code: protected void tick (long tickStamp)
      {
          long start = 0L, paint = 0L;
          if (_perfDebug.getValue()) {
              start = paint = _timer.getElapsedMicros();
          }
  
          // if our frame is not showing (or is impossibly sized), don't try rendering anything
          if (_window.isShowing() && _window.getWidth() > 0 && _window.getHeight() > 0) {
              // tick our participants
              tickParticipants(tickStamp);
              paint = _timer.getElapsedMicros();
              // repaint our participants and components
              paint(tickStamp);
          }
  
          if (_perfDebug.getValue()) {
              long end = _timer.getElapsedMicros();
              getPerfMetrics()[1].record((int)(paint-start)/100);
              getPerfMetrics()[2].record((int)(end-paint)/100);
          }
      }
docs: Called to perform the frame processing and rendering.