abstract static class Surface extends JPanel {


  public Object AntiAlias = RenderingHints.VALUE_ANTIALIAS_ON;
  public Object Rendering = RenderingHints.VALUE_RENDER_SPEED;
  public AlphaComposite composite;
  public Paint texture;
  public BufferedImage bimg;
  public int imageType;
  public String name;
  public boolean clearSurface = true;
  // Demos using animated gif's that implement ImageObserver set dontThread.
  public boolean dontThread;

  protected long sleepAmount = 50; // max20 fps

  private long orig, start, frame;
  private Toolkit toolkit;
  private boolean perfMonitor, outputPerf;
  private int biw, bih;
  private boolean clearOnce;
  private boolean toBeInitialized = true;


  public Surface() {
    setDoubleBuffered(false);
    toolkit = getToolkit();
    name = this.getClass().getName();
    name = name.substring(name.indexOf(".", 7)+1);
    setImageType(0);

    // To launch an individual demo with the performance str output  :
    //    java -Djava2demo.perf= -cp Java2Demo.jar demos.Clipping.ClipAnim
    try {
      if (System.getProperty("java2demo.perf") != null) {
        perfMonitor = outputPerf = true;
      }
    } catch (Exception ex) { }
  }


    /*protected Image getImage(String name) {
        return DemoImages.getImage(name, this);
    }


    protected Font getFont(String name) {
        return DemoFonts.getFont(name);
    }*/


  public int getImageType() {
    return imageType;
  }


  public void setImageType(int imgType) {
    if (imgType == 0) {
      imageType = 1;
    } else {
      imageType = imgType;
    }
    bimg = null;
  }


  public void setAntiAlias(boolean aa) {
    AntiAlias = aa
      ? RenderingHints.VALUE_ANTIALIAS_ON
      : RenderingHints.VALUE_ANTIALIAS_OFF;
  }


  public void setRendering(boolean rd) {
    Rendering = rd
      ? RenderingHints.VALUE_RENDER_QUALITY
      : RenderingHints.VALUE_RENDER_SPEED;
  }


  public void setTexture(Object obj) {
    if (obj instanceof GradientPaint) {
      texture = new GradientPaint(0, 0, Color.white,
        getSize().width*2, 0, Color.green);
    } else {
      texture = (Paint) obj;
    }
  }


  public void setComposite(boolean cp) {
    composite = cp
      ? AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f)
      : null;
  }


  public void setMonitor(boolean pm) {
    perfMonitor = pm;
  }


  public void setSleepAmount(long amount) {
    sleepAmount = amount;
  }


  public long getSleepAmount() {
    return sleepAmount;
  }


  public BufferedImage createBufferedImage(Graphics2D g2,
                                           int w,
                                           int h,
                                           int imgType) {
    BufferedImage bi = null;
    if (imgType == 0) {
      bi = (BufferedImage) g2.getDeviceConfiguration().
        createCompatibleImage(w, h);
    } else if (imgType > 0 && imgType < 14) {
      bi = new BufferedImage(w, h, imgType);
    } else if (imgType == 14) {
      bi = createBinaryImage(w, h, 2);
    } else if (imgType == 15) {
      bi = createBinaryImage(w, h, 4);
    } else if (imgType == 16) {
      bi = createSGISurface(w, h, 32);
    } else if (imgType == 17) {
      bi = createSGISurface(w, h, 16);
    }
    biw = w;
    bih = h;
    return bi;
  }


  // Lookup tables for BYTE_BINARY 1, 2 and 4 bits.
  static byte[] lut1Arr = new byte[] {0, (byte)255 };
  static byte[] lut2Arr = new byte[] {0, (byte)85, (byte)170, (byte)255};
  static byte[] lut4Arr = new byte[] {0, (byte)17, (byte)34, (byte)51,
    (byte)68, (byte)85,(byte) 102, (byte)119,
    (byte)136, (byte)153, (byte)170, (byte)187,
    (byte)204, (byte)221, (byte)238, (byte)255};


  private BufferedImage createBinaryImage(int w, int h, int pixelBits) {
    int bytesPerRow = w * pixelBits / 8;
    if (w * pixelBits % 8 != 0) {
      bytesPerRow++;
    }
    byte[] imageData = new byte[h * bytesPerRow];
    IndexColorModel cm = null;
    switch (pixelBits) {
      case 1:
        cm = new IndexColorModel(pixelBits, lut1Arr.length,
          lut1Arr, lut1Arr, lut1Arr);
        break;
      case 2:
        cm = new IndexColorModel(pixelBits, lut2Arr.length,
          lut2Arr, lut2Arr, lut2Arr);
        break;
      case 4:
        cm = new IndexColorModel(pixelBits, lut4Arr.length,
          lut4Arr, lut4Arr, lut4Arr);
        break;
      default:
      {new Exception("Invalid # of bit per pixel").printStackTrace();}
    }

    DataBuffer db = new DataBufferByte(imageData, imageData.length);
    WritableRaster r = Raster.createPackedRaster(db, w, h, pixelBits, null);
    return new BufferedImage(cm, r, false, null);
  }

  private BufferedImage createSGISurface(int w, int h, int pixelBits) {
    int rMask32 = 0xFF000000;
    int rMask16 = 0xF800;
    int gMask32 = 0x00FF0000;
    int gMask16 = 0x07C0;
    int bMask32 = 0x0000FF00;
    int bMask16 = 0x003E;

    DirectColorModel dcm = null;
    DataBuffer db = null;
    WritableRaster wr = null;
    switch (pixelBits) {
      case 16:
        short[] imageDataUShort = new short[w * h];
        dcm = new DirectColorModel(16, rMask16, gMask16, bMask16);
        db = new DataBufferUShort(imageDataUShort, imageDataUShort.length);
        wr = Raster.createPackedRaster(db, w, h, w,
          new int[] {rMask16, gMask16, bMask16},
          null);
        break;
      case 32:
        int[] imageDataInt = new int[w * h];
        dcm = new DirectColorModel(32, rMask32, gMask32, bMask32);
        db = new DataBufferInt(imageDataInt, imageDataInt.length);
        wr = Raster.createPackedRaster(db, w, h, w,
          new int[] {rMask32, gMask32, bMask32},
          null);
        break;
      default:
      {new Exception("Invalid # of bit per pixel").printStackTrace();}
    }

    return new BufferedImage(dcm, wr, false, null);
  }

  public Graphics2D createGraphics2D(int width,
                                     int height,
                                     BufferedImage bi,
                                     Graphics g) {

    Graphics2D g2 = null;

    if (bi != null) {
      g2 = bi.createGraphics();
    } else {
      g2 = (Graphics2D) g;
    }

    g2.setBackground(getBackground());
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, AntiAlias);
    g2.setRenderingHint(RenderingHints.KEY_RENDERING, Rendering);

    if (clearSurface || clearOnce) {
      g2.clearRect(0, 0, width, height);
      clearOnce = false;
    }

    if (texture != null) {
      // set composite to opaque for texture fills
      g2.setComposite(AlphaComposite.SrcOver);
      g2.setPaint(texture);
      g2.fillRect(0, 0, width, height);
    }

    if (composite != null) {
      g2.setComposite(composite);
    }

    return g2;
  }

  public abstract void render(int w, int h, Graphics2D g);


  /**
   * It's possible to turn off double-buffering for just the repaint
   * calls invoked directly on the non double buffered component.
   * This can be done by overriding paintImmediately() (which is called
   * as a result of repaint) and getting the current RepaintManager and
   * turning off double buffering in the RepaintManager before calling
   * super.paintImmediately(g).
   */
  public void paintImmediately(int x,int y,int w, int h) {
    RepaintManager repaintManager = null;
    boolean save = true;
    if (!isDoubleBuffered()) {
      repaintManager = RepaintManager.currentManager(this);
      save = repaintManager.isDoubleBufferingEnabled();
      repaintManager.setDoubleBufferingEnabled(false);
    }
    super.paintImmediately(x, y, w, h);

    if (repaintManager != null) {
      repaintManager.setDoubleBufferingEnabled(save);
    }
  }


  public void paint(Graphics g) {

    Dimension d = getSize();

    if (imageType == 1)
      bimg = null;
    else if (bimg == null || biw != d.width || bih != d.height) {
      bimg = createBufferedImage((Graphics2D)g,
        d.width, d.height, imageType-2);
      clearOnce = true;
      toBeInitialized = true;
    }

    if (toBeInitialized) {
      toBeInitialized = false;
      startClock();
    }

    Graphics2D g2 = createGraphics2D(d.width, d.height, bimg, g);
    render(d.width, d.height, g2);
    g2.dispose();

    if (bimg != null)  {
      g.drawImage(bimg, 0, 0, null);
      toolkit.sync();
    }

  }


  public void startClock() {
    orig = System.currentTimeMillis();
    start = orig;
    frame = 0;
  }

  private static final int REPORTFRAMES = 30;


  public static void setAlpha(Graphics2D g, float alpha) {
    g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
  }
}