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glReadBuffer - select a color buffer source for pixels
void
glReadBuffer( GLenum mode )
- 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.
glReadBuffer
specifies a color buffer as the source for subsequent glReadPixels, glCopyTexImage1D,
glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D,
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.
mode is initially GL_FRONT in single-buffered configurations,
and GL_BACK in double-buffered configurations.
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.
glGet with argument
GL_READ_BUFFER
glCopyPixels(3G)
, glCopyTexImage1D(3G)
, glCopyTexImage2D(3G)
,
glCopyTexSubImage1D(3G)
, glCopyTexSubImage2D(3G)
, glCopyTexSubImage3D(3G)
,
glDrawBuffer(3G)
, glReadPixels(3G)
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