1GL_EXT_depth_bounds_test 2http://www.nvidia.com/dev_content/nvopenglspecs/GL_EXT_depth_bounds_test.txt 3GL_EXT_depth_bounds_test 4 5 GL_DEPTH_BOUNDS_TEST_EXT 0x8890 6 GL_DEPTH_BOUNDS_EXT 0x8891 7 void glDepthBoundsEXT (GLclampd zmin, GLclampd zmax) 8