glReadBuffer(3G) OpenGL Reference glReadBuffer(3G)
NAME
glReadBuffer - select a color buffer source for pixels
C SPECIFICATION
void glReadBuffer( GLenum mode )
PARAMETERS
mode Specifies a color buffer. Accepted values are GLFRONTLEFT,
GLFRONTRIGHT, GLBACKLEFT, GLBACKRIGHT, GLFRONT, GLBACK,
GLLEFT, GLRIGHT, and GLAUXi, where i is between 0 and
GLAUXBUFFERS -1.
DESCRIPTION
glReadBuffer specifies a color buffer as the source for subsequent
glReadPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, and glCopyPixels commands. mode accepts one of
twelve or more predefined values. (GLAUX0 through GLAUX3 are always
defined.) In a fully configured system, GLFRONT, GLLEFT, and
GLFRONTLEFT all name the front left buffer, GLFRONTRIGHT and GLRIGHT
name the front right buffer, and GLBACKLEFT and GLBACK 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.
mode is initially GLFRONT in single-buffered configurations, and GLBACK
in double-buffered configurations.
ERRORS
GLINVALIDENUM is generated if mode is not one of the twelve (or more)
accepted values.
GLINVALIDOPERATION is generated if mode specifies a buffer that does
not exist.
GLINVALIDOPERATION is generated if glReadBuffer is executed between the
execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GLREADBUFFER
SEE ALSO
glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glDrawBuffer, glReadPixels
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