GLX_INTEL_swap_event http://www.opengl.org/registry/specs/INTEL/swap_event.txt GLX_INTEL_swap_event GLX_EXCHANGE_COMPLETE_INTEL 0x8180 GLX_COPY_COMPLETE_INTEL 0x8181 GLX_FLIP_COMPLETE_INTEL 0x8182 GLX_BUFFER_SWAP_COMPLETE_INTEL_MASK 0x04000000