glReadBuffer3x
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, andGL_AUXi, where i is between 0 andGL_AUX_BUFFERS-1.
Overview
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.
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 gets
glGet with argument GL_READ_BUFFER