GL_EXT_read_format_bgra
https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_read_format_bgra.txt
GL_EXT_read_format_bgra

	GL_BGRA_EXT 0x80E1
	GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT 0x8365
	GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT 0x8366