code: void render()
      {
          if (screen.isReady())
          {
              final Graphic g = screen.getGraphic();
              if (buf == null)
              {
                  // Direct rendering
                  target.render(g);
              }
              else
              {
                  target.render(graphic);
                  g.drawImage(filter.filter(buf), transform, 0, 0);
              }
          }
      }
docs: Local render routine.