1GLX_EXT_fbconfig_packed_float 2http://developer.download.nvidia.com/opengl/specs/GL_EXT_packed_float.txt 3GLX_EXT_fbconfig_packed_float 4 5 GLX_RGBA_UNSIGNED_FLOAT_TYPE_EXT 0x20B1 6 GLX_RGBA_UNSIGNED_FLOAT_BIT_EXT 0x00000008 7