GL_NV_sample_locations
http://www.opengl.org/registry/specs/NV/sample_locations.txt
GL_NV_sample_locations
	GL_SAMPLE_LOCATION_NV 0x8E50
	GL_SAMPLE_LOCATION_SUBPIXEL_BITS_NV 0x933D
	GL_SAMPLE_LOCATION_PIXEL_GRID_WIDTH_NV 0x933E
	GL_SAMPLE_LOCATION_PIXEL_GRID_HEIGHT_NV 0x933F
	GL_PROGRAMMABLE_SAMPLE_LOCATION_TABLE_SIZE_NV 0x9340
	GL_PROGRAMMABLE_SAMPLE_LOCATION_NV 0x9341
	GL_FRAMEBUFFER_PROGRAMMABLE_SAMPLE_LOCATIONS_NV 0x9342
	GL_FRAMEBUFFER_SAMPLE_LOCATION_PIXEL_GRID_NV 0x9343
	void glFramebufferSampleLocationsfvNV (GLenum target, GLuint start, GLsizei count, const GLfloat* v)
	void glNamedFramebufferSampleLocationsfvNV (GLuint framebuffer, GLuint start, GLsizei count, const GLfloat* v)
