroutines are generated when the
map is evaluated. However, the current color is not updated with the
value of these glColor4 subroutines.
Each control point is three floating-point values representing the x, y,
and z components of a normal vector. Internal glNormal subroutines
are generated when the map is evaluated. However, the current normal
is not updated with the value of these glNormal subroutines.
Each control point is a single floating-point value representing the s
texture coordinate. Internal glTexCoord1 subroutines are generated
when the map is evaluated. However, the current texture coordinates
are not updated with the value of these glTexCoord subroutines.
Each control point is two floating-point values representing the s and t
texture coordinates. Internal glTexCoord2 subroutines are generated
when the map is evaluated. However, the current texture coordinates
are not updated with the value of these glTexCoord subroutines.
Each control point is three floating-point values representing the s, t,
and r texture coordinates. Internal glTexCoord3 subroutines are
generated when the map is evaluated. However, the current texture
coordinates are not updated with the value of these glTexCoord
subroutines.
Each control point is four floating-point values representing the s, t, r,
and q texture coordinates. Internal glTexCoord4 subroutines are
generated when the map is evaluated. However, the current texture
coordinates are not updated with the value of these glTexCoord
subroutines.
The uStride, uOrder, vStride, vOrder, and Points parameters define the array addressing for accessing the
control points. The Points parameter is the location of the first control point, which occupies one, two,
three, or four contiguous memory locations, depending on which map is being defined. There are uOrder
times vOrder control points in the array. The uStride parameter tells how many float or double locations
are skipped to advance the internal memory pointer from control point Rij to control point R(i+1)j. The
vStride parameter tells how many float or double locations are skipped to advance the internal memory
pointer from control point Rij to control point Ri(j+1).
224
OpenGL 2.1 Reference Manual
Parameters
Target
Specifies the kind of values that are generated by the evaluator. The following symbolic constants are
accepted:
v GL_MAP2_VERTEX_3
v GL_MAP2_VERTEX_4
v GL_MAP2_INDEX
v GL_MAP2_COLOR_4
v GL_MAP2_NORMAL
v GL_MAP2_TEXTURE_COORD_1
v GL_MAP2_TEXTURE_COORD_2
v GL_MAP2_TEXTURE_COORD_3
u1, u2
uStride
uOrder
v1, v2
vStride
vOrder
Points
v GL_MAP2_TEXTURE_COORD_4
Specify a linear mapping of u, as presented to glEvalCoord2, to u1, one of the two variables that is
evaluated by the equations specified by this subroutine.
Specifies the number of floats or doubles between the beginning of control point Rij and the beginning
of control point R(i+1)j, where i and j are the u and y control-point indexes, respectively. This allows
control points to be embedded in arbitrary data structures. The only constraint is that the values for a
particular control point must occupy contiguous memory locations.
Specifies the dimension of the control point array in the u axis. Must be positive.
Specify a linear mapping of v, as presented to glEvalCoord2, to v1, one of the two variables that is
evaluated by the equations specified by this subroutine.
Specifies the number of floats or doubles between the beginning of control point Rij and the beginning
of control point Ri(j+1), where i and j are the u and v control point indexes, respectively. This allows
control points to be embedded in arbitrary data structures. The only constraint is that the values for a
particular control point must occupy contiguous memory locations.
Specifies the dimension of the control point array in the v axis. Must be positive.
Specifies a pointer to the array of control points.
Notes
For all GL subroutines that accept pointers to data, it is as if the contents of Points were copied by
glMap2 before it returned. Changes to the contents of Points have no effect after glMap2 is called.
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_VALUE
GL_INVALID_VALUE
GL_INVALID_OPERATION
Target is not an accepted value.
u1 is equal to u2, or if v1 is equal to v2.
uStride or vStride is less than the number of values in a control point.
uOrder or vOrder is less than one or greater than GL_MAX_EVAL_ORDER.
The glMap2 subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glMap2 subroutine are as follows. (See the glGet subroutine for more information.)
glGetMap
glGet with argument GL_MAX_EVAL_ORDER
glIsEnabled with argument GL_MAP2_VERTEX_3
glIsEnabled with argument GL_MAP2_VERTEX_4
Chapter 1. OpenGL Subroutines
225
glIsEnabled with argument GL_MAP2_INDEX
glIsEnabled with argument GL_MAP2_COLOR_4
glIsEnabled with argument GL_MAP2_NORMAL
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_1
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_2
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_3
glIsEnabled with argument GL_MAP2_TEXTURE_COORD_4.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColor subroutine, glEnable or Disable subroutine, glEvalCoord
subroutine, glEvalMesh subroutine, glEvalPoint subroutine, glGetMap subroutine, glIndex subroutine,
glMap1 subroutine, glMapGrid subroutine, glNormal subroutine, glTexCoord subroutine, glVertex
subroutine.
glMapGrid Subroutine
Purpose
Defines a 1-dimensional (1D) or 2-dimensional (2D) mesh.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMapGrid1d(GLint
GLdouble u1,
GLdouble u2)
un,
void glMapGrid1f(GLint
GLfloat u1,
GLfloat u2)
un,
void glMapGrid2d(GLint
GLdouble u1,
GLdouble u2,
GLint vn,
GLdouble v1,
GLdouble v2)
un,
void glMapGrid2f(GLint
GLfloat u1,
GLfloat u2,
un,
226
OpenGL 2.1 Reference Manual
GLint vn,
GLfloat v1,
GLfloat v2)
Description
The glMapGrid and glEvalMesh subroutines are used in tandem to efficiently generate and evaluate a
series of evenly spaced map domain values. The glEvalMesh subroutine steps through the integer
domain of a 1D or 2D grid, whose range is the domain of the evaluation maps specified by the glMap1
and glMap2 subroutines.
The glMapGrid1 and glMapGrid2 subroutines specify the linear grid mappings between the i (or i and j)
integer grid coordinates, to the u (or u and v) floating-point evaluation map coordinates. See the glMap1
subroutine and the glMap2 subroutine for details of how u and v coordinates are evaluated.
The glMapGrid1 subroutine specifies a single linear mapping such that integer grid coordinate 0 (zero)
maps exactly to u1, and integer grid coordinate un maps exactly to u2. All other integer grid coordinates i
are mapped such that
u = i(u2 - u1)/un + u1
The glMapGrid2 subroutine specifies two such linear mappings. One maps integer grid coordinate i=0
exactly to u1, and integer grid coordinate i=un exactly to u2. The other maps integer grid coordinate j=0
exactly to v1, and integer grid coordinate j=vn exactly to v2. Other integer grid coordinates i and j are
mapped such that
u = i(u2 - u1)/un + u1
v = j(v2 - v1)/vn + v1
The mappings specified by glMapGrid are identically used by glEvalMesh and glEvalPoint.
Parameters
un
u1, u2
vn
v1, v2
Specifies the number of partitions in the grid range interval [u1, u2]. Must be positive.
Specify the mappings for integer grid domain values i=0 and i=un.
Specifies the number of partitions in the grid range interval [v1, v2] (glMapGrid2 only).
Specify the mappings for integer grid domain values j=0 and j=vn (glMapGrid2 only).
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
un or vn is not positive.
The glMapGrid subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glMapGrid subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MAP1_GRID_DOMAIN
glGet with argument GL_MAP2_GRID_DOMAIN
glGet with argument GL_MAP1_GRID_SEGMENTS
glGet with argument GL_MAP2_GRID_SEGMENTS.
Chapter 1. OpenGL Subroutines
227
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEvalCoord subroutine, glEvalMesh subroutine, glEvalPoint
subroutine, glMap1 subroutine, glMap2 subroutine.
glMaterial Subroutine
Purpose
Specifies material parameters for the lighting model.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMaterialf(GLenum Face,
GLenum pName,
GLfloat Parameter)
void glMateriali(GLenum
GLenum pName,
GLint Parameter)
Face,
void glMaterialfv(GLenum Face,
GLenum pName,
const GLfloat * Parameters)
void glMaterialiv(GLenum Face,
GLenum pName,
const GLint * Parameters)
Description
The glMaterial subroutine assigns values to material parameters. There are two matched sets of material
parameters. One, the frontfacing set, is used to shade points, lines, bitmaps, and all polygons (when
two-sided lighting is disabled), or just frontfacing polygons (when two-sided lighting is enabled). The other
set, backfacing, is used to shade backfacing polygons only when two-sided lighting is enabled. See the
glLightModel subroutine for details concerning one- and two-sided lighting calculations.
The glMaterial subroutine takes three arguments:
v The Face parameter specifies whether the GL_FRONT materials, the GL_BACK materials, or both
GL_FRONT_AND_BACK materials are modified.
v The pName parameter specifies which of several parameters in one or both sets are modified.
v The Parameters parameter specifies what value or values are assigned to the specified parameter.
Material parameters are used in the lighting equation that is optionally applied to each vertex. See the
glLightModel subroutine for details about the lighting equation. The following parameters and their
interpretations by the lighting equation can be specified using glMaterial:
228
OpenGL 2.1 Reference Manual
GL_AMBIENT
GL_DIFFUSE
GL_SPECULAR
GL_EMISSION
GL_SHININESS
GL_AMBIENT_AND_DIFFUSE
GL_COLOR_INDEXES
Parameters contains four integer or floating-point values that specify the
ambient red, green, blue, alpha (RGBA) reflectance of the material.
Integer values are mapped linearly such that the most positive
representable value maps to 1.0, and the most negative representable
value maps to -1.0. Floating-point values are mapped directly. Neither
integer nor floating-point values are clamped. The default ambient
reflectance for both front and backfacing materials is (0.2, 0.2, 0.2, 1.0).
Parameters contains four integer or floating-point values that specify the
diffuse RGBA reflectance of the material. Integer values are mapped
linearly such that the most positive representable value maps to 1.0, and
the most negative representable value maps to -1.0. Floating-point values
are mapped directly. Neither integer nor floating-point values are clamped.
The default diffuse reflectance for both front and backfacing materials is
(0.8, 0.8, 0.8, 1.0).
Parameters contains four integer or floating-point values that specify the
specular RGBA reflectance of the material. Integer values are mapped
linearly such that the most positive representable value maps to 1.0, and
the most negative representable value maps to -1.0. Floating-point values
are mapped directly. Neither integer nor floating-point values are clamped.
The default specular reflectance for both front and backfacing materials is
(0.0, 0.0, 0.0, 1.0).
Parameters contains four integer or floating-point values that specify the
RGBA emitted light intensity of the material. Integer values are mapped
linearly such that the most positive representable value maps to 1.0, and
the most negative representable value maps to -1.0. Floating-point values
are mapped directly. Neither integer nor floating-point values are clamped.
The default emission intensity for both front and backfacing materials is
(0.0, 0.0, 0.0, 1.0).
Parameters is a single integer or floating-point value that specifies the
RGBA specular exponent of the material. Integer and floating-point values
are mapped directly. Only values in the range [0,128] are accepted. The
default specular exponent for both frontfacing and backfacing materials is
0.
Equivalent to calling glMaterial twice with the same parameter values,
once with GL_AMBIENT and once with GL_DIFFUSE.
Parameters contains three integer or floating-point values specifying the
color indices for ambient, diffuse, and specular lighting. These three
values, and GL_SHININESS, are the only material values used by the
color index mode lighting equation. See the glLightModel subroutine for
a discussion of color index lighting.
Parameters
materialf and materiali
Face
pName
Parameter
Specifies which face or faces are being updated. The Face parameter must be one of GL_FRONT,
GL_BACK or GL_FRONT_AND_BACK.
Specifies the single-valued material parameter of the face or faces that is being updated. Must be
GL_SHININESS.
Specifies the value to which GL_SHININESS is set.
materialfv and materialiv
Face
Specifies which face or faces are being updated. Must be one of GL_FRONT, GL_BACK, or
GL_FRONT_AND_BACK.
Chapter 1. OpenGL Subroutines
229
pName
Specifies the material parameter of the face or faces that is being updated. Must be one of the
following:
v GL_AMBIENT
v GL_DIFFUSE
v GL_SPECULAR
v GL_EMISSION
v GL_SHININESS
v GL_AMBIENT_AND_DIFFUSE
Parameters
v GL_COLOR_INDEXES
Specifies a pointer to the value or values to which the pName parameter is set.
Notes
The material parameters can be updated at any time. In particular, glMaterial can be called between a call
to the glBegin subroutine and the corresponding call to the glEnd subroutine. If only a single material
parameter is to be changed per vertex, however, glColorMaterial is preferred over glMaterial. (See the
glColorMaterial subroutine for information on tracking the current color with the material color.)
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
Face or pName is not an accepted value.
A specular exponent outside the range [0,128] is specified.
Associated Gets
Associated get for the glMaterial subroutine is as follows. (See the glGet subroutine for more information.)
glGetMaterial.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColorMaterial subroutine, glGetMaterial subroutine, glLight
subroutine, glLightModel subroutine.
glMatrixMode Subroutine
Purpose
Specifies the current matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMatrixMode(GLenum
230
Mode)
OpenGL 2.1 Reference Manual
Description
The glMatrixMode subroutine sets the current matrix mode. The Mode parameter can assume one of the
following three values:
GL_MODELVIEW
GL_PROJECTION
GL_TEXTURE
Applies subsequent matrix operations to the model view matrix stack.
Applies subsequent matrix operations to the projection matrix stack.
Applies subsequent matrix operations to the texture matrix stack.
Parameters
Mode
Specifies which matrix stack is the target for subsequent matrix operations. The following three values are
accepted:
v GL_MODELVIEW
v GL_PROJECTION
v GL_TEXTURE
Associated Gets
Associated gets for the glMatrixMode subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Mode is not an accepted value.
The glMatrixMode subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glLoadMatrix subroutine, glPushMatrix subroutine.
glMultiDrawArraysEXT Subroutine
Purpose
Renders multiple primitives from array data.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMultiDrawArraysEXT(GLenum mode,
GLint *first,
GLsizei *count,
GLsizei primcount)
Chapter 1. OpenGL Subroutines
231
Description
The glMultiDrawArraysEXT subroutine lets you specify multiple geometric primitives with very few
subroutine calls. Instead of calling a GL procedure to pass each individual vertex, normal, texture
coordinate, edge flag, or color, you can prespecify separate arrays of vertexes, normals, and colors and
use them to construct a sequence of primitives with a single call to glMultiDrawArraysEXT.
When glMultiDrawArraysEXT is called, it uses count sequential elements from each enabled array to
construct a sequence of geometric primitives, beginning with element first. The mode parameter specifies
what kind of primitives are constructed, and how the array elements construct these primitives. If
GL_VERTEX_ARRAY is not enabled, no geometric primitives are generated.
Vertex attributes that are modified by glMultiDrawArraysEXT have an unspecified value after
glMultiDrawArraysEXT returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current
color is undefined after glMultiDrawArraysEXT executes. Attributes that are not modified remain well
defined.
Behaves identically to DrawArrays except that a list of arrays is specified instead. The number of lists is
specified in the primcount parameter. It has the same effect as:
for(i=0; i<primcount; i++) {
if (*(count+i)>0) DrawArrays(mode, *(first+i), *(count+i));
}
Parameters
mode
first
count
primcount
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Points to an array of the starting indeces in the enabled arrays.
Points to an array of the number of indices to be rendered.
Specifies the size of first and count.
Notes
The glMultiDrawArraysEXT subroutine is included in display lists. If glMultiDrawArraysEXT is entered
into a display list, the necessary array data (determined by the array pointers and enables) is also entered
into the display list. Because the array pointers and enables are client side state, their values affect display
lists when the lists are created, not when the lists are executed.
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative.
GL_INVALID_OPERATION is generated if glMultiDrawArraysEXT is executed between the execution of
glBegin and the corresponding glEnd.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glMultiDrawElementsEXT subroutine,
glEdgeFlagPointer subroutine, glGetPointerv subroutine, glIndexPointer subroutine, glNormalPointer
subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
232
OpenGL 2.1 Reference Manual
glMultiDrawElementsEXT Subroutine
Purpose
Renders multiple primitives from array data.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMultiDrawElementsEXT(GLenum mode,
GLsizei *count,
GLenum type,
const GLvoid **indices,
GLsizei primcount)
Description
The glMultiDrawElementsEXT subroutine lets you specify multiple geometric primitives with very few
subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate,
edge flag, or color, you can prespecify separate arrays of vertexes, normals, and so on and use them to
construct a sequence of primitives with a single call to glMultiDrawElementsEXT.
When glMultiDrawElementsEXT is called, it uses count sequential elements from indices to construct a
sequence of geometric primitives. GLenum mode specifies what kind of primitives are constructed and
how the array elements construct these primitives. If GL_VERTEX_ARRAY is not enabled, no geometric
primitives are generated.
Vertex attributes that are modified by glMultiDrawElementsEXT have an unspecified value after
glMultiDrawElementsEXT returns. For example, if GL_COLOR_ARRAY is enabled, the value of the
current color is undefined after glMultiDrawElementsEXT executes. Attributes that are not modified
remain well defined.
Parameters
mode
count
type
indices
primcount
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Points to an array of the element counts.
Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE,
GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
Specifies a pointer to the location where the indices are stored.
Specifies the size of the count array.
Notes
The glMultiDrawElementsEXT subroutine is included in display lists. If glMultiDrawElementsEXT is
entered into a display list, the necessary array data (determined by the array pointers and enables) is also
entered into the display list. Because the array pointers and enables are client side state, their values
affect display lists when the lists are created, not when the lists are executed.
glMultiDrawElementsEXT is part of the _extname(EXT_multi_draw_arrays) extension, not part of the core
GL command set. If _extstring(EXT_multi_draw_arrays) is included in the string returned by glGetString,
when called with argument GL_EXTENSIONS, extension _extname(EXT_multi_draw_arrays) is supported.
Chapter 1. OpenGL Subroutines
233
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative.
GL_INVALID_OPERATION is generated if glMultiDrawElementsEXT is executed between the execution
of glBegin and the corresponding glEnd.
Associated Gets
glGetTexImage, glIsEnabled with argument GL_TEXTURE_1D.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glMultiDrawArraysEXT subroutine,
glEdgeFlagPointer subroutine, glGetPointerv subroutine, glIndexPointer subroutine, glNormalPointer
subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glMultiModeDrawArraysIBM Subroutine
Purpose
Renders primitives of multiple primitive types from array data.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMultiModeDrawArraysIBM( GLenum * mode,
GLint
* first,
GLsizei * count,
GLsizei primcount,
GLint
modestride)
Description
The glMultiModeDrawArraysIBM subroutine behaves identically to glDrawArrays except that a list of
arrays and a list of primitive modes is specified instead. The number of lists is specified in the primcount
parameter. It has the same effect as:
for(i=0; i < primcount; i++) {
if (*(count+i) > 0)
glDrawArrays(*((GLenum *)((char *)mode+i*modestride)),
*(first+i),
*(count+i));
}
Parameters
mode
first
count
primcount
modestride
234
Points to an array of primitive modes. Symbolic constants GL_POINTS, GL_LINE_STRIP,
GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
Points to an array of the starting indices in the enabled arrays.
Points to an array of the number of indices to be rendered for each primitive.
Specifies the word size of the mode, first and count arrays.
Specifies how to stride through the mode array. Typical values are 0 (single primitive mode for all
primitives) and sizeof(GLenum) (separate primitive mode for each primitive).
OpenGL 2.1 Reference Manual
Notes
The glMultiModeDrawArraysIBM subroutine is available only if the IBM_multi_mode_draw_arrays
extension is supported.
The glMultiModeDrawArraysIBM subroutine is included in display lists. If glMultiModeDrawArraysIBM is
entered into a display list, the necessary array data (determined by the array pointers and enables) is also
entered into the display list. Because the array pointers and enables are client side state, their values
affect display lists when the lists are created, not when the lists are executed.
Error Codes
v GL_INVALID_ENUM is generated if any of the primitive modes in the mode array is not an accepted
value.
v GL_INVALID_OPERATION is generated if glMultiModeDrawArraysIBM is executed between the
execution of glBegin and the corresponding glEnd.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glColorPointerListIBM subroutine,
glDrawElements subroutine, glEdgeFlagPointer subroutine, glEdgeFlagPointerListIBM subroutine,
glGetPointerv subroutine, glIndexPointer subroutine, glIndexPointerListIBM subroutine,
glInterleavedArrays subroutine, glMultiModeDrawElementsIBM subroutine, glNormalPointer
subroutine, glNormalPointerListIBM subroutine, glTexCoordPointer subroutine,
glTexCoordPointerListIBM subroutine, glVertexPointer subroutine, glVertexPointerListIBM subroutine.
glMultiModeDrawElementsIBM Subroutine
Purpose
Renders primitives of multiple primitive types from array data.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMultiModeDrawElementsIBM(GLenum
GLsizei
*count,
GLenum
type,
const GLvoid
**indices,
GLsizei
primcount,
GLint
modestride)
*mode,
Description
glMultiModeDrawElementsIBM behaves identically to glDrawElements except that a list of arrays and a
list of primitive modes is specified instead. The number of lists is specified in the primcount parameter. It
has the same effect as:
for(i=0; i < primcount; i++) {
if (*(count+i) > 0)
glDrawElements(*((GLenum *)((char *)mode+i*modestride)),
*(count+i),
type,
*(indices+i));
}
Chapter 1. OpenGL Subroutines
235
Parameters
mode
count
type
indices
primcount
modestride
Points to an array of primitive modes, Specifying what kind of primitives to render. Symbolic
constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP,
GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON
are accepted.
Points to an array of the element counts. Each count specifies the number of elements to be
rendered for that primitive.
Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE,
GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
Specifies a pointer to the list of index arrays.
Specifies the number of elements to be read from the mode array and from the count array (and
how many arrays there are in the indices list). Each such (mode,count,indices[]) triple tells us
how many vertices of the indicated mode are to be rendered, and the location of their array of
indices.
Specifies how to stride through the mode array. Typical values are 0 (single primitive mode for all
primitives)and sizeof(GLenum) (separate primitive mode for each primitive)
Notes
The glMultiModeDrawElementsIBM subroutine is available only if the IBM_multimode_draw_arrays
extension is supported.
The glMultiModeDrawElementsIBM subroutine is included in display lists. If
glMultiModeDrawElementsIBM is entered into a display list, the necessary array data (determined by the
array pointers and enables) is also entered into the display list. Because the array pointers and enables
are client side state, their values affect display lists when the lists are created, not when the lists are
executed.
Errors
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_OPERATION is generated if glMultiModeDrawElementsIBM is executed between the
execution of glBegin and the corresponding glEnd.
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glColorPointerListIBM subroutine,
glDrawArrays subroutine, glEdgeFlagPointer subroutine, glEdgeFlagPointerListIBM subroutine,
glGetPointerv subroutine, glIndexPointer subroutine, glIndexPointerListIBM subroutine,
glMultiModeDrawArraysIBM subroutine, glNormalPointer subroutine, glNormalPointerListIBM
subroutine, glTexCoordPointer subroutine, glTexCoordPointerListIBM subroutine, glVertexPointer
subroutine, glVertexPointerListIBM subroutine.
glMultiTexCoordARB Subroutine
Purpose
Sets the current texture coordinates.
Library
OpenGL C bindings library: (libGL.a)
236
OpenGL 2.1 Reference Manual
C Syntax
void glMultiTexCoord1dARB( GLenum target,
GLdouble s )
void glMultiTexCoord1fARB( GLenum target,
GLfloat s )
void glMultiTexCoord1iARB( GLenum target,
GLint s )
void glMultiTexCoord1sARB( GLenum target,
GLshort s )
void glMultiTexCoord2dARB( GLenum target,
GLdouble s,
GLdouble t )
void glMultiTexCoord2fARB( GLenum target,
GLfloat s,
GLfloat t )
void glMultiTexCoord2iARB( GLenum target,
GLint s,
GLint t )
void glMultiTexCoord2sARB( GLenum target,
GLshort s,
GLshort t )
void glMultiTexCoord3dARB( GLenum target,
GLdouble s,
GLdouble t,
GLdouble r )
void glMultiTexCoord3fARB( GLenum target,
GLfloat s,
GLfloat t,
GLfloat r )
void glMultiTexCoord3iARB( GLenum target,
GLint s,
GLint t,
GLint r )
void glMultiTexCoord3sARB( GLenum target,
GLshort s,
GLshort t,
GLshort r )
void glMultiTexCoord4dARB( GLenum target,
GLdouble s,
GLdouble t,
GLdouble r,
GLdouble q )
void glMultiTexCoord4fARB( GLenum target,
GLfloat s,
GLfloat t,
GLfloat r,
GLfloat q )
void glMultiTexCoord4iARB( GLenum target,
GLint s,
GLint t,
GLint r,
GLint q )
void glMultiTexCoord4sARB( GLenum target,
GLshort s,
GLshort t,
Chapter 1. OpenGL Subroutines
237
void
void
void
void
void
void
void
void
void
void
void
void
void
void
void
void
GLshort r,
GLshort q )
glMultiTexCoord1dvARB( GLenum target,
GLdouble *v )
glMultiTexCoord1fvARB( GLenum target,
GLfloat *v )
glMultiTexCoord1ivARB( GLenum target,
GLint *v )
glMultiTexCoord1svARB( GLenum target,
GLshort *v )
glMultiTexCoord2dvARB( GLenum target,
GLdouble *v )
glMultiTexCoord2fvARB( GLenum target,
GLfloat *v )
glMultiTexCoord2ivARB( GLenum target,
GLint *v )
glMultiTexCoord2svARB( GLenum target,
GLshort *v )
glMultiTexCoord3dvARB( GLenum target,
GLdouble *v )
glMultiTexCoord3fvARB( GLenum target,
GLfloat *v )
glMultiTexCoord3ivARB( GLenum target,
GLint *v )
glMultiTexCoord3svARB( GLenum target,
GLshort *v )
glMultiTexCoord4dvARB( GLenum target,
GLdouble *v )
glMultiTexCoord4fvARB( GLenum target,
GLfloat *v )
glMultiTexCoord4ivARB( GLenum target,
GLint *v )
glMultiTexCoord4svARB( GLenum target,
GLshort *v )
Description
glMultiTexCoordARB specifies texture coordinates in one, two, three or four dimensions. If t is not
specified it is taken to be 0. If r is not specified it is taken to be 0. If q is not specified, it is taken to be 1.
The current texture coordinates are part of the data that is associated with each vertex and with the
current raster position. Initially, the values for s, t, r and q are (0, 0, 0, 1).
Parameters
target
s, t, r, q
v
238
OpenGL 2.1 Reference Manual
specifies texture unit whose coordinates should be
modified. The number of texture units is implementation
dependent, but must be at least two. Must be one of
GL_TEXTUREi_ARB, where 0 <= i < the
implementation-dependent value of
GL_MAX_TEXTURE_UNITS_ARB.
specifies the s, t, r, and q texture coordinates for target
texture unit. Not all parameters are present in all forms of
the command.
specifies a pointer to an array of one, two, three or four
elements, which in turn specify the s, t, r, and q texture
coordinates.
Notes
glMultiTexCoordARB is only supported if GL_ARB_multitexture is included in the string returned by
glGetString when called with the argument GL_EXTENSIONS.
The current texture coordinates can be updated at any time. In particular, glMultiTexCoordARB can be
called between a call to glBegin and the corresponding call to glEnd.
It is always the case that GL_TEXTUREi_ARB = GL_TEXTURE0_ARB + i.
Associated Gets
Associated gets for the glMultiTexCoordARB subroutine are as follows. (See the glGet subroutine for
more information.)
glGet GL_CURRENT_TEXTURE_COORDS with appropriate texture unit selected.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glActiveTextureARB subroutine, the glClientActiveTextureARB subroutine, the glTexCoord
subroutine, the glTexCoordPointer subroutine.
glMultMatrix Subroutine
Purpose
Multiplies the current matrix by an arbitrary matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glMultMatrixd(const GLdouble
void glMultMatrixf(const GLfloat
*Matrix)
*Matrix)
Description
The glMultMatrix subroutine multiplies the current matrix with the one specified in the Matrix parameter.
For example, if M is the current matrix and T is the matrix passed to glMultMatrix, M is replaced with MT.
The current matrix is the projection matrix, model view matrix, or texture matrix, determined by the current
matrix mode. (See the glMatrixMode subroutine for information on specifying the current matrix.)
The Matrix parameter points to a 4 x 4 matrix of single- or double-precision floating-point values stored in
column-major order. That is, the matrix is stored as in the following figure:
Chapter 1. OpenGL Subroutines
239
a0
a4
a8
a12
a1
a5
a9
a13
a2
a6
a10 a14
a3
a7
a11 a15
Figure 15. Stored Matrix. This diagram shows a matrix enclosed in brackets. The matrix consists of four lines
containing four characters each. The first line contains the following (from left to right): a subscript zero, a subscript
four, a subscript eight, a subscript twelve. The second line contains the following (from left to right): a subscript one, a
subscript five, a subscript nine, a subscript thirteen. The third line contains the following (from left to right): a subscript
two, a subscript six, a subscript ten, a subscript fourteen. The fourth line contains the following (from left to right): a
subscript three, a subscript seven, a subscript eleven, a subscript fifteen.
Parameters
Matrix
Specifies a pointer to 4 x 4 matrix stored in column-major order as 16 consecutive values.
Errors
GL_INVALID_OPERATION
The glMultMatrix subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glMultMatrix subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE.
glGet with argument GL_MODELVIEW_MATRIX.
glGet with argument GL_PROJECTION_MATRIX.
glGet with argument GL_TEXTURE_MATRIX.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glLoadIdentity subroutine, glLoadMatrix subroutine, glMatrixMode
subroutine, glPushMatrix subroutine, glMultTransposeMatrixARB subroutine.
glMultTransposeMatrixARB Subroutine
Purpose
Multiplies the current matrix by a matrix specified in row-major order, rather than column-major order.
240
OpenGL 2.1 Reference Manual
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glMultTransposeMatrixfARB(const GLfloat *Matrix)
void glMultTransposeMatrixdARB(const GLdouble *Matrix)
Description
The glMultTransposeMatrixARB subroutine replaces the current matrix with the product of the current
matrix and the one specified in the Matrix parameter. The current matrix is the projection matrix, model
view matrix, or texture matrix, determined by the current matrix mode. (See the glMatrixMode subroutine
for information on specifiying the current matrix.) The Matrix parameter points to a 4 x 4 matrix of singleor double-precision floating-point values stored in row-major order. That is, the matrix is stored as the
following:
/
|
|
\
a0
a4
a8
a12
a1
a5
a9
a13
a2
a6
a10
a14
a3
a7
a11
a15
\
|
|
/
The effect on an input vertex is as if it is first multiplied by the matrix specified in this call, and then
subsequently multiplied by the previous ″current″ matrix.
Parameters
Matrix
is an array of 16 values, specified in row-major order.
Error Codes
GL_INVALID_OPERATION
is generated if glMultTransposeMatrixARB is executed
between the execution of glBegin and the corresponding
execution of glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glMultMatrix subroutine, the glMatrixMode subroutine.
glNewList or glEndList Subroutine
Purpose
Creates or replaces a display list.
Library
OpenGL C bindings library: libGL.a
Chapter 1. OpenGL Subroutines
241
C Syntax
void glNewList(GLuint
GLenum Mode)
List,
Description
Display lists are groups of GL commands that have been stored for subsequent execution. The display
lists are created with the glNewList subroutine. All subsequent commands are placed in the display list, in
the order issued, until the glEndList subroutine is called.
The glNewList subroutine has two arguments. The first argument, List, is a positive integer that becomes
the unique name for the display list. Names can be created and reserved with the glGenLists subroutine
and tested for uniqueness with the glIsList subroutine. The second argument, Mode, is a symbolic
constant that can assume one of two values:
GL_COMPILE
GL_COMPILE_AND_EXECUTE
Commands are compiled only.
Commands are performed as they are compiled into the display list.
The following subroutines are not compiled into the display list, but are performed immediately, regardless
of the display-list mode:
v
v
v
v
v
glIsList
glGenLists
glDeleteLists
glFeedbackBuffer
glSelectBuffer
v glRenderMode
v glReadPixels
v
v
v
v
v
glPixelStore
glFlush
glFinish
glIsEnabled
All glGet subroutines
When glEndList is encountered, the display-list definition is completed by associating the list with the
unique name List (specified in glNewList). If a display list with the name List already exists, it is replaced
only when glEndList is called.
Parameters
List
Mode
Specifies the display list name.
Specifies the compilation mode, which can be GL_COMPILE or GL_COMPILE_AND_EXECUTE.
Notes
The glCallList and glCallLists subroutines can be entered into display lists. The commands in the display
list or lists run by glCallList or glCallLists are not included in the display list being created, even if the list
creation mode is GL_COMPILE_AND_EXECUTE.
Error Codes
GL_INVALID_VALUE
GL_INVALID_ENUM
242
OpenGL 2.1 Reference Manual
List is 0 (zero).
Mode is not an accepted value.
GL_INVALID_OPERATION
The glEndList subroutine is called without a preceding glNewList.
OR
GL_INVALID_OPERATION
The glNewList subroutine is called while a display list is being defined.
The glNewList subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glNewList and glEndList subroutines are as follows. (See the glGet subroutine
for more information.)
glIsList.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallList subroutine, glCallLists subroutine, glDeleteLists subroutine,
glGenLists subroutine.
glNormal Subroutine
Purpose
Set the current normal vector; for use in lighting calculations.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glNormal3b(
GLbyte
nx,
GLbyte
ny,
GLbyte
nz)
void glNormal3d(
GLdouble
nx,
GLdouble
ny,
GLdouble
nz)
void glNormal3f(
GLfloat
nx,
GLfloat
ny,
GLfloat
nz)
void glNormal3i(
GLint
nx,
GLint
ny,
GLint
nz)
void glNormal3s(
GLshort
nx,
GLshort
ny,
GLshort
nz)
Chapter 1. OpenGL Subroutines
243
void glNormal3bv(
const GLbyte *v)
void glNormal3dv(
const GLdouble *v)
void glNormal3fv(
const GLfloat *v)
void glNormal3iv(
const GLint *v)
void glNormal3sv(
const GLshort *v)
Description
The current normal is set to the given coordinates whenever glNormal is issued. Byte, short, or integer
arguments are converted to floating-point format with a linear mapping that maps the most positive
representable integer value to 1.0, and the most negative representable integer value to - 1.0.
Normals specified with glNormal need not have unit length. If normalization is enabled, then normals
specified with glNormal are normalized after transformation. To enable and disable normalization, call
glEnable and glDisable with the argument GL_NORMALIZE. Normalization is initially disabled.
Parameters
nx, ny, nz
v
Specify the x, y, and z coordinates of the new current
normal. The initial value of the current normal is the unit
vector, (0, 0, 1).
Specifies a pointer to an array of three elements: the x, y,
and z coordinates of the new current normal.
Notes
The current normal can be updated at any time. In particular, glNormal can be called between a call to
glBegin and the corresponding call to glEnd.
Associated Gets
glGet with argument GL_CURRENT_NORMAL
glIsEnabled with argument GL_NORMALIZE
Related Information
The glBegin subroutine, glColor subroutine, glIndex subroutine, glNormalPointer subroutine,
glTexCoord subroutine, and the glVertex subroutine.
glNormalPointer Subroutine
Purpose
Defines an array of normals.
Library
OpenGL C bindings library: libGL.a
244
OpenGL 2.1 Reference Manual
C Syntax
void glNormalPointer( GLenum
GLsizei stride,
const GLvoid * pointer)
type,
Description
The glNormalPointer subroutine specifies the location and data format of an array of normals to use
when rendering. The type parameter specifies the data type of the normal coordinates and stride gives the
byte stride from one normal to the next allowing vertices and attributes to be packed into a single array or
stored in separate arrays. (Single array storage may be more efficient on some implementations; see
glInterleavedArrays). When a normal array is specified, type, stride, and pointer are saved as client side
state.
To enable and disable the normal array, call glEnableClientState and glDisableClientState with the
argument GL_NORMAL_ARRAY. If enabled, the normal array is used when glDrawArrays,
glDrawElements or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Normal array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
pointer
Specifies the the data type of each coordinate in the array. Symbolic constants GL_BYTE,
GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Specifies the byte offset between consecutive normals. The initial value is 0.
Specifies a pointer to the first coordinate of the first normal in the array. The initial value is 0 (NULL
pointer).
Notes
The glNormalPointer subroutine is available only if the GL version is 1.1 or greater.
The normal array is initially disabled and it won’t be accessed when glArrayElement, glDrawElements or
glDrawArrays is called.
Execution of glNormalPointer is not allowed between glBegin and the corresponding glEnd, but an error
may or may not be generated. If an error is not generated, the operation is undefined.
The glNormalPointer subroutine is typically implemented on the client side with no protocol.
Since the normal array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
The glNormalPointer subroutine is not included in display lists.
Chapter 1. OpenGL Subroutines
245
Errors
v GL_INVALID_ENUM is generated if type is not an accepted value.
v GL_INVALID_VALUE is generated if stride is negative.
Associated Gets
v
v
v
v
glIsEnabled with argument GL_NORMAL_ARRAY
glGet with argument GL_NORMAL_ARRAY_TYPE
glGet with argument GL_NORMAL_ARRAY_STRIDE
glGetPointerv with argument GL_NORMAL_ARRAY_POINTER
Related Information
The glArrayElement subroutine, glColorPointer subroutine, glDrawArrays subroutine, glDrawElements
subroutine, glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine,
glIndexPointer subroutine, glNormalPointerListIBM subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glNormalPointerEXT Subroutine
Purpose
Defines an array of normals.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glNormalPointerEXT(GLenum
GLsizei stride,
GLsizei count,
const GLvoid *pointer)
type,
Description
glNormalPointerEXT specifies the location and data format of an array of normals to use when rendering.
type specifies the data type of the normal coordinates and stride gives the byte stride from one normal to
the next allowing vertexes and attributes to be packed into a single array or stored in separate arrays.
(Single-array storage may be more efficient on some implementations.) count indicates the number of
array elements (counting from the first) that are static. Static elements may be modified by the application,
but once they are modified, the application must explicitly respecify the array before using it for any
rendering. When a normal array is specified, type, stride, count and pointer are saved as client-side state,
and static array elements may be cached by the implementation.
The normal array is enabled and disabled using glEnable and glDisable with the argument
GL_NORMAL_ARRAY_EXT. If enabled, the normal array is used when glDrawArraysEXT or
glArrayElementEXT is called.
Use glDrawArraysEXT to define a sequence of primitives (all of the same type) from pre-specified vertex
and vertex attribute arrays. Use glArrayElementEXT to specify primitives by indexing vertexes and vertex
attributes.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
246
OpenGL 2.1 Reference Manual
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Normal array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
count
pointer
Specifies the the data type of each coordinate in the array. Symbolic constants GL_BYTE,
GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE_EXT are accepted.
Specifies the byte offset between consecutive normals.
Specifies the number of normals, counting from the first, that are static.
Specifies a pointer to the first coordinate of the first normal in the array.
Notes
Non-static array elements are not accessed until glArrayElementEXT or glDrawArraysEXT is executed.
By default the normal array is disabled and it won’t be accessed when glArrayElementEXT or
glDrawArraysEXT is called.
Although, it is not an error to call glNormalPointerEXT between the execution of glBegin and the
corresponding execution of glEnd, the results are undefined.
glNormalPointerEXT will typically be implemented on the client side with no protocol.
Since the normal array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib.
glNormalPointerEXT commands are not entered into display lists.
glNormalPointerEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Errors
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride or count is negative.
Associated Gets
glIsEnabled with argument GL_NORMAL_ARRAY_EXT .
glGet with argument GL_NORMAL_ARRAY_TYPE_EXT.
glGet with argument GL_NORMAL_ARRAY_STRIDE_EXT.
glGet with argument GL_NORMAL_ARRAY_COUNT_EXT.
glGetPointervEXT with argument GL_NORMAL_ARRAY_POINTER_EXT.
Chapter 1. OpenGL Subroutines
247
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glDrawArraysEXT subroutine,
glEdgeFlagPointerEXT subroutine, glGetPointervEXT subroutine, glIndexPointerEXT subroutine,
glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.
glNormalPointerListIBM Subroutine
Purpose
Defines a list of normal arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glNormalPointerListIBM(GLenum
GLint stride,
const GLvoid ** pointer,
GLint ptrstride)
type,
Description
The glNormalPointerListIBM subroutine specifies the location and data format of a list of arrays of
normal components to use when rendering. The type parameter specifies the data type of each normal
component. The stride parameter gives the byte stride from one normal to the next allowing vertices and
attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more
efficient on some implementations; see glInterleavedArrays). The ptrstride parameter specifies the byte
stride from one pointer to the next in the pointer array.
When a normal array is specified, type, stride, pointer and ptrstride are saved as client side state.
A stride value of 0 does not specify a ″tightly packed″ array as it does in glNormalPointer. Instead, it
causes the first array element of each array to be used for each vertex. Also, a negative value can be
used for stride, which allows the user to move through each array in reverse order.
To enable and disable the normal arrays, call glEnableClientState and glDisableClientState with the
argument GL_NORMAL_ARRAY. The normal array is initially disabled. When enabled, the normal arrays
are used when glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, glDrawArrays, glDrawElements or glArrayElement is called. The last
three calls in this list will only use the first array (the one pointed at by pointer[0]). See the descriptions of
these routines for more information on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
248
OpenGL 2.1 Reference Manual
If enabled, the Normal array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
type
stride
pointer
ptrstride
Specifies the data type of each normal component in the array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Specifies the byte offset between consecutive normal. The initial value is 0.
Specifies a list of normal arrays. The initial value is 0 (NULL pointer).
Specifies the byte stride between successive pointers in the pointer array. The initial value is 0.
Notes
The glNormalPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists extension is
supported.
Execution of glNormalPointerListIBM is not allowed between glBegin and the corresponding glEnd, but
an error may or may not be generated. If an error is not generated, the operation is undefined.
The glNormalPointerListIBM subroutine is typically implemented on the client side.
Since the normal array parameters are client side state, they are not saved or restored by glPushAttrib
and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glNormalPointerListIBM call is encountered while compiling a display list, the information it
contains does NOT contribute to the display list, but is used to update the immediate context instead.
The glNormalPointer call and the glNormalPointerListIBM call share the same state variables. A
glNormalPointer call will reset the normal list state to indicate that there is only one normal list, so that
any and all lists specified by a previous glNormalPointerListIBM call will be lost, not just the first list that
it specified.
Error Codes
GL_INVALID_ENUM is generated if type is not an accepted value.
Associated Gets
glIsEnabled with argument GL_NORMAL_ARRAY
glGetPointerv with argument GL_NORMAL_ARRAY_LIST_IBM
glGet with argument GL_NORMAL_ARRAY_LIST_STRIDE_IBM
glGet with argument GL_NORMAL_ARRAY_STRIDE
glGet with argument GL_NORMAL_ARRAY_TYPE
Related Information
The glArrayElement subroutine, glDrawArrays subroutine, glDrawElements subroutine,
glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine, glIndexPointer
subroutine, glInterleavedArrays subroutine, glMultiDrawArraysEXT subroutine,
glMultiDrawElementsEXT subroutine, glMultiModeDrawArraysIBM subroutine,
Chapter 1. OpenGL Subroutines
249
glMultiModeDrawElementsIBM subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine,
glPushClientAttrib subroutine, glTexCoordPointer subroutine, glVertexPointer subroutine.
glNormalVertexSUN Subroutine
Purpose
Specifies a normal and a vertex in one call.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glNormal3fVertex3fSUN (GLfloat nx,
GLfloat ny,
GLfloat nz,
GLfloat x,
GLfloat y,
GLfloat z)
void glNormal3fVertex3fvSUN (const GLfloat
const GLfloat
*n,
*v)
Description
This subroutine can be used as a replacement for the following calls:
glNormal();
glVertex();
For example, glNormal3fVertex3fvSUN replaces the following calls:
glNormal3f();
glVertex3fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
x, y, z
v
nx, ny, nz
n
Specifies the x, y, and z coordinates of a vertex. Not all
parameters are present in all forms of the command.
Specifies a pointer to an array of the three elements x, y,
and z.
Specify x, y, and z coordinates of the normal vector for
this vertex.
Specifies a pointer to an array of the three elements nx,
ny and nz.
Notes
Calling glNormalVertexSUN outside of a glBegin/glEnd subroutine pair results in undefined behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
250
OpenGL 2.1 Reference Manual
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
glOrtho Subroutine
Purpose
Multiplies the current matrix by an orthographic matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glOrtho(GLdouble Left,
GLdouble Right,
GLdouble Bottom,
GLdouble Top,
GLdouble Near,
GLdouble Far)
Description
The glOrtho subroutine describes a perspective matrix that produces a parallel projection. (Left, Bottom,
-Near) and (Right, Top, -Near) specify the points on the near clipping plane that are mapped to the lower
left and upper right corners of the window, respectively, assuming that the eye is located at (0, 0, 0). -Far
specifies the location of the far clipping plane. Both Near and Far can be either positive or negative. The
corresponding matrix is as follows:
2
0
0
tx
0
ty
Right–Left
2
0
Top–Bottom
–2
0
0
Far–Near
0
0
0
tz
1
Figure 16. Parallel Projection Perspective Matrix. This diagram shows a matrix enclosed in brackets. The matrix
consists of four lines containing four characters each. The first line contains the following (from left to right): 2 /
Right-Left, zero, zero, t subscript x. The second line contains the following (from left to right): zero, 2 / Top-Bottom,
zero, t subscript y. The third line contains the following (from left to right): zero, zero, -2 / Far-Near, t subscript z. The
fourth line contains the following (from left to right): zero, zero, zero, one.
where the following statements apply:
Chapter 1. OpenGL Subroutines
251
Right+Left
tx = –
Right–Left
Top+Bottom
ty = –
Top–Bottom
Far+Near
tz = –
Far–Near
Figure 17. Statements. This figure shows three equations. The first equation shows that t subscript x (from the above
matrix) is equal to negative Right+Left / Right–Left. The second equation shows that t subscript y (from the above
matrix) is equal to negative Top+Bottom / Top–Bottom. The third equation shows that t subscript z (from the above
matrix) is equal to negative Far+Near / Far–Near.
The current matrix is multiplied by this matrix with the result replacing the current matrix. That is, if M is
the current matrix and O is the ortho matrix, M is replaced with MO.
Use the glPushMatrix and glPopMatrix subroutines to save and restore the current matrix stack.
Parameters
Left, Right
Bottom, Top
Near, Far
Specify the coordinates for the left and right vertical clipping planes.
Specify the coordinates for the bottom and top horizontal clipping planes.
Specify the distances to the nearer and farther depth clipping planes. These distances are
negative if the plane is to be behind the viewer.
Errors
GL_INVALID_OPERATION
The glOrtho subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glOrtho subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFrustum subroutine, glMatrixMode subroutine, glMultMatrix
subroutine, glPushMatrix subroutine, glViewport subroutine.
252
OpenGL 2.1 Reference Manual
glPassThrough Subroutine
Purpose
Places a marker in the feedback buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPassThrough(GLfloat
Token)
Description
Feedback is a GL render mode. The mode is selected by calling the glRenderMode subroutine with
GL_FEEDBACK. When the GL is in feedback mode, no pixels are produced by rasterization. Instead,
information about primitives that would have been rasterized is fed back to the application using the GL.
See the glFeedbackBuffer subroutine for a description of the feedback buffer and the values in the
feedback buffer.
The glPassThrough subroutine inserts a user-defined marker in the feedback buffer when it is executed
in feedback mode. The Token parameter is returned as if it were a primitive; it is indicated with its own
unique identifying value: GL_PASS_THROUGH_TOKEN. The order of glPassThrough commands with
respect to the specification of graphics primitives is maintained.
Parameters
Token
Specifies a marker value to be placed in the feedback buffer following a GL_PASS_THROUGH_TOKEN
value.
Notes
The glPassThrough subroutine is ignored if the GL is not in feedback mode.
Errors
GL_INVALID_OPERATION
The glPassThrough subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPassThrough subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_RENDER_MODE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFeedbackBuffer subroutine, glRenderMode subroutine.
Chapter 1. OpenGL Subroutines
253
glPixelMap Subroutine
Purpose
Sets up pixel transfer maps.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPixelMapfv(GLenum Map,
GLint MapSize,
const GLfloat * Values)
void glPixelMapuiv(GLenum Map,
GLint MapSize,
const GLuint * Values)
void glPixelMapusv(GLenum Map,
GLint MapSize,
const GLushort * Values)
Description
The glPixelMap subroutine sets up translation tables, or maps, used by the glDrawPixels, glReadPixels,
glCopyPixels, glTexImage1D, and glTexImage2D subroutines. See the glPixelTransfer subroutine for a
complete description on using these maps. Use of these maps is also described in part in the pixel and
texture image subroutines. Only the specification of the maps is described here.
The Map parameter is a symbolic map name, indicating one of 10 maps to set. The MapSize parameter
specifies the number of entries in the map, and the Values parameter is a pointer to an array of MapSize
map values.
The 10 maps are:
GL_PIXEL_MAP_I_TO_I
GL_PIXEL_MAP_S_TO_S
GL_PIXEL_MAP_I_TO_R
GL_PIXEL_MAP_I_TO_G
GL_PIXEL_MAP_I_TO_B
GL_PIXEL_MAP_I_TO_A
GL_PIXEL_MAP_R_TO_R
GL_PIXEL_MAP_G_TO_G
GL_PIXEL_MAP_B_TO_B
GL_PIXEL_MAP_A_TO_A
Maps
Maps
Maps
Maps
Maps
Maps
Maps
Maps
Maps
Maps
color indexes to color indexes.
stencil indexes to stencil indexes.
color indexes to red components.
color indexes to green components.
color indexes to blue components.
color indexes to alpha components.
red components to red components.
green components to green components.
blue components to blue components.
alpha components to alpha components.
The entries in a map can be specified as single precision floating-point numbers, unsigned short integers,
or unsigned long integers. Maps that store color component values (all but the GL_PIXEL_MAP_I_TO_I
and GL_PIXEL_MAP_S_TO_S maps) retain their values in floating-point format, with unspecified mantissa
and exponent sizes. Floating-point values specified by glPixelMapfv are converted directly to the internal
floating-point format of these maps, then clamped to the range [0,1]. Unsigned integer values specified by
glPixelMapusv and glPixelMapuiv are converted linearly such that the largest representable integer
maps to 1.0, and 0 (zero) maps to 0.0.
254
OpenGL 2.1 Reference Manual
Maps that store indices, GL_PIXEL_MAP_I_TO_I and GL_PIXEL_MAP_S_TO_S, retain their values in
fixed-point format, with an unspecified number of bits to the right of the binary point. Floating-point values
specified by glPixelMapfv are converted directly to the internal fixed-point format of these maps. Unsigned
integer values specified by glPixelMapusv and glPixelMapuiv specify integer values, with all 0s to the
right of the binary point.
The following table shows the initial sizes and values for each of the maps. Maps that are indexed by
either color or stencil indexes must have MapSize = 2n for some n or results are undefined. The maximum
allowable size for each map depends on the implementation and can be determined by calling the glGet
subroutine with argument GL_MAX_PIXEL_MAP_TABLE. The single maximum applies to all maps, and it
is at least 32.
Map
Lookup Index
Lookup Value
Initial Size
Initial Value
GL_PIXEL_MAP_I_TO_I
color index
color index
1
0.0
GL_PIXEL_MAP_S_TO_S
stencil index
stencil index
1
0
GL_PIXEL_MAP_I_TO_R
color index
R
1
0.0
GL_PIXEL_MAP_I_TO_G
color index
G
1
0.0
GL_PIXEL_MAP_I_TO_B
color index
B
1
0.0
GL_PIXEL_MAP_I_TO_A
color index
A
1
0.0
GL_PIXEL_MAP_R_TO_R
R
R
1
0.0
GL_PIXEL_MAP_G_TO_G
G
G
1
0.0
GL_PIXEL_MAP_B_TO_B
B
B
1
0.0
GL_PIXEL_MAP_A_TO_A
A
A
1
0.0
Parameters
Map
Specifies a symbolic map name. Map must be one of the following:
v GL_PIXEL_MAP_I_TO_I
v GL_PIXEL_MAP_S_TO_S
v GL_PIXEL_MAP_I_TO_R
v GL_PIXEL_MAP_I_TO_G
v GL_PIXEL_MAP_I_TO_B
v GL_PIXEL_MAP_I_TO_A
v GL_PIXEL_MAP_R_TO_R
v GL_PIXEL_MAP_G_TO_G
v GL_PIXEL_MAP_B_TO_B
MapSize
Values
v GL_PIXEL_MAP_A_TO_A
Specifies the size of the map being defined.
Specifies an array of MapSize values.
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_VALUE
Map is not an accepted value.
MapSize is negative or larger than GL_MAX_PIXEL_MAP_TABLE.
Map is GL_PIXEL_MAP_I_TO_I, GL_PIXEL_MAP_S_TO_S,
GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G,
GL_PIXEL_MAP_I_TO_B, or GL_PIXEL_MAP_I_TO_A, and MapSize is not
a power of two.
Chapter 1. OpenGL Subroutines
255
GL_INVALID_OPERATION
The glPixelMap subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPixelMap subroutine are as follows. (See the glGet subroutine for more
information.)
glGetPixelMap
glGet with argument GL_PIXEL_MAP_I_TO_I_SIZE
glGet with argument GL_PIXEL_MAP_S_TO_S_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_R_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_G_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_B_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_A_SIZE
glGet with argument GL_PIXEL_MAP_R_TO_R_SIZE
glGet with argument GL_PIXEL_MAP_G_TO_G_SIZE
glGet with argument GL_PIXEL_MAP_B_TO_B_SIZE
glGet with argument GL_PIXEL_MAP_A_TO_A_SIZE
glGet with argument GL_MAX_PIXEL_MAP_TABLE.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCopyPixels subroutine, glDrawPixels subroutine, glGetPixelMap
subroutine, glPixelStore subroutine, glPixelTransfer subroutine, glReadPixels subroutine, glTexImage1D
subroutine, glTexImage2D subroutine.
glPixelStore Subroutine
Purpose
Sets pixel storage modes.
Library
OpenGL C bindings library: libGL.a
256
OpenGL 2.1 Reference Manual
C Syntax
void glPixelStoref(GLenum
GLfloat Parameter)
pName,
void glPixelStorei(GLenum
GLint Parameter)
pName,
Description
The glPixelStore subroutine sets pixel storage modes that affect the operation of subsequent
glDrawPixels and glReadPixels subroutines as well as the unpacking of polygon stipple patterns (see the
glPolygonStipple subroutine ), bitmaps (see the glBitmap subroutine ), and texture patterns (see the
glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3DEXT subroutine, glTexSubImage1D
subroutine, glTexSubImage2D subroutine, and the glTexSubImage3DEXT subroutine).
The pName parameter is a symbolic constant indicating the parameter to be set, and the Parameter
parameter is the new value. The following parameters affect how pixel data is returned to client memory,
and are therefore significant only for glReadPixels commands. They are as follows:
GL_PACK_SWAP_BYTES
GL_PACK_LSB_FIRST
GL_PACK_ROW_LENGTH
If True, byte ordering for multibyte color components, depth components,
color indexes, or stencil indexes is reversed. That is, if a 4-byte component is
made up of bytes b0, b1, b2, b3, it is stored in memory as b3, b2, b1, b0 if
GL_PACK_SWAP_BYTES is True. GL_PACK_SWAP_BYTES has no effect
on the memory order of components within a pixel, only on the order of bytes
within components or indexes. For example, the three components of a
GL_RGB format pixel are always stored with red first, green second, and blue
third, regardless of the value of GL_PACK_SWAP_BYTES.
If True, bits are ordered within a byte from least significant to most significant;
otherwise, the first bit in each byte is the most significant one. This parameter
is significant for bitmap data only.
If greater than 0 (zero), GL_PACK_ROW_LENGTH defines the number of
pixels in a row. If the first pixel of a row is placed at location p in memory, the
location of the first pixel of the next row is obtained by skipping the result of
the equation in Figure 18.
Where n is the number of components or indexes in a pixel, l is the number
of pixels in a row (GL_PACK_ROW_LENGTH if it is greater than 0;
otherwise, the width argument to the pixel routine), a is the value of
GL_PACK_ALIGNMENT, and s is the size, in bytes, of a single component (if
a < s, it is as if a = s). In the case of 1-bit values, the location of the next row
is obtained by skipping the result of the equation in Figure 19 on page 258.
The word component in this description refers the nonindex values red,
green, blue, alpha, and depth. Storage format GL_RGB, for example, has
three components per pixel; first red, then green, and finally blue.
nl
k=
s>a
a
snl
s
a
s<a
components
or indexes
Figure 18. GL_PACK_ROW_LENGTH Equation. This figure shows an equation where k is equal to the following two
lines preceded by a single curly brace: nl s greater than or equal to a. Below the first line is the second line as follows:
a / s [snl / a] s less than a components or indexes.
Chapter 1. OpenGL Subroutines
257
nl
k = 8a
8a
components
or indexes
Figure 19. GL_PACK_ROW_LENGTH 1–bit Values Equation. This figure shows an equation where k is equal to 8a[nl /
8a] components or indexes.
GL_PACK_IMAGE_HEIGHT
GL_PACK_SKIP_PIXELS,
GL_PACK_SKIP_ROWS, and
GL_PACK_SKIP_IMAGES
GL_PACK_ALIGNMENT
If greater than 0 (zero), GL_PACK_IMAGE_HEIGHT defines the number of
rows in a 3D image, otherwise the number of rows is defined to be the height
of the 3D image.
These values are provided as a convenience to the programmer; they provide
no functionality that cannot be duplicated simply by incrementing the pointer
passed to the glReadPixels subroutine. Setting GL_PACK_SKIP_PIXELS to
i is equivalent to incrementing the pointer by in components or indexes,
where n is the number of components or indexes in each pixel. Setting
GL_PACK_SKIP_ROWS to j is equivalent to incrementing the pointer by jk
components or indexes, where k is the number of components or indexes per
row, as computed in the GL_PACK_ROW_LENGTH section. Setting the
GL_PACK_SKIP_IMAGES to l is equivalent to incrementing the pointer by
lmk components or indexes, where m is the number of rows per image as
specified by GL_PACK_IMAGE_HEIGHT.
Specifies the alignment requirements for the start of each pixel row in
memory. The allowable values are 1 (one) (byte alignment), 2 (rows aligned
to even-numbered bytes), 4 (word alignment), and 8 (rows start on
double-word boundaries).
The remaining parameters affect how pixel data is read from client memory. These values are significant
for the glDrawPixels, glTexImage1D, glTexImage2D, glBitmap, and glPolygonStipple subroutines.
They are as follows:
GL_UNPACK_SWAP_BYTES
GL_UNPACK_LSB_FIRST
258
OpenGL 2.1 Reference Manual
If True, byte ordering for a multibyte color components, depth
components, color indexes, or stencil indexes is reversed. That is, if a
4-byte component is made up of bytes b0, b1, b2, b3, it is taken from
memory as b3, b2, b1, b0 if GL_UNPACK_SWAP_BYTES is True.
GL_UNPACK_SWAP_BYTES has no effect on the memory order of
components within a pixel, only on the order of bytes within
components or indexes. For example, the three components of a
GL_RGB format pixel are always stored with red first, green second,
and blue third, regardless of the value of
GL_UNPACK_SWAP_BYTES.
If True, bits are ordered within a byte from least significant to most
significant; otherwise, the first bit in each byte is the most significant
one. This is significant for bitmap data only.
GL_UNPACK_ROW_LENGTH
If greater than 0, GL_UNPACK_ROW_LENGTH defines the number
of pixels in a row. If the first pixel of a row is placed at location p in
memory, then the location of the first pixel of the next row is obtained
by skipping the result of the equation in Figure 20.
Where n is the number of components or indexes in a pixel, i is the
number of pixels in a row (GL_UNPACK_ROW_LENGTH if it is
greater than 0; otherwise, the width argument to the pixel routine), a
is the value of GL_UNPACK_ALIGNMENT, and s is the size, in
bytes, of a single component (if a < s, it is as if a = s). In the case of
1-bit values, the location of the next row is obtained by skipping the
result of the equation in Figure 21.
The word component in this description refers the nonindex values
red, green, blue, alpha, and depth. Storage format GL_RGB, for
example, has three components per pixel, first red, then green, and
finally blue.
nl
k=
s>a
a
snl
s
a
s<a
components
or indexes
Figure 20. GL_UNPACK_ROW_LENGTH Equation. This figure shows an equation where k is equal to the following
two lines preceded by a single curly brace: nl s greater than or equal to a. Below the first line is the second line as
follows: a / s [snl / a] s less than a components or indexes.
nl
k = 8a
8a
components
or indexes
Figure 21. GL_UNPACK_ROW_LENGTH 1–bit Values Equation. This figure shows an equation where k is equal to
8a[nl / 8a] components or indexes.
GL_UNPACK_IMAGE_HEIGHT
GL_UNPACK_SKIP_PIXELS,
GL_UNPACK_SKIP_ROWS, and
GL_UNPACK_SKIP_IMAGES
If greater than 0 (zero), GL_UNPACK_IMAGE_HEIGHT defines the
number of rows in a 3D image, otherwise the number of rows is
defined to be the height of the 3D image.
These values are provided as a convenience to the programmer; they
provide no functionality that cannot be duplicated simply by
incrementing the pointer passed to glDrawPixels, glTexImage1D,
glTexImage2D, glTexImage3DEXT, glBitmap, or glPolygonStipple.
Setting GL_UNPACK_SKIP_PIXELS to i is equivalent to incrementing
the pointer by in components or indexes, where n is the number of
components or indexes in each pixel. Setting
GL_UNPACK_SKIP_ROWS to j is equivalent to incrementing the
pointer by jk components or indexes, where k is the number of
components or indexes per row, as computed in the
GL_UNPACK_ROW_LENGTH section. Setting the
GL_UNPACK_SKIP_IMAGES to l is equivalent to incrementing the
pointer by lmk components or indexes, where m is the number of
rows per image as specified by GL_UNPACK_IMAGE_HEIGHT.
Chapter 1. OpenGL Subroutines
259
GL_UNPACK_ALIGNMENT
Specifies the alignment requirements for the start of each pixel row in
memory. The allowable values are 1 (byte alignment), 2 (rows aligned
to even-numbered bytes), 4 (word alignment), and 8 (rows start on
double-word boundaries).
The following table gives the type, initial value, and range of valid values for each of the storage
parameters that can be set with glPixelStore.
pName
Type
Initial Value
Valid Range
GL_PACK_SWAP_BYTES
Boolean
False
True or False
GL_PACK_LSB_FIRST
Boolean
False
True or False
GL_PACK_ROW_LENGTH
integer
0
[0,+infinity)
GL_PACK_SKIP_ROWS
integer
0
[0,+infinity)
GL_PACK_SKIP_PIXELS
integer
0
[0,+infinity)
GL_PACK_ALIGNMENT
integer
4
1, 2, 4, or 8
GL_PACK_IMAGE_HEIGTH
integer
0
[0,+infinity)
GL_PACK_SKIP_IMAGES
integer
0
[0,+infinity)
GL_UNPACK_SWAP_BYTES
Boolean
False
True or False
GL_UNPACK_LSB_FIRST
Boolean
False
True or False
GL_UNPACK_ROW_LENGTH
integer
0
[0,+infinity)
GL_UNPACK_SKIP_ROWS
integer
0
[0,+infinity)
GL_UNPACK_SKIP_PIXELS
integer
0
[0,+infinity)
GL_UNPACK_ALIGNMENT
integer
4
1, 2, 4, or 8
GL_UNPACK_IMAGE_HEIGTH
integer
0
[0,+infinity)
GL_UNPACK_SKIP_IMAGES
integer
0
[0,+infinity)
The glPixelStoref subroutine can be used to set any pixel store parameter. If the parameter type is
Boolean, and if Parameter is 0.0, the parameter is False; otherwise it is set to True. If pName is an integer
type parameter, Parameter is rounded to the nearest integer.
Likewise, glPixelStorei can also be used to set any of the pixel store parameters. Boolean parameters are
set to False if Parameter is 0 and True otherwise. Parameter is converted to floating-point format before
being assigned to real-valued parameters.
260
OpenGL 2.1 Reference Manual
Parameters
pName
Specifies the symbolic name of the parameter to be set. The following values affect the packing of pixel
data into memory:
v GL_PACK_SWAP_BYTES
v GL_PACK_LSB_FIRST
v GL_PACK_ROW_LENGTH
v GL_PACK_SKIP_PIXELS
v GL_PACK_SKIP_ROWS
v GL_PACK_ALIGNMENT
v GL_PACK_IMAGE_HEIGHT
v GL_PACK_SKIP_IMAGES
The following values affect the unpacking of pixel data from memory:
v GL_UNPACK_SWAP_BYTES
v GL_UNPACK_LSB_FIRST
v GL_UNPACK_ROW_LENGTH
v GL_UNPACK_SKIP_PIXELS
v GL_UNPACK_SKIP_ROWS
v GL_UNPACK_ALIGNMENT
v GL_UNPACK_IMAGE_HEIGHT
v GL_UNPACK_SKIP_IMAGES
Notes
The pixel storage modes in effect when glDrawPixels, glReadPixels, glTexImage, glBitmap, or
glPolygonStipple is placed in a display list control the interpretation of memory data. The pixel storage
modes in effect when a display list is executed are not significant.
Errors
GL_INVALID_ENUM
GL_INVALID_VALUE
pName is not an accepted value.
A negative row length, pixel skip, or row skip value is specified, or alignment is
specified as other than 1, 2, 4, or 8.
Associated Gets
Associated gets for the glPixelStore subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_PACK_SWAP_BYTES
glGet with argument GL_PACK_LSB_FIRST
glGet with argument GL_PACK_ROW_LENGTH
glGet with argument GL_PACK_SKIP_ROWS
glGet with argument GL_PACK_SKIP_PIXELS
glGet with argument GL_PACK_ALIGNMENT
glGet with argument GL_PACK_IMAGE_HEIGTH
Chapter 1. OpenGL Subroutines
261
glGet with argument GL_PACK_SKIP_IMAGES
glGet with argument GL_UNPACK_SWAP_BYTES
glGet with argument GL_UNPACK_LSB_FIRST
glGet with argument GL_UNPACK_ROW_LENGTH
glGet with argument GL_UNPACK_SKIP_ROWS
glGet with argument GL_UNPACK_SKIP_PIXELS
glGet with argument GL_UNPACK_ALIGNMENT.
glGet with argument GL_UNPACK_IMAGE_HEIGTH
glGet with argument GL_UNPACK_SKIP_IMAGES
GL_INVALID_OPERATION
The glPixelStore subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glBitmap subroutine, glDrawPixels subroutine, glPixelMap subroutine,
glPixelTransfer subroutine, glPixelZoom subroutine, glPolygonStipple subroutine, glReadPixels
subroutine, glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3DEXT subroutine,
glTexSubImage1D subroutine, glTexSubImage2D subroutine, glTexSubImage3DEXT subroutine.
glPixelTransfer Subroutine
Purpose
Sets pixel transfer modes.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPixelTransferf(GLenum
GLfloat Parameter)
pName,
void glPixelTransferi(GLenum
GLint Parameter)
pName,
Description
The glPixelTransfer subroutine sets pixel transfer modes that affect the operation of subsequent
glDrawPixels, glReadPixels, glCopyPixels, glCopyTexImage1D, glCopyTexImage2D,
glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3DEXT, glTexImage1D,
262
OpenGL 2.1 Reference Manual
glTexImage2D, glTexImage3DEXT, glTexSubImage1D, glTexSubImage2D, and glTexSubImage3DEXT
subroutines. The algorithms that are specified by pixel transfer modes operate on pixels after they are
read from the frame buffer (glReadPixels and glCopyPixels) or unpacked from client memory
(glDrawPixels, glReadPixels, glCopyPixels, glCopyTexImage1D, glCopyTexImage2D,
glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3DEXT, glTexImage1D,
glTexImage2D, glTexImage3DEXT, glTexSubImage1D, glTexSubImage2D, and glTexSubImage3DEXT
subroutines). Pixel transfer operations happen in the same order, and in the same manner, regardless of
the command that resulted in the pixel operation. Pixel storage modes control the unpacking of pixels
being read from client memory and the packing of pixels being written back into client memory. (See the
glPixelStore subroutine for information on setting pixel storage modes.)
Pixel transfer operations handle four fundamental pixel types: color, color index, depth, and stencil. Color
pixels are made up of four floating-point values with unspecified mantissa and exponent sizes, scaled such
that 0.0 represents 0 (zero) intensity and 1.0 represents full intensity. Color indexes comprise a single
fixed-point value, with unspecified precision to the right of the binary point. Depth pixels comprise a single
floating-point value, with unspecified mantissa and exponent sizes, scaled such that 0.0 represents the
minimum depth buffer value and 1.0 represents the maximum depth buffer value. Finally, stencil pixels
comprise a single fixed-point value, with unspecified precision to the right of the binary point.
The pixel transfer operations performed on the four basic pixel types are as follows:
color
Each of the four color components is multiplied by a scale factor, then added to a bias factor.
That is, the red component is multiplied by GL_RED_SCALE, then added to GL_RED_BIAS;
the green component is multiplied by GL_GREEN_SCALE, then added to GL_GREEN_BIAS;
the blue component is multiplied by GL_BLUE_SCALE, then added to GL_BLUE_BIAS; and
the alpha component is multiplied by GL_ALPHA_SCALE, then added to GL_ALPHA_BIAS.
After all four color components are scaled and biased, each is clamped to the range [0,1]. All
color scale and bias values are specified with glPixelTransfer.
If GL_MAP_COLOR is True, each color component is scaled by the size of the corresponding
color-to-color map, then replaced by the contents of that map indexed by the scaled
component. That is, the red component is scaled by GL_PIXEL_MAP_R_TO_R_SIZE, then
replaced by the contents of GL_PIXEL_MAP_R_TO_R indexed by itself. The green component
is scaled by GL_PIXEL_MAP_G_TO_G_SIZE, then replaced by the contents of
GL_PIXEL_MAP_G_TO_G indexed by itself. The blue component is scaled by
GL_PIXEL_MAP_B_TO_B_SIZE, then replaced by the contents of GL_PIXEL_MAP_B_TO_B
indexed by itself. The alpha component is scaled by GL_PIXEL_MAP_A_TO_A_SIZE, then
replaced by the contents of GL_PIXEL_MAP_A_TO_A indexed by itself. All components taken
from the maps are then clamped to the range [0,1]. GL_MAP_COLOR is specified with
glPixelTransfer. The contents of the various maps are specified with the glPixelMap
subroutine.
Chapter 1. OpenGL Subroutines
263
color index
Each color index is shifted left by GL_INDEX_SHIFT bits, and any bits beyond the number of
fraction bits carried by the fixed-point index are filled with 0s. If GL_INDEX_SHIFT is negative,
the shift is to the right, again 0 filled. Then GL_INDEX_OFFSET is added to the index.
GL_INDEX_SHIFT and GL_INDEX_OFFSET are specified with glPixelTransfer.
From this point, operation diverges depending on the required format of the resulting pixels. If
the resulting pixels are to be written to a color index buffer, or if they are being read back to
client memory in GL_COLOR_INDEX format, the pixels continue to be treated as indexes. If
GL_MAP_COLOR is True, each index is masked by 2n-1, where n is
GL_PIXEL_MAP_I_TO_I_SIZE, then replaced by the contents of GL_PIXEL_MAP_I_TO_I
indexed by the masked value. GL_MAP_COLOR is specified with glPixelTransfer. The
contents of the index map are specified with the glPixelMap subroutine.
If the resulting pixels are to be written to a red, green, blue, alpha (RGBA) color buffer, or if
they are being read back to client memory in a format other than GL_COLOR_INDEX, the
pixels are converted from indexes to colors by referencing the four maps
GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A. Before being dereferenced, the index is masked by 2n-1, where n is
GL_PIXEL_MAP_I_TO_R_SIZE for the red map, GL_PIXEL_MAP_I_TO_G_SIZE for the green
map, GL_PIXEL_MAP_I_TO_B_SIZE for the blue map, and GL_PIXEL_MAP_I_TO_A_SIZE
for the alpha map. All components taken from the maps are then clamped to the range [0,1].
The contents of the four maps are specified with the glPixelMap subroutine.
Each depth value is multiplied by GL_DEPTH_SCALE, added to GL_DEPTH_BIAS, then
clamped to the range [0,1].
Each index is shifted GL_INDEX_SHIFT bits just as a color index is, then added to
GL_INDEX_OFFSET. If GL_MAP_STENCIL is True, each index is masked by 2n-1, where n is
GL_PIXEL_MAP_S_TO_S_SIZE, then replaced by the contents of GL_PIXEL_MAP_S_TO_S
indexed by the masked value.
depth
stencil
The following table gives the type, initial value, and range of valid values for each of the pixel transfer
parameters that are set with glPixelTransfer.
pName
Type
Initial Value
Valid Range
GL_MAP_COLOR
Boolean
False
True or False
GL_MAP_STENCIL
Boolean
False
True or False
GL_INDEX_SHIFT
integer
0
(-infinity,+infinity)
GL_INDEX_OFFSET
integer
0
(-infinity,+infinity)
GL_RED_SCALE
float
1.0
(-infinity,+infinity)
GL_GREEN_SCALE
float
1.0
(-infinity,+infinity)
GL_BLUE_SCALE
float
1.0
(-infinity,+infinity)
GL_ALPHA_SCALE
float
1.0
(-infinity,+infinity)
GL_DEPTH_SCALE
float
1.0
(-infinity,+infinity)
GL_RED_BIAS
float
0.0
(-infinity,+infinity)
GL_GREEN_BIAS
float
0.0
(-infinity,+infinity)
GL_BLUE_BIAS
float
0.0
(-infinity,+infinity)
GL_ALPHA_BIAS
float
0.0
(-infinity,+infinity)
GL_DEPTH_BIAS
float
0.0
(-infinity,+infinity)
The glPixelTransferf subroutine can be used to set any pixel transfer parameter. If the parameter type is
Boolean, 0.0 implies False and any other value implies True. If pName is an integer parameter, Parameter
is rounded to the nearest integer.
264
OpenGL 2.1 Reference Manual
Likewise, glPixelTransferi can be used to set any of the pixel transfer parameters. Boolean parameters
are set to False if Parameter is 0 and True otherwise. Parameter is converted to floating-point format
before being assigned to real-valued parameters.
Parameters
pName
Specifies the symbolic name of the pixel transfer parameter to be set. Must be one of the following:
v GL_MAP_COLOR
v GL_MAP_STENCIL
v GL_INDEX_SHIFT
v GL_INDEX_OFFSET
v GL_RED_SCALE
v GL_RED_BIAS
v GL_GREEN_SCALE
v GL_GREEN_BIAS
v GL_BLUE_SCALE
v GL_BLUE_BIAS
v GL_ALPHA_SCALE
v GL_ALPHA_BIAS
v GL_DEPTH_SCALE
Parameter
v GL_DEPTH_BIAS
Specifies the value to which pName is set.
Notes
If a glDrawPixels, glReadPixels, glCopyPixels, glTexImage1D, or glTexImage2D subroutine is placed
in a display list (see the glNewList subroutine and the glCallList subroutine for information about display
lists), the pixel transfer mode settings in effect when the display list is executed are the ones that are
used. They may be different from the settings when the command was compiled into the display list.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
pName is not an accepted value.
The glPixelTransfer subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPixelTransfer subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MAP_COLOR
glGet with argument GL_MAP_STENCIL
glGet with argument GL_INDEX_SHIFT
glGet with argument GL_INDEX_OFFSET
glGet with argument GL_RED_SCALE
glGet with argument GL_RED_BIAS
Chapter 1. OpenGL Subroutines
265
glGet with argument GL_GREEN_SCALE
glGet with argument GL_GREEN_BIAS
glGet with argument GL_BLUE_SCALE
glGet with argument GL_BLUE_BIAS
glGet with argument GL_ALPHA_SCALE
glGet with argument GL_ALPHA_BIAS
glGet with argument GL_DEPTH_SCALE
glGet with argument GL_DEPTH_BIAS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCallList subroutine, glCopyPixels subroutine, glCopyTexImage1D
subroutine, glCopyTexImage2D subroutine, glCopyTexSubImage1D subroutine, glCopyTexSubImage2D
subroutine, glCopyTexSubImage3DEXT subroutine, glDrawPixels subroutine, glNewList subroutine,
glPixelMap subroutine, glPixelStore subroutine, glPixelZoom subroutine, glReadPixels subroutine,
glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3DEXT subroutine, glTexSubImage1D
subroutine, glTexSubImage2D subroutine, glTexSubImage3DEXT subroutine, .
glPixelZoom Subroutine
Purpose
Specifies the pixel zoom factors.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPixelZoom(GLfloat xFactor,
GLfloat yFactor)
Parameters
xFactor and yFactor
Specify the x and y zoom factors for pixel write operations.
Description
The glPixelZoom subroutine specifies values for the x and y zoom factors. During the execution of the
glDrawPixels or glCopyPixels subroutines, if (xr, yr) is the current raster position, and a given element is
in the nth row and mth column of the pixel rectangle, then pixels whose centers are in the rectangle with
corners at
(xr + n x xFactor, yr + m x yFactor)
266
OpenGL 2.1 Reference Manual
and
(xr + (n+1) x xFactor, yr + (m+1) x yFactor)
are candidates for replacement. Any pixel whose center lies on the bottom or left edge of this rectangular
region is also modified.
Pixel zoom factors are not limited to positive values. Negative zoom factors reflect the resulting image
about the current raster position.
Errors
GL_INVALID_OPERATION
The glPixelZoom subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPixelZoom subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_ZOOM_X.
glGet with argument GL_ZOOM_Y.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCopyPixels subroutine, glDrawPixels subroutine.
glPointSize Subroutine
Purpose
Specifies the diameter of rasterized points.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPointSize(GLfloat
Size)
Description
The glPointSize subroutine specifies the rasterized diameter of both aliased and antialiased points. Using
a point size other than 1.0 has different effects, depending on whether point antialiasing is enabled. Point
antialiasing is controlled by calling the glEnable and glDisable subroutines with argument
GL_POINT_SMOOTH.
If point antialiasing is disabled, the actual size is determined by rounding the supplied size to the nearest
integer. (If the rounding results in the value 0 (zero), it is as if the point size were 1 (one).) If the rounded
size is odd, the center point (x, y) of the pixel fragment that represents the point is computed as
Chapter 1. OpenGL Subroutines
267
(floor(xw) + 0.5, floor(yw) + 0.5)
where w subscripts indicate window coordinates. All pixels that lie within the square grid of the rounded
size centered at (x, y) make up the fragment. If the size is even, the center point is
(floor(xw + 0.5), floor(yw + 0.5))
and the rasterized fragment’s centers are the half-integer window coordinates within the square of the
rounded size centered at (x, y). All pixel fragments produced in rasterizing a nonantialiased point are
assigned the same associated data, that of the vertex corresponding to the point.
If antialiasing is enabled, point rasterization produces a fragment for each pixel square that intersects the
region lying within the circle having diameter equal to the current point size and centered at the point’s
(xw, yw). The coverage value for each fragment is the window coordinate area of the intersection of the
circular region with the corresponding pixel square. This value is saved and used in the final rasterization
step. The data associated with each fragment is the data associated with the point being rasterized.
Not all sizes are supported when point antialiasing is enabled. If an unsupported size is requested, the
nearest supported size is used. Only size 1.0 is guaranteed to be supported; others are dependent on the
implementation. The range of supported sizes and the size difference between supported sizes within the
range can be queried by calling the glGet subroutine with the GL_POINT_SIZE_RANGE and
GL_POINT_SIZE_GRANULARITY arguments.
Notes
The point size specified by glPointSize is always returned when GL_POINT_SIZE is queried. Clamping
and rounding for aliased and antialiased points have no effect on the specified value.
Nonantialiased point size may be clamped to a maximum that depends on the implementation. Although
this maximum cannot be queried, it must be no less than the maximum value for antialiased points,
rounded to the nearest integer value.
Parameters
Size
Specifies the diameter of rasterized points. The default is 1.0.
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
Size is less than or equal to 0.
The glPointSize subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPointSize subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_POINT_SIZE
glGet with argument GL_POINT_SIZE_RANGE
glGet with argument GL_POINT_SIZE_GRANULARITY
glIsEnabled with argument GL_POINT_SMOOTH.
268
OpenGL 2.1 Reference Manual
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable or Disable subroutine.
glPolygonMode Subroutine
Purpose
Selects a polygon rasterization mode.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPolygonMode(GLenum
GLenum Mode)
Face,
Description
The glPolygonMode subroutine controls the interpretation of polygons for rasterization. The Face
parameter describes which polygons the Mode parameters applies to: frontfacing polygons (GL_FRONT),
backfacing polygons (GL_BACK), or both (GL_FRONT_AND_BACK). The polygon mode affects only the
final rasterization of polygons. In particular, a polygon’s vertices are lit and the polygon is clipped and
possibly culled before these modes are applied.
Three modes are defined and can be specified in the Mode parameter:
GL_POINT
GL_LINE
GL_FILL
Polygon vertices that are marked as the start of a boundary edge are drawn as points. Point
attributes such as GL_POINT_SIZE and GL_POINT_SMOOTH control the rasterization of the points.
Polygon rasterization attributes other than GL_POLYGON_MODE have no effect.
Boundary edges of the polygon are drawn as line segments. They are treated as connected line
segments for line stippling; the line stipple counter and pattern are not reset between segments. (See
the glLineStipple subroutine for information on specifying the line stipple pattern.) Line attributes
such as GL_LINE_WIDTH and GL_LINE_SMOOTH control the rasterization of the lines. Polygon
rasterization attributes other than GL_POLYGON_MODE have no effect.
The interior of the polygon is filled. Polygon attributes such as GL_POLYGON_STIPPLE and
GL_POLYGON_SMOOTH control the rasterization of the polygon.
Parameters
Face
Mode
Specifies the polygons to which Mode applies. Must be GL_FRONT for frontfacing polygons, GL_BACK for
backfacing polygons, or GL_FRONT_AND_BACK for frontfacing and backfacing polygons.
Specifies the way polygons are rasterized. Accepted values are GL_POINT, GL_LINE, and GL_FILL. The
default is GL_FILL for both frontfacing and backfacing polygons.
Notes
Vertices are marked as boundary or nonboundary with an edge flag. Edge flags are generated internally
by the GL when it decomposes polygons, and they can be set explicitly with the glEdgeFlag subroutine.
Chapter 1. OpenGL Subroutines
269
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Face or Mode is not an accepted value.
The glPolygonMode subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPolygonMode subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_POLYGON_MODE.
Examples
To draw a surface with filled backfacing polygons and outlined frontfacing polygons, enter the following:
glPolygonMode(GL_FRONT, GL_LINE);
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEdgeFlag subroutine, glLineStipple subroutine, glLineWidth
subroutine, glPointSize subroutine, glPolygonStipple subroutine.
glPolygonOffset Subroutine
Purpose
Sets the scale and bias used to calculate depth values.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPolygonOffset(GLfloat
GLfloat units)
factor,
Description
When GL_POLYGON_OFFSET is enabled, each fragment’s depth value will be offset after it is
interpolated from the depth values of the appropriate vertices. The value of the offset is factor * DZ + r *
units, where DZ is a measurement of the change in depth relative to the screen area of the polygon, and r
is the smallest value which is guaranteed to produce a resolveable offset for a given implementation. The
offset is added before the depth test is performed and before the value is written into the depth buffer.
This is useful for rendering hidden line images, for applying decals to surfaces, and for rendering solids
with highlighted edges.
270
OpenGL 2.1 Reference Manual
Parameters
factor
units
Specifies a scale factor which is used to create a variable depth offset for each polygon. The initial value
is 0.
Is multiplied by an implementation specific value to create a constant depth offset. The initial value is 0.
Notes
The glPolygonOffset subroutine is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_OPERATION is generated if glPolygonOffset is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glIsEnabled with argument GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFFSET_LINE, or
GL_POLYGON_OFFSET_POINT.
glGet with argument GL_POLYGON_OFFSET_FACTOR or GL_POLYGON_OFFSET_UNITS.
Related Information
The glDepthFunc subroutine, glDisable subroutine, glEnable subroutine, glGet subroutine, glIsEnabled
subroutine, glLineWidth subroutine, glStencilOp subroutine, glTexEnv subroutine.
glPolygonOffsetEXT Subroutine
Purpose
Sets the scale and bias used to calculate z values.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPolygonOffsetEXT(GLfloat
GLfloat bias)
factor,
Description
When GL_POLYGON_OFFSET_EXT is enabled, each fragment’s z value will be offset after it is
interpolated from the z values of the appropriate vertices. The value of the offset is factor * DZ + bias,
where DZ is a measurement of the change in z relative to the screen area of the polygon. The offset is
added before the Depth Test is performed and before the value is written into the Depth Buffer.
Initially GL_POLYGON_OFFSET_FACTOR_EXT and GL_POLYGON_OFFSET_BIAS_EXT are both set to
0.0.
This is useful for rendering hidden line images, for applying decals to surfaces, and for rendering solids
with highlighted edges.
Parameters
factor
specifies a scale factor which is used to create a offset for each polygon.
Chapter 1. OpenGL Subroutines
271
bias
specifies a constant which is added to each polygon’s z offset.
Notes
glPolygonOffsetEXT is part of the EXT_polygon_offset extension, not part of the core GL command set.
If GL_EXT_polygon_offset is included in the string returned by glGetString, when called with argument
GL_EXTENSIONS, extension EXT_polygon_offset is supported by the connection.
Errors
GL_INVALID_OPERATION is generated if glPolygonOffsetEXT is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glIsEnabled with argument GL_POLYGON_OFFSET_EXT.
glGet with argument GL_POLYGON_OFFSET_FACTOR_EXT or GL_POLYGON_OFFSET_BIAS_EXT .
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glDepthFunc subroutine, glEnable orglDisable subroutine, glGet subroutine, glIsEnabled
subroutine, glLineWidth subroutine, glStencilOp subroutine, glTexEnv subroutine.
glPolygonStipple Subroutine
Purpose
Sets the polygon stippling pattern.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPolygonStipple(const GLubyte * Mask)
Description
Polygon stippling, like line stippling, masks out certain fragments produced by rasterization, creating a
pattern. (See the glLineStipple subroutine .) Stippling is independent of polygon antialiasing.
The Mask parameter is a pointer to a 32 x 32 stipple pattern that is stored in memory just like the pixel
data supplied to a glDrawPixels subroutine with height and width both equal to 32, a pixel format of
GL_COLOR_INDEX, and data type of GL_BITMAP. That is, the stipple pattern is represented as a 32 x
32 array of 1-bit color indexes packed in unsigned bytes. The glPixelStore subroutine parameters such as
GL_UNPACK_SWAP_BYTES and GL_UNPACK_LSB_FIRST affect the assembling of the bits into a
stipple pattern. Pixel transfer operations (shift, offset, pixel map) are not applied to the stipple image,
however.
272
OpenGL 2.1 Reference Manual
Polygon stippling is enabled and disabled with the glEnable/glDisable subroutine pair, using argument
GL_POLYGON_STIPPLE. If enabled, a rasterized polygon fragment with window coordinates xw and yw
is sent to the next stage of the GL if and only if the (xw mod 32)th bit in the (yw mod 32)th row of the
stipple pattern is 1 (one). When polygon stippling is disabled, it is as if the stipple pattern were all 1s.
Parameters
Mask
Specifies a pointer to a 32 x 32 stipple pattern that is unpacked from memory in the same way that the
glDrawPixels subroutine unpacks pixels.
Associated Gets
Associated gets for the glPolygonStipple subroutine are as follows. (See the glGet subroutine for more
information.)
glGetPolygonStipple
glIsEnabled with argument GL_POLYGON_STIPPLE.
Error Codes
GL_INVALID_OPERATION
The glPolygonStipple subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glDrawPixels subroutine, glEnable or glDisable subroutine,
glGetPolygonStipple subroutine, glLineStipple subroutine, glPixelStore subroutine, glPixelTransfer
subroutine.
glPrioritizeTextures Subroutine
Purpose
Sets texture residence priority.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPrioritizeTextures(GLsizei n,
const GLuint *textures,
const GLclampf *priorities)
Parameters
n
textures
Specifies the number of textures to be prioritized.
Specifies an array containing the names of the textures to be prioritized.
Chapter 1. OpenGL Subroutines
273
priorities
Specifies an array containing the texture priorities. A priority given in an element of priorities
applies to the texture named by the corresponding element of textures.
Description
The glPrioritizeTextures subroutine assigns the n texture priorities given in priorities to the n textures
named in textures.
On machines with a limited amount of texture memory, GL establishes a ′′working set’’ of textures that are
resident in texture memory. These textures may be bound to a texture target much more efficiently than
textures that are not resident. By specifying a priority for each texture, glPrioritizeTextures allows
applications to guide the GL implementation in determining which textures should be resident.
The priorities given in priorities are clamped to the range [0.0, 1.0] before being assigned. Zero indicates
the lowest priority; textures with priority zero are least likely to be resident. One indicates the highest
priority; textures with priority one are most likely to be resident. However, textures are not guaranteed to
be resident until they are bound.
The glPrioritizeTextures subroutine silently ignores attempts to prioritize texture zero, or any texture
name that does not correspond to an existing texture.
The glPrioritizeTextures subroutine does not require that any of the textures named by textures be bound
to a texture target. It can also be used to set the priority of a texture, but only if the texture is currently
bound. This is the only way to set the priority of a default texture.
The glPrioritizeTextures subroutine is included in display lists.
Notes
The glPrioritizeTextures subroutine is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glPrioritizeTextures is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexParameter with parameter name GL_TEXTURE_PRIORITY retrieves the priority of a currently
bound texture.
Related Information
The glAreTexturesResident subroutine, glBindTexture subroutine, glTexImage1D subroutine,
glTexImage2D subroutine, glTexImage3DEXT subroutine, glTexParameter subroutine.
glPrioritizeTexturesEXT Subroutine
Purpose
Sets texture residence priority.
Library
OpenGL C bindings library: libGL.a
274
OpenGL 2.1 Reference Manual
C Syntax
void glPrioritizeTexturesEXT(GLsizei n,
const GLuint *textures,
const GLclampf *priorities)
Parameters
n
textures
priorities
The number of textures to be prioritized.
An array containing the names of the textures to be prioritized.
An array containing the texture priorities. A priority given in an element of priorities applies to the
texture named by the corresponding element of textures.
Description
glPrioritizeTexturesEXT assigns the n texture priorities given in priorities to the n textures named in
textures.
On machines with a limited amount of texture memory, OpenGL establishes a ′′working set’’ of textures
that are resident in texture memory. These textures may be bound to a texture target much more efficiently
than textures that are not resident. By specifying a priority for each texture, glPrioritizeTexturesEXT
allows applications to guide the OpenGL implementation in determining which textures should be resident.
The priorities given in priorities are clamped to the range [0.0, 1.0] before being assigned. Zero indicates
the lowest priority, and hence textures with priority zero are least likely to be resident. One indicates the
highest priority, and hence textures with priority one are most likely to be resident. However, textures are
not guaranteed to be resident until they are bound.
glPrioritizeTexturesEXT silently ignores attempts to prioritize texture zero, or any texture name that does
not correspond to an existing texture.
glPrioritizeTexturesEXT does not require that any of the textures named by textures be bound to a
texture target. glTexParameter may also be used to set a texture’s priority, but only if the texture is
currently bound. This is the only way to set the priority of a default texture.
glPrioritizeTexturesEXT is included in display lists.
Notes
glPrioritizeTexturesEXT is part of the EXT_texture_object extension, not part of the core GL command
set. If GL_EXT_texture_object is included in the string returned by glGetString, when called with
argument GL_EXTENSIONS, extension EXT_texture_object is supported by the connection.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glPrioritizeTexturesEXT is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexParameter with parameter name GL_TEXTURE_PRIORITY_EXT retrieves the priority of a
currently-bound texture.
Chapter 1. OpenGL Subroutines
275
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glAreTexturesResidentEXT subroutine, glBindTextureEXT subroutine, glTexImage1D subroutine,
glTexImage2D subroutine, glTexImage3DEXT subroutine, glTexParameter subroutine.
glPushAttrib or glPopAttrib Subroutine
Purpose
Pushes and pops the attribute stack.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPushAttrib(GLbitfield mask)
void glPopAttrib(void)
Parameters
mask
Specifies a mask that indicates which attributes to save. Values for Mask are provided in the preceding list.
Description
The glPushAttrib subroutine takes one argument, a mask that indicates which groups of state variables to
save on the attribute stack. Symbolic constants are used to set bits in the mask. The Mask parameter is
typically constructed by ORing several of these constants together. The GL_ALL_ATTRIB_BITS special
mask can be used to save all stackable states.
The symbolic mask constants and their associated GL states are in the following list.
Mask
GL_ACCUM_BUFFER_BIT
Attributes saved
Accumulation buffer clear value
GL_COLOR_BUFFER_BIT
GL_ALPHA_TEST enable bit
Alpha test function and reference value
GL_BLEND enable bit
Blending source and destination functions
GL_COLOR_LOGIC_OP enable bit
GL_DITHER enable bit
GL_DRAW_BUFFER setting
GL_LOGIC_OP enable bit
Logic op function
Color mode and index mode clear values
Color mode and index mode write masks
GL_BLEND_EQUATION_EXT setting
GL_CURRENT_BIT
Current red, green, blue, alpha (RGBA) color
276
OpenGL 2.1 Reference Manual
GL_DEPTH_BUFFER_BIT
GL_ENABLE_BIT
GL_EVAL_BIT
GL_FOG_BIT
Current color index
Current normal vector
Current texture coordinates
Current raster position
GL_CURRENT_RASTER_POSITION_VALID flag
RGBA color associated with current raster position
Color index associated with current raster position
Texture coordinates associated with current raster position
GL_EDGE_FLAG flag
GL_DEPTH_TEST enable bit
Depth buffer test function
Depth buffer clear value
GL_DEPTH_WRITEMASK enable bit
GL_ALPHA_TEST flag
GL_AUTO_NORMAL flag
GL_BLEND flag
Enable bits for the user-definable clipping planes
GL_COLOR_LOGIC_OP flag
GL_COLOR_MATERIAL
GL_CULL_FACE flag
GL_DEPTH_TEST flag
GL_DITHER flag
GL_FOG flag
GL_LIGHTi, where 0 < i<GL_MAX_LIGHTS
GL_LIGHTING flag
GL_LINE_SMOOTH flag
GL_LINE_STIPPLE flag
GL_LOGIC_OP flag
GL_MAP1_x, where x is a map type
GL_MAP2_x, where x is a map type
GL_NORMALIZE flag
GL_POINT_SMOOTH flag
GL_POLYGON_OFFSET_EXT flag
GL_POLYGON_OFFSET_FILL flag
GL_POLYGON_OFFSET_LINE flag
GL_POLYGON_OFFSET_POINT flag
GL_POLYGON_SMOOTH flag
GL_POLYGON_STIPPLE flag
GL_SCISSOR_TEST flag
GL_STENCIL_TEST flag
GL_TEXTURE_1D flag
GL_TEXTURE_2D flag
GL_TEXTURE_3D_EXT flag
Flags GL_TEXTURE_GEN_x, where x is S, T, R, or Q
GL_MAP1_x enable bits, where x is a map type
GL_MAP2_x enable bits, where x is a map type
1-dimensional (1D) grid endpoints and divisions
2-dimensional (2D) grid endpoints and divisions
GL_AUTO_NORMAL enable bit
GL_FOG enable flag
Fog color
Fog density
Linear fog start
Linear fog end
Fog index
Chapter 1. OpenGL Subroutines
277
GL_HINT_BIT
GL_LIGHTING_BIT
GL_LINE_BIT
GL_LIST_BIT
GL_PIXEL_MODE_BIT
GL_POINT_BIT
GL_POLYGON_BIT
GL_POLYGON_STIPPLE_BIT
GL_SCISSOR_BIT
278
OpenGL 2.1 Reference Manual
GL_FOG_MODE value
GL_PERSPECTIVE_CORRECTION_HINT setting
GL_POINT_SMOOTH_HINT setting
GL_LINE_SMOOTH_HINT setting
GL_POLYGON_SMOOTH_HINT setting
GL_FOG_HINT setting
GL_SUBPIXEL_HINT_IBM setting
GL_COLOR_MATERIAL enable bit
GL_COLOR_MATERIAL_FACE value
Color material parameters that are tracking the current color
Ambient scene color
GL_LIGHT_MODEL_LOCAL_VIEWER value
GL_LIGHT_MODEL_TWO_SIDE setting
GL_LIGHTING enable bit
Enable bit for each light
Ambient, diffuse, and specular intensity for each light
Direction, position, exponent, and cutoff angle for each light
Constant,
linear, and quadratic attenuation factors for each light
Ambient, diffuse, specular, and emissive color for each material
Ambient, diffuse, and specular color indices for each material
Specular exponent for each material
GL_SHADE_MODEL setting
GL_LINE_SMOOTH flag
GL_LINE_STIPPLE enable bit
Line stipple pattern and repeat counter
Line width
GL_LIST_BASE setting
GL_RED_BIAS and GL_RED_SCALE settings
GL_GREEN_BIAS and GL_GREEN_SCALE values
GL_BLUE_BIAS and GL_BLUE_SCALE
GL_ALPHA_BIAS and GL_ALPHA_SCALE
GL_DEPTH_BIAS and GL_DEPTH_SCALE
GL_INDEX_OFFSET and GL_INDEX_SHIFT values
GL_MAP_COLOR and GL_MAP_STENCIL flags
GL_ZOOM_X and GL_ZOOM_Y factors
GL_READ_BUFFER setting
GL_POINT_SMOOTH flag
Point size
GL_CULL_FACE enable bit
GL_CULL_FACE_MODE value
GL_FRONT_FACE indicator
GL_POLYGON_OFFSET_BIAS_EXT setting
GL_POLYGON_OFFSET_EXT flag
GL_POLYGON_OFFSET_FACTOR setting
GL_POLYGON_OFFSET_FACTOR_EXT setting
GL_POLYGON_OFFSET_FILL flag
GL_POLYGON_OFFSET_LINE flag
GL_POLYGON_OFFSET_POINT flag
GL_POLYGON_OFFSET_UNITS setting
GL_POLYGON_MODE setting
GL_POLYGON_SMOOTH flag
GL_POLYGON_STIPPLE enable bit
Polygon stipple image
GL_SCISSOR_TEST flag
Scissor box
GL_STENCIL_BUFFER_BIT
GL_TEXTURE_BIT
GL_TRANSFORM_BIT
GL_VIEWPORT_BIT
GL_STENCIL_TEST enable bit
Stencil function and reference value
Stencil value mask
Stencil fail, pass, and depth buffer pass actions
Stencil buffer clear value
Stencil buffer writemask
Enable bits for the four texture coordinates
Border color for each texture image
Minification function for each texture image
Magnification function for each texture image
Texture coordinates and wrap mode for each texture image
Color and mode for each texture environment
Enable bits GL_TEXTURE_GEN_x, x is S, T, R, and Q
GL_TEXTURE_GEN_MODE setting for S, T, R, and Q
glTexGen plane equations for S, T, R, and Q
Enables for 1D, 2D, and 3D_EXT testures
Coefficients of the six clipping planes
Enable bits for the user-definable clipping planes
GL_MATRIX_MODE value
GL_NORMALIZE flag
Depth range (near and far)
Viewport origin and extent
The glPopAttrib subroutine restores the values of the state variables saved with the last glPushAttrib
subroutine. Those not saved are left unchanged.
It is an error to push attributes onto a full stack, or to pop attributes off an empty stack. In either case, the
error flag is set, and no other change is made to GL state.
Initially, the attribute stack is empty.
Notes
Not all values for the GL state can be saved on the attribute stack. For example, pixel pack and unpack
state, render mode state, and select and feedback state cannot be saved.
The depth of the attribute stack is dependent on the implementation, but it must be at least 16.
Errors
GL_STACK_OVERFLOW
GL_STACK_UNDERFLOW
GL_INVALID_OPERATION
The glPushAttrib subroutine is called while the attribute stack is full.
The glPopAttrib subroutine is called while the attribute stack is empty.
The glPushAttrib subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
glGet with argument GL_ATTRIB_STACK_DEPTH
glGet with argument GL_MAX_ATTRIB_STACK_DEPTH.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Chapter 1. OpenGL Subroutines
279
Related Information
The glBegin subroutine, glEnd subroutine, glGet subroutine, glGetClipPlane subroutine, glGetError
subroutine, glGetLight subroutine, glGetMap subroutine, glGetMaterial subroutine, glGetPixelMap
subroutine, glGetPolygonStipple subroutine, glGetString subroutine, glGetTexEnv subroutine,
glGetTexGen subroutine, glGetTexImage subroutine, glGetTexLevelParameter subroutine,
glGetTexParameter subroutine, glIsEnabled subroutine, glPushClientAttrib or PopClientAttrib
subroutine.
glPushClientAttrib or glPopClientAttrib Subroutine
Purpose
Pushes and pops the attribute stack.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPushClientAttrib(GLbitfield mask)
void glPopClientAttrib(void)
Parameters
mask
Specifies a mask that indicates which attributes to save. Values for mask are listed below.
Description
The glPushClientAttrib subroutine takes one argument, a mask that indicates which groups of client state
variables to save on the client attribute stack. Symbolic constants are used to set bits in the mask. The
mask parameter is typically constructed by OR’ing several of these constants together. The special mask
GL_CLIENT_ALL_ATTRIB_BITS can be used to save all stackable client state.
The symbolic mask constants and their associated GL client state are as follows (the second column lists
which attributes are saved):
GL_CLIENT_PIXEL_STORE_BIT
GL_CLIENT_VERTEX_ARRAY_BIT
Pixel storage modes
Vertex arrays (and enables)
The glPopClientAttrib subroutine restores the values of the client state variables saved with the last
glPushClientAttrib. Those not * saved are left unchanged.
It is an error to push attributes onto a full client attribute stack, or to pop attributes off an empty stack. In
either case, the error flag is set, and no other change is made to GL state.
Initially, the client attribute stack is empty.
Notes
The glPushClientAttrib subroutine is available only if the GL version is 1.1 or greater.
Not all values for GL client state can be saved on the attribute stack. For example, select and feedback
state cannot be saved.
280
OpenGL 2.1 Reference Manual
The depth of the attribute stack depends on the implementation, but it must be at least 16.
The glPushClientAttrib and glPopClientAttrib subroutines are not compiled
into display lists, but are executed immediately.
Use glPushAttrib and glPopAttrib to push and restore state which is kept on the server. Only pixel
storage modes and vertex array state may be pushed and popped with glPushClientAttrib and
glPopClientAttrib.
Errors
GL_STACK_OVERFLOW is generated if glPushClientAttrib is called while the attribute stack is full.
GL_STACK_UNDERFLOW is generated if glPopClientAttrib is called while the attribute stack is empty.
Associated Gets
glGet with argument GL_ATTRIB_STACK_DEPTH
glGet with argument GL_MAX_CLIENT_ATTRIB_STACK_DEPTH
Related Information
The glColorPointer subroutine, glDisableClientState subroutine, glEdgeFlagPointer subroutine,
glEnableClientState subroutine, glGet subroutine, glGetError subroutine, glIndexPointer subroutine,
glNewList subroutine, glNormalPointer subroutine, glPixelStore subroutine, glPushAttrib subroutine,
glTexCoordPointer subroutine, glVertexPointer subroutine.
glPushMatrix or glPopMatrix Subroutine
Purpose
Pushes and pops the current matrix stack.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glPushMatrix(void)
void glPopMatrix(void)
Description
There is a stack of matrices for each of the matrix modes. In GL_MODELVIEW mode, the stack depth is
at least 32. In the other two modes, GL_PROJECTION and GL_TEXTURE, the depth is at least 2. The
current matrix in any mode is the matrix on the top of the stack for that mode.
The glPushMatrix subroutine pushes the current matrix stack down by one, duplicating the current matrix.
That is, after a glPushMatrix call, the matrix on the top of the stack is identical to the one below it.
The glPopMatrix subroutine pops the current matrix stack, replacing the current matrix with the one below
it on the stack.
Initially, each of the stacks contains one matrix, an identity matrix.
Chapter 1. OpenGL Subroutines
281
It is an error to push a full matrix stack, or to pop a matrix stack that contains only a single matrix. In
either case, the error flag is set, and no other change is made to GL state.
Error Codes
GL_STACK_OVERFLOW
GL_STACK_UNDERFLOW
GL_INVALID_OPERATION
The glPushMatrix subroutine is called while the current matrix stack is full.
The glPopMatrix subroutine is called while the current matrix stack contains
only a single matrix.
The glPushMatrix subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glPushMatrix or glPopMatrix subroutine are as follows. (See the glGet
subroutine for more information.)
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX
glGet with argument GL_MODELVIEW_STACK_DEPTH
glGet with argument GL_PROJECTION_STACK_DEPTH
glGet with argument GL_TEXTURE_STACK_DEPTH
glGet with argument GL_MAX_MODELVIEW_STACK_DEPTH
glGet with argument GL_MAX_PROJECTION_STACK_DEPTH
glGet with argument GL_MAX_TEXTURE_STACK_DEPTH.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFrustum subroutine, glLoadIdentity subroutine, glLoadMatrix
subroutine, glMatrixMode subroutine, glMultMatrix subroutine, glOrtho subroutine, glRotate subroutine,
glScale subroutine, glTranslate subroutine, glViewport subroutine.
glPushName or glPopName Subroutine
Purpose
Pushes and pops the name stack.
Library
OpenGL C bindings library: libGL.a
282
OpenGL 2.1 Reference Manual
C Syntax
void glPushName(GLuint Name)
void glPopName(void)
Parameters
Name
Specifies a name that will be pushed onto the name stack.
Description
The name stack is used during selection mode to allow sets of rendering commands to be uniquely
identified. It consists of an ordered set of unsigned integers. The glPushName subroutine causes the
Name parameter to be pushed onto the name stack, which is initially empty. The glPopName subroutine
pops one name off the top of the stack.
It is an error to push a name onto a full stack, or to pop a name off an empty stack. It is also an error to
manipulate the name stack between a call to the glBegin subroutine and the corresponding call to the
glEnd subroutine. In any of these cases, the error flag is set and no other change is made to GL state.
The name stack is always empty while the render mode is not GL_SELECT. Calls to glPushName or
glPopName while the render mode is not GL_SELECT are ignored.
Associated Gets
Associated gets for the glPushName or glPopName subroutine are as follows. (See the glGet subroutine
for more information.)
glGet with argument GL_NAME_STACK_DEPTH
glGet with argument GL_MAX_NAME_STACK_DEPTH.
Error Codes
GL_STACK_OVERFLOW
GL_STACK_UNDERFLOW
GL_INVALID_OPERATION
The glPushName subroutine is called while the name stack is full.
The glPopName subroutine is called while the name stack is empty.
The glPushName or glPopName subroutine is called between a call to
glBegin and the corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glInitNames subroutine, glLoadName subroutine, glRenderMode
subroutine, glSelectBuffer subroutine.
glRasterPos Subroutine
Purpose
Specifies the raster position for pixel operations.
Chapter 1. OpenGL Subroutines
283
Library
OpenGL C bindings library: libGL.a
C Syntax
void glRasterPos2d(GLdouble
GLdouble Y)
void glRasterPos2f(GLfloat
void glRasterPos2i(GLint
GLint Y)
X,
X,
X,
void glRasterPos2s(GLshort
GLshort Y)
X,
void glRasterPos3d(GLdouble
GLdouble Y,
GLdouble Z)
void glRasterPos3f(GLfloat
GLfloat Y,
GLfloat Z)
void glRasterPos3i(GLint
GLint Y,
GLint Z)
X,
X,
X,
void glRasterPos3s(GLshort
GLshort Y,
GLshort Z)
X,
void glRasterPos4d(GLdouble
GLdouble Y,
GLdouble Z,
GLdouble W)
void glRasterPos4f(GLfloat
GLfloat Y,
GLfloat Z,
GLfloat W)
void glRasterPos4i(GLint
GLint Y,
GLint Z,
GLint W)
void glRasterPos4s(GLshort
GLshort Y,
GLshort Z,
GLshort W)
GLfloat
X,
X,
X,
X,
void glRasterPos2dv(const GLdouble * V)
void glRasterPos2fv(const GLfloat * V)
284
OpenGL 2.1 Reference Manual
Y)
void glRasterPos2iv(const GLint * V)
void glRasterPos2sv(const GLshort * V)
void glRasterPos3dv(const GLdouble * V)
void glRasterPos3fv(const GLfloat * V)
void glRasterPos3iv(const GLint * V)
void glRasterPos3sv(const GLshort * V)
void glRasterPos4dv(const GLdouble * V)
void glRasterPos4fv(const GLfloat * V)
void glRasterPos4iv(const GLint * V)
void glRasterPos4sv(const GLshort * V)
Parameters
X, Y, Z, W
V
Specify the x, y, z, and w object coordinates (if present) for the raster position.
Specifies a pointer to an array of two, three, or four elements, specifying x, y, z, and w
coordinates, respectively.
Description
The GL maintains a 3-dimensional (3D) position in window coordinates. This position, called the raster
position, is maintained with subpixel accuracy. It is used to position pixel and bitmap write operations. (See
the glBitmap subroutine for information on drawing bitmaps; the glCopyPixels subroutine for information
on copying pixels to the frame buffer; and the glDrawPixels subroutine for information on writing a block
of pixels to the frame buffer.)
The current raster position consists of four window coordinates (X, Y, Z, W), a valid bit, and associated
color data and texture coordinates. The W coordinate is actually a clip coordinate, because W is not
projected to window coordinates. The glRasterPos4 subroutine specifies object coordinates X, Y, Z, and
W explicitly. The glRasterPos3 subroutine specifies object coordinates X, Y, and Z explicitly, while W is
implicitly set to 1 (one). The glRasterPos2 subroutine uses the argument values for X and Y while
implicitly setting Z and W to 0 (zero) and 1.
The object coordinates presented by glRasterPos are treated just like those of a glVertex subroutine:
they are transformed by the current modelview and projection matrices and passed to the clipping stage. If
the vertex is not culled, it is projected and scaled to window coordinates, which become the new current
raster position, and the GL_CURRENT_RASTER_POSITION_VALID flag is set. If the vertex is culled, the
valid bit is cleared and the current raster position and associated color and texture coordinates are
undefined.
The current raster position also includes some associated color data and texture coordinates. If lighting is
enabled, GL_CURRENT_RASTER_COLOR in red, green, blue, alpha (RGBA) mode or the
GL_CURRENT_RASTER_INDEX in color index mode is set to the color produced by the lighting
calculation. (See the glLight subroutine for information on setting light source parameters; the
glLightModel subroutine for information on setting lighting model parameters; and the glShadeModel
subroutine for information on selecting flat or smooth shading.) If lighting is disabled, current color (in
RGBA mode, state variable GL_CURRENT_COLOR) or color index (in color index mode, state variable
GL_CURRENT_INDEX) is used to update the current raster color.
Chapter 1. OpenGL Subroutines
285
Likewise, the GL_CURRENT_RASTER_TEXTURE_COORDS is updated as a function of the
GL_CURRENT_TEXTURE_COORDS, based on the texture matrix and the texture generation functions.
(See the glTexGen subroutine for information on generating texture coordinates.)
Initially, the current raster position is (0,0,0,1), the valid bit is set, the associated RGBA color is (1,1,1,1),
the associated color index is 1, and the associated texture coordinates are (0,0,0,1). In RGBA mode,
GL_CURRENT_RASTER_INDEX is always 1; in color index mode, the current raster RGBA color always
maintains its initial value.
Notes
The raster position is modified both by glRasterPos and by glBitmap.
When the raster position coordinates are not valid, drawing commands that are based on the raster
position are ignored (that is, they do not result in changes to GL state).
Errors
GL_INVALID_OPERATION
The glRasterPos subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glRasterPos subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_RASTER_POSITION
glGet with argument GL_CURRENT_RASTER_POSITION_VALID
glGet with argument GL_CURRENT_RASTER_COLOR
glGet with argument GL_CURRENT_RASTER_INDEX
glGet with argument GL_CURRENT_RASTER_TEXTURE_COORDS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glBitmap subroutine, glCopyPixels subroutine, glDrawPixels
subroutine, glLight subroutine, glLightModel subroutine, glShadeModel subroutine, glTexCoord
subroutine, glTexGen subroutine, glVertex subroutine.
glReadBuffer Subroutine
Purpose
Selects a color buffer source for pixels.
Library
OpenGL C bindings library: libGL.a
286
OpenGL 2.1 Reference Manual
C Syntax
void glReadBuffer(GLenum Mode)
Parameters
Mode
Specifies a color buffer. Accepted values are as follows:
v GL_FRONT_LEFT
v GL_FRONT_RIGHT
v GL_BACK_LEFT
v GL_BACK_RIGHT
v GL_FRONT, GL_BACK
v GL_LEFT
v GL_RIGHT
v GL_AUXi, where i is between 0 (zero) and GL_AUX_BUFFERS - 1
Description
The glReadBuffer subroutine specifies a color buffer as the source for subsequent glReadPixels and
glCopyPixels subroutines. The Mode parameter accepts one of twelve or more predefined values.
(GL_AUX0 through GL_AUX3 are always defined.) In a fully configured system, GL_FRONT, GL_LEFT,
and GL_FRONT_LEFT all name the front left buffer, GL_FRONT_RIGHT and GL_RIGHT name the front
right buffer, and GL_BACK_LEFT and GL_BACK name the back left buffer. Nonstereo configurations
have only a left buffer, or a front left and a back left buffer if double-buffered. Single-buffered
configurations have only a front buffer, or a front left and a front right buffer if stereo. It is an error to
specify a nonexistent buffer to glReadBuffer.
By default, the Mode parameter is GL_FRONT in single-buffered configurations and GL_BACK in
double-buffered configurations.
Error Codes
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Mode is not one of the twelve (or more) accepted values.
Mode specifies a buffer that does not exist.
The glReadBuffer subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glReadBuffer subroutine are as follows. (See the glGet subroutine.)
glGet with argument GL_READ_BUFFER.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCopyPixels subroutine, glDrawBuffer subroutine, glReadPixels
subroutine.
Chapter 1. OpenGL Subroutines
287
glReadPixels Subroutine
Purpose
Reads a block of pixels from the frame buffer.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glReadPixels(GLint X,
GLint Y,
GLsizei Width,
GLsizei Height,
GLenum Format,
GLenum Type,
GLvoid *Pixels)
Parameters
X, Y
Width, Height
Format
Type
Pixels
Specify the window coordinates of the first pixel that is read from the frame buffer. This
location is the lower left corner of a rectangular block of pixels.
Specify the dimensions of the pixel rectangle. Width and Height of 1 (one) correspond to a
single pixel.
Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX,
GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA, GL_ABGR_EXT,
GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_422_EXT, GL_422_REV_EXT,
GL_422_AVERAGE_EXT and GL_422_REV_AVERAGE_EXT are accepted.
Specifies the data type for Pixels. Sybolic constants GL_UNSIGNED_BYTE, GL_BYTE,
GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
Returns the pixel data.
Description
The glReadPixels subroutine returns pixel data from the frame buffer, starting with the pixel whose lower
left corner is at location (X, Y), and puts it into client memory starting at the location specified by the Pixels
parameter. Several parameters control the processing of the pixel data before it is placed into client
memory. These parameters are set with three subroutines: glPixelStore, glPixelTransfer, and
glPixelMap. The effects on glReadPixels of most, but not all, of the parameters specified by these three
subroutines are described here.
The glReadPixels subroutine returns values from each pixel with the lower left-hand corner at (x + i, y + j)
for 0 < i < Width and 0 < j < Height. This pixel is said to be the ith pixel in the jth row. Pixels are returned
in row order from the lowest to the highest row, left to right in each row.
The Format parameter specifies the format for the returned pixel values. Accepted values for Format are
as follows:
288
OpenGL 2.1 Reference Manual
GL_COLOR_INDEX
GL_STENCIL_INDEX
GL_DEPTH_COMPONENT
GL_ABGR_EXT
GL_RED
GL_GREEN
GL_BLUE
GL_ALPHA
GL_RGB
Color indexes are read from the color buffer selected by the
glReadBuffer subroutine. Each index is converted to fixed-point format,
shifted left or right depending on the value and sign of
GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET. If
GL_MAP_COLOR is GL_TRUE, indexes are replaced by their mappings
in the table GL_PIXEL_MAP_I_TO_I.
Stencil values are read from the stencil buffer. Each index is converted to
fixed-point format, shifted left or right depending on the value and sign of
GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET. If
GL_MAP_STENCIL is GL_TRUE, indexes are replaced by their
mappings in the table GL_PIXEL_MAP_S_TO_S.
Depth values are read from the depth buffer. Each component is
converted to floating-point format such that the minimum depth value
maps to 0.0 and the maximum value maps to 1.0. Each component is
then multiplied by GL_DEPTH_SCALE, added to GL_DEPTH_BIAS, and
finally clamped to the range [0,1].
Each pixel is a four-component group: for GL_RGBA, the red component
is first, followed by green, followed by blue, followed by alpha; for
GL_BGRA, the blue component is first, followed by green, followed by
red, followed by alpha; for GL_ABGR_EXT the order is alpha, blue,
green, and then red. Floating-point values are converted directly to an
internal floatingpoint format with unspecified precision. Signed integer
values are mapped linearly to the internal floating-point format such that
the most positive representable integer value maps to 1.0, and the most
negative representable value maps to -1.0. Unsigned integer data is
mapped similarly: the largest integer value maps to 1.0, and zero maps to
0.0. The resulting floating-point color values are then multiplied by
GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN,
BLUE, and ALPHA for the respective color components. The results are
clamped to the range [0,1].
Each pixel is a single red component. This component is converted to the
internal floating-point format in the same way as the red component of an
RGBA pixel is, then it is converted to an RGBA pixel with green and blue
set to 0.0, and alpha set to 1.0. After this conversion, the pixel is treated
just as if it had been read as an RGBA pixel.
Each pixel is a single green component. This component is converted to
the internal floating-point format in the same way as the green component
of an RGBA pixel is, then it is converted to an RGBA pixel with red and
blue set to 0.0, and alpha set to 1.0. After this conversion, the pixel is
treated just as if it had been read as an RGBA pixel.
Each pixel is a single blue component. This component is converted to
the internal floating-point format in the same way as the blue component
of an RGBA pixel is, then it is converted to an RGBA pixel with red and
green set to 0.0, and alpha set to 1.0. After this conversion, the pixel is
treated just as if it had been read as an RGBA pixel.
Each pixel is a single alpha component. This component is converted to
the internal floating-point format in the same way as the alpha component
of an RGBA pixel is, then it is converted to an RGBA pixel with red,
green, and blue set to 0.0. After this conversion, the pixel is treated just
as if it had been read as an RGBA pixel.
Each pixel is a three-component group, red first, followed by green,
followed by blue. Each component is converted to the internal
floating-point format in the same way as the red, green, and blue
components of an RGBA pixel are. The color triple is converted to an
RGBA pixel with alpha set to 1.0. After this conversion, the pixel is treated
just as if it had been read as an RGBA pixel.
Chapter 1. OpenGL Subroutines
289
GL_RGBA
Each pixel is a four-component group, red first, followed by green,
followed by blue, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is RED,
GREEN, BLUE, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is R, G, B, or A, respectively.
GL_BGR
GL_BGRA
The resulting RGBA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
Each pixel is a three-component group, blue first, followed by green,
followed by red. Each component is converted to the internal floating-point
format in the same way as the blue, green, and red components of an
BGRA pixel are. The color triple is converted to an BGRA pixel with alpha
set to 1.0. After this conversion, the pixel is treated just as if it had been
read as an BGRA pixel.
Each pixel is a four-component group, blue first, followed by green,
followed by red, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is BLUE,
GREEN, RED, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is B, G, R, or A, respectively.
GL_LUMINANCE
290
OpenGL 2.1 Reference Manual
The resulting BGRA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
Each pixel is a single luminance component. This component is converted
to the internal floating-point format in the same way as the red component
of an RGBA pixel is, then it is converted to an RGBA pixel with red,
green, and blue set to the converted luminance value, and alpha set to
1.0. After this conversion, the pixel is treated just as if it had been read as
an RGBA pixel.
GL_LUMINANCE_ALPHA
Processing differs depending on whether color buffers store color indexes
or red, green, blue, alpha (RGBA) color components. If color indexes are
stored, they are read from the color buffer selected by glReadBuffer.
Each index is converted to fixed-point format, shifted left or right
depending on the value and sign of GL_INDEX_SHIFT, and added to
GL_INDEX_OFFSET. Indexes are then replaced by the RGBA values
obtained by indexing the GL_PIXEL_MAP_I_TO_R,
GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A tables.
If RGBA color components are stored in the color buffers, they are read
from the color buffer selected by glReadBuffer. Each color component is
converted to floating-point format such that zero intensity maps to 0.0 and
full intensity maps to 1.0. Each component is then multiplied by
GL_c_SCALE and added to GL_c_BIAS, where c is GL_RED,
GL_GREEN, GL_BLUE, and GL_ALPHA. Each component is clamped to
the range [0,1]. Finally, if GL_MAP_COLOR is GL_TRUE, each color
component c is replaced by its mapping in the table
GL_PIXEL_MAP_c_TO_c, where c again is GL_RED, GL_GREEN,
GL_BLUE, and GL_ALPHA. Each component is scaled to the size its
corresponding table before the lookup is performed.
GL_422_EXT
GL_422_REV_EXT
Finally, unneeded data is discarded. For example, GL_RED discards the
green, blue, and alpha components, while GL_RGB discards only the
alpha component. GL_LUMINANCE computes a single component value
as the sum of the red, green, and blue components, and
GL_LUMINANCE_ALPHA does the same, while keeping alpha as a
second value.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_RGB_TO_YCBCR_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glReadPixels is called with this
parameter. The internal RGB values are sent through the RGB_to_YCbCr
matrix to create Y, Cb, and Cr values. Each returned pixel is a
two-component group. The first component is Y. The second component
is Cb in the even pixels and Cr in the odd pixels. The Cb for each even
pixel comes from the Cb value for that pixel. The Cr in each odd pixel
comes from the Cr value of its neighbor to the left. (If the width of the
image is odd, then the colors will be undefined in the rightmost column.).
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_RGB_TO_YCBCR_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glReadPixels is called with this
parameter. The internal RGB values are sent through the RGB_to_YCbCr
matrix to create Y, Cb, and Cr values. Each returned pixel is a
two-component group. The first component is Cb in the even pixels and
Cr in the odd pixels. The second component is Y. The Cb for each even
pixel comes from the Cb value for that pixel. The Cr in each odd pixel
comes from its neighbor to the left. (If the width of the image is odd, then
the colors will be undefined in the rightmost column.).
Chapter 1. OpenGL Subroutines
291
GL_422_AVERAGE_EXT
GL_422_REV_AVERAGE_EXT
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_RGB_TO_YCBCR_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glReadPixels is called with this
parameter. The internal RGB values are sent through the RGB_to_YCbCr
matrix to create Y, Cb, and Cr values. Each returned pixel is a
two-component group. The first component is Y. The second component
is Cb in the even pixels and Cr in the odd pixels. Each even pixel gets its
Cb from itself, and its Cr from its neighbor to the right. Each odd pixel
gets its Cb from the average of its own Cb and that of its left neighbor,
and gets its Cr from the average of its own Cr and that of its left neighbor.
(If the width of the image is odd, then the colors will be undefined in the
rightmost column. If the neighbors to the right are not present for a given
fragment, we use GL_422_EXT to compute that fragment.).
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_RGB_TO_YCBCR_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glReadPixels is called with this
parameter. The internal RGB values are sent through the RGB_to_YCbCr
matrix to create Y, Cb, and Cr values. Each returned pixel is a
two-component group. The first component is Cb in the even pixels and
Cr in the odd pixels. The second component is Y. Each even pixel gets its
Cb from itself, and its Cr from its neighbor to the right. Each odd pixel
gets its Cb from the average of its own Cb and that of its left neighbor,
and gets its Cr from the average of its own Cr and that of its left neighbor.
(If the width of the image is odd, then the colors will be undefined in the
rightmost column. If the neighbors to the right are not present for a given
fragment, we use GL_422_EXT to compute that fragment.).
The shift, scale, bias, and lookup factors described in the preceding section are all specified by
glPixelTransfer. The lookup table contents themselves are specified by the glPixelMap subroutine.
The final step involves converting the indexes or components to the proper format, as specified by the
Type parameter. If the Format parameter is GL_COLOR_INDEX or GL_STENCIL_INDEX and Type is not
GL_FLOAT, each index is masked with the mask value given in the following table. If the Type parameter
is GL_FLOAT, each integer index is converted to single-precision floating-point format.
If the Format parameter is any legal value other than GL_COLOR_INDEX, GL_STENCIL_INDEX, or
GL_DEPTH_COMPONENT, and the Type parameter is not GL_FLOAT, each component is multiplied by
the multiplier shown in the following table. If Type is GL_FLOAT, each component is passed as is (or
converted to the client’s single-precision floating-point format if it is different from the one used by the GL).
Type
Index Mask
8
Component Conversion
GL_UNSIGNED_BYTE
2 -1
(28 -1)c
GL_BYTE
27 -1
[(27 -1)c-1]/2
GL_BITMAP
1
1
16
-1
(216 -1)c
GL_UNSIGNED_SHORT
2
GL_SHORT
215 -1
[(215 -1)c-1]/2
GL_UNSIGNED_INT
232 -1
(232 -1)c
GL_INT
231 -1
[(231 -1)c-1]/2
GL_FLOAT
none
c
GL_UNSIGNED_BYTE_3_3_2
GL_UNSIGNED_BYTE_2_3_3_REV
292
OpenGL 2.1 Reference Manual
8
(2N -1)c
8
(2N -1)c
2 -1
2 -1
Type
Index Mask
GL_UNSIGNED_SHORT_5_6_5
GL_UNSIGNED_SHORT_5_6_5_REV
GL_UNSIGNED_SHORT_4_4_4_4
GL_UNSIGNED_SHORT_4_4_4_4_REV
GL_UNSIGNED_SHORT_5_5_5_1
GL_UNSIGNED_SHORT_1_5_5_5_REV
GL_UNSIGNED_INT_8_8_8_8
GL_UNSIGNED_INT_8_8_8_8_REV
GL_UNSIGNED_INT_10_10_10_2
GL_UNSIGNED_INT_2_10_10_10_REV
Component Conversion
2
16
-1
(2N -1)c
2
16
-1
(2N -1)c
2
16
-1
(2N -1)c
2
16
-1
(2N -1)c
2
16
-1
(2N -1)c
2
16
-1
(2N -1)c
2
32
-1
(2N -1)c
2
32
-1
(2N -1)c
2
32
-1
(2N -1)c
2
32
-1
(2N -1)c
Equations with N as the exponent are performed for each bitfield of the packed data type, with N set to the
number of bits in the bitfield.
Return values are placed in memory as follows. If the Format parameter is GL_COLOR_INDEX,
GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, or
GL_LUMINANCE, a single value is returned and the data for the ith pixel in the jth row is placed in
location (j) Width + i. GL_RGB and GL_BGR return three values, GL_RGBA, GL_BGRA, and
GL_ABGR_EXT return four values, and GL_LUMINANCE_ALPHA, GL_422_EXT, GL_422_REV_EXT,
GL_422_AVERAGE_EXT and GL_422_REV_AVERAGE_EXT return two values for each pixel, with all
values corresponding to a single pixel occupying contiguous space in Pixels. Storage parameters set by
glPixelStore, such as GL_PACK_SWAP_BYTES and GL_PACK_LSB_FIRST, affect the way that data is
written into memory. See the glPixelStore subroutine for a description.
Notes
Values for pixels that lie outside the window connected to the current GL context are undefined. If an error
is generated, no change is made to the contents of Pixels.
Format of GL_ABGR_EXT is part of the _extname (EXT_abgr) extension, not part of the core GL
command set.
Packed pixel types and BGR/BGRA formats are only supported in OpenGL 1.2 and later.
Error Codes
GL_INVALID_ENUM
GL_INVALID_VALUE
GL_INVALID_OPERATION
GL_INVALID_OPERATION
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Format or Type is not an accepted value.
Width or Height is negative.
Format is GL_COLOR_INDEX and the color buffers store RGBA color
components.
Format is GL_STENCIL_INDEX and there is no stencil buffer.
Format is GL_DEPTH_COMPONENT and there is no depth buffer.
The glReadPixels subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glReadPixels subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_INDEX_MODE.
Chapter 1. OpenGL Subroutines
293
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glCopyPixels subroutine, glDrawPixels subroutine, glPixelMap
subroutine, glPixelStore subroutine, glPixelTransfer subroutine, glReadBuffer subroutine.
glRect Subroutine
Purpose
Draws a rectangle.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glRectd(GLdouble
GLdouble Y1,
GLdouble X2,
GLdouble Y2)
void glRectf(GLfloat
GLfloat Y1,
GLfloat X2,
GLfloat Y2)
void glRecti(GLint
GLint Y1,
GLint X2,
GLint Y2)
void glRects(GLshort
GLshort Y1,
GLshort X2,
GLshort Y2)
X1,
X1,
X1,
X1,
void glRectdv(const GLdouble * V1,
const GLdouble * V2)
void glRectfv(const GLfloat * V1,
const GLfloat * V2)
void glRectiv(const GLint * V1,
const GLint * V2)
void glRectsv(const GLshort * V1,
const GLshort * V2)
294
OpenGL 2.1 Reference Manual
Parameters
X1, Y1
X2, Y2
V1
V2
Specify one vertex of a rectangle.
Specify the opposite vertex of the rectangle.
Specifies a pointer to one vertex of a rectangle.
Specifies a pointer to the opposite vertex of the rectangle.
Description
The glRect subroutine supports efficient specification of rectangles as two corner points. Each rectangle
command takes four arguments, organized either as two consecutive pairs of (x,y) coordinates, or as two
pointers to arrays, each containing an (x,y) pair. The resulting rectangle is defined in the z=0 plane.
glRect(X1, Y1, X2, Y2) is equivalent to the following sequence:
glBegin(GL_POLYGON);
glVertex2(X1, Y1);
glVertex2(X2, Y1);
glVertex2(X2, Y2);
glVertex2(X1, Y2);
glEnd();
Note: If the second vertex is above and to the right of the first vertex, the rectangle is constructed
with a counterclockwise winding.
Errors
GL_INVALID_OPERATION
The glRect subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glVertex subroutine.
glRenderMode Subroutine
Purpose
Sets rasterization mode.
Library
OpenGL C bindings library: libGL.a
C Syntax
GLint glRenderMode(GLenum Mode)
Parameters
Mode
Specifies the rasterization mode. Four values are accepted: GL_RENDER, GL_SELECT, GL_FEEDBACK,
and GL_VISIBILITY_IBM. The default value is GL_RENDER.
Chapter 1. OpenGL Subroutines
295
Description
The glRenderMode subroutine sets the rasterization mode. It takes one argument, the Mode parameter,
which can assume one of four predefined values:
GL_RENDER
GL_SELECT
GL_FEEDBACK
GL_VISIBILITY_IBM
Render mode. Primitives are rasterized, producing pixel fragments, which are
written into the frame buffer. This is the normal mode, and also the default mode.
Selection mode. No pixel fragments are produced, and no change to the frame
buffer contents is made. Instead, a record of the names of primitives that would
have been drawn if the render mode was GL_RENDER is returned in a select
buffer, which must be created before selection mode is entered. (See the
glSelectBuffer subroutine for information about establishing a buffer for selection
mode values.)
Feedback mode. No pixel fragments are produced, and no change to the frame
buffer contents is made. Instead, the coordinates and attributes of vertices that
would have been drawn had the render mode been GL_RENDER are returned in a
feedback buffer, which must be created before feedback mode is entered. (See the
glFeedbackBuffer subroutine for information about controlling the feedback mode.)
Visibility RenderMode is identical to render RenderMode, except whenever a
fragment passes all tests (in other words, depth, stencil, alpha, scissor and
window-ownership) then a visibility hit results. Whenever a name stack manipulation
command is executed or RenderMode is called, and there is a hit since the last
time the stack was manipulated or RenderMode was called, then a hit record is
written into the visibility array. The hit record consists of the number of names in the
name stack at the time of the event, followed by the name stack contents (bottom
name first). (See the glVisibilityBufferIBM subroutine for information about
controlling the visibility mode.)
The return value of glRenderMode is determined by the render mode at the time glRenderMode is
called, rather than by the Mode parameter.
Refer to glSelectBuffer, glFeedbackBuffer and glVisibilityBufferIBM for more details concerning
selection, feedback and visibility operation.
Notes
If an error is generated, glRenderMode returns 0 (zero) regardless of the current render mode.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
GL_INVALID_OPERATION
GL_INVALID_OPERATION
GL_INVALID_OPERATION
296
OpenGL 2.1 Reference Manual
Mode is not one of the four accepted values.
The glSelectBuffer subroutine is called while the render mode is
GL_SELECT, or glRenderMode is called with the GL_SELECT argument
before glSelectBuffer is called at least once.
The glFeedbackBuffer subroutine is called while the render mode is
GL_FEEDBACK, or glRenderMode is called with the GL_FEEDBACK
argument before glFeedbackBuffer is called at least once.
The glRenderMode subroutine is called between a call to glBegin and the
corresponding call to glEnd.
The glVisibilityBufferIBM subroutine is called while the render mode is
GL_VISIBILITY_IBM, or glRenderMode is called with the
GL_VISIBILITY_IBM argument before glVisibilityBufferIBM is called at least
once.
Associated Gets
Associated gets for the glRenderMode subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_RENDER_MODE.
Return Values
GL_RENDER
GL_SELECT
GL_FEEDBACK
GL_VISIBILITY_IBM
0.
The number of hit records transferred to the select buffer.
The number of values (not vertices) transferred to the feedback buffer.
The number of hit records transferred to the visibility buffer.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFeedbackBuffer subroutine, glVisibilityBufferIBM subroutine,
glInitNames subroutine, glLoadName subroutine, glPassThrough subroutine, glPushName subroutine,
glSelectBuffer subroutine.
glRotate Subroutine
Purpose
Multiplies the current matrix by a rotation matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glRotated(GLdouble Angle,
GLdouble X,
GLdouble Y,
GLdouble Z)
void glRotatef(GLfloat Angle,
GLfloat X,
GLfloat Y,
GLfloat Z)
Parameters
Angle
X, Y, Z
Specifies the angle of rotation, in degrees.
Specify the X, Y, and Z coordinates of a vector, respectively.
Description
The glRotate subroutine computes a matrix that performs a counterclockwise rotation of Angle degrees
about the vector from the origin through the point (X, Y, Z).
Chapter 1. OpenGL Subroutines
297
The current matrix is multiplied by this rotation matrix, with the product replacing the current matrix. That
is, if M is the current matrix and R is the translation matrix, M is replaced with MR. (See the glMatrixMode
subroutine for information on specifying the current matrix.)
If the matrix mode is either GL_MODELVIEW or GL_PROJECTION, all objects drawn after glRotate is
called are rotated. Use the glPushMatrix and glPopMatrix subroutines to save and restore the unrotated
coordinate system.
Associated Gets
Associated gets for the glRotate subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX.
Errors
GL_INVALID_OPERATION
The glRotate subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glMatrixMode subroutine, glMultMatrix subroutine, glPushMatrix
subroutine, glScale subroutine, glTranslate subroutine.
glScale Subroutine
Purpose
Multiplies the current matrix by a general scaling matrix.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glScaled(GLdouble X,
GLdouble Y,
GLdouble Z)
void glScalef(GLfloat X,
GLfloat Y,
GLfloat Z)
298
OpenGL 2.1 Reference Manual
Parameters
X, Y, Z
Specify scale factors along the X, Y, and Z axes, respectively.
Description
The glScale subroutine produces a general scaling along the X, Y, and Z axes. The three arguments
indicate the desired scale factors along each of the three axes. The resulting matrix is as follows:
x 0 0 0
0 y 0 0
0 0 z 0
0 0 0 1
Figure 22. Resulting Matrix. This diagram shows a matrix enclosed in brackets. The matrix consists of four lines
containing four characters each. The first line contains the following (from left to right): x, zero, zero, zero. The second
line contains the following (from left to right): zero, y, zero, zero. The third line contains the following (from left to right):
zero, zero, z, zero. The fourth line contains the following (from left to right): zero, zero, zero, one.
The current matrix is multiplied by this scale matrix, with the product replacing the current matrix. That is, if
M is the current matrix and S is the scale matrix, M is replaced with MS. (See the glMatrixMode
subroutine for information on specifying the current matrix.)
If the matrix mode is either GL_MODELVIEW or GL_PROJECTION, all objects drawn after glScale is
called are scaled. Use the glPushMatrix and glPopMatrix subroutines to save and restore the unscaled
coordinate system.
Notes
If scale factors other than 1.0 are applied to the modelview matrix and lighting is enabled, automatic
normalization of normals should probably also be enabled. (Use the glEnable and glDisable subroutines
with the GL_NORMALIZE argument.)
Errors
GL_INVALID_OPERATION
The glScale subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glScale subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX.
Chapter 1. OpenGL Subroutines
299
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable subroutine, glMatrixMode subroutine, glMultMatrix
subroutine, glPushMatrix subroutine, glRotate subroutine, glTranslate subroutine.
glScissor Subroutine
Purpose
Defines the scissor box.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glScissor(GLint X,
GLint Y,
GLsizei Width,
GLsizei Height)
When the scissor test is disabled, it is as though the scissor box includes the entire window.
Parameters
X, Y
Width, Height
Specify the lower left corner of the scissor box. Initially (0,0).
Specify the width and height of the scissor box. When a GL context is first attached to a
window, Width and Height are set to the dimensions of that window.
Description
The glScissor subroutine defines a rectangle, called the scissor box, in window coordinates. The first two
arguments, X and Y, specify the lower left corner of the box. The Width and Height parameters specify the
width and height of the box.
The scissor test is enabled and disabled with the glEnable and glDisable subroutines with the
GL_SCISSOR_TEST argument. While the scissor test is enabled, only pixels that lie within the scissor box
can be modified by drawing commands. Window coordinates have integer values at the shared corners of
frame buffer pixels, so glScissor(0,0,1,1) allows only the lower left pixel in the window to be modified,
and glScissor(0,0,0,0) disallows modification to all pixels in the window.
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
300
OpenGL 2.1 Reference Manual
Width or Height is negative.
The glScissor subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glScissor subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_SCISSOR_BOX
glIsEnabled with argument GL_SCISSOR_TEST.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable or glDisable subroutine, glViewport subroutine.
glSecondaryColorEXT Subroutine
Purpose
Specifies an RGB color used by the Color Sum stage.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glSecondaryColorbEXT(GLbyte Red,
GLbyte Green,
GLbyte Blue)
void glSecondaryColorsEXT(GLshort Red,
GLshort Green,
GLshort Blue)
void glSecondaryColoriEXT(GLint Red,
GLint Green,
GLint Blue)
void glSecondaryColorfEXT(GLfloat Red,
GLfloat Green,
GLfloat Blue)
void glSecondaryColordEXT(GLdouble Red,
GLdouble Green,
GLdouble Blue)
void glSecondaryColorubEXT(GLubyte Red,
GLubyte Green,
GLubyte Blue)
void glSecondaryColorusEXT(GLushort Red,
GLushort Green,
GLushort Blue)
void glSecondaryColoruiEXT(GLuint Red,
GLuint Green,
GLuint Blue)
void glSecondaryColorbvEXT(GLbyte *Variable)
void glSecondaryColorsvEXT(GLshort *Variable)
void glSecondaryColorivEXT(GLint *Variable)
Chapter 1. OpenGL Subroutines
301
void
void
void
void
void
glSecondaryColorfvEXT(GLfloat *Variable)
glSecondaryColordvEXT(GLdouble *Variable)
glSecondaryColorubvEXT(GLubyte *Variable)
glSecondaryColorusvEXT(GLushort *Variable)
glSecondaryColoruivEXT(GLuint *Variable)
Description
This extension allows specifying the RGB components of the secondary color used in the Color Sum
stage, instead of using the default (0,0,0,0) color. It applies only in RGBA mode and when LIGHTING is
disabled.
Secondary alpha is always implicitly set to 0.0.
After texturing, a fragment has two RGBA colors: a primary color c_pri (which texturing, if enabled, may
have modified) and a secondary color c_sec.
If color sum is enabled, the components of these two colors are summed to produce a single
post-texturing RGBA color c (the A component of the secondary color is always 0). The components of c
are then clamped to the range [0,1]. If color sum is disabled, then c_pri is assigned to the post texturing
color. Color sum is enabled or disabled using the generic Enable and Disable commands, respectively,
with the symbolic constant GL_COLOR_SUM_EXT.
Parameters
Red,Green,Blue
Variable
Specify the red, green and blue values of the Secondary
color.
Specifies a pointer to an array of three values. These are
interpreted, respectively, as the red, green and blue
values of the Secondary color.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
glSecondaryColorPointerEXT Subroutine
Purpose
Specifies an array of secondary colors.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glSecondaryColorPointerEXT(GLint size,
GLenum type,
GLsizei stride,
const GLvoid *pointer)
302
OpenGL 2.1 Reference Manual
Description
The glSecondaryColorPointerEXT extension specifies the location and data format of an array of
secondary color components to use when rendering. The size parameter specifies the number of
components per color, and must be 3 or 4. The type parameter specifies the data type of each color
component and stride gives the byte stride from one color to the next allowing vertices and attributes to be
packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on
some implementations; see glInterleavedArrays).
When a secondary color array is specified, size, type, stride, and pointer are saved as client side state.
To enable and disable the secondary color array, call glEnableClientState and glDisableClientState with
the argument GL_SECONDARY_COLOR_ARRAY. If enabled, the secondary color array is used when
glDrawArrays, glDrawElements or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Secondary Color array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
type
stride
pointer
specifies the number of components per color. It must be
3 or 4. The initial value is 4.
specifies the data type of each color component in the
array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT,
GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial
value is GL_FLOAT.
specifies the byte offset between consecutive colors. If
stride is zero (the initial value), the colors are understood
to be tightly packed in the array. The initial value is 0.
specifies a pointer to the first component of the first color
element in the array. The initial value is 0 (NULL pointer).
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElement subroutine, the glColorPointer subroutine, the glDrawArrays subroutine, the
glDrawElements subroutine, the glEdgeFlagPointer subroutine, the glEnable subroutine, the
glGetPointerv subroutine, the glIndexPointer subroutine, the glInterleavedArrays subroutine, the
glNormalPointer subroutine, the glPushClientAttrib or glPopClientAttrib subroutine, the
glSecondaryColorPointerListIBM subroutine, the glTexCoordPointer subroutine, the glVertexPointer
subroutine.
Chapter 1. OpenGL Subroutines
303
glSecondaryColorPointerListIBM Subroutine
Purpose
Defines a list of arrays of secondary colors.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glColorPointerListIBM (GLint size,
GLenum type,
GLint stride,
const GLvoid **pointer,
GLint ptrstride)
Description
The glSecondaryColorPointerListIBM subroutine specifies the location and data format of a list of arrays
of color components to use when rendering. The size parameter specifies the number of components per
color, and must be 3 or 4. The type parameter specifies the data type of each color component. The stride
parameter gives the byte stride from one color to the next allowing vertices and attributes to be packed
into a single array or stored in separate arrays. (Single-array storage may be more efficient on some
implementations; see glInterleavedArrays). The ptrstride parameter specifies the byte stride from one
pointer to the next in the pointer array.
When a secondary color array is specified, size, type, stride, pointer and ptrstride are saved as client side
state.
A stride value of 0 does not specify a ″tightly packed″ array as it does in glSecondaryColorPointer.
Instead, it causes the first array element of each array to be used for each vertex. Also, a negative value
can be used for stride, which allows the user to move through each array in reverse order.
To enable and disable the secondary color arrays, call glEnableClientState and glDisableClientState
with the argument GL_COLOR_ARRAY. The secondary color array is initially disabled. When enabled, the
secondary color arrays are used when glMultiDrawArraysEXT, glMultiDrawElementsEXT,
glMultiModeDrawArraysIBM, glMultiModeDrawElementsIBM, glDrawArrays, glDrawElements or
glArrayElement is called. The last three calls in this list will only use the first array (the one pointed at by
pointer[0]). See the descriptions of these routines for more information on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Secondary Color array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
304
specifies the number of components per secondary color.
This must be 3 or 4. The initial value is 4.
OpenGL 2.1 Reference Manual
type
specifies the data type of each secondary color
component in the array. Symbolic constants GL_BYTE,
GL_UNSIGNED_BYTE, GL_SHORT,
GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial
value is GL_FLOAT.
specifies the byte offset between consecutive secondary
colors. The initial value is 0.
specifies a list of secondary color arrays. The initial value
is 0 (NULL pointer).
specifies the byte stride between successive pointers in
the pointer array. The initial value is 0.
stride
pointer
ptrstride
Notes
The glSecondaryColorPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists
extension is supported.
Execution of glSecondaryColorPointerListIBM is not allowed between glBegin and the corresponding
glEnd, but an error may or may not be generated. If an error is not generated, the operation is undefined.
The glSecondaryColorPointerListIBM subroutine is typically implemented on the client side.
Since the secondary color array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glSecondaryColorPointerListIBM call is encountered while compiling a display list, the
information it contains does NOT contribute to the display list, but is used to update the immediate context
instead.
The glSecondaryColorPointer call and the glSecondaryColorPointerListIBM call share the same state
variables. A glSecondaryColorPointer call will reset the secondary color list state to indicate that there is
only one secondary color list, so that any and all lists specified by a previous
glSecondaryColorPointerListIBM call will be lost, not just the first list that it specified.
Error Codes
GL_INVALID_VALUE
GL_INVALID_ENUM
is generated if size is not 3 or 4.
is generated if type is not an accepted value.
Associated gets for the glSecondaryColorPointerListIBM subroutine are as follows. (See the glGet
subroutine for more information.)
glIsEnabled with argument GL_COLOR_ARRAY..
glGetPointerv with argument GL_COLOR_ARRAY_LIST_IBM.
glGet with argument GL_COLOR_ARRAY_LIST_STRIDE_IBM.
glGet with argument GL_COLOR_ARRAY_SIZE.
glGet with argument GL_COLOR_ARRAY_STRIDE.
glGet with argument GL_COLOR_ARRAY_TYPE.
Chapter 1. OpenGL Subroutines
305
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElement subroutine, the glColorPointer subroutine, the glDrawArrays subroutine, the
glDrawElements subroutine, the glEdgeFlagPointer subroutine, the glEnable subroutine, the
glGetPointerv subroutine, the glIndexPointer subroutine, the glInterleavedArrays subroutine, the
glMultiDrawArraysEXT subroutine, the glMultiDrawElementsEXT subroutine, the
glMultiModeDrawArraysIBM subroutine, the glMultiModeDrawElementsIBM subroutine, the
glNormalPointer subroutine, the glPushClientAttrib or glPopClientAttrib subroutine, the
glTexCoordPointer subroutine, the glVertexPointer subroutine.
glSelectBuffer Subroutine
Purpose
Establishes a buffer for selection mode values.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glSelectBuffer(GLsizei Size,
GLuint *Buffer)
Parameters
Size
Buffer
Specifies the size of Buffer.
Returns the selection data.
Description
The glSelectBuffer subroutine has two arguments: the Buffer parameter is a pointer to an array of
unsigned integers, and the Size parameter indicates the size of the array. Buffer returns values from the
name stack when the rendering mode is GL_SELECT. (See the glInitNames subroutine for information on
initializing the name stack; the glLoadName subroutine for information on loading names onto the name
stack; the glPushName subroutine for pushing and popping the name stack; and the glRenderMode
subroutine for information on setting the rasterization mode.) The glSelectBuffer subroutine must be
issued before selection mode is enabled, and it must not be issued while the rendering mode is
GL_SELECT.
Selection is used by a programmer to determine which primitives are drawn into some region of a window.
The region is defined by the current modelview and perspective matrices.
In selection mode, no pixel fragments are produced from rasterization. Instead, if a primitive intersects the
clipping volume defined by the viewing frustum and the user-defined clipping planes, this primitive causes
a selection hit. (With polygons, no hit occurs if the polygon is culled.) When a change is made to the name
stack, or when the glRenderMode subroutine is called, a hit record is copied to Buffer if any hits have
occurred since the last such event (name stack change or glRenderMode call). The hit record consists of
306
OpenGL 2.1 Reference Manual
the number of names in the name stack at the time of the event, followed by the minimum and maximum
depth values of all vertices that hit since the previous event, followed by the name stack contents, bottom
name first.
Returned depth values are mapped such that the largest unsigned integer value corresponds to window
coordinate depth 1.0, and 0 (zero) corresponds to window coordinate depth 0.0.
An internal index into Buffer is reset to 0 whenever selection mode is entered. Each time a hit record is
copied into Buffer, the index is incremented to point to the cell just past the end of the block of names,
that is, to the next available cell. If the hit record is larger than the number of remaining locations in Buffer,
as much data as can fit is copied, and the overflow flag is set. If the name stack is empty when a hit
record is copied, that record consists of 0 followed by the minimum and maximum depth values.
Selection mode is exited by calling glRenderMode with an argument other than GL_SELECT. Whenever
glRenderMode is called while the render mode is GL_SELECT, it returns the number of hit records
copied to Buffer, resets the overflow flag and the selection buffer pointer, and initializes the name stack to
be empty. If the overflow bit was set when glRenderMode was called, a negative hit record count is
returned.
Notes
The contents of Buffer are undefined until glRenderMode is called with an argument other than
GL_SELECT.
The glBegin/glEnd subroutine primitives and calls to glRasterPos can result in hits.
Errors
GL_INVALID_VALUE
GL_INVALID_OPERATION
GL_INVALID_OPERATION
Size is negative.
The glSelectBuffer subroutine is called while the render mode is
GL_SELECT, or glRenderMode is called with the GL_SELECT argument
before glSelectBuffer is called at least once.
The glSelectBuffer subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glSelectBuffer subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_NAME_STACK_DEPTH.
glGetPointerv with argument GL_SELECTION_BUFFER_POINTER.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glFeedbackBuffer subroutine, glGetPointerv subroutine, glInitNames
subroutine, glLoadName subroutine, glPushName subroutine, glRenderMode subroutine.
Chapter 1. OpenGL Subroutines
307
glShadeModel Subroutine
Purpose
Selects flat or smooth shading.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glShadeModel(GLenum Mode)
Parameters
Mode
Specifies a symbolic value representing a shading technique. Accepted values are GL_FLAT and
GL_SMOOTH. The default is GL_SMOOTH.
Description
GL primitives can have either flat or smooth shading. Smooth shading, the default, causes the computed
colors of vertices to be interpolated as the primitive is rasterized, typically assigning different colors to
each resulting pixel fragment. Flat shading selects the computed color of just one vertex and assigns it to
all the pixel fragments generated by rasterizing a single primitive. In either case, the computed color of a
vertex is the result of lighting, if lighting is enabled, or it is the current color at the time the vertex was
specified, if lighting is disabled.
Flat and smooth shading are indistinguishable for points. Counting vertices and primitives from 1 (one)
starting when the glBegin subroutine is issued, each flat-shaded line segment i is given the computed
color of vertex i + 1, its second vertex. Counting similarly from 1, each flat-shaded polygon is given the
computed color of the vertex in the following list. This is the last vertex to specify the polygon in all cases
except single polygons, where the first vertex specifies the flat-shaded color.
Primitive type of polygon i
Single polygon (i == 1)
Triangle strip
Triangle fan
Independent triangle
Quad strip
Independent quad
Vertex
1
i+2
i+2
3i
2i+2
4i
Flat and smooth shading are specified by glShadeModel with the Mode parameter set to GL_FLAT and
GL_SMOOTH, respectively.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Mode is any value other than GL_FLAT or GL_SMOOTH.
The glShadeModel subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glShadeModel subroutine are as follows. (See the glGet subroutine for more
information.)
308
OpenGL 2.1 Reference Manual
glGet with argument GL_SHADE_MODEL.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColor subroutine, glLight subroutine, glLightModel subroutine.
glStencilFunc Subroutine
Purpose
Sets function and reference values for stencil testing.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glStencilFunc(GLenum Function,
GLint Reference,
GLuint Mask)
Parameters
Function
Specifies the test function. Eight tokens are valid:
v GL_NEVER
v GL_LESS
v GL_LEQUAL
v GL_GREATER
v GL_GEQUAL
v GL_EQUAL
v GL_NOTEQUAL
Reference
Mask
v GL_ALWAYS
Specifies the reference value for the stencil test. Reference is clamped to the range [0,2n-1], where
n is the number of bit planes in the stencil buffer.
Specifies a mask that is ANDed with both the reference value and the stored stencil value when
the test is done.
Description
Stenciling, like z-buffering, enables and disables drawing on a per-pixel basis. You draw into the stencil
planes using GL drawing primitives, and then render geometry and images, using the stencil planes to
mask out portions of the screen. Stenciling is typically used in multipass rendering algorithms to achieve
special effects, such as decals, outlining, and constructive solid geometry rendering.
The stencil test conditionally eliminates a pixel based on the outcome of a comparison between the
reference value and the value in the stencil buffer. The test is enabled by the glEnable and glDisable
subroutines with the GL_STENCIL argument. Actions taken based on the outcome of the stencil test are
specified with the glStencilOp subroutine.
Chapter 1. OpenGL Subroutines
309
The Function parameter is a symbolic constant that determines the stencil comparison function. It accepts
one of the eight following values. The Reference parameter is an integer reference value that is used in
the stencil comparison. It is clamped to the range [0,2n-1], where n is the number of bit planes in the
stencil buffer. The Mask parameter is bitwise ANDed with both the reference value and the stored stencil
value, with the ANDed values participating in the comparison.
If stencil represents the value stored in the corresponding stencil buffer location, the following list shows
the effect of each comparison function that can be specified by the Function parameter. Only if the
comparison succeeds is the pixel passed through to the next stage in the rasterization process. (See the
glStencilOp subroutine for information on setting stencil test actions.) All tests treat stencil values as
unsigned integers in the range [0,2n-1], where n is the number of bit planes in the stencil buffer.
The following values are accepted by the Function parameter:
GL_NEVER
GL_LESS
GL_LEQUAL
GL_GREATER
GL_GEQUAL
GL_EQUAL
GL_NOTEQUAL
GL_ALWAYS
Always fails.
Passes if ( Reference
Passes if ( Reference
Passes if ( Reference
Passes if ( Reference
Passes if ( Reference
Passes if ( Reference
Always passes.
&
&
&
&
&
&
Mask
Mask
Mask
Mask
Mask
Mask
)
)
)
)
)
)
is
is
is
is
is
is
less than ( stencil & Mask ).
less than or equal to ( stencil & Mask ).
greater than ( stencil & Mask ).
greater than or equal to ( stencil & Mask ).
equal to ( stencil & Mask ).
not equal to ( stencil & Mask ).
Notes
Initially, the stencil test is disabled. If there is no stencil buffer, no stencil modification can occur and it is
as if the stencil test always passes.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Function is not one of the eight accepted values.
The glStencilFunc subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glStencilFunc subroutine are as follows. (See the glGet subroutine.)
glGet with argument GL_STENCIL_FUNC
glGet with argument GL_STENCIL_VALUE_MASK
glGet with argument GL_STENCIL_REF
glGet with argument GL_STENCIL_BITS
glIsEnabled with argument GL_STENCIL_TEST.
Files
/usr/include/GL/gl.h
310
OpenGL 2.1 Reference Manual
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glAlphaFunc subroutine, glBegin or glEnd subroutine, glBlendFunc subroutine, glDepthFunc
subroutine, glEnable or glDisable subroutine, glLogicOp subroutine, glStencilOp subroutine.
glStencilMask Subroutine
Purpose
Controls the writing of individual bits in the stencil planes.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glStencilMask(GLuint Mask)
Parameters
Mask
Specifies a bit mask to enable and disable writing of individual bits in the stencil planes. Initially, the mask is
all 1s.
Description
The glStencilMask subroutine controls the writing of individual bits in the stencil planes. The least
significant n bits of the Mask parameter, where n is the number of bits in the stencil buffer, specify a mask.
Wherever a 1 (one) appears in the mask, the corresponding bit in the stencil buffer is made writable.
Where a 0 (zero) appears, the bit is write-protected. Initially, all bits are enabled for writing.
Errors
GL_INVALID_OPERATION
The glStencilMask subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glStencilMask subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_STENCIL_WRITEMASK
glGet with argument GL_STENCIL_BITS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glColorMask subroutine, glDepthMask subroutine, glIndexMask
subroutine, glStencilFunc subroutine, glStencilOp subroutine.
Chapter 1. OpenGL Subroutines
311
glStencilOp Subroutine
Purpose
Sets stencil test actions.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glStencilOp(GLenum Fail,
GLenum zFail,
GLenum zPass)
Parameters
Fail
Specifies the action to take when the stencil test fails. Six symbolic constants are accepted:
v GL_KEEP
v GL_ZERO
v GL_REPLACE
v GL_INCR
v GL_DECR
v GL_INCR_WRAP_EXT
v GL_DECR_WRAP_EXT
v GL_INVERT
Specifies stencil action when the stencil test passes but the depth test fails. zFail accepts the same
symbolic constants as Fail.
Specifies stencil action when both the stencil test and the depth test pass, or when the stencil test passes
and either there is no depth buffer or depth testing is not enabled. zPass accepts the same symbolic
constants as Fail.
zFail
zPass
Description
Stenciling, like z-buffering, enables and disables drawing on a per-pixel basis. You draw into the stencil
planes using GL drawing primitives, and then render geometry and images, using the stencil planes to
mask out portions of the screen. Stenciling is typically used in multipass rendering algorithms to achieve
special effects, such as decals, outlining, and constructive solid geometry rendering.
The stencil test conditionally eliminates a pixel based on the outcome of a comparison between the value
in the stencil buffer and a reference value. The test is enabled with the glEnable and glDisable
subroutine calls with the GL_STENCIL argument, and controlled with the glStencilFunc subroutine.
The glStencilOp subroutine takes three arguments that indicate what happens to the stored stencil value
while stenciling is enabled. If the stencil test fails, no change is made to the pixel’s color or depth buffers,
and the Fail parameter specifies what happens to the stencil buffer contents. The eight possible actions
are as follows:
GL_KEEP
GL_ZERO
GL_REPLACE
GL_INCR
GL_DECR
312
Keeps the current value.
Sets the stencil buffer value to 0 (zero).
Sets the stencil buffer value to the Reference parameter, as specified by the
glStencilFunc subroutine.
Increments the current stencil buffer value. Clamps to the maximum representable
unsigned value.
Decrements the current stencil buffer value. Clamps to 0.
OpenGL 2.1 Reference Manual
GL_INCR_WRAP_EXT
GL_DECR_WRAP_EXT
GL_INVERT
Increments the current stencil buffer value. A GL_INCR_WRAP_EXT on the
maximum representable unsigned value yields a 0 value.
Decrements the current stencil buffer value. A GL_DECR_WRAP_EXT on 0 yields
the maximum representable unsigned value.
Bitwise inverts the current stencil buffer value.
Stencil buffer values are treated as unsigned integers. The maximum representable value is 2n-1, where n
is the value returned by querying GL_STENCIL_BITS.
The other two arguments to glStencilOp specify stencil buffer actions should subsequent depth buffer
tests succeed (the zPass parameter) or fail (the zFail parameter). (See the glDepthFunc for information
about specifying the function used for depth buffer comparisons.) They are specified using the same eight
symbolic constants as the Fail parameter. Note that the zFail parameter is ignored when there is no depth
buffer, or when the depth buffer is not enabled. In these cases, the Fail and zPass parameters specify
stencil action when the stencil test fails and passes, respectively.
Notes
Initially the stencil test is disabled. If there is no stencil buffer, no stencil modification can occur and it is as
if the stencil tests always pass, regardless of any call to the glStencilOp subroutine.
The GL_INCR_WRAP_EXT and GL_DECR_WRAP_EXT stencil actions are only supported if the
GL_EXT_stencil_wrap extension is supported.
Errors
GL_INVALID_ENUM
GL_INVALID_OPERATION
Fail, zFail, or zPass is any value other than the eight defined constant values.
The glStencilOp subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glStencilOp subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_STENCIL_FAIL
glGet with argument GL_STENCIL_PASS_DEPTH_PASS
glGet with argument GL_STENCIL_PASS_DEPTH_FAIL
glGet with argument GL_STENCIL_BITS
glIsEnabled with argument GL_STENCIL_TEST.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glAlphaFunc subroutine, glBegin or glEnd subroutine, glBlendFunc subroutine, glDepthFunc
subroutine, glEnable or glDisable subroutine, glLogicOp subroutine, glStencilFunc subroutine.
Chapter 1. OpenGL Subroutines
313
glTexCoord Subroutine
Purpose
Sets the current texture coordinates.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexCoord1d(GLdouble
S)
void glTexCoord1f(GLfloat
void glTexCoord1i(GLint
S)
S)
void glTexCoord1s(GLshort
S)
void glTexCoord2d(GLdouble
GLdouble T)
S,
void glTexCoord2f(GLfloat
GLfloat T)
S,
void glTexCoord2i(GLint
GLint T)
S,
void glTexCoord2s(GLshort
GLshort T)
S,
void glTexCoord3d(GLdouble
GLdouble T,
GLdouble R)
S,
void glTexCoord3f(GLfloat
GLfloat T,
GLfloat R)
void glTexCoord3i(GLint
GLint T,
GLint R)
S,
void glTexCoord3s(GLshort
GLshort T,
GLshort R)
void glTexCoord4d(GLdouble
GLdouble T,
GLdouble R,
GLdouble Q)
void glTexCoord4f(GLfloat
GLfloat T,
GLfloat R,
GLfloat Q)
314
S,
S,
S,
S,
OpenGL 2.1 Reference Manual
void glTexCoord4i(GLint
GLint T,
GLint R,
GLint Q)
void glTexCoord4s(GLshort
GLshort T,
GLshort R,
GLshort Q)
S,
S,
void glTexCoord1dv(const GLdouble * V)
void glTexCoord1fv(const GLfloat * V)
void glTexCoord1iv(const GLint * V)
void glTexCoord1sv(const GLshort * V)
void glTexCoord2dv(const GLdouble * V)
void glTexCoord2fv(const GLfloat * V)
void glTexCoord2iv(const GLint * V)
void glTexCoord2sv(const GLshort * V)
void glTexCoord3dv(const GLdouble * V)
void glTexCoord3fv(const GLfloat * V)
void glTexCoord3iv(const GLint * V)
void glTexCoord3sv(const GLshort * V)
void glTexCoord4dv(const GLdouble * V)
void glTexCoord4fv(const GLfloat * V)
void glTexCoord4iv(const GLint * V)
void glTexCoord4sv(const GLshort * V)
Parameters
S, T, R, Q
V
Specify S, T, R, and A texture coordinates. Not all parameters are present in all forms of the
command.
Specifies a pointer to an array of one, two, three, or four elements, which in turn specify the S, T,
R, and Q texture coordinates.
Description
The glTexCoord subroutine specifies texture coordinates in one, two, three, or four dimensions. The
glTexCoord1 subroutine sets the current texture coordinates to (S,0,0,1); a call to glTexCoord2 sets them
to (S,T,0,1). Similarly, glTexCoord3 specifies the texture coordinates as (S,T,R,1), and glTexCoord4
defines all four components explicitly as (S,T,R,Q).
Chapter 1. OpenGL Subroutines
315
The current texture coordinates are part of the data that is associated with each vertex and with the
current raster position. Initially, the values for S, T, R, and Q are (0, 0, 0, 1).
Notes
The current texture coordinates can be updated at any time. In particular, the glTexCoord subroutine can
be called between a call to glBegin and the corresponding call to glEnd.
If the GL_ARB_multitexture extension is present, then there will be multiple texture units present. This
call will only affect the current textrue coordinate on Texture Unit 0. Use glMultiTexCoord*ARB to affect
texture coordinates on other Texture Units.
Associated Gets
Associated gets for the glTexCoord subroutine are as follows. (See the glGet subroutine for more
information.)
glGet with argument GL_CURRENT_TEXTURE_COORDS.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glTexCoordPointer subroutine, glTexCoordPointerEXT subroutine,
glVertex subroutine.
glTexCoordColorNormalVertexSUN Subroutine
Purpose
Specifies a texture coordinate, a color, a normal and a vertex in one call.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glTexCoord2fColor4fNormal3fVertex3fSUN (GLfloat s,
GLfloat t,
GLfloat r,
GLfloat g,
GLfloat b,
GLfloat a,
GLfloat nx,
GLfloat ny,
GLfloat nz,
GLfloat x,
GLfloat y,
GLfloat z)
void glTexCoord2fColor4fNormal3fVertex3fvSUN (const GLfloat *tc,
const GLfloat *c,
const GLfloat *n,
const GLfloat *v)
316
OpenGL 2.1 Reference Manual
void glTexCoord4fColor4fNormal3fVertex4fSUN (GLfloat s,
GLfloat t,
GLfloat p,
GLfloat q,
GLfloat r,
GLfloat g,
GLfloat b,
GLfloat a,
GLfloat nx,
GLfloat ny,
GLfloat nz,
GLfloat x,
GLfloat y,
GLfloat z,
GLfloat w)
void glTexCoord4fColor4fNormal3fVertex4fvSUN (const GLfloat *tc,
const GLfloat *c,
const GLfloat *n,
const GLfloat *v)
Description
This subroutine can be used as a replacement for the following calls:
glColor();
glNormal();
glVertex();
glTexCoord();
For example:
glTexCoord4fColor4fNormal3fVertex4fvSUN replaces the following calls:
glTexCoord4f();
glColor4f();
glNormal3f();
glVertex4fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
s, t, p, q
tc
r, g, b, a
c
nx, ny, nz
n
x, y, z, w
Specifies the s, t, p, and q components of the texture
coordinate for this vertex. Not all parameters are present
in all forms of the command.
Specifies a pointer to an array of texture coordinate
values. The elements of a two-element array are s and t.
The elements of a four-element array are s, t, p, and q.
Specifies the r, g, b, and a components of the color for
this vertex.
Specifies a pointer to an array of the four components r,
g, b, and a.
Specifies the x, y, and z coordinates of the normal vector
for this vertex.
Specifies a pointer to an array of the three elements nx,
ny and nz.
Specifies the x, y, z, and w coordinates of a vertex. Not all
parameters are present in all forms of the command.
Chapter 1. OpenGL Subroutines
317
v
Specifies a pointer to an array of vertex coordinates. The
elements of a three-element array are x, y, and z. The
elements of a four-element array are x, y, z, and w.
Notes
Calling glTexCoordColorNormalVertexSUN outside of a glBegin/glEnd subroutine pair results in
undefined behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
glTexCoordColorVertexSUN Subroutine
Purpose
Specifies a texture coordinate, a color, and a vertex in one call.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
extern void glTexCoord2fColor4ubVertex3fSUN (GLfloat s,
GLfloat t,
GLubyte r,
GLubyte g,
GLubyte b,
GLubyte a,
GLfloat x,
GLfloat y,
GLfloat z)
extern void glTexCoord2fColor4ubVertex3fvSUN (const GLfloat *tc,
const GLubyte *c,
const GLfloat *v)
extern void glTexCoord2fColor3fVertex3fSUN (GLfloat s,
GLfloat t,
GLfloat r,
GLfloat g,
GLfloat b,
GLfloat x,
GLfloat y,
GLfloat z)
extern void glTexCoord2fColor3fVertex3fvSUN (const GLfloat *tc,
const GLfloat *c,
const GLfloat *v)
318
OpenGL 2.1 Reference Manual
Description
This subroutine can be used as a replacement for the following calls:
glColor();
glVertex();
glTexCoord();
For example, glTexCoord2fColor3fVertex3fvSUN replaces the following calls:
glTexCoord2f();
glColor3f();
glVertex3fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
s, t
tc
r, g, b, a
c
x, y, z
v
Specifies the s and t components of the texture coordinate
for this vertex.
Specifies a pointer to an array of texture coordinate
values. The elements of a two-element array are s and t.
The elements of a four-element array are s, t, p, and q.
Specifies the red, green, blue, and alpha components of a
color. Not all parameters are present in all forms of the
command.
Specifies a pointer to an array of three or four elements.
The elements of a three-element array are r, g, and b.
The elements of a four-element array are r, g, b, and a.
Specifies the x, y, and z coordinates of a vertex.
Specifies a pointer to an array of the three elements x, y,
and z.
Notes
Calling glTexCoordColorVertexSUN outside of a glBegin/glEnd subroutine pair results in undefined
behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
glTexCoordNormalVertexSUN Subroutine
Purpose
Specifies a texture coordinate, a normal and a vertex in one call.
Library
OpenGL C bindings library: (libGL.a)
Chapter 1. OpenGL Subroutines
319
C Syntax
void glTexCoord2fNormal3fVertex3fSUN (GLfloat s,
GLfloat t,
GLfloat nx,
GLfloat ny,
GLfloat nz,
GLfloat x,
GLfloat y,
GLfloat z)
void glTexCoord2fNormal3fVertex3fvSUN (const GLfloat *tc,
const GLfloat *n,
const GLfloat *v)
Description
This subroutine can be used as a replacement for the following calls:
glTexCoord();
glNormal();
glVertex();
For example, glTexCoord2fNormal3fVertex3fvSUN replaces the following calls:
glTexCoord2f();
glNormal3f();
glVertex3fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
s, t
tc
x, y, z
v
nx, ny, nz
n
Specifies
Specifies
Specifies
Specifies
Specifies
Specifies
the texture coordinate s and t values.
a pointer to an array of the two texture coordinate values s and t.
the x, y, and z coordinates of a vertex.
a pointer to an array of the three elements x, y, and z.
the x, y, and z coordinates of the normal vector for this vertex.
a pointer to an array of the three elements nx, ny and nz.
Notes
Calling glTexCoordNormalVertexSUN outside of a glBegin/glEnd subroutine pair results in undefined
behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
320
OpenGL 2.1 Reference Manual
glTexCoordPointer Subroutine
Purpose
Defines an array of texture coordinates.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexCoordPointer( GLint
GLenum type,
GLsizei stride,
const GLvoid * pointer)
size,
Description
The glTexCoordPointer subroutine specifies the location and data format of an array of texture
coordinates to use when rendering. The size parameter specifies the number of coordinates per element,
and must be 1, 2, 3, or 4. The type parameter specifies the data type of each texture coordinate and stride
gives the byte stride from one array element to the next allowing vertices and attributes to be packed into
a single array or stored in separate arrays. (Single array storage may be more efficient on some
implementations; see glInterleavedArrays). When a texture coordinate array is specified, size, type,
stride, and pointer are saved client side state.
To enable and disable the texture coordinate array, call glEnableClientState and glDisableClientState
with the argument GL_TEXTURE_COORD_ARRAY. If enabled, the texture coordinate array is used when
glDrawArrays, glDrawElements or glArrayElement is called.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Tex Coord array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
type
stride
pointer
Specifies the number of coordinates per array element. Must be 1, 2, 3 or 4. The initial value is 4.
Specifies the data type of each texture coordinate. Symbolic constants GL_SHORT, GL_INT,
GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Specifies the byte offset between consecutive array elements. If stride is 0, the array elements are
understood to be tightly packed. The initial value is 0.
Specifies a pointer to the first coordinate of the first element in the array. The initial value is 0 (NULL
pointer).
Notes
The glTexCoordPointer subroutine is available only if the GL version is 1.1 or greater.
The texture coordinate array is initially disabled and it won’t be accessed when glArrayElement,
glDrawElements or glDrawArrays is called.
Chapter 1. OpenGL Subroutines
321
Execution of glTexCoordPointer is not allowed between glBegin and the corresponding glEnd, but an
error may or may not be generated. If an error is not generated, the operation is undefined.
The glTexCoordPointer subroutine is typically implemented on the client side with no protocol.
Since the texture coordinate array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
The glTexCoordPointer subroutine is not included in display lists.
Errors
v GL_INVALID_VALUE is generated if size is not 1, 2, 3, or 4.
v GL_INVALID_ENUM is generated if type is not an accepted value.
v GL_INVALID_VALUE is generated if stride is negative.
Associated Gets
v glIsEnabled with argument GL_TEXTURE_COORD_ARRAY
v glGet with argument GL_TEXTURE_COORD_ARRAY_SIZE
v glGet with argument GL_TEXTURE_COORD_ARRAY_TYPE
v glGetPointerv with argument GL_TEXTURE_COORD_ARRAY_POINTER
Related Information
The glArrayElement subroutine, glClientActiveTextureARB subroutine, glColorPointer subroutine,
glDrawArrays subroutine, glDrawElements subroutine, glDrawRangeElements subroutine,
glEdgeFlagPointer subroutine, glEnable subroutine, glGetPointerv subroutine, glIndexPointer
subroutine, glNormalPointer subroutine, glPopClientAttrib subroutine, glPushClientAttrib subroutine,
glTexCoord subroutine, glTexCoordPointerListIBM subroutine, glVertexPointer subroutine.
glTexCoordPointerEXT Subroutine
Purpose
Defines an array of texture coordinates.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexCoordPointerEXT(GLint size,
GLenum type,
GLsizei stride,
GLsizei count,
const GLvoid *pointer)
Parameters
size
type
stride
count
322
Specifies the number of coordinates per array element. It must be 1, 2, 3 or 4.
Specifies the data type of each texture coordinate. Symbolic constants GL_SHORT, GL_INT,
GL_FLOAT, or GL_DOUBLE_EXT, are accepted.
Specifies the byte offset between consecutive array elements. If stride is zero the array elements are
understood to be tightly packed.
Specifies the number of array elements, counting from the first, that are static.
OpenGL 2.1 Reference Manual
pointer
Specifies a pointer to the first coordinate of the first element in the array.
Description
glTexCoordPointerEXT specifies the location and data format of an array of texture coordinates to use
when rendering. size specifies the number of coordinates per element, and must be 1, 2, 3, or 4. type
specifies the data type of each texture coordinate and stride gives the byte stride from one array element
to the next allowing vertexes and attributes to be packed into a single array or stored in separate arrays.
(Single-array storage may be more efficient on some implementations.) count indicates the number of
array elements (counting from the first) that are static. Static elements may be modified by the application,
but once they are modified, the application must explicitly respecify the array before using it for any
rendering. When a texture coordinate array is specified, size, type, stride, count, and pointer are saved as
client-side state, and static array elements may be cached by the implementation.
The texture coordinate array is enabled and disabled using glEnable and glDisable with the argument
GL_TEXTURE_COORD_ARRAY_EXT. If enabled, the texture coordinate array is used when
glDrawArraysEXT or glArrayElementEXT is called.
Notes
Non-static array elements are not accessed until glArrayElementEXT or glDrawArraysEXT is executed.
By default the texture coordinate array is disabled and it won’t be accessed when glArrayElementEXT or
glDrawArraysEXT is called.
Although, it is not an error to call glTexCoordPointerEXT between the execution of glBegin and the
corresponding execution of glEnd, the results are undefined.
glTexCoordPointerEXT will typically be implemented on the client side with no protocol.
Since the texture coordinate array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib.
glTexCoordPointerEXT commands are not entered into display lists.
glTexCoordPointerEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL
command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when
called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Tex Coord array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Errors
GL_INVALID_VALUE is generated if size is not 1, 2, 3, or 4.
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride or count is negative
Chapter 1. OpenGL Subroutines
323
Associated Gets
glIsEnabled with argument GL_TEXTURE_COORD_ARRAY_EXT
glGet with argument GL_TEXTURE_COORD_ARRAY_SIZE_EXT
glGet with argument GL_TEXTURE_COORD_ARRAY_TYPE_EXT
glGet with argument GL_TEXTURE_COORD_ARRAY_STRIDE_EXT
glGet with argument GL_TEXTURE_COORD_ARRAY_COUNT_EXT
glGetPointervEXT with argument GL_TEXTURE_COORD_ARRAY_POINTER_EXT
File
/usr/include/GL/glext.h
Contains extensions to C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glDrawArraysEXT subroutine,
glEdgeFlagPointerEXT subroutine, glGetPointervEXT subroutine, glIndexPointerEXT subroutine,
glNormalPointerEXT subroutine, glVertexPointerEXT subroutine.
glTexCoordPointerListIBM Subroutine
Purpose
Defines a list of texture coordinate arrays.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexCoordPointerListIBM(GLint
GLenum type,
GLint stride,
const GLvoid ** pointer,
GLint ptrstride)
size,
Description
The glTexCoordPointerListIBM subroutine specifies the location and data format of a list of arrays of
texture coordinate components to use when rendering. The size parameter specifies the number of
components per texture coordinate, and must be 1, 2, 3 or 4. The type parameter specifies the data type
of each texture coordinate component. The stride parameter gives the byte stride from one texture
coordinate to the next allowing vertices and attributes to be packed into a single array or stored in
separate arrays. (Single-array storage may be more efficient on some implementations; see
glInterleavedArrays). The ptrstride parameter specifies the byte stride from one pointer to the next in the
pointer array.
When a texture coordinate array is specified, size, type, stride, pointer and ptrstride are saved as client
side state.
324
OpenGL 2.1 Reference Manual
A stride value of 0 does not specify a “tightly packed” array as it does in glTexCoordPointer. Instead, it
causes the first array element of each array to be used for each vertex. Also, a negative value can be
used for stride, which allows the user to move through each array in reverse order.
To enable and disable the texture coordinate arrays, call glEnableClientState and glDisableClientState
with the argument GL_TEXTURE_COORD_ARRAY. The texture coordinate array is initially disabled.
When enabled, the texture coordinate arrays are used when glMultiDrawArraysEXT,
glMultiDrawElementsEXT, glMultiModeDrawArraysIBM, glMultiModeDrawElementsIBM,
glDrawArrays, glDrawElements or glArrayElement is called. The last three calls in this list will only use
the first array (the one pointed at by pointer[0]). See the descriptions of these routines for more information
on their use.
Use glDrawArrays, glMultiDrawArraysEXT, or glMultiModeDrawArraysIBM to construct a sequence of
primitives from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives
by indexing vertices and vertex attributes. Use glDrawElements, glMultiDrawElementsEXT,
glMultiModeDrawElementsIBM, or glDrawRangeElements to construct a sequence of primitives by
indexing vertices and vertex attributes.
If enabled, the Tex Coord array is used when glDrawArrays, glDrawElements, glArrayElements,
glMultiDrawArraysEXT, glMultiDrawElementsEXT, glMultiModeDrawArraysIBM,
glMultiModeDrawElementsIBM, or glDrawRangeElements is called.
Parameters
size
type
stride
pointer
ptrstride
Specifies the number of components per texture coordinate. It must be 1, 2, 3 or 4. The initial value
is 4.
Specifies the data type of each texture coordinate component in the array. Symbolic constants
GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT,
GL_UNSIGNED_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
Specifies the byte offset between consecutive texture coordinates. The initial value is 0.
Specifies a list of texture coordinate arrays. The initial value is 0 (NULL pointer).
Specifies the byte stride between successive pointers in the pointer array. The initial value is 0.
Notes
The glTexCoordPointerListIBM subroutine is available only if the GL_IBM_vertex_array_lists extension is
supported.
Execution of glTexCoordPointerListIBM is not allowed between glBegin and the corresponding glEnd,
but an error may or may not be generated. If an error is not generated, the operation is undefined.
The glTexCoordPointerListIBM subroutine is typically implemented on the client side.
Since the texture coordinate array parameters are client side state, they are not saved or restored by
glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.
When a glTexCoordPointerListIBM call is encountered while compiling a display list, the information it
contains does NOT contribute to the display list, but is used to update the immediate context instead.
The glTexCoordPointer call and the glTexCoordPointerListIBM call share the same state variables. A
glTexCoordPointer call will reset the texture coordinate list state to indicate that there is only one texture
coordinate list, so that any and all lists specified by a previous glTexCoordPointerListIBM call will be lost,
not just the first list that it specified.
Chapter 1. OpenGL Subroutines
325
Error Codes
v GL_INVALID_VALUE is generated if size is not 1, 2, 3 or 4.
v GL_INVALID_ENUM is generated if type is not an accepted value.
Associated Gets
v
v
v
v
glIsEnabled with argument GL_TEXTURE_COORD_ARRAY
glGetPointerv with argument GL_TEXTURE_COORD_ARRAY_LIST_IBM
glGet with argument GL_TEXTURE_COORD_ARRAY_LIST_STRIDE_IBM
glGet with argument GL_TEXTURE_COORD_ARRAY_SIZE
v glGet with argument GL_TEXTURE_COORD_ARRAY_STRIDE
v glGet with argument GL_TEXTURE_COORD_ARRAY_TYPE
Related Information
The glArrayElement subroutine, glClientActiveTextureARB subroutine, glDrawArrays subroutine,
glDrawElements subroutine, glDrawRangeElements subroutine, glEdgeFlagPointer subroutine,
glEnable subroutine, glGetPointerv subroutine, glIndexPointer subroutine, glInterleavedArrays
subroutine, glMultiDrawArraysEXT subroutine, glMultiDrawElementsEXT subroutine,
glMultiModeDrawArraysIBM subroutine, glMultiModeDrawElementsIBM subroutine, glNormalPointer
subroutine, glPopClientAttrib subroutine, glPushClientAttrib subroutine, glTexCoordPointer subroutine,
glVertexPointer subroutine.
glTexCoordVertexSUN Subroutine
Purpose
Specifies a texture coordinate and a vertex in one call.
Library
OpenGL C bindings library: (libGL.a)
C Syntax
void glTexCoord2fVertex3fSUN (GLfloat s,
GLfloat t,
GLfloat x,
GLfloat y,
GLfloat z)
void glTexCoord2fVertex3fvSUN (const GLfloat *tc,
const GLfloat *v)
void glTexCoord4fVertex4fSUN (GLfloat s,
GLfloat t,
GLfloat p,
GLfloat q,
GLfloat x,
GLfloat y,
GLfloat z,
GLfloat w)
void glTexCoord4fVertex4fvSUN (const GLfloat *tc,
const GLfloat *v)
Description
This subroutine can be used as a replacement for the following calls:
326
OpenGL 2.1 Reference Manual
glVertex();
glTexCoord();
For example, glTexCoord4fVertex4fvSUN replaces the following calls:
glTexCoord4f();
glVertex4fv();
The only reason for using this call is that it reduces the use of bus bandwidth.
Parameters
s, t, p, q
tc
x, y, z, w
v
Specifies the s, t, p, and q components of the texture
coordinate for this vertex. Not all parameters are present
in all forms of the command.
Specifies a pointer to an array of texture coordinate
values. The elements of a two-element array are s and t.
The elements of a four-element array are s, t, p, and q.
Specifies the x, y, z, and w coordinates of a vertex. Not all
parameters are present in all forms of the command.
Specifies a pointer to an array of vertex coordinates. The
elements of a three-element array are x, y, and z. The
elements of a four-element array are x, y, z, and w.
Notes
Calling glTexCoordVertexSUN outside of a glBegin/glEnd subroutine pair results in undefined behavior.
This subroutine is only valid if the GL_SUN_vertex extension is defined.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions,
and ANSI function prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, the glColor subroutine, the glNormal subroutine, the glTexCoord
subroutine, the glVertex subroutine.
glTexEnv Subroutine
Purpose
Sets texture environment parameters.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexEnvf(GLenum Target,
GLenum pName,
GLfloat Parameter)
Chapter 1. OpenGL Subroutines
327
void glTexEnvi(GLenum
GLenum pName,
GLint Parameter)
Target,
void glTexEnvfv(GLenum Target,
GLenum pName,
const GLfloat * Parameters)
void glTexEnviv(GLenum Target,
GLenum pName,
const GLint * Parameters)
Parameters
glTexEnvf or glTexEnvi
Target
Specifies a texture environment. Must be
GL_TEXTURE_ENV.
Specifies the symbolic name of a single-valued texture
environment parameter. Accepted values are:
pName
v GL_TEXTURE_ENV_MODE
v GL_COMBINE_RGB_EXT
v GL_COMBINE_ALPHA_EXT
v GL_SOURCE0_RGB_EXT
v GL_SOURCE1_RGB_EXT
v GL_SOURCE2_RGB_EXT
v GL_SOURCE0_ALPHA_EXT
v GL_SOURCE1_ALPHA_EXT
v GL_SOURCE2_ALPHA_EXT
v GL_OPERAND0_RGB_EXT
v GL_OPERAND1_RGB_EXT
v GL_OPERAND2_RGB_EXT
v GL_OPERAND0_ALPHA_EXT
v GL_OPERAND1_ALPHA_EXT
v GL_OPERAND2_ALPHA_EXT
v GL_RGB_SCALE_EXT, or
v GL_ALPHA_SCALE
Specifies a single symbolic constant, one of
GL_MODULATE, GL_DECAL, GL_BLEND,
GL_COMBINE_EXT, GL_ADD, GL_REPLACE,
GL_ADD_SIGNED_EXT or GL_INTERPOLATE_EXT.
Parameter
glTexEnvfv or glTexEnviv
Target
328
Specifies a texture environment. Must be GL_TEXTURE_ENV.
OpenGL 2.1 Reference Manual
pName
Specifies the symbolic name of a texture environment parameter. Accepted values are:
v GL_TEXTURE_ENV_MODE
v GL_TEXTURE_ENV_COLOR
v GL_COMBINE_RGB_EXT
v GL_COMBINE_ALPHA_EXT
v GL_SOURCE0_RGB_EXT
v GL_SOURCE1_RGB_EXT
v GL_SOURCE2_RGB_EXT
v GL_SOURCE0_ALPHA_EXT
v GL_SOURCE1_ALPHA_EXT
v GL_SOURCE2_ALPHA_EXT
v GL_OPERAND0_RGB_EXT
v GL_OPERAND1_RGB_EXT
v GL_OPERAND2_RGB_EXT
v GL_OPERAND0_ALPHA_EXT
v GL_OPERAND1_ALPHA_EXT
v GL_OPERAND2_ALPHA_EXT
v GL_RGB_SCALE_EXT
Parameters
v GL_ALPHA_SCALE
Specifies a pointer to an array of parameters: either a single symbolic constant or an RGBA
color.
Description
A texture environment specifies how texture values are interpreted when a fragment is textured.
If the pName parameter is GL_TEXTURE_ENV_MODE, the Parameter(s) parameter is (or points to) the
symbolic name of a texture function. Six texture functions are defined: GL_MODULATE, GL_DECAL,
GL_BLEND, GL_REPLACE, GL_ADD or GL_COMBINE. GL_TEXTURE_ENV_MODE defaults to
GL_MODULATE
If the pName parameter is GL_TEXTURE_ENV_COLOR, the Parameters parameter is a pointer to an
array that holds an RGBA color consisting of four values. Integer color components are interpreted linearly
such that the most positive integer maps to 1.0, and the most negative integer maps to -1.0. The values
are clamped to the range [0,1] when they are specified. Cc (see tables below) takes these four values.
GL_TEXTURE_ENV_COLOR defaults to (0,0,0,0).
If the pName parameter is GL_COMBINE_RGB_EXT or GL_COMBINE_ALPHA_EXT, the Parameter(s)
parameter is (or points to) the symbolic name of a texture function. Five texture functions are defined:
GL_MODULATE, GL_REPLACE, GL_ADD, GL_ADD_SIGNED_EXT or GL_INTERPOLATE_EXT. The
default value for these pNames is GL_MODULATE.
If the pName parameter is GL_SOURCE0_RGB_EXT, GL_SOURCE1_RGB_EXT,
GL_SOURCE2_RGB_EXT, GL_SOURCE0_ALPHA_EXT, GL_SOURCE1_ALPHA_EXT, or
GL_SOURCE2_ALPHA_EXT, the Parameter(s) parameter is (or points to) the symbolic name of a texture
operator. Four texture operators are defined: GL_TEXTURE, GL_CONSTANT_EXT,
GL_PRIMARY_COLOR_EXT, or GL_PREVIOUS_EXT. The default value for these pNames are shown in
the following table:
Parameter
Default value
GL_SOURCE0_RGB_EXT
GL_TEXTURE
GL_SOURCE1_RGB_EXT
GL_PREVIOUS_EXT
Chapter 1. OpenGL Subroutines
329
GL_SOURCE2_RGB_EXT
GL_CONSTANT_EXT
GL_SOURCE0_ALPHA_EXT
GL_TEXTURE
GL_SOURCE1_ALPHA_EXT
GL_PREVIOUS_EXT
GL_SOURCE2_ALPHA_EXT
GL_CONSTANT_EXT
If the pName parameter is GL_OPERAND0_RGB_EXT, or GL_OPERAND1_RGB_EXT, the Parameter(s)
parameter is (or points to) the symbolic name of a texture operand. Four texture operands are defined:
GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_SRC_ALPHA, or
GL_ONE_MINUS_SRC_ALPHA. The default value for these pNames is GL_SRC_COLOR.
If the pName parameter is GL_OPERAND0_ALPHA_EXT, or GL_OPERAND1_ALPHA_EXT, the
Parameter(s) parameter is (or points to) the symbolic name of a texture operand. Two texture operands
are defined: GL_SRC_ALPHA, or GL_ONE_MINUS_SRC_ALPHA. The default value for these pNames is
GL_SRC_ALPHA.
If the pName parameter is GL_OPERAND2_RGB_EXT, or GL_OPERAND2_ALPHA_EXT, the
Parameter(s) parameter is (or points to) the symbolic name of a texture operand. One texture operand is
defined: GL_SRC_ALPHA.
If the pName parameter is GL_RGB_SCALE_EXT, or GL_ALPHA_SCALE, the Parameter(s) parameter is
(or points to) a floating-point scale factor. Only three such scale factors are valid: 1.0, 2.0, and 4.0. The
default value is 1.0.
A texture function acts on the fragment to be textured using the texture image value that applies to the
fragment and produces a red, green, blue, alpha (RGBA) color for that fragment. (See the
glTexParameter subroutine for details on setting texture parameters.)
A texture image can have up to four components per texture element. (See the glTexImage1D subroutine,
the glTexImage2D subroutine, and the glTexImage3DEXT subroutine.) In a one-component image, Lt
indicates that single component. A two-component image uses Lt and At. A three-component image has
only a color value, Ct. A four-component image has both a color value, Ct, and an alpha value, At.
The following table shows how the RGBA color is produced when the GL_TEXTURE_ENV_MODE is NOT
GL_COMBINE_EXT. C is a triple of color values (RGB) and A is the associated alpha value. RGBA values
extracted from a texture image are in the range [0,1]. The subscript f refers to the incoming fragment, the
subscript t to the texture image, the subscript c to the texture environment color, and subscript v indicates
a value produced by the texture function.
Note: In the following table, ″It″ equals the texture intensity.
Texture Functions
Internal Formats
GL_ DECAL
GL_ BLEND
GL_ REPLACE
GL_ ADD
GL_ LUMINANCE Cv=LtCf Av=Af
or 1
undefined
Cv=(1<I>Lt) Cf+LtCc
Av=Af
Cv=Lt Av=Af
Cv=Cf+Lt Av=Af
GL_
LUMINANCE_
ALPHA or 2
Cv=LtCf Av=AtAf
undefined
Cv=(1Lt) Cf+LtCc
Av=AtAf
Cv=Lt Av=At
Cv=Cf+Lt Av=AfAt
GL_ RGB or 3
Cv=CtCf Av=Af
Cv=Ct Av=Af
Cv=(1Ct) Cf+CtCc
Av=Af
Cv=Ct Av=Af
Cv=Cf+Ct Av=Af
330
GL_ MODULATE
OpenGL 2.1 Reference Manual
GL_ RGBA or 4
Cv=CtCf Av=AtAf
Cv=(1At) Cf+AtCt
Av=Af
Cv=(1Ct) Cf+CtCc
Av=AtAf
Cv=Ct Av=At
Cv=Cf+Ct
Av=AfAt
GL_ INTENSITY
Cv=ItCf Av=ItAf
undefined
Cv=(1-It) Cf+ItCc
Av=(1-It) Af+ItAc
Cv=It Av=It
Cv=Cf+It Av=Af+It
GL_ ALPHA
Cv=Cf Av=AtAf
undefined
Cv=Cf Av=AtAf
Cv=Cf Av=At
Cv=Cf Av=AfAt
If the value of GL_TEXTURE_ENV_MODE is GL_COMBINE_EXT, the form of the texture function
depends on the values of GL_COMBINE_RGB_EXT and GL_COMBINE_ALPHA_EXT, according to the
following table:
Combine Function
Texture Function
GL_REPLACE
Arg0
GL_MODULATE
Arg0 * Arg1
GL_ADD
Arg0 + Arg1
GL_ADD_SIGNED_EXT
Arg0 + Arg1 - 0.5
GL_INTERPOLATE_EXT
Arg0 * (Arg2) + Arg1 * (1-Arg2)
The RGB and ALPHA results of the texture function are then multiplied by the values of
GL_RGB_SCALE_EXT and GL_ALPHA_SCALE, respectively. The results are clamped to [0,1].
The arguments Arg0, Arg1 and Arg2 are determined by the values of GL_SOURCE(n)_RGB_EXT,
GL_SOURCE(n)_ALPHA_EXT, GL_OPERAND(n)_RGB_EXT and GL_OPERAND(n)_ALPHA_EXT. In
the following two tables, Ct and At are the filtered texture RGB and alpha values; Cc and Ac are the
texture environment RGB and alpha values; Cf and Af are the RGB and alpha of the primary color of the
incoming fragment; and Cp and Ap are the RGB and alpha values resulting from the previous texture
environment. On texture unit 0, Cp and Ap are identical to Cf and Af, respectively. The relationship is
described in the following two tables:
GL_ SOURCE(n)_
RGB_ EXT
GL_ SRC_ COLOR
GL_ ONE_ MINUS_
SRC_ COLOR
GL_ SRC_ ALPHA
GL_ ONE_ MINUS_
SRC_ ALPHA
GL_ TEXTURE
Ct
(1-Ct)
At
(1-At)
GL_ CONSTANT_
EXT
Cc
(1-Cc)
Ac
(1-Ac)
GL_ PRIMARY_
COLOR_ EXT
Cf
(1-Cf)
Af
(1-Af)
GL_ PREVIOUS_
EXT
Cp
(1-Cp)
Ap
(1-Ap)
GL_SOURCE(n)_ALPHA_EXT
GL_SRC_ALPHA
GL_ONE_MINUS_SRC_ALPHA
GL_TEXTURE
At
(1-At)
GL_CONSTANT_EXT
Ac
(1-Ac)
GL_PRIMARY_COLOR_EXT
Af
(1-Af)
GL_PREVIOUS_EXT
Ap
(1-Ap)
The mapping of texture components to source components is summarized in the following table, where At,
Lt, It, Rt, Gt and Bt are the filtered texel values.
Chapter 1. OpenGL Subroutines
331
Base Internal Format>
RGB Values
Alpha Value
GL_ALPHA
0, 0, 0
At
GL_LUMINANCE
Lt, Lt, Lt
1
GL_LUMINANCE_ALPHA
Lt, Lt, Lt
At
GL_INTENSITY
It, It, It
It
GL_RGB
Rt, Gt, Bt
1
GL_RGBA
Rt, Gt, Bt
At
Notes
GL_ADD is only valid if the GL_EXT_texture_env_add extension is present.
GL_COMBINE_EXT, GL_ADD_SIGNED_EXT, GL_INTERPOLATE_EXT, GL_COMBINE_RGB_EXT,
GL_COMBINE_ALPHA_EXT,GL_SOURCEn_RGB_EXT, GL_SOURCEn_ALPHA_EXT,
GL_OPERANDn_RGB_EXT, GL_OPERANDn_ALPHA_EXT, GL_RGB_SCALE_EXT, and
GL_ALPHA_SCALE are only valid if the GL_EXT_texture_env_combine extension is present.
Error Codes
GL_INVALID_ENUM
INVALID_ENUM
INVALID_ENUM
INVALID_ENUM
INVALID_ENUM
INVALID_ENUM
INVALID_VALUE
GL_INVALID_OPERATION
Target or pName is not one of the accepted defined values, or Parameters
should have a defined constant value (based on the value of pName) and
does not.
The Parameter(s) value for GL_COMBINE_RGB_EXT or
GL_COMBINE_ALPHA_EXT is not one of GL_REPLACE, GL_MODULATE,
GL_ADD, GL_ADD_SIGNED_EXT, or GL_INTERPOLATE_EXT.
The Parameter(s) value for GL_SOURCE0_RGB_EXT,
GL_SOURCE1_RGB_EXT, GL_SOURCE2_RGB_EXT,
GL_SOURCE0_ALPHA_EXT, GL_SOURCE1_ALPHA_EXT or
GL_SOURCE2_ALPHA_EXT is not one of GL_TEXTURE,
GL_CONSTANT_EXT, GL_PRIMARY_COLOR_EXT or
GL_PREVIOUS_EXT.
The Parameter(s) value for GL_OPERAND0_RGB_EXT or
GL_OPERAND1_RGB_EXT is not one of GL_SRC_COLOR,
GL_ONE_MINUS_SRC_COLOR, GL_SRC_ALPHA or
GL_ONE_MINUS_SRC_ALPHA.
The Parameter(s) value for GL_OPERAND0_ALPHA_EXT or
GL_OPERAND1_ALPHA_EXT is not one of GL_SRC_ALPHA or
GL_ONE_MINUS_SRC_ALPHA.
The Parameter(s) value for GL_OPERAND2_RGB_EXT or
GL_OPERAND2_ALPHA_EXT is not GL_SRC_ALPHA.
The Parameter(s) value for RGB_SCALE_EXT or ALPHA_SCALE is not one
of 1.0, 2.0, or 4.0.
The glTexEnv subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glTexEnv subroutine are as follows. (See the glGet subroutine for more
information.)
glGetTexEnv.
332
OpenGL 2.1 Reference Manual
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glGetTexEnv subroutine, glTexImage1D subroutine, glTexImage2D
subroutine, glTexParameter subroutine.
glTexGen Subroutine
Purpose
Controls the generation of texture coordinates.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexGend(GLenum Coordinate,
GLenum pName,
GLdouble Parameter)
void glTexGenf(GLenum Coordinate,
GLenum pName,
GLfloat Parameter)
void glTexGeni(GLenum Coordinate,
GLenum pName,
GLint Parameter)
void glTexGendv(GLenum Coordinate,
GLenum pName,
const GLdouble * Parameters)
void glTexGenfv(GLenum Coordinate,
GLenum pName,
const GLfloat * Parameters)
void glTexGeniv(GLenum Coordinate,
GLenum pName,
const GLint * Parameters)
Parameters
glTexGend, glTexGenf or glTexGeni
Coordinate
Specifies a texture coordinate. Must be one of the following:
v GL_S
v GL_T
v GL_R
v GL_Q
Chapter 1. OpenGL Subroutines
333
pName
Parameter
Specifies the symbolic name of the texture-coordinate generation function. Must be
GL_TEXTURE_GEN_MODE.
Specifies a single-valued texture generation parameter, one of GL_OBJECT_LINEAR,
GL_EYE_LINEAR, or GL_SPHERE_MAP.
glTexGendv, glTexGenfv or glTexGeniv
Coordinate
Specifies a texture coordinate. Must be one of the following:
v GL_S
v GL_T
v GL_R
pName
Parameters
v GL_Q
Specifies the symbolic name of the texture-coordinate generation function or function parameters.
Must be GL_TEXTURE_GEN_MODE, GL_OBJECT_PLANE, or GL_EYE_PLANE.
Specifies a pointer to an array of texture generation parameters. If pName is
GL_TEXTURE_GEN_MODE, the array must contain a single symbolic constant, one of
GL_OBJECT_LINEAR, GL_EYE_LINEAR, or GL_SPHERE_MAP. Otherwise, Parameters holds
the coefficients for the texture-coordinate generation function specified by pName.
Description
The glTexGen subroutine selects a texture-coordinate generation function or supplies coefficients for one
of the functions. The Coordinate parameter names one of the (s, t, r, q) texture coordinates, and it must be
one of these symbols: GL_S, GL_T, GL_R, or GL_Q. The pName parameter must be one of three
symbolic constants: GL_TEXTURE_GEN_MODE, GL_OBJECT_PLANE, or GL_EYE_PLANE. If pName
is GL_TEXTURE_GEN_MODE, the Parameters parameter chooses a mode, one of
GL_OBJECT_LINEAR, GL_EYE_LINEAR, or GL_SPHERE_MAP. If pName is either
GL_OBJECT_PLANE or GL_EYE_PLANE, the Parameters parameter contains coefficients for the
corresponding texture generation function.
If the texture generation function is GL_OBJECT_LINEAR, the following function is used:
g=p1 x0 +p2 y0 +p3 z0 +p4 w0
Figure 23. GL_OBJECT_LINEAR Function. This figure shows that g is equal to p subscript one x subscript zero + p
subscript two y subscript zero + p subscript three z subscript zero + p subscript four w subscript zero.
where g is the value computed for the coordinate named in the Coordinate parameter, p1, p2, p3, and p4
are the four values supplied in the Parameters parameter, and x0, y0, z0, w0 are the object coordinates of
the vertex. This function can be used to texture-map terrain using sea level as a reference plane (defined
by p1, p2, p3, and p4). The altitude of a terrain vertex is computed by the GL_OBJECT_LINEAR
coordinate generation function as its distance from sea level; that altitude is used to index the texture
image to map white snow onto peaks and green grass onto foothills, for example.
If the texture generation function is GL_EYE_LINEAR, the following function is used:
334
OpenGL 2.1 Reference Manual
g=p1′xe +p2′ye +p3′ze +p4′we
Figure 24. GL_EYE_LINEAR Function. This figure shows that g is equal to p subscript one′ x subscript e + p subscript
two′ y subscript e + p subscript three′ z subscript e + p subscript four′ w subscript e.
where:
(p1′ p2′ p3′ p4′)=(p1 p2 p3 p4 )M –1
Figure 25. GL_EYE_LINEAR Function Definition. This figure shows that (p subscript one′ p subscript two′ p subscript
three′ p subscript four′) equals (p subscript one p subscript two p subscript three p subscript four)M to the power of -1.
and xe, ye, ze, and we are the eye coordinates of the vertex, p1, p2, p3, p4 are the values supplied in
Parameters, and M is the modelview matrix when glTexGen is invoked. If M is poorly conditioned or
singular, texture coordinates generated by the resulting function may be inaccurate or undefined.
Note that the values in the Parameters parameter define a reference plane in eye coordinates. The
modelview matrix that is applied to them may not be the same one in effect when the polygon vertices are
transformed. This function establishes a field of texture coordinates that can produce dynamic contour
lines on moving objects.
If the pName parameter is GL_SPHERE_MAP and the Coordinate parameter is either GL_R or GL_Q, s
and t texture coordinates are generated as follows. Let u be the unit vector pointing from the origin to the
polygon vertex (in eye coordinates). Let n’ be the current normal, after transformation to eye coordinates.
Let f=(fx fy fz)T be the reflection vector such that
f=u-2n'n'Tu
Finally, let m=2(square root (fx2+fy2+(fz+1)2)). Then the values assigned to the s and t texture
coordinates are the following:
s=
fx
+1/2
m
t=
fy
+1/2
m
Figure 26. s and t Values. This figure shows two equations, one for each texture coordinate. The first equation shows
that texture coordinate s is equal to f subscript x / m + 1/2. The second equation shows that texture coordinate t is
equal to f subscript y / m + 1/2.
A texture-coordinate generation function is enabled or disabled using the glEnable or glDisable
subroutines with one of the symbolic texture-coordinate names (GL_TEXTURE_GEN_S,
GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, or GL_TEXTURE_GEN_Q) as the argument. When
enabled, the specified texture coordinate is computed according to the generating function associated with
that coordinate. When disabled, subsequent vertices take the specified texture coordinate from the current
Chapter 1. OpenGL Subroutines
335
set of texture coordinates. Initially, all texture generation functions are set to GL_EYE_LINEAR and are
disabled. Both s plane equations are (1,0,0,0), both t plane equations are (0,1,0,0), and all r and q plane
equations are (0,0,0,0).
Error Codes
GL_INVALID_ENUM
GL_INVALID_ENUM
GL_INVALID_OPERATION
Coordinate or pName is not an accepted defined value, or pName is
GL_TEXTURE_GEN_MODE and Parameters is not an accepted defined
value.
pName is GL_TEXTURE_GEN_MODE, Parameters is GL_SPHERE_MAP,
and Coordinate is either GL_R or GL_Q.
The glTexGen subroutine is called between a call to glBegin and the
corresponding call to glEnd.
Associated Gets
Associated gets for the glTexGen subroutine are as follows. (See the glGet subroutine for more
information.)
glGetTexGen
glIsEnabled with argument GL_TEXTURE_GEN_S
glIsEnabled with argument GL_TEXTURE_GEN_T
glIsEnabled with argument GL_TEXTURE_GEN_R
glIsEnabled with argument GL_TEXTURE_GEN_Q.
Files
/usr/include/GL/gl.h
Contains C language constants, variable type definitions, and ANSI function
prototypes for OpenGL.
Related Information
The glBegin or glEnd subroutine, glEnable or glDisable subroutine, glGetTexGen subroutine, glTexEnv
subroutine, glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3DEXT subroutine,
glTexParameter subroutine.
glTexImage1D Subroutine
Purpose
Specifies a one-dimensional (1D) texture image.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexImage1D(GLenum target,
GLint level,
GLint internalformat,
GLsizei width,
336
OpenGL 2.1 Reference Manual
GLint border,
GLenum format,
GLenum type,
const GLvoid * pixels)
Parameters
target
level
internalformat
width
border
format
type
pixels
Specifies the target texture. Must be GL_TEXTURE_1D of GL_PROXY_TEXTURE_1D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth
mipmap reduction image.
Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of
the following symbolic constants: GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4,
GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB,
GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1,GL_RGBA8,
GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
Specifies the width of the texture image. Must be 2n + 2 x border for some integer n. All
implementations support texture images that are at least 64 texels wide. The height of the
1D texture image is 1.
Specifies the width of the border. Must be either 0 or 1.
Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX, GL_RED,
GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA,
GL_ABGR_EXT, GL_LUMINANCE, GL_422_EXT, GL_422_REV_EXT,
GL_422_AVERAGE_EXT, GL_422_REV_AVERAGE_EXT, and
GL_LUMINANCE_ALPHA are accepted.
Specifies the data type for Pixels. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE,
GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are
accepted.
Specifies a pointer to the image data in memory.
Description
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is
enabled. To enable and disable one-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_1D.
Texture images are defined with glTexImage1D. The arguments describe the parameters of the texture
image, such as width, width of the border, level-of-detail number (See glTexParameter), and the internal
resolution and format used to store the image. The last three arguments describe how the image is
represented in memory; they are identical to the pixel formats used for glDrawPixels.
If target is GL_PROXY_TEXTURE_1D no data is read from pixels, but all of the texture image state is
recalculated, checked for consistency, and checked against the
implementation’s capabilities. If the implementation cannot handle a texture of the requested texture size, it
sets all of the image state to 0, but does not generate an error (See glGetError). To query for an entire
mipmap array, use an image array level greater than or equal to 1.
Chapter 1. OpenGL Subroutines
337
If target is GL_TEXTURE_1D, data is read from pixels as a sequence of signed or unsigned bytes, shorts,
or longs, or single-precision floating-point values, depending on type. These values are grouped into sets
of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data
is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is
treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (See
glPixelStore).
The first element corresponds to the left end of the texture array. Subsequent elements progress
left-to-right through the remaining texels in the texture array. The final element corresponds to the right
end of the texture array.
The format parameter determines the composition of each element in pixels. It can assume one of 16
symbolic values:
GL_COLOR_INDEX
GL_RED
GL_GREEN
GL_BLUE
GL_ALPHA
GL_RGB
GL_RGBA
GL_BGR
338
OpenGL 2.1 Reference Manual
Each element is a single value, a color index. The GL converts it to fixed
point (with an unspecified number of zero bits to the right of the binary
point), shifted left or right depending on the value and sign of
GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (See
glPixelTransfer). The resulting index is converted to a set of color
components using the GL_PIXEL_MAP_I_TO_R,
GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
Each element is a single red component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for green
and blue, and 1.0 for alpha. Each component is then multiplied by the
signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS,
and clamped to the range [0,1] (See glPixelTransfer).
Each element is a single green component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
blue, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (See glPixelTransfer).
Each element is a single blue component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
green, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (See glPixelTransfer).
Each element is a single alpha component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red,
green, and blue. Each component is then multiplied by the signed scale
factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
to the range [0,1] (See glPixelTransfer).
Each element is an RGB triple. The GL converts it to floating point and
assembles it into an RGBA element by attaching 1.0 for alpha.
Eachcomponent is then multiplied by the signed scale factor
GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the
range [0,1] (See glPixelTransfer).
Each element contains all four components. Each *component is then
multiplied by the signed scale factor GL_c_SCALE, added to the signed
bias GL_c_BIAS, and clamped to the range [0,1] (See glPixelTransfer).
Each pixel is a three-component group, blue first, followed by green,
followed by red. Each component is converted to the internal floating-point
format in the same way as the blue, green, and red components of an
BGRA pixel are. The color triple is converted to an BGRA pixel with alpha
set to 1.0. After this conversion, the pixel is treated just as if it had been
read as an BGRA pixel.
GL_BGRA
Each pixel is a four-component group, blue first, followed by green,
followed by red, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is BLUE,
GREEN, RED, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is B, G, R, or A, respectively.
GL_ABGR_EXT
The resulting BGRA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
Each pixel is a four-component group: for GL_RGBA, the red component
is first, followed by green, followed by blue, followed by alpha; for
GL_BGRA, the blue component is first, followed by green, followed by
red, followed by alpha; for GL_ABGR_EXT the order is alpha, blue,
green, and then red. Floating-point values are converted directly to an
internal floatingpoint format with unspecified precision. Signed integer
values are mapped linearly to the internal floating-point format such that
the most positive representable integer value maps to 1.0, and the most
negative representable value maps to -1.0. Unsigned integer data is
mapped similarly: the largest integer value maps to 1.0, and zero maps to
0.0. The resulting floating-point color values are then multiplied by
GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN,
BLUE, and ALPHA for the respective color components. The results are
clamped to the range [0,1].
If GL_MAP_COLOR is true, each color component is scaled by the size
of lookup table GL_PIXEL_MAP_c_TO _c, then replaced by the value
that it references in that table. c is R, G, B, or A, respectively.
The resulting RGBA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that
xn = xr + n mod width
yn = yr + |
GL_LUMINANCE
n
bwidthc
where (xr,yr) is the current raster position. These pixel fragments are then
treated just like the fragments generated by rasterizing points, lines, or
polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
Each element is a single luminance value. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue and attaching 1.0 for
alpha. Each component is then multiplied by the signed scale factor
GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the
range [0,1] (See glPixelTransfer).
Chapter 1. OpenGL Subroutines
339
GL_LUMINANCE_ALPHA
GL_422_EXT
GL_422_REV_EXT
GL_422_AVERAGE_EXT
340
OpenGL 2.1 Reference Manual
Each element is a luminance/alpha pair. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue. Each component is
then multiplied by the signed scale factor GL_c_SCALE, added to the
signed bias GL_c_BIAS, and clamped to the range [0,1] (See
glPixelTransfer).
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. The Cb for each even pixel is used as the Cb value for that pixel
and its neighbor to the right. The Cr in each odd pixel is used as the Cr
value for that pixel and its neighbor to the left. (If the width of the image is
odd, then the colors will be undefined in the rightmost column.) Through
the use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. The Cb for each even pixel is used as the Cb value for that pixel and
its neighbor to the right. The Cr in each odd pixel is used as the Cr value
for that pixel and its neighbor to the left. (If the width of the image is odd,
then the colors will be undefined in the rightmost column.) Through the
use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it ha d been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. Each even pixel gets its Cb from itself, and its Cr from its neighbor
to the right. Each odd pixel gets its Cb from the average of its left and
right neighbor, and its Cr from the average of itself and its neighbor two to
the right. (If the width of the image is odd, then the colors will be
undefined in the rightmost column. If the neighbors to the right are not
present for a given fragment, we use GL_422_EXT to compute that
fragment.) Through the use of the color matrix, Y then assumes the role
of red, Cb becomes green and Cr becomes blue. After this conversion,
the pixel is treated just as if it had been sent in as an RGB pixel.
GL_422_REV_AVERAGE_EXT
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. Each even pixel gets its Cb from itself, and its Cr from its neighbor to
the right. Each odd pixel gets its Cb from the average of its left and right
neighbor, and its Cr from the average of itself and its neighbor two to the
right. (If the width of the image is odd, then the colors will be undefined in
the rightmost column. If the neighbors to the right are not present for a
given fragment, we use GL_422_REV_EXT to compute that fragment.)
Through the use of the color matrix, Y then assumes the role of red, Cb
becomes green and Cr becomes blue. After this conversi on, the pixel is
treated just as if it had been sent in as an RGB pixel.
For applications that store the texture at a certain resolution or in a certain format, request the resolution
and format with internalformat. The GL will choose an internal representation that closely approximates
that requested by internalformat, but it may not match exactly. (The representations specified by
GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly. The numeric
values 1, 2, 3, and 4 may also be used to specify the above representations.)
Use the GL_PROXY_TEXTURE_1D target to try out a resolution and format. The implementation will
update and recompute its best match for the requested storage resolution and format. To query this state,
call glGetTexLevelParameter. If the texture cannot be accomodated, texture state is set to 0.
A one-component texture image uses only the red component of the RGBA color extracted from pixels. A
two-component image uses the R and A values. A three-component image uses the R, G, and B values. A
four-component image uses all of the RGBA components.
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
Texturing has no effect in color index mode.
The texture image can be represented by the same data formats as the pixels in a glDrawPixels
command, except that GL_STENCIL_INDEX and GL_DEPTH_COMPONENT cannot be used. The
glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect
glDrawPixels.
GL_PROXY_TEXTURE_1D can only be used if the GL version is 1.1 or greater.
Internal formats other than 1, 2, 3, or 4 can only be used if the GL version is 1.1 or greater.
In GL version 1.1 or greater, pixels may be a null pointer. In this case texture memory is allocated to
accomodate a texture of width width. You can then download subtextures to initialize the texture memory.
The image is undefined if the user tries to apply an uninitialized portion of the texture image to a primitive.
Format of GL_ABGR_EXT is part of the _extname (EXT_abgr) extension, not part of the core GL
command set.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_1D or GL_PROXY_TEXTURE_1D.
Chapter 1. OpenGL Subroutines
341
GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other
than GL_STENCIL_INDEX and GL_DEPTH_COMPONENT are accepted.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value
of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if internalformat is not 1, 2, 3, 4, or one of the accepted resolution and
format symbolic constants.
GL_INVALID_VALUE is generated if width is less than zero or greater than 2 +
GL_MAX_TEXTURE_SIZE, or if it cannot be represented as 2n + 2 x border for some integer value of n.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_OPERATION is generated if glTexImage1D is executed between the execution of glBegin
and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D.
Related Information
The glCopyTexImage1D subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage2D
subroutine, glTexParameter subroutine, glTexSubImage1D subroutine.
glTexImage2D Subroutine
Purpose
Specifies a two-dimensional (2D) texture image.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexImage2D(GLenum target,
GLint level,
GLint internalformat,
GLsizei width,
GLsizei height,
GLint border,
GLenum format,
GLenum type,
const GLvoid * pixels)
342
OpenGL 2.1 Reference Manual
Parameters
target
level
internalformat
width
height
border
format
type
pixels
Specifies the target texture. Must be GL_TEXTURE_2D or GL_PROXY_TEXTURE_2D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth
mipmap reduction image.
Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of
the following symbolic constants: GL_ABGR_EXT, GL_ALPHA,GL_ALPHA4,
GL_ALPHA8, GL_ALPHA12, GL_ALPHA16,GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8,GL_LUMINANCE12, GL_LUMINANCE16,
GL_LUMINANCE_ALPHA,GL_LUMINANCE4_ALPHA4,
GL_LUMINANCE6_ALPHA2,GL_LUMINANCE8_ALPHA8,
GL_LUMINANCE12_ALPHA4,GL_LUMINANCE12_ALPHA12,
GL_LUMINANCE16_ALPHA16,GL_INTENSITY, GL_INTENSITY4,
GL_INTENSITY8,GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2,
GL_RGB,GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10,GL_RGB12, GL_RGB16,
GL_RGBA, GL_RGBA2,GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
GL_RGB10_A2,GL_RGBA12, or GL_RGBA16.
Specifies the width of the texture image. Must be 2n + 2 x border for some integer n. All
implementations support texture images that are at least 64 texels wide.
Specifies the height of the texture image. Must be 2m + 2 x border for some integer m.
All implementations support texture images that are at least 64 texels high.
Specifies the width of the border. Must be either 0 or 1.
Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX, GL_RED,
GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA,
GL_ABGR_EXT, GL_LUMINANCE, GL_422_EXT, GL_422_REV_EXT,
GL_422_AVERAGE_EXT, GL_422_REV_AVERAGE_EXT, and
GL_LUMINANCE_ALPHA are accepted.
Specifies the data type for Pixels. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE,
GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV, are
accepted.
Specifies a pointer to the image data in memory.
Description
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is
enabled. To enable and disable two-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_2D.
To define texture images, call glTexImage2D. The arguments describe the parameters of the texture
image, such as height, width, width of the border, level-of-detail number (see glTexParameter), and
number of color components provided. The last three arguments describe how the image is represented in
memory. They are identical to the pixel formats used for glDrawPixels.
If target is GL_PROXY_TEXTURE_2D no data is read from pixels, but all of the texture image state is
recalculated, checked for consistency, and checked against the implementation’s capabilities. If the
implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but
does not generate an error (see glGetError). To query for an entire mipmap array, use an image array
level greater than or equal to 1.
If target is GL_TEXTURE_2D, data is read from pixels as a sequence of signed or unsigned bytes, shorts,
or longs, or single-precision floating-point values, depending on type. These values are grouped into sets
of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data
Chapter 1. OpenGL Subroutines
343
is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is
treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see
glPixelStore).
The first element corresponds to the lower-left corner of the texture image. Subsequent elements progress
left-to-right through the remaining texels in the lowest row of the texture image, and then in successively
higher rows of the texture image. The final element corresponds to the upper-right corner of the texture
image.
The format parameter determines the composition of each element in pixels. It can assume one of 16
symbolic values:
GL_COLOR_INDEX
GL_RED
GL_GREEN
GL_BLUE
GL_ALPHA
GL_RGB
GL_RGBA
GL_BGR
344
OpenGL 2.1 Reference Manual
Each element is a single value, a color index. The GL converts it to fixed
point (with an unspecified number of zero bits to the right of the binary
point), shifted left or right depending on the value and sign of
GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see
glPixelTransfer). The resulting index is converted to a set of color
components using the GL_PIXEL_MAP_I_TO_R,
GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
Each element is a single red component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for green
and blue, and 1.0 for alpha. Each component is then multiplied by the
signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS,
and clamped to the range [0,1] (see glPixelTransfer).
Each element is a single green component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
blue, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (see glPixelTransfer).
Each element is a single blue component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
green, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (see glPixelTransfer).
Each element is a single alpha component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red,
green, and blue. Each component is then multiplied by the signed scale
factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
to the range [0,1] (see glPixelTransfer).
Each element is an RGB triple. The GL converts it to floating point and
assembles it into an RGBA element by attaching 1.0 for alpha. Each
component is then multiplied by the signed scale factor GL_c_SCALE,
added to the signed bias GL_c_BIAS, and clamped to the range [0,1]
(see glPixelTransfer).
Each element contains all four components. Each *component is
multiplied by the signed scale factor GL_c_SCALE, added to the signed
bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
Each pixel is a three-component group, blue first, followed by green,
followed by red. Each component is converted to the internal floating-point
format in the same way as the blue, green, and red components of an
BGRA pixel are. The color triple is converted to an BGRA pixel with alpha
set to 1.0. After this conversion, the pixel is treated just as if it had been
read as an BGRA pixel.
GL_BGRA
Each pixel is a four-component group, blue first, followed by green,
followed by red, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is BLUE,
GREEN, RED, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is B, G, R, or A, respectively.
GL_ABGR_EXT
The resulting BGRA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
Each pixel is a four-component group: for GL_RGBA, the red component
is first, followed by green, followed by blue, followed by alpha; for
GL_BGRA, the blue component is first, followed by green, followed by
red, followed by alpha; for GL_ABGR_EXT the order is alpha, blue,
green, and then red. Floating-point values are converted directly to an
internal floatingpoint format with unspecified precision. Signed integer
values are mapped linearly to the internal floating-point format such that
the most positive representable integer value maps to 1.0, and the most
negative representable value maps to -1.0. Unsigned integer data is
mapped similarly: the largest integer value maps to 1.0, and zero maps to
0.0. The resulting floating-point color values are then multiplied by
GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN,
BLUE, and ALPHA for the respective color components. The results are
clamped to the range [0,1].
If GL_MAP_COLOR is true, each color component is scaled by the size
of lookup table GL_PIXEL_MAP_c_TO _c, then replaced by the value
that it references in that table. c is R, G, B, or A, respectively.
The resulting RGBA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that
xn = xr + n mod width
yn = yr + |
GL_LUMINANCE
n
bwidthc
where (xr,yr) is the current raster position. These pixel fragments are then
treated just like the fragments generated by rasterizing points, lines, or
polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
Each element is a single luminance value. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue and attaching 1.0 for
alpha. Each component is then multiplied by the signed scale factor
GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the
range [0,1] (see glPixelTransfer).
Chapter 1. OpenGL Subroutines
345
GL_LUMINANCE_ALPHA
GL_422_EXT
GL_422_AVERAGE_EXT
GL_422_REV_AVERAGE_EXT
Each element is a luminance/alpha pair. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue. Each component is
then multiplied by the signed scale factor GL_c_SCALE, added to the
signed bias GL_c_BIAS, and clamped to the range [0,1] (see
glPixelTransfer).
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. The Cb for each even pixel is used as the Cb value for that pixel
and its neighbor to the right. The Cr in each odd pixel is used as the Cr
value for that pixel and its neighbor to the left. (If the width of the image is
odd, then the colors will be undefined in the rightmost column.) Through
the use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. Each even pixel gets its Cb from itself, and its Cr from its neighbor
to the right. Each odd pixel gets its Cb from the average of its left and
right neighbor, and its Cr from the average of itself and its neighbor two to
the right. (If the width of the image is odd, then the colors will be
undefined in the rightmost column. If the neighbors to the right are not
present for a given fragment, we use GL_422_EXT to compute that
fragment.) Through the use of the color matrix, Y then assumes the role
of red, Cb becomes green and Cr becomes blue. After this conversion,
the pixel is treated just as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. Each even pixel gets its Cb from itself, and its Cr from its neighbor to
the right. Each odd pixel gets its Cb from the average of its left and right
neighbor, and its Cr from the average of itself and its neighbor two to the
right. (If the width of the image is odd, then the colors will be undefined in
the rightmost column. If the neighbors to the right are not present for a
given fragment, we use GL_422_REV_EXT to compute that fragment.)
Through the use of the color matrix, Y then assumes the role of red, Cb
becomes green and Cr becomes blue. After this convers ion, the pixel is
treated just as if it had been sent in as an RGB pixel.
Refer to the glDrawPixels subroutine for a description of the acceptable values for the type parameter.
For applications that store the texture at a certain resolution or in a certain format, request the resolution
and format with internalformat. The GL will choose an internal representation that closely approximates
that requested by internalformat, but it may not match exactly. (The representations specified by
GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly. The numeric
values 1, 2, 3, and 4 may also be used to specify the above representations.)
346
OpenGL 2.1 Reference Manual
Use the GL_PROXY_TEXTURE_2D target to try out a resolution and format. The implementation will
update and recompute its best match for the requested storage resolution and format. To then query this
state, call glGetTexLevelParameter. If the texture cannot be accomodated, texture state is set to 0.
A one-component texture image uses only the red component of the RGBA color extracted from pixels. A
two-component image uses the R and A values. A three-component image uses the R, G, and B values. A
four-component image uses all of the RGBA components.
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
Texturing has no effect in color index mode.
The texture image can be represented by the same data formats as the pixels in a glDrawPixels
command, except that GL_STENCIL_INDEX and GL_DEPTH_COMPONENT cannot be used. The
glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect
glDrawPixels.
The GL_PROXY_TEXTURE_2D target are only available if the GL version is 1.1 or greater.
Internal formats other than 1, 2, 3, or 4 may only be used if the GL version is 1.1 or greater.
In GL version 1.1 or greater, pixels may be a null pointer. In this case texture memory is allocated to
accomodate a texture of width width and height height. You can then download subtextures to initialize this
texture memory. The image is undefined if the user tries to apply an uninitialized portion of the texture
image to a primitive.
Format of GL_ABGR_EXT is part of the _extname (EXT_abgr) extension, not part of the core GL
command set.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D or GL_PROXY_TEXTURE_2D.
GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other
than GL_STENCIL_INDEX and GL_DEPTH_COMPONENT are accepted.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2(max), where max is the returned
value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if internalformat is not 1, 2, 3, 4, or one of the accepted resolution and
format symbolic constants.
GL_INVALID_VALUE is generated if width or height is less than zero or greater than 2 +
GL_MAX_TEXTURE_SIZE, or if either cannot be represented as 2k + 2 x border for some integer value of
k.
GL_INVALID_VALUE is generated if border is not 0 or 1.
Chapter 1. OpenGL Subroutines
347
GL_INVALID_OPERATION is generated if glTexImage2D is executed between the execution of glBegin
and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_2D.
Related Information
The glCopyTexImage2D subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage1D
subroutine, glTexParameter subroutine, glTexSubImage2D subroutine.
glTexImage3D Subroutine
Purpose
Specifies a three-dimensional (3D) texture subimage.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexImage3D
(GLenum target,
GLint level,
GLint internalformat,
GLsizei width,
GLsizei height,
GLsizei depth,
GLint border,
GLenum format,
GLenum type,
const GLvoid * pixels)
Parameters
target
level
internalformat
width
height
depth
border
348
Specifies the target texture. Must be GL_TEXTURE_3D or GL_PROXY_TEXTURE_3D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth
mipmap reduction image.
Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of
the following symbolic constants: GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4,
GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16,
GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
Specifies the width of the texture image. Must be 2n + 2 x border for some integer n.
Specifies the height of the texture image. Must be 2m + 2 x border for some integer m.
Specifies the depth of the texture image. Must be 2l + 2 x border for some integer l.
Specifies the width of the border. Must be either 0 or 1.
OpenGL 2.1 Reference Manual
format
type
pixels
Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX, GL_RED,
GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA,
GL_ABGR_EXT, GL_LUMINANCE, GL_422_EXT, GL_422_REV_EXT,
GL_422_AVERAGE_EXT, GL_422_REV_AVERAGE_EXT, and accepted.
Specifies the data type for Pixels. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE,
GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are
accepted.
Specifies a pointer to the image data in memory.
Description
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is
enabled. To enable and disable three-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_3D.
To define 3D texture images, call glTexImage3D. The arguments describe the parameters of the texture
image, such as height, width, depth, width of the border, level-of-detail number (see glTexParameter), and
number of color components provided. The last three arguments describe how the image is represented in
memory; they are identical to the pixel formats used for glDrawPixels.
If target is GL_PROXY_TEXTURE_3D no data is read from pixels, but all of the texture image state is
recalculated, checked for consistency, and checked against the implementation’s capabilities. If the
implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but
does not generate an error (see glGetError). To query for an entire mipmap array, use an image array
level greater than or equal to 1.
If target is GL_TEXTURE_3D, data is read from pixels as a sequence of signed or unsigned bytes, shorts,
or longs, or single-precision floating-point values, depending on type. These values are grouped into sets
of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data
is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is
treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see
glPixelStore).
The first element corresponds to the lower-left corner of the texture image. Subsequent elements progress
left-to-right through the remaining texels in the lowest row of the texture image, and then in successively
higher rows of the texture image. The final element corresponds to the upper-right corner of the texture
image.
The format parameter determines the composition of each element in pixels. It can assume one of 16
symbolic values:
GL_COLOR_INDEX
Each element is a single value, a color index. The GL converts it to fixed
point (with an unspecified number of zero bits to the right of the binary
point), shifted left or right depending on the value and sign of
GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see
glPixelTransfer). The resulting index is converted to a set of color
components using the GL_PIXEL_MAP_I_TO_R,
GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
Chapter 1. OpenGL Subroutines
349
GL_RED
GL_GREEN
GL_BLUE
GL_ALPHA
GL_RGB
GL_RGBA
GL_BGR
GL_BGRA
Each element is a single red component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for green
and blue, and 1.0 for alpha. Each component is then multiplied by the
signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS,
and clamped to the range [0,1] (see glPixelTransfer).
Each element is a single green component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
blue, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (see glPixelTransfer).
Each element is a single blue component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
green, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (see glPixelTransfer).
Each element is a single alpha component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red,
green, and blue. Each component is then multiplied by the signed scale
factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
to the range [0,1] (see glPixelTransfer).
Each element is an RGB triple. The GL converts it to floating point and
assembles it into an RGBA element by attaching 1.0 for alpha. Each
component is then multiplied by the signed scale factor GL_c_SCALE,
added to the signed bias GL_c_BIAS, and clamped to the range [0,1]
(see glPixelTransfer).
Each element contains all four components. Each *component is
multiplied by the signed scale factor GL_c_SCALE, added to the signed
bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
Each pixel is a three-component group, blue first, followed by green,
followed by red. Each component is converted to the internal floating-point
format in the same way as the blue, green, and red components of an
BGRA pixel are. The color triple is converted to an BGRA pixel with alpha
set to 1.0. After this conversion, the pixel is treated just as if it had been
read as an BGRA pixel.
Each pixel is a four-component group, blue first, followed by green,
followed by red, followed by alpha. Floating-point values are converted
directly to an internal floating-point format with unspecified precision.
Signed integer values are mapped linearly to the internal floating-point
format such that the most positive representable integer value maps to
1.0, and the most negative representable value maps to -1.0. Unsigned
integer data are mapped similarly: the largest integer value maps to 1.0,
and 0 maps to 0.0. The resulting floating-point color values are then
multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is BLUE,
GREEN, RED, and ALPHA for the respective color components. The
results are clamped to the range [0,1].
If GL_MAP_COLOR is True, each color component is scaled by the size
of the lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value
that it references in that table. c is B, G, R, or A, respectively.
The resulting BGRA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that xn = xr + n mod Width and yn = yr + [n/Width], where (xr, yr) is the
current raster position. These pixel fragments are then treated just like the
fragments generated by rasterizing points, lines, or polygons. Texture
mapping, fog, and all the fragment operations are applied before the
fragments are written to the frame buffer.
350
OpenGL 2.1 Reference Manual
GL_ABGR_EXT
Each pixel is a four-component group: for GL_RGBA, the red component
is first, followed by green, followed by blue, followed by alpha; for
GL_BGRA, the blue component is first, followed by green, followed by
red, followed by alpha; for GL_ABGR_EXT the order is alpha, blue,
green, and then red. Floating-point values are converted directly to an
internal floatingpoint format with unspecified precision. Signed integer
values are mapped linearly to the internal floating-point format such that
the most positive representable integer value maps to 1.0, and the most
negative representable value maps to -1.0. Unsigned integer data is
mapped similarly: the largest integer value maps to 1.0, and zero maps to
0.0. The resulting floating-point color values are then multiplied by
GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN,
BLUE, and ALPHA for the respective color components. The results are
clamped to the range [0,1].
If GL_MAP_COLOR is true, each color component is scaled by the size
of lookup table GL_PIXEL_MAP_c_TO _c, then replaced by the value
that it references in that table. c is R, G, B, or A, respectively.
The resulting RGBA colors are then converted to fragments by attaching
the current raster position z coordinate and texture coordinates to each
pixel, then assigning x and y window coordinates to the nth fragment such
that
xn = xr + n mod width
yn = yr + |
GL_LUMINANCE
GL_LUMINANCE_ALPHA
GL_422_EXT
n
bwidthc
where (xr,yr) is the current raster position. These pixel fragments are then
treated just like the fragments generated by rasterizing points, lines, or
polygons. Texture mapping, fog, and all the fragment operations are
applied before the fragments are written to the frame buffer.
Each element is a single luminance value. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue and attaching 1.0 for
alpha. Each component is then multiplied by the signed scale factor
GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the
range [0,1] (see glPixelTransfer).
Each element is a luminance/alpha pair. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue. Each component is
then multiplied by the signed scale factor GL_c_SCALE, added to the
signed bias GL_c_BIAS, and clamped to the range [0,1] (see
glPixelTransfer).
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. The Cb for each even pixel is used as the Cb value for that pixel
and its neighbor to the right. The Cr in each odd pixel is used as the Cr
value for that pixel and its neighbor to the left. (If the width of the image is
odd, then the colors will be undefined in the rightmost column.) Through
the use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
Chapter 1. OpenGL Subroutines
351
GL_422_REV_EXT
GL_422_AVERAGE_EXT
GL_422_REV_AVERAGE_EXT
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. The Cb for each even pixel is used as the Cb value for that pixel and
its neighbor to the right. The Cr in each odd pixel is used as the Cr value
for that pixel and its neighbor to the left. (If the width of the image is odd,
then the colors will be undefined in the rightmost column.) Through the
use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. Each even pixel gets its Cb from itself, and its Cr from its neighbor
to the right. Each odd pixel gets its Cb from the average of its left and
right neighbor, and its Cr from the average of itself and its neighbor two to
the right. (If the width of the image is odd, then the colors will be
undefined in the rightmost column. If the neighbors to the right are not
present for a given fragment, we use GL_422_EXT to compute that
fragment.) Through the use of the color matrix, Y then assumes the role
of red, Cb becomes green and Cr becomes blue. After this conversion,
the pixel is treated just as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. Each even pixel gets its Cb from itself, and its Cr from its neighbor to
the right. Each odd pixel gets its Cb from the average of its left and right
neighbor, and its Cr from the average of itself and its neighbor two to the
right. (If the width of the image is odd, then the colors will be undefined in
the rightmost column. If the neighbors to the right are not present for a
given fragment, we use GL_422_REV_EXT to compute that fragment.)
Through the use of the color matrix, Y then assumes the role of red, Cb
becomes green and Cr becomes blue. After this conversion, the pixel is
treated just as if it had been sent in as an RGB pixel.
Refer to the glDrawPixels reference page for a description of the acceptable values for the type
parameter. If an application must store the texture at a certain resolution or in a certain format, use
internalformat to request the resolution and format. The GL will choose an internal representation that
closely approximates that requested by internalformat, but it may not match exactly. (The representations
specified by GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly.
The numeric values 1, 2, 3, and 4 may also be used to specify the above representations.)
Use the GL_PROXY_TEXTURE_3D target to try out a resolution and format. The implementation will
update and recompute its best match for the requested storage resolution and format. To then query this
state, call glGetTexLevelParameter. If the texture cannot be accommodated, texture state is set to 0.
A one-component texture image uses only the red component of the RGBA color extracted from pixels. A
two-component image uses the R and A values. A three-component image uses the R, G, and B values. A
four-component image uses all of the RGBA components.
352
OpenGL 2.1 Reference Manual
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
Texturing has no effect in color index mode.
The texture image can be represented by the same data formats as the pixels in a glDrawPixels
command, except that GL_STENCIL_INDEX and GL_DEPTH_COMPONENT cannot be used. The
glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect
glDrawPixels.
Internal formats other than 1, 2, 3, or 4 may only be used if the GL version is 1.2 or greater.
In GL version 1.2 or greater, pixels may be a null pointer. In this case texture memory is allocated to
accomodate a texture of width width and height height. You can then download subtextures to initialize this
texture memory. The image is undefined if the user tries to apply an uninitialized portion of the texture
image to a primitive.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D or GL_PROXY_TEXTURE_3D.
GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other
than GL_STENCIL_INDEX and GL_DEPTH_COMPONENT are accepted.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2(max), where max is the returned
value of GL_MAX_3D_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if internalformat is not 1, 2, 3, 4, or one of the accepted resolution and
format symbolic constants.
GL_INVALID_VALUE is generated if width, height, or depth is less than zero or greater than 2 +
GL_MAX_3D_TEXTURE_SIZE, or if either cannot be represented as 2k + 2 x border for some integer
value of k.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_OPERATION is generated if glTexImage3D is executed between the execution of glBegin
and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D
Related Information
The glCopyTexSubImage3D subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage1D
subroutine, glTexParameter subroutine, glTexImage2D subroutine.
Chapter 1. OpenGL Subroutines
353
glTexImage3DEXT Subroutine
Purpose
Specifies a three-dimensional (3D) texture subimage.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexImage3DEXT(GLenum target,
GLint level,
GLint internalformat,
GLsizei width,
GLsizei height,
GLsizei depth,
GLint border,
GLenum format,
GLenum type,
const GLvoid * pixels)
Parameters
target
level
internalformat
width
height
depth
border
format
type
pixels
354
Specifies the target texture. Must be GL_TEXTURE_3D_EXT or
GL_PROXY_TEXTURE_3D_EXT.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth
mipmap reduction image.
Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of
the following symbolic constants: GL_ABGR_EXT, GL_ALPHA, GL_ALPHA4,
GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16,
GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
Specifies the width of the texture image. Must be 2n + 2 x border for some integer n.
Specifies the height of the texture image. Must be 2m + 2 x border for some integer m.
Specifies the depth of the texture image. Must be 2l + 2 x border for some integer l.
Specifies the width of the border. Must be either 0 or 1.
Specifies the format of the pixel data. The following symbolic values are accepted:
GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB,
GL_RGBA, GL_LUMINANCE, GL_422_EXT, GL_422_REV_EXT,
GL_422_AVERAGE_EXT, GL_422_REV_AVERAGE_EXT, and
GL_LUMINANCE_ALPHA.
Specifies the data type of the pixel data. The following symbolic values are accepted:
GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT,
GL_UNSIGNED_INT, GL_INT, and GL_FLOAT.
Specifies a pointer to the image data in memory.
OpenGL 2.1 Reference Manual
Description
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is
enabled. To enable and disable three-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_3D_EXT.
To define 3D texture images, call glTexImage3DEXT. The arguments describe the parameters of the
texture image, such as height, width, depth, width of the border, level-of-detail number (see
glTexParameter), and number of color components provided. The last three arguments describe how the
image is represented in memory; they are identical to the pixel formats used for glDrawPixels.
If target is GL_PROXY_TEXTURE_3D_EXT no data is read from pixels, but all of the texture image state
is recalculated, checked for consistency, and checked against the implementation’s capabilities. If the
implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but
does not generate an error (see glGetError). To query for an entire mipmap array, use an image array
level greater than or equal to 1.
If target is GL_TEXTURE_3D_EXT, data is read from pixels as a sequence of signed or unsigned bytes,
shorts, or longs, or single-precision floating-point values, depending on type. These values are grouped
into sets of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP,
the data is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data
byte is treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see
glPixelStore).
The first element corresponds to the lower-left corner of the texture image. Subsequent elements progress
left-to-right through the remaining texels in the lowest row of the texture image, and then in successively
higher rows of the texture image. The final element corresponds to the upper-right corner of the texture
image.
The format parameter determines the composition of each element in pixels. It can assume one of 16
symbolic values:
GL_COLOR_INDEX
GL_RED
GL_GREEN
GL_BLUE
Each element is a single value, a color index. The GL converts it to fixed
point (with an unspecified number of zero bits to the right of the binary
point), shifted left or right depending on the value and sign of
GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see
glPixelTransfer). The resulting index is converted to a set of color
components using the GL_PIXEL_MAP_I_TO_R,
GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and
GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
Each element is a single red component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for green
and blue, and 1.0 for alpha. Each component is then multiplied by the
signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS,
and clamped to the range [0,1] (see glPixelTransfer).
Each element is a single green component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
blue, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (see glPixelTransfer).
Each element is a single blue component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red and
green, and 1.0 for alpha. Each component is then multiplied by the signed
scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and
clamped to the range [0,1] (see glPixelTransfer).
Chapter 1. OpenGL Subroutines
355
GL_ALPHA
GL_RGB
GL_RGBA
GL_LUMINANCE
GL_LUMINANCE_ALPHA
GL_422_EXT
GL_422_REV_EXT
356
OpenGL 2.1 Reference Manual
Each element is a single alpha component. The GL converts it to floating
point and assembles it into an RGBA element by attaching 0.0 for red,
green, and blue. Each component is then multiplied by the signed scale
factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped
to the range [0,1] (see glPixelTransfer).
Each element is an RGB triple. The GL converts it to floating point and
assembles it into an RGBA element by attaching 1.0 for alpha. Each
component is then multiplied by the signed scale factor GL_c_SCALE,
added to the signed bias GL_c_BIAS, and clamped to the range [0,1]
(see glPixelTransfer).
Each element contains all four components. Each *component is
multiplied by the signed scale factor GL_c_SCALE, added to the signed
bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
Each element is a single luminance value. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue and attaching 1.0 for
alpha. Each component is then multiplied by the signed scale factor
GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the
range [0,1] (see glPixelTransfer).
Each element is a luminance/alpha pair. The GL converts it to floating
point, then assembles it into an RGBA element by replicating the
luminance value three times for red, green, and blue. Each component is
then multiplied by the signed scale factor GL_c_SCALE, added to the
signed bias GL_c_BIAS, and clamped to the range [0,1] (see
glPixelTransfer).
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. The Cb for each even pixel is used as the Cb value for that pixel
and its neighbor to the right. The Cr in each odd pixel is used as the Cr
value for that pixel and its neighbor to the left. (If the width of the image is
odd, then the colors will be undefined in the rightmost column.) Through
the use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. The Cb for each even pixel is used as the Cb value for that pixel and
its neighbor to the right. The Cr in each odd pixel is used as the Cr value
for that pixel and its neighbor to the left. (If the width of the image is odd,
then the colors will be undefined in the rightmost column.) Through the
use of the color matrix, Y then assumes the role of red, Cb becomes
green and Cr becomes blue. After this conversion, the pixel is treated just
as if it had been sent in as an RGB pixel.
GL_422_AVERAGE_EXT
GL_422_REV_AVERAGE_EXT
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Y. The second component is Cb in the even pixels and Cr in the odd
pixels. Each even pixel gets its Cb from itself, and its Cr from its neighbor
to the right. Each odd pixel gets its Cb from the average of its left and
right neighbor, and its Cr from the average of itself and its neighbor two to
the right. (If the width of the image is odd, then the colors will be
undefined in the rightmost column. If the neighbors to the right are not
present for a given fragment, we use GL_422_EXT to compute that
fragment.) Through the use of the color matrix, Y then assumes the role
of red, Cb becomes green and Cr becomes blue. After this conversion,
the pixel is treated just as if it had been sent in as an RGB pixel.
This extension is for use with the ″YCbCr″ color space, and should only
be used in systems that have the IBM_YCbCr extension. The
GL_YCBCR_TO_RGB_MATRIX_IBM matrix should be loaded using
glLoadNamedMatrixIBM before glDrawPixels is called with this
parameter. Each pixel is a two-component group. The first component is
Cb in the even pixels and Cr in the odd pixels. The second component is
Y. Each even pixel gets its Cb from itself, and its Cr from its neighbor to
the right. Each odd pixel gets its Cb from the average of its left and right
neighbor, and its Cr from the average of itself and its neighbor two to the
right. (If the width of the image is odd, then the colors will be undefined in
the rightmost column. If the neighbors to the right are not present for a
given fragment, we use GL_422_REV_EXT to compute that fragment.)
Through the use of the color matrix, Y then assumes the role of red, Cb
becomes green and Cr becomes blue. After this convers ion, the pixel is
treated just as if it had been sent in as an RGB pixel.
Refer to the glDrawPixels reference page for a description of the acceptable values for the type
parameter. If an application must store the texture at a certain resolution or in a certain format, use
internalformat to request the resolution and format. The GL will choose an internal representation that
closely approximates that requested by internalformat, but it may not match exactly. (The representations
specified by GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly.
The numeric values 1, 2, 3, and 4 may also be used to specify the above representations.)
Use the GL_PROXY_TEXTURE_3D_EXT target to try out a resolution and format. The implementation will
update and recompute its best match for the requested storage resolution and format. To then query this
state, call glGetTexLevelParameter. If the texture cannot be accomodated, texture state is set to 0.
A one-component texture image uses only the red component of the RGBA color extracted from pixels. A
two-component image uses the R and A values. A three-component image uses the R, G, and B values. A
four-component image uses all of the RGBA components.
Notes
GL_ABGR_EXT is only valid if the GL_EXT_abgr extension is defined.
Texturing has no effect in color index mode.
The texture image can be represented by the same data formats as the pixels in a glDrawPixels
command, except that GL_STENCIL_INDEX and GL_DEPTH_COMPONENT cannot be used. The
glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect
glDrawPixels.
Chapter 1. OpenGL Subroutines
357
The glTexImage3DEXT subroutine and GL_PROXY_TEXTURE_3D_EXT are available only if the
EXT_texture3D extension is supported.
Internal formats other than 1, 2, 3, or 4 may only be used if the GL version is 1.1 or greater.
In GL version 1.1 or greater, pixels may be a null pointer. In this case texture memory is allocated to
accomodate a texture of width width and height height. You can then download subtextures to initialize this
texture memory. The image is undefined if the user tries to apply an uninitialized portion of the texture
image to a primitive.
Format of GL_ABGR_EXT is part of the _extname (EXT_abgr) extension, not part of the core GL
command set.
Errors
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D_EXT or
GL_PROXY_TEXTURE_3D_EXT.
GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other
than GL_STENCIL_INDEX and GL_DEPTH_COMPONENT are accepted.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.
GL_INVALID_VALUE is generated if level is less than zero.
GL_INVALID_VALUE may be generated if level is greater than log2(max), where max is the returned
value of GL_MAX_3D_TEXTURE_SIZE_EXT.
GL_INVALID_VALUE is generated if internalformat is not 1, 2, 3, 4, or one of the accepted resolution and
format symbolic constants.
GL_INVALID_VALUE is generated if width, height, or depth is less than zero or greater than 2 +
GL_MAX_3D_TEXTURE_SIZE_EXT, or if either cannot be represented as 2k + 2 x border for some
integer value of k.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_OPERATION is generated if glTexImage3DEXT is executed between the execution of
glBegin and the corresponding execution of glEnd.
Associated Gets
glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D_EXT
Related Information
The glCopyTexSubImage3DEXT subroutine, glDrawPixels subroutine, glFog subroutine, glPixelStore
subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexGen subroutine, glTexImage1D
subroutine, glTexParameter subroutine, glTexImage2D subroutine.
358
OpenGL 2.1 Reference Manual
glTexParameter Subroutine
Purpose
Sets texture parameters.
Library
OpenGL C bindings library: libGL.a
C Syntax
void glTexParameterf(GLenum target,
GLenum pname,
GLfloat param)
void glTexParameteri(GLenum target,
GLenum pname,
GLint param)
void glTexParameterfv(GLenum target,
GLenum pname,
const GLfloat * params)
void glTexParameteriv(GLenum target,
GLenum pname,
const GLint * params)
Parameters
glTexParameterf or glTexParameteri
target
pname
param
Specifies the target texture, which must be either GL_TEXTURE_1D, GL_TEXTURE_2D,
GL_TEXTURE_3D, or GL_TEXTURE_3D_EXT.
Specifies the symbolic name of a single-valued texture parameter. The pname parameter can be one of
the following: GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MAG_FILTER, GL_TEXTURE_WRAP_S,
GL_TEXTURE_WRAP_T, GL_TEXTURE_WRAP_R, GL_TEXTURE_PRIORITY,
GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_TEXTURE_BASE_LEVEL,
GL_TEXTURE_MAX_LEVEL, GL_TEXTURE_MAX_ANISOTROPY_EXT.
Specifies the value of pname.
glTexParameterfv or glTexParameteriv
target
pname
params
Specifies the target texture, which must be either GL_TEXTURE_1D, GL_TEXTURE_2D,
GL_TEXTURE_3D, or GL_TEXTURE_3D_EXT.
Specifies the symbolic name of a texture parameter. The pname parameter can be one of the following:
GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MAG_FILTER, GL_TEXTURE_WRAP_S,
GL_TEXTURE_WRAP_T, GL_TEXTURE_WRAP_R, GL_TEXTURE_BORDER_COLOR,
GL_TEXTURE_PRIORITY, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD,
GL_TEXTURE_BASE_LEVEL, GL_TEXTURE_MAX_LEVEL, GL_TEXTURE_MAX_ANISOTROPY_EXT
.
Specifies a pointer to an array where the value or values of pname are stored.
Chapter 1. OpenGL Subroutines
359
Description
Texture mapping is a technique that applies an image onto an object’s surface as if the image were a
decal or cellophane shrink-wrap. The image is created in texture space, with an (s, t) coordinate system. A
texture is a one-dimensional (1D) or two-dimensional (2D) image and a set of parameters that determine
how samples are derived from the image.
The glTexParameter subroutine assigns the value or values in params to the texture parameter specified
as pname. The target parameter defines the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D,
GL_TEXTURE_3D, or GL_TEXTURE_3D_EXT. The following symbols are accepted in pname:
GL_TEXTURE_BORDER_COLOR
Sets a border color. The params parameter contains four values that comprise the red, green,
blue, alpha (RGBA) color of the texture border. Integer color components are interpreted linearly
such that the most positive integer maps to 1.0, and the most negative integer maps to -1.0. The
values are clamped to the range [0,1] when they are specified. Initially, the border color is (0, 0, 0,
0).
GL_TEXTURE_MIN_FILTER
The texture minifying function is used whenever the pixel being textured maps to an area greater
than one texture element. There are six defined minifying functions. Two of them use the nearest
one or nearest four texture elements to compute the texture value. The other four use mipmaps.
A mipmap is an ordered set of arrays representing the same image at progressively lower
resolutions. If the texture has dimensions 2n x 2m there are max(n,m)+1 mipmaps. The first
mipmap is the original texture, with dimensions 2n x 2m. Each subsequent mipmap has
dimensions 2k-1 x 2l-1 where 2k x 2l are the dimensions of the previous mipmap, until either
k=0 or l=0. At that point, subsequent mipmaps have the dimension 1 x 2l-1 or 2k-1 x 1 until the
final mipmap, which has the dimension 1 x 1. Mipmaps are defined using the glTexImage1D,
glTexImage2D, or glTexImage3DEXT subroutines with the level-of-detail argument indicating the
order of the mipmaps. Level 0 is the original texture; level max(n,m) is the final 1 x 1 mipmap.
The paramrs parameter supplies a function for minifying the texture as one of the following:
GL_NEAREST returns the value of the texture element that is nearest (in Manhattan distance) to
the center of the pixel being textured.
GL_LINEAR returns the weighted average of the four texture elements that are closest to the
center of the pixel being textured. These can include border texture elements, depending on the
values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T, and on the exact mapping.
GL_NEAREST_MIPMAP_NEAREST chooses the mipmap that most closely matches the size of
the pixel being textured and uses the GL_NEAREST criterion (the texture element nearest to the
center of the pixel) to produce a texture value.
GL_LINEAR_MIPMAP_NEAREST chooses the mipmap that most closely matches the size of the
pixel being textured and uses the GL_LINEAR criterion (a weighted average of the four texture
elements that are closest to the center of the pixel) to produce a texture value.
GL_NEAREST_MIPMAP_LINEAR chooses the two mipmaps that most closely match the size of
the pixel being textured and uses the GL_NEAREST criterion (the texture element nearest to the
center of the pixel) to produce a texture value from each mipmap. The final texture value is a
weighted average of those two values.
GL_LINEAR_MIPMAP_LINEAR chooses the two mipmaps that most closely match the size of the
pixel being textured and uses the GL_LINEAR criterion (a weighted average of the four texture
elements that are closest to the center of the pixel) to produce a texture value from each mipmap.
The final texture value is a weighted average of those two values.
As more texture elements are sampled in the minification process, fewer aliasing artifacts will be
apparent. While the GL_NEAREST and GL_LINEAR minification functions can be faster than the
other four, they sample only one or four texture elements to determine the texture value of the
360
OpenGL 2.1 Reference Manual
pixel being rendered and can produce moire patterns or ragged transitions. The default value of
GL_TEXTURE_MIN_FILTER is GL_NEAREST_MIPMAP_LINEAR.
GL_TEXTURE_MAG_FILTER
The texture magnification function is used when the pixel being textured maps to an area less than
or equal to one texture element. It sets the texture magnification function to either GL_NEAREST
or GL_LINEAR. GL_NEAREST is generally faster than GL_LINEAR, but it can produce textured
images with sharper edges because the transition between texture elements is not as smooth. The
initial value of GL_TEXTURE_MAG_FILTER is GL_LINEAR.
GL_NEAREST returns the value of the texture element that is nearest (in Manhattan distance) to
the center of the pixel being textured.
GL_LINEAR returns the weighted average of the four texture elements that are closest to the
center of the pixel being textured. These can include border texture elements, depending on the
values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T, and on the exact mapping.
GL_NEAREST is generally faster than GL_LINEAR, but can produce textured images with
sharper edges because the transition between texture elements is not as smooth. The default
value of GL_TEXTURE_MAG_FILTER is GL_LINEAR.
GL_TEXTURE_PRIORITY
Specifies the texture residence priority of the currently bound texture. Permissible values are in the
range [0.0, 1.0]. See glPrioritizeTextures and glBindTexture for more information.
GL_TEXTURE_MAX_LOD
Specifies for the texture the maximum level of detail of the image array. Any floating-point value is
permissable. Supported in OpenGL 1.2 and later.
GL_TEXTURE_MIN_LOD
Specifies for the texture the minimum level of detail of the image array. Any floating-point value is
permissable. Supported in OpenGL 1.2 and later.
GL_TEXTURE_BASE_LEVEL
Specifies for the texture the base array level. Any non-negative integer value is permissable.
Supported in OpenGL 1.2 and later.
GL_TEXTURE_MAX_LEVEL
Specifies for the texture the maximum array level. Any non-negative integer value is permissable.
Supported in OpenGL 1.2 and later.
GL_TEXTURE_WRAP_R
Sets the wrap parameter for texture coordinate r to either GL_CLAMP,
GL_CLAMP_NODRAW_IBM, GL_CLAMP_TO_EDGE, or GL_REPEAT. See the discussion under
GL_TEXTURE_WRAP_S. Initially, GL_TEXTURE_WRAP_R is set to GL_REPEAT.
GL_TEXTURE_WRAP_S
Sets the wrap parameter for texture coordinate s to either GL_CLAMP,
GL_CLAMP_NODRAW_IBM, GL_CLAMP_TO_EDGE, or GL_REPEAT. GL_CLAMP causes s, t,
or r coordinates to be clamped to the range [0,1] and is useful for preventing wrapping artifacts
when mapping a single image onto an object. GL_CLAMP_NODRAW_IBM clamps texture
coordinates at all mipmap levels such that any pixels whose corresponding texture coordinate falls
outside the specified texture map are not drawn at all. GL_CLAMP_TO_EDGE clamps texture
coordinates at all mipmap levels such that the texture filter never samples a border texel. The
color returned when clamping is derived only from texels at the edge of the texture image.
GL_REPEAT causes the integer part of the s, t, or r coordinates to be ignored; the GL uses only
the fractional part, thereby creating a repeating pattern. Border texture elements are accessed only
if wrapping is set to GL_CLAMP. Initially, GL_TEXTURE_WRAP_S is set to GL_REPEAT.
GL_TEXTURE_WRAP_T
Sets the wrap parameter for texture coordinate t to either GL_CLAMP,
Chapter 1. OpenGL Subroutines
361
GL_CLAMP_NODRAW_IBM, GL_CLAMP_TO_EDGE, or GL_REPEAT. See the discussion under
GL_TEXTURE_WRAP_S. Initially, GL_TEXTURE_WRAP_T is set to GL_REPEAT.
GL_TEXTURE_MAX_ANISOTROPIC_EXT
Sets the maximum degree of anisotropy for this texture map. Initially,
GL_TEXTURE_MAX_ANISOTROPIC_EXT is set to 1.0.
Notes
Suppose that a program has enabled texturing (by calling glEnable with argument GL_TEXTURE_1D,
GL_TEXTURE_2D, or GL_TEXTURE_3D) and has set GL_TEXTURE_MIN_FILTER to one of the
functions that requires a mipmap. If either the dimensions of the texture images currently defined (with
previous calls to glTexImage1D, glTexImage2D, or glTexImage3D) do not follow the proper sequence for
mipmaps (described above) or there are fewer texture images defined than are needed or the set of
texture images have differing numbers of texture components, then it is as if texture mapping were
disabled.
Linear filtering accesses the four nearest texture elements only in 2D textures. In 1D textures, linear
filtering accesses the two nearest texture elements.
GL_TEXTURE_3D is supported in OpenGL 1.2 and later.
GL_TEXTURE_3D_EXT requires the 3D texture extension.
GL_TEXTURE_MAX_ANISOTROPY_EXT requires the EXT_texture_filter_anisotropic extension.
Errors
GL_INVALID_ENUM is generated if target or pname is not one of the accepted defined values.
GL_INVALID_ENUM is generated if params should have a defined constant value (based on the value of
pname) and does not.
GL_INVALID_OPERATION is generated if glTexParameter is executed between the execution of glBegin
and the corresponding execution of glEnd.
Associated Gets
glGetTexParameter
glGetTexLevelParameter
Related Information
The glBindTexture subroutine, glPrioritizeTextures subroutine, glTexEnv subroutine, glTexGen
subroutine, glTexImage1D subroutine, glTexImage2D subroutine, glTexImage3D subroutine,
glTexImage3DEXT subroutine.
glTexSubImage1D Subroutine
Purpose
Specifies a one-dimensional (1D) texture subimage.
Library
OpenGL C bindings library: libGL.a
362
OpenGL 2.1 Reference Manual
C Syntax
void glTexSubImage1D(GLenum target,
GLint level,
GLint xoffset,
GLsizei width,
GLenum format,
GLenum type,
const GLvoid * pixels)
Parameters
target
level
xoffset
width
format
type
pixels
Specifies the target texture. Must be GL_TEXTURE_1D.
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
reduction image.
Specifies a texel offset in the x direction within the texture array.
Specifies the width of the texture subimage.
Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX, GL_RED, GL_GREEN,
GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA, GL_ABGR_EXT,
GL_LUMINANCE, GL_422_EXT, GL_422_REV_EXT, GL_422_AVERAGE_EXT,
GL_422_REV_AVERAGE_EXT, and GL_LUMINANCE_ALPHA are accepted.
Specifies the data type for Pixels. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE,
GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
Specifies a pointer to the image data in memory.
Description
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is
enabled. To enable or disable one-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_1D.
The glTexSubImage1D subroutine redefines a contiguous subregion of an existing one-dimensional
texture image. The texels referenced by pixels replace the portion of the existing texture array with x
indices xoffset and xoffset + width - 1, inclusive. This region may not include any texels outside the range
of the texture array as it was originally specified. It is not an error to specify a subtexture with zero width,
but such a specification has no

advertisement

Was this manual useful for you? Yes No
Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Related manuals

Bull AIX 4.3 Specialized reference

Bull

AIX 4.3

  • Specialized reference
Bull AIX 5.3 Specialized reference

Bull

AIX 5.3

  • Specialized reference
Bull AIX 5.2 Specialized reference

Bull

AIX 5.2

  • Specialized reference
Bull AIX 5.2 Specialized reference

Bull

AIX 5.2

  • Specialized reference
IBM AS/400 User's Manual

IBM

AS/400

  • User's Manual
Bull AIX 5.3 Specialized reference

Bull

AIX 5.3

  • Specialized reference
Bull AIX 4.3 Specialized reference

Bull

AIX 4.3

  • Specialized reference
Download PDF

advertisement