internal PhongLight(IPhongLightParameters p)
 {
     Parameters = p;
 }
 internal PhongPositionalLight(Vector4 position, IPhongLightParameters p) : base(p)
 {
     Position = position;
 }
 internal PhongHeadlight(IPhongLightParameters p) : base(p)
 {
 }
 public static PhongPositionalLight Create(Vector4 position, IPhongLightParameters p)
 {
     return(new PhongPositionalLight(position, p));
 }
 public static PhongHeadlight Create(IPhongLightParameters p)
 {
     return(new PhongHeadlight(p));
 }