createBufferStrategy and Full Screen

Java 2D
#1

Long time lurker, first time poster… ::slight_smile:

I’m running jdk 1.4.2 on Windows XP and I’m using createBufferStrategy with my own rendering loop. The problem I have is that if I createBufferStrategy(1), then the drawing of graphics seems fine, but if I try it with 2 or more, then the screen is blank, ie no redrawing or redrawing in the back buffer but is never shown.

I am using a JFrame and an extended class of Canvas added to the content pane of the frame.

Any thoughts? Thanks.

#2

Post some code in [ code] [/ code] tags and perhaps we can help spot the error.

#3

are you missing the obvious bufferStrategy.show() @ the end of your render loop?

#4

Thanks for asking…here’s an exerpt:

public abstract class Game extends Canvas { /** The stragey that allows us to use accelerate page flipping */ private BufferStrategy strategy;

public abstract void redraw( Graphics g, long delta );

public void init()
{
// create a frame to contain our game
container = new JFrame(“Space Invaders 101”);

        // get hold the content of the frame and set up the resolution of the game
        JPanel panel = (JPanel) container.getContentPane();
        panel.setPreferredSize(new Dimension(WIDTH,HEIGHT));
        panel.setLayout(null);
  
  container.setUndecorated( true );
  setBackground(Color.black);
  setForeground(Color.white);

  GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment()
     .getDefaultScreenDevice();
  gd.setFullScreenWindow(container);

  GraphicsConfiguration gc = gd.getDefaultConfiguration();
  BufferCapabilities bufCap = gc.getBufferCapabilities();
  boolean page = bufCap.isPageFlipping();

  if (page) {
     // Page flipping is supported
  } else {
     // Page flipping is not supported
     System.out.println("Page flipping is not supported" );
  }
  
        // setup our canvas size and put it into the content of the frame
        setBounds(0,0,WIDTH,HEIGHT);
        panel.add(this);
        
        // Tell AWT not to bother repainting our canvas since we're
        // going to do that our self in accelerated mode
        setIgnoreRepaint(true);
        
        // finally make the window visible 
        container.pack();
        container.setResizable(false);
        container.setVisible(true);
        
        // add a listener to respond to the user closing the window. If they
        // do we'd like to exit the game
        container.addWindowListener(new WindowAdapter() {
              public void windowClosing(WindowEvent e) {
                    System.exit(0);
              }
        });
        
        // request the focus so key events come to us
        requestFocus();

        // create the buffering strategy which will allow AWT
        // to manage our accelerated graphics
        createBufferStrategy(2);
        strategy = getBufferStrategy();

}
public void gameLoop() {

  GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment()
     .getDefaultScreenDevice();
  GraphicsConfiguration gc = gd.getDefaultConfiguration();
  BufferCapabilities bufCap = gc.getBufferCapabilities();
  bufCap = strategy.getCapabilities();
  BufferCapabilities.FlipContents flipContents = bufCap.getFlipContents();
  
        long lastLoopTime = System.currentTimeMillis();
        
  long t0 = System.currentTimeMillis();

        // keep looping round til the game ends
        while (gameRunning) {
              long delta = System.currentTimeMillis() - lastLoopTime;
              lastLoopTime = System.currentTimeMillis();
        
              // Get hold of a graphics context for the accelerated 
              // surface and blank it out
              Graphics/*2D*/ g = /*(Graphics2D)*/ strategy.getDrawGraphics();

     try { 

     // System.out.println( delta ); 
     //
     redraw( (Graphics) g, delta );

              // finally, we've completed drawing so clear up the graphics
              // and flip the buffer over

     } catch ( Exception e )
     {
        e.printStackTrace();
     } 
              strategy.show();
              g.dispose();
              
              // finally pause for a bit. Note: this should run us at about
              // 100 fps but on windows this might vary each loop due to
              // a bad implementation of timer
              try { Thread.sleep(10); } catch (Exception e) {}
        }
  }

}

class MyCanvas extends Game
implements ImageObserver
{
public void redraw( Graphics g, long delta )
{
// some application specific drawing using
// Graphics g.

  //    eg.   g.clearRect();
  //            g.drawImage();
  //            g.drawString();

}

public static void main( String[] args )
{
MyCanvas canvas = new MyCanvas();
canvas.init();
canvas.gameLoop();
}

}

#5

Never mind.

I modified my code similar to the Background.jar code from Woogley in another thread and the problem is solved.

It must have had to do with inheriting from Canvas instead of JFrame. At any rate. I’m happy.

Thanks Woogley!!