glReadBuffer(3G)glReadBuffer(3G)NAMEglReadBuffer - select a color buffer source for pixels
SYNOPSIS
void glReadBuffer(
GLenum mode );
PARAMETERS
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.
DESCRIPTIONglReadBuffer() specifies a color buffer as the source for subsequent
glReadPixels(), glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubIm‐
age1D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(), and glCopyPix‐
els() 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 non‐
stereo. It is an error to specify a nonexistent buffer to glRead‐
Buffer().
mode is initially GL_FRONT in single-buffered configurations, and
GL_BACK in double-buffered configurations.
ERRORS
GL_INVALID_ENUM is generated if mode is not one 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 executed between
the execution of glBegin() and the corresponding execution of glEnd().
ASSOCIATED GETSglGet() with argument GL_READ_BUFFER
SEE ALSOglCopyPixels(3), glCopyTexImage1D(3), glCopyTexImage2D(3), glCopyTex‐
SubImage1D(3), glCopyTexSubImage2D(3), glCopyTexSubImage3D(3), glDraw‐
Buffer(3), glReadPixels(3)glReadBuffer(3G)