internal void StartDragging()
        {
            Rectangle boundingRect = new Rectangle(
                (int)BoundingCircleRadius,
                (int)BoundingCircleRadius,
                (int)(m_parent.SceneGraph.ViewportSize.X - BoundingCircleRadius),
                (int)(m_parent.SceneGraph.ViewportSize.Y - BoundingCircleRadius));

            Vector2 withinBounds = boundingRect.Clamp(m_parent.HandPosition);

            DragStartLocation = withinBounds;
            CurrentKnobLocation = withinBounds;
        }