# File lib/gd2/image.rb, line 583
    def rotate!(angle, axis_x = width / 2.0, axis_y = height / 2.0)
      ptr = self.class.create_image_ptr(width, height, alpha_blending?)
      SYM[:gdImageCopyRotated].call(ptr, image_ptr,
        axis_x.to_f, axis_y.to_f, 0, 0, width, height, angle.to_degrees.round)
      init_with_image(ptr)
    end