GL_EXT_texture_compression_bptc
http://www.opengl.org/registry/specs/EXT/texture_compression_bptc.txt
GL_EXT_texture_compression_bptc

	GL_COMPRESSED_RGBA_BPTC_UNORM_EXT 0x8E8C
	GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_EXT 0x8E8D
	GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_EXT 0x8E8E
	GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_EXT 0x8E8F