public void Rotate(float angle)
 {
     matrix = AffineMatrix.MultMatrices(AffineMatrix.RotateMatrix(angle), matrix);
 }
 public void Scale(float width, float height)
 {
     matrix = AffineMatrix.MultMatrices(AffineMatrix.ScaleMatrix(width, height), matrix);
 }
 public void Translate(float dx, float dy)
 {
     matrix = AffineMatrix.MultMatrices(AffineMatrix.TranslateMatrix(dx, dy), matrix);
 }