- select a color buffer source for pixels
C SPECIFICATION
PARAMETERS
_param1 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, glCopyTexImage1D,
glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glCopyTexSubImage3D, and glCopyPixels
commands. _param1 accepts one of twelve or more prede-
fined 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 configura-
tions 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.
_param1 is initially GL_FRONT in single-buffered configu-
rations, and GL_BACK in double-buffered configurations.
ERRORS
GL_INVALID_ENUM is generated if _param1 is not one of the
twelve (or more) accepted values.
GL_INVALID_OPERATION is generated if _param1 specifies a
buffer that does not exist.
GL_INVALID_OPERATION is generated if glReadBuffer is exe-
cuted between the execution of glBegin and the correspond-
ing execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_READ_BUFFER
SEE ALSO
glCopyPixels, glCopyTexImage1D, glCopyTexImage2D,
glCopyTexSubImage1D, glCopyTexSubImage2D,
glCopyTexSubImage3D, glDrawBuffer, glReadPixels