protected void paintComponent(Graphics g) {
      super.paintComponent(g);
      Graphics2D g2 = (Graphics2D)g;
      g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
          RenderingHints.VALUE_INTERPOLATION_BICUBIC);

      // Endow this graphics object with a scaling transformation
      // that it will use from this point on.
      g2.scale(_scale, _scale);
      if (_scene != null) _scene.draw(g2);
    }