# File gtk/sample/misc/cairo-pong.rb, line 151
    def draw(cr)
      cr.set_source_rgba(1, 1, 1)
      cr.rectangle(0, 0, 1, 1)
      cr.fill

      cr.save do
        cr.set_source_rgba(0.8, 0.8, 0.8, 0.8)
        cr.set_line_join(Cairo::LINE_JOIN_ROUND)
        @paddles.each do |paddle|
          cr.save {paddle.draw(cr)}
        end
      end
      
      cr.set_source_rgba(0, 0, 0)
      cr.save {@ball.draw(cr)}
    end