GLREADBUFFER() MachTen Programmer’s Manual 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, glCopyTexImage1D, glCopyTexIm-
age2D, glCopyTexSubImage1D, glCopyTexSubImage2D, 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 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.

mode is initially GL_FRONT in single-buffered configura-
tions, 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 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, glCopy-
TexSubImage1D, glCopyTexSubImage2D, glDrawBuffer, glRead-
Pixels

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