GL_EXT_texture_lod_bias
http://www.opengl.org/registry/specs/EXT/texture_lod_bias.txt
GL_EXT_texture_lod_bias
	GL_MAX_TEXTURE_LOD_BIAS_EXT 0x84FD
	GL_TEXTURE_FILTER_CONTROL_EXT 0x8500
	GL_TEXTURE_LOD_BIAS_EXT 0x8501
