glDrawBuffer function

The glDrawBuffer function specifies which color buffers are to be drawn into.

Syntax

void WINAPI glDrawBuffer(
   GLenum mode
);

Parameters

mode

Specifies up to four color buffers to be drawn into with the following acceptable symbolic constants.

Value Meaning
GL_NONE
No color buffers are written.
GL_FRONT_LEFT
Only the front-left color buffer is written.
GL_FRONT_RIGHT
Only the front-right color buffer is written.
GL_BACK_LEFT
Only the back-left color buffer is written.
GL_BACK_RIGHT
Only the back-right color buffer is written.
GL_FRONT
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.
GL_BACK
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.
GL_LEFT
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.
GL_RIGHT
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
All the front and 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.
GL_AUXi
Only the auxiliary color buffer i is written; i is between 0 and GL_AUX_BUFFERS - 1. (GL_AUX_BUFFERS is not the upper limit; use glGet to query the number of available auxiliary buffers.)

The default value is GL_FRONT for single-buffered contexts, and GL_BACK for double-buffered contexts.

Return value

This function does not return a value.

Error codes

The following error codes can be retrieved by the glGetError function.

Name Meaning
GL_INVALID_ENUM
mode was not an accepted value.
GL_INVALID_OPERATION
None of the buffers indicated by mode existed.
GL_INVALID_OPERATION
The function was called between a call to glBegin and the corresponding call to glEnd.

Error codes

The following error codes can be retrieved by the glGetError function.

Name Meaning
GL_INVALID_ENUM
mode was not an accepted value.
GL_INVALID_OPERATION
None of the buffers indicated by mode existed.
GL_INVALID_OPERATION
The function was called between a call to glBegin and the corresponding call to glEnd.

Remarks

When colors are written to the framebuffer, they are written into the color buffers specified by glDrawBuffer.

If more than one color buffer is selected for drawing, then blending or logical operations are computed and applied independently for each color buffer and can produce different results in each buffer.

Monoscopic contexts include only left buffers, and stereoscopic contexts include both left and right buffers. Likewise, single-buffered contexts include only front buffers, and double-buffered contexts include both front and back buffers. The context is selected at OpenGL initialization.

It is always the case that GL_AUX i = GL_AUX0 + i.

The following functions retrieve information related to the glDrawBuffer function:

glGet with argument GL_DRAW_BUFFER

glGet with argument GL_AUX_BUFFERS

Requirements

Minimum supported client
Windows 2000 Professional [desktop apps only]
Minimum supported server
Windows 2000 Server [desktop apps only]
Header
Gl.h
Library
Opengl32.lib
DLL
Opengl32.dll

See also

glBegin

glBlendFunc

glColorMask

glEnd

glGet

glIndexMask

glLogicOp

glReadBuffer