FlatRedBall_Spriter.SpriterObject.SetInterpolatedValues C# (CSharp) Method

        private void SetInterpolatedValues(KeyValuePair<PositionedObject, KeyFrameValues> currentPair, float percentage)
        {
            var currentValues = currentPair.Value;
            var nextValues = NextKeyFrame == null
                ? currentValues
                : NextKeyFrame.Values.ContainsKey(currentPair.Key)
                    ? NextKeyFrame.Values[currentPair.Key]
                    : currentValues;

            //var nextValues = NextKeyFrame.Values[currentPair.Key];
            var currentObject = currentPair.Key;

            if (currentValues.Parent == null)
            {
                currentObject.AttachTo(this, true);
            }
            else if (currentObject.Parent != currentValues.Parent)
            {
                currentObject.AttachTo(currentValues.Parent, true);
            }

            // Position
            // In a single dimension, if the spriterobject is on x = 5, and the position to move a subobject to is x=8, then it should actually move to x=13, because we add the spriterobject's position to the subobject's interpolated value, since while positions are absolute, they are "absolute" relative to the container
            currentObject.RelativePosition = Vector3.Lerp(currentValues.RelativePosition, nextValues.RelativePosition,
                percentage);

            if (float.IsNaN(currentObject.RelativePosition.X) ||
                float.IsNaN(currentObject.RelativePosition.Y)
                || float.IsNaN(currentObject.RelativePosition.Z))
            {
                throw new Exception(string.Format("Float.IsNaN true! Object name {0} RelativePosition: {1}",
                    currentObject.Name, currentObject.RelativePosition));
            }

            // Angle
            int spin = currentValues.Spin;
            float angleA = currentValues.RelativeRotation.Z;
            float angleB = nextValues.RelativeRotation.Z;

            if (spin == 1 && angleB - angleA < 0)
            {
                angleB += 360f;
            }
            else if (spin == -1 && angleB - angleA > 0)
            {
                angleB -= 360f;
            }

            currentObject.RelativeRotationZ =
                MathHelper.ToRadians(MathHelper.Lerp(angleA,
                    angleB, percentage));

            // Sprite specific stuff
            var sprite = currentObject as ScaledSprite;
            if (sprite != null)
            {
                sprite.Texture = currentValues.Texture;
                sprite.Alpha = MathHelper.Lerp(currentValues.Alpha, nextValues.Alpha, percentage);
            }

            var spo = currentObject as IRelativeScalable;
            if (spo != null)
            {
                spo.RelativeScaleX = MathHelper.Lerp(currentValues.RelativeScaleX, nextValues.RelativeScaleX, percentage);
                spo.RelativeScaleY = MathHelper.Lerp(currentValues.RelativeScaleY, nextValues.RelativeScaleY, percentage);
            }
        }