Difference between revisions of "GLAPI/glReadBuffer"

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m (Renaming category: 'API Reference 4' to 'Core API Reference'.)
m (Bot: Adding better formatting.)
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== Function Definition ==
 
== Function Definition ==
  
   void '''glReadBuffer'''(GLenum ''mode'');
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   void '''glReadBuffer'''(GLenum {{param|mode}});
  
 
; mode
 
; mode
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== Description ==
 
== Description ==
  
'''glReadBuffer''' specifies a color buffer as the source for subsequent [[GLAPI/glReadPixels|glReadPixels]], [[GLAPI/glCopyTexImage1D|glCopyTexImage1D]], [[GLAPI/glCopyTexImage2D|glCopyTexImage2D]], [[GLAPI/glCopyTexSubImage1D|glCopyTexSubImage1D]], [[GLAPI/glCopyTexSubImage2D|glCopyTexSubImage2D]], and [[GLAPI/glCopyTexSubImage3D|glCopyTexSubImage3D]] commands. ''mode'' accepts one of twelve or more predefined values. In a fully configured system, {{code|GL_FRONT}}, {{code|GL_LEFT}}, and {{code|GL_FRONT_LEFT}} all name the front left buffer, {{code|GL_FRONT_RIGHT}} and {{code|GL_RIGHT}} name the front right buffer, and {{code|GL_BACK_LEFT}} and {{code|GL_BACK}} name the back left buffer. Further more, the constants {{code|GL_COLOR_ATTACHMENT''i''}} may be used to indicate the ''i''<sup>th</sup> color attachment where ''i'' ranges from zero to the value of {{code|GL_MAX_COLOR_ATTACHMENTS}} minus one.
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'''glReadBuffer''' specifies a color buffer as the source for subsequent {{apifunc|glReadPixels}}, {{apifunc|glCopyTexImage1D}}, {{apifunc|glCopyTexImage2D}}, {{apifunc|glCopyTexSubImage1D}}, {{apifunc|glCopyTexSubImage2D}}, and {{apifunc|glCopyTexSubImage3D}} commands. {{param|mode}} accepts one of twelve or more predefined values. In a fully configured system, {{code|GL_FRONT}}, {{code|GL_LEFT}}, and {{code|GL_FRONT_LEFT}} all name the front left buffer, {{code|GL_FRONT_RIGHT}} and {{code|GL_RIGHT}} name the front right buffer, and {{code|GL_BACK_LEFT}} and {{code|GL_BACK}} name the back left buffer. Further more, the constants {{code|GL_COLOR_ATTACHMENT''i''}} may be used to indicate the ''i''<sup>th</sup> color attachment where ''i'' ranges from zero to the value of {{code|GL_MAX_COLOR_ATTACHMENTS}} minus one.
  
 
Nonstereo double-buffered configurations have only a front left and a back left buffer. Single-buffered configurations have a front left and a front right buffer if stereo, and only a front left buffer if nonstereo. It is an error to specify a nonexistent buffer to '''glReadBuffer'''.
 
Nonstereo double-buffered configurations have only a front left and a back left buffer. Single-buffered configurations have a front left and a front right buffer if stereo, and only a front left buffer if nonstereo. It is an error to specify a nonexistent buffer to '''glReadBuffer'''.
  
''mode'' is initially {{code|GL_FRONT}} in single-buffered configurations and {{code|GL_BACK}} in double-buffered configurations.
+
{{param|mode}} is initially {{code|GL_FRONT}} in single-buffered configurations and {{code|GL_BACK}} in double-buffered configurations.
  
 
== Errors ==
 
== Errors ==
  
{{code|GL_INVALID_ENUM}} is generated if ''mode'' is not one of the twelve (or more) accepted values.
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{{code|GL_INVALID_ENUM}} is generated if {{param|mode}} is not one of the twelve (or more) accepted values.
  
{{code|GL_INVALID_OPERATION}} is generated if ''mode'' specifies a buffer that does not exist.
+
{{code|GL_INVALID_OPERATION}} is generated if {{param|mode}} specifies a buffer that does not exist.
  
 
== Associated Gets ==
 
== Associated Gets ==
  
[[GLAPI/glGet|glGet]] with argument {{code|GL_READ_BUFFER}}
+
{{apifunc|glGet}} with argument {{code|GL_READ_BUFFER}}
  
 
== See Also ==
 
== See Also ==
  
[[GLAPI/glCopyTexImage1D|glCopyTexImage1D]], [[GLAPI/glCopyTexImage2D|glCopyTexImage2D]], [[GLAPI/glCopyTexSubImage1D|glCopyTexSubImage1D]], [[GLAPI/glCopyTexSubImage2D|glCopyTexSubImage2D]], [[GLAPI/glCopyTexSubImage3D|glCopyTexSubImage3D]], [[GLAPI/glDrawBuffer|glDrawBuffer]], [[GLAPI/glReadPixels|glReadPixels]]
+
{{apifunc|glCopyTexImage1D}}, {{apifunc|glCopyTexImage2D}}, {{apifunc|glCopyTexSubImage1D}}, {{apifunc|glCopyTexSubImage2D}}, {{apifunc|glCopyTexSubImage3D}}, {{apifunc|glDrawBuffer}}, {{apifunc|glReadPixels}}
  
 
== Copyright ==
 
== Copyright ==

Revision as of 21:24, 28 April 2012

glReadBuffer
Core in version 4.5
Core since version 1.0

glReadBuffer: select a color buffer source for pixels

Function Definition

 void glReadBuffer(GLenum mode​);
mode
Specifies a color buffer. Accepted values are GL_FRONT_LEFT​, GL_FRONT_RIGHT​, GL_BACK_LEFT​, GL_BACK_RIGHT​, GL_FRONT​, GL_BACK​, GL_LEFT​, GL_RIGHT​, and the constants GL_COLOR_ATTACHMENTi.

Description

glReadBuffer specifies a color buffer as the source for subsequent glReadPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, and glCopyTexSubImage3D commands. mode​ accepts one of twelve or more predefined values. 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. Further more, the constants GL_COLOR_ATTACHMENTi may be used to indicate the ith color attachment where i ranges from zero to the value of GL_MAX_COLOR_ATTACHMENTS​ minus one.

Nonstereo double-buffered configurations have only a front left and a back left buffer. Single-buffered configurations have a front left and a front right buffer if stereo, and only a front left buffer if nonstereo. It is an error to specify a nonexistent buffer to glReadBuffer.

mode​ is initially GL_FRONT​ in single-buffered configurations and GL_BACK​ in double-buffered configurations.

Errors

GL_INVALID_ENUM​ is generated if mode​ is not one of the twelve (or more) accepted values.

GL_INVALID_OPERATION​ is generated if mode​ specifies a buffer that does not exist.

Associated Gets

glGet with argument GL_READ_BUFFER​

See Also

glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawBuffer, glReadPixels

Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2011 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.