1991-2006
Silicon Graphics, Inc.
2010-2014
Khronos Group
glReadBuffer
3G

# glReadBuffer

select a color buffer source for pixels

## C Specification

                    void glReadBuffer
                    GLenum mode

## Parameters

`mode`

  Specifies a color buffer. Accepted values are `GL_BACK`, `GL_NONE`, and `GL_COLOR_ATTACHMENTi`.

## Description

`glReadBuffer` specifies a color buffer as the source for subsequent glReadPixels, , glCopyTexImage2D, glCopyTexSubImage2D, and glCopyTexSubImage3D commands. `mode` accepts one of the following values: `GL_NONE`, `GL_BACK` names the back buffer of the default framebuffer, and `GL_COLOR_ATTACHMENTi` names a color attachment of the current framebuffer,

## Errors

`GL_INVALID_ENUM` is generated if `mode` is not `GL_BACK`, `GL_NONE`, or `GL_COLOR_ATTACHMENTi`, where i is less than `GL_MAX_COLOR_ATTACHMENTS`.

`GL_INVALID_OPERATION` is generated if the current framebuffer is the default framebufer and `mode` is not `GL_NONE` or `GL_BACK`.

`GL_INVALID_OPERATION` is generated if the current framebuffer is a named framebufer and `mode` is not `GL_NONE` or `GL_COLOR_ATTACHMENTi`.

## Associated Gets

glGet with argument `GL_READ_BUFFER`

## API Version Support

glReadBuffer

## See Also

glCopyTexImage2D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawBuffers, glReadPixels

## Copyright

Copyright 1991-2006 Silicon Graphics, Inc. Copyright 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.