private void GetActiveSet(GShape gShape)
        {
            if (Shapes.Count <= 1)
            {
                return;
            }

            foreach (var shape in Shapes.Take(Shapes.Count - 1))
            {
                gShape.IntersectWith(shape);
            }
        }
 private void CheckIntersection(GShape gShape)
 {
     //check intersection
     // more optimized algo will be done here
     if (Shapes.Count <= 1)
     {
         return;
     }
     foreach (var shape in Shapes.Take(Shapes.Count - 1))
     {
         gShape.IntersectWith(shape);
     }
 }