1GL_ARB_ES3_compatibility 2https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_ES3_compatibility.txt 3GL_ARB_ES3_compatibility 4 5 GL_TEXTURE_IMMUTABLE_LEVELS 0x82DF 6 GL_PRIMITIVE_RESTART_FIXED_INDEX 0x8D69 7 GL_ANY_SAMPLES_PASSED_CONSERVATIVE 0x8D6A 8 GL_MAX_ELEMENT_INDEX 0x8D6B 9 GL_COMPRESSED_R11_EAC 0x9270 10 GL_COMPRESSED_SIGNED_R11_EAC 0x9271 11 GL_COMPRESSED_RG11_EAC 0x9272 12 GL_COMPRESSED_SIGNED_RG11_EAC 0x9273 13 GL_COMPRESSED_RGB8_ETC2 0x9274 14 GL_COMPRESSED_SRGB8_ETC2 0x9275 15 GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2 0x9276 16 GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2 0x9277 17 GL_COMPRESSED_RGBA8_ETC2_EAC 0x9278 18 GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC 0x9279 19