GL_AMD_compressed_ATC_texture
https://www.khronos.org/registry/OpenGL/extensions/AMD/AMD_compressed_ATC_texture.txt
GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD 0x87EE
GL_ATC_RGB_AMD 0x8C92
GL_ATC_RGBA_EXPLICIT_ALPHA_AMD 0x8C93