GL_ARB_ES3_compatibility http://www.opengl.org/registry/specs/gl/ARB/ES3_compatibility.txt GL_ARB_ES3_compatibility GL_TEXTURE_IMMUTABLE_LEVELS 0x82DF GL_PRIMITIVE_RESTART_FIXED_INDEX 0x8D69 GL_ANY_SAMPLES_PASSED_CONSERVATIVE 0x8D6A GL_MAX_ELEMENT_INDEX 0x8D6B GL_COMPRESSED_R11_EAC 0x9270 GL_COMPRESSED_SIGNED_R11_EAC 0x9271 GL_COMPRESSED_RG11_EAC 0x9272 GL_COMPRESSED_SIGNED_RG11_EAC 0x9273 GL_COMPRESSED_RGB8_ETC2 0x9274 GL_COMPRESSED_SRGB8_ETC2 0x9275 GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2 0x9276 GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2 0x9277 GL_COMPRESSED_RGBA8_ETC2_EAC 0x9278 GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC 0x9279