glDrawBuffer
NAME
glDrawBuffer -- specify which color buffers are to be drawn into
C SPECIFICATION
void glDrawBuffer(GLenum mode)
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. The default value
is GL_FRONT for single buffered contexts, and
GL_BACK for double-buffered contexts.
DESCRIPTION
When colors are written to the frame buffer, they are written into the color
buffers specified by glDrawBuffer. The specifications are as follows:
- 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 auxiliary color buffer i 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.
NOTES
It is always the case, that GL_AUXi = GL_AUX0+i.
ERRORS
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_OPERATION is generated if none of the buffers indicated by
mode exists.
GL_INVALID_OPERATION is generated if glDrawBuffer is called
between a call to glBegin and the
corresponding call to glEnd.
ASSOCIATED GETS
glGet with argument
GL_DRAW_BUFFER
glGet with argument
GL_AUX_BUFFERS
SEE ALSO
glBlendFunc,
glColorMask,
glIndexMask,
glLogicOp,
glReadSource
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© 1995 Uwe Behrens. All rights reserved.