code: protected void createBackBuffer (GraphicsConfiguration gc)
      {
          // if we have an old image, clear it out
          if (_backimg != null) {
              _backimg.flush();
              _bgfx.dispose();
          }
  
          // create the offscreen buffer
          int width = _window.getWidth(), height = _window.getHeight();
          _backimg = gc.createCompatibleVolatileImage(width, height);
  
          // fill the back buffer with white
          _bgfx = (Graphics2D)_backimg.getGraphics();
          _bgfx.fillRect(0, 0, width, height);
  
          // clear out our frame graphics in case that became invalid for
          // the same reasons our back buffer became invalid
          if (_fgfx != null) {
              _fgfx.dispose();
              _fgfx = null;
          }
  
  //         Log.info("Created back buffer [" + width + "x" + height + "].");
      }
docs: Creates the off-screen buffer used to perform double buffered rendering of the animated
  panel.