public static CurveChangeType GetChangeType(this AnimationClip clip, ref UInt64 curveVersion) { var version = clip.ClipVersion(); var changeType = CurveChangeType.None; if ((curveVersion >> 32) != (version >> 32)) { changeType = CurveChangeType.CurveAddedOrRemoved; } else if (curveVersion != version) { changeType = CurveChangeType.CurveModified; } curveVersion = version; return(changeType); }