public void Interact(List <Light> lightList, Graphics g)
        {
            Light  last       = lightList[lightList.Count - 1];
            PointF pi         = last.pi;
            PointF pf         = last.pf;
            Color  lightColor = last.LightColor;
            Region mediumReg  = this.GetRegion();
            Region rayReg     = last.GetRegion();
            double angle      = last.GetAngle();


            mediumReg.Intersect(rayReg); //Intersect area of lens and the last light
            if (!mediumReg.IsEmpty(g))
            {
                double n1 = AdvanceInformation.screenIndex;
                double n2 = this.Index;

                if (n1 == n2) //act as nothing
                {
                    //
                }
                else if (n1 > n2) //act like a mirror
                {
                    AlgoritemHelper.MirrorAlgoritem(lightList, g, this);
                }
                else //act like medium
                {
                    AlgoritemHelper.MediumAlgoritem(lightList, g, this, n1, n2);
                }
            }
        }
 public void Interact(List <Light> lightList, Graphics g)
 {
     AlgoritemHelper.MirrorAlgoritem(lightList, g, this);
 }