internal static void SetKeyRightTangentMode(ref MovieCurve curve, int index, TangentUtility.TangentMode tangentMode)
        {
            int curTangentMode = curve.GetTangentMode(index);

            curTangentMode &= ~TangentUtility.kRightTangentMask;
            curTangentMode |= (int)((int)tangentMode << 5);
            curve.SetTangentMode(index, curTangentMode);
        }
        internal static void SetKeyBroken(ref MovieCurve curve, int index, bool broken)
        {
            int curTangentMode = curve.GetTangentMode(index);

            if (broken)
            {
                curTangentMode |= TangentUtility.kBrokenMask;
            }
            else
            {
                curTangentMode &= ~TangentUtility.kBrokenMask;
            }
            curve.SetTangentMode(index, curTangentMode);
        }