GLDRAWBUFFER(3G)GLDRAWBUFFER(3G)NAMEglDrawBuffer - specify which color buffers are to be drawn into
C SPECIFICATION
void glDrawBuffer( GLenum mode )
delim $$
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 (GL_AUX_BUFFERS is not the
upper limit; use glGet to query the number of available aux
buffers.) The initial 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_AUX$i$ = 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 executed between
the execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_DRAW_BUFFER
glGet with argument GL_AUX_BUFFERS
SEE ALSOglBlendFunc(3G), glColorMask(3G), glIndexMask(3G), glLogicOp(3G),
glReadBuffer(3G)
March 1, 2011
