GLDRAWBUFFER
Section: [FIXME: manual] (3G)
Updated: 01/26/2021
Page Index
NAME
glDrawBuffer, glNamedFramebufferDrawBuffer - specify which color buffers are to be drawn into
C SPECIFICATION
-
void glDrawBuffer(GLenum buf);
-
void glNamedFramebufferDrawBuffer(GLuint framebuffer, GLenum buf);
PARAMETERS
framebuffer
-
- Specifies the name of the framebuffer object for
glNamedFramebufferDrawBuffer
function. Must be zero or the name of a framebuffer object.
buf
-
For default framebuffer, the argument 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, and
GL_FRONT_AND_BACK
are accepted. The initial value is
GL_FRONT
for single-buffered contexts, and
GL_BACK
for double-buffered contexts. For framebuffer objects,
GL_COLOR_ATTACHMENT$m$
and
GL_NONE
enums are accepted, where
$m$
is a value between 0 and
GL_MAX_COLOR_ATTACHMENTS.
DESCRIPTION
When colors are written to the frame buffer, they are written into the color buffers specified by
glDrawBuffer. One of the following values can be used for default framebuffer:
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.
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 GL initialization.
For framebuffer objects,
GL_COLOR_ATTACHMENT$m$
and
GL_NONE
enums are accepted, where
$m$
is a value between 0 and
GL_MAX_COLOR_ATTACHMENTS. glDrawBuffer will set the draw buffer for fragment colors other than zero to
GL_NONE.
ERRORS
GL_INVALID_OPERATION
error is generated by
glNamedFramebufferDrawBuffer
if
framebuffer
is not zero or the name of an existing framebuffer object.
GL_INVALID_ENUM
is generated if
buf
is not an accepted value.
GL_INVALID_OPERATION
is generated if the default framebuffer is affected and none of the buffers indicated by
buf
exists.
GL_INVALID_OPERATION
is generated if a framebuffer object is affected and
buf
is not equal to
GL_NONE
or
GL_COLOR_ATTACHMENT$m$, where
$m$
is a value between 0 and
GL_MAX_COLOR_ATTACHMENTS.
ASSOCIATED GETS
glGet()
with argument
GL_DRAW_BUFFER
VERSION SUPPORT
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OpenGL Version
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Function / Feature Name
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2.0
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2.1
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3.0
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3.1
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3.2
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3.3
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4.0
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4.1
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4.2
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4.3
|
4.4
|
4.5
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glDrawBuffer
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✔
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✔
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✔
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✔
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✔
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✔
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✔
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✔
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✔
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✔
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glNamedFramebufferDrawBuffer
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-
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-
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✔
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SEE ALSO
glBlendFunc(),
glColorMask(),
glDrawBuffers(),
glLogicOp(),
glReadBuffer()
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
m[blue]http://oss.sgi.com/projects/FreeB/m[].
COPYRIGHT
Copyright © 1991-2006 Silicon Graphics, Inc.
Copyright © 2010-2014 Khronos Group