glReadBuffer — select a color buffer source for pixels
Specifies a color buffer. Accepted values are
GL_AUXi, where i is between 0 and the value of
GL_AUX_BUFFERS minus 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_AUX3 are always defined.) In a fully configured system,
GL_FRONT_LEFT all name the front left buffer,
GL_RIGHT name the front right buffer, 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
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.
glGet with argument
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