GL_NV_primitive_shading_rate
https://www.khronos.org/registry/OpenGL/extensions/NV/NV_primitive_shading_rate.txt
GL_NV_primitive_shading_rate

	GL_SHADING_RATE_IMAGE_PER_PRIMITIVE_NV 0x95B1
	GL_SHADING_RATE_IMAGE_PALETTE_COUNT_NV 0x95B2