glReadBuffer
NAME
glReadBuffer -- select a color buffer source for pixels
C SPECIFICATION
void glReadBuffer(GLenum mode)
PARAMETERS
- mode
-
Specifies a color buffer. Accepted values are GL_FRONT_LEFT,
GL_FRONT_RIGHT, GL_BACK_LEFT, GL_BACK_RIGHT,
GL_FRONT, GL_BACK, GL_LEFT, GL_RIGHT, and
GL_AUXi, where i is between 0 and
GL_AUX_BUFFERS - 1.
DESCRIPTION
glReadBuffer specifies a color buffer as the source for subsequent
glReadPixels and
glCopyPixels commands.
mode accepts one of twelve or more predefined values.
(GL_AUX0 through GL_AUX3 are always defined.) In a fully
configured system, GL_FRONT, GL_LEFT, and GL_FRONT_LEFT
all name the front left buffer, GL_FRONT_RIGHT and GL_RIGHT
name the front right buffer, and GL_BACK_LEFT and GL_BACK
name the back left buffer.
Nonstereo double-buffered configurations have only a front left and a
back left buffer. Single-buffered configurations have a front left and a
front right buffer if stereo, and only a front left buffer if nonstereo.
It is an error to specify a nonexistent buffer to glReadBuffer.
By default, mode is GL_FRONT in single-buffered configurations,
and GL_BACK in double-buffered configurations.
ERRORS
GL_INVALID_ENUM is generated if mode is none of the twelve (or
more) accepted values.
GL_INVALID_OPERATION is generated if mode specifies a buffer
that does not exist.
GL_INVALID_OPERATION is generated if glReadBuffer is called
between a call to glBegin and the
corresponding call to glEnd.
ASSOCIATED GETS
glGet with argument
GL_READ_BUFFER
SEE ALSO
glCopyPixels,
glDrawBuffer,
glReadPixels
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© 1995 Uwe Behrens. All rights reserved.