UnityEditor.CurveUtility.CalculateSmoothTangent C# (CSharp) Method

        public static float CalculateSmoothTangent(Keyframe key)
        {
            if (key.inTangent == float.PositiveInfinity)
            {
                key.inTangent = 0f;
            }
            if (key.outTangent == float.PositiveInfinity)
            {
                key.outTangent = 0f;
            }
            return ((key.outTangent + key.inTangent) * 0.5f);
        }

        public void SetBoth(AnimationUtility.TangentMode mode, List <KeyIdentifier> keysToSet)
        {
            List <ChangedCurve> list = new List <ChangedCurve>();

            foreach (KeyIdentifier current in keysToSet)
            {
                AnimationCurve curve    = current.curve;
                Keyframe       keyframe = current.keyframe;
                AnimationUtility.SetKeyBroken(ref keyframe, false);
                AnimationUtility.SetKeyRightTangentMode(ref keyframe, mode);
                AnimationUtility.SetKeyLeftTangentMode(ref keyframe, mode);
                if (mode == AnimationUtility.TangentMode.Free)
                {
                    float num = CurveUtility.CalculateSmoothTangent(keyframe);
                    keyframe.inTangent  = num;
                    keyframe.outTangent = num;
                }
                curve.MoveKey(current.key, keyframe);
                AnimationUtility.UpdateTangentsFromModeSurrounding(curve, current.key);
                ChangedCurve item = new ChangedCurve(curve, current.curveId, current.binding);
                if (!list.Contains(item))
                {
                    list.Add(item);
                }
            }
            this.updater.UpdateCurves(list, "Set Tangents");
        }