on windows: extension function pointers are context specific, so technically it should be storing a table of function pointers per context. In practice it is probably safe to reuse the pointers for contexts from same device (or even same driver for multiple similar GPUs), but won't work with GPUs from multiple vendors.
on all platforms: error checking problem in #10
on windows: extension function pointers are context specific, so technically it should be storing a table of function pointers per context. In practice it is probably safe to reuse the pointers for contexts from same device (or even same driver for multiple similar GPUs), but won't work with GPUs from multiple vendors.