There’s sometime ago I wanted to see how java 2D was working.
I came from Amiga computers, where doing double buffering was part of your job in C. But using accellerated 2D java engine seems a lot simpler as it do the job for you ;)
Below is a little java class I coded to experiment java 2D with double buffering.
It may be wrong now since this code is quite old and its also a lot slower than the same code on an Amiga 4000 using C language.
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
// main window
public class MainWindow extends Canvas
{
/* The stragey that allows us to use accelerate page flipping */
private BufferStrategy strategy;
// constructor
public MainWindow()
{
// create window
JFrame container = new JFrame("Java 2d test");
// get hold the content of the frame and set up the resolution of the game
JPanel panel = (JPanel) container.getContentPane();
panel.setPreferredSize(new Dimension(800,600));
panel.setLayout(null);
// setup our canvas size and put it into the content of the frame
setBounds(0,0,800,600);
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);
}
});
addKeyListener(new keyhandler());
// get focus to receive key events
requestFocus();
// create the buffering strategy which will allow AWT
// to manage our accelerated graphics
createBufferStrategy(2);
strategy = getBufferStrategy();
// start
Draw();
}
public void Draw()
{
int j = 0 , i = 0, r = 255,g = 255, b=255, mr = -1,mg = -1,mb = -1;
int endw = 800, endh = 600, mw=1, mh = -1;
// Get hold of a graphics context for the accelerated
// surface and blank it out
Graphics2D gfx = (Graphics2D) strategy.getDrawGraphics();
gfx.setColor(Color.black);
gfx.fillRect(0,0,endw,endh);
gfx.setColor(Color.white);
while(true)
{
gfx.setColor(new Color(r,g,b));
gfx.drawLine(i,j,endw-i,endh-j);
//gfx.draw3DRect(i,endh,i,endw,false);
gfx.drawArc(i, j, endw, endh, 45-i, 90+j);
// finally, we've completed drawing so clear up the graphics
// and flip the buffer over
//g.dispose();
strategy.show();
if(i < 800) i++;
else
{
j++;
if(j > 600)
{
j = 0;
i = 0;
}
}
r = r + (2*mr);
g = g + (5*mg);
b = b + (10*mb);
if(r <= 5) mr = 1;
else if(r >= 250) mr = -1;
if(g <= 5) mg = 1;
else if(g >= 250) mg = -1;
if(b <= 5) mb = 1;
else if(b >= 250) mb = -1;
endw+=mw;
endh+=mh;
if(endw >= 1200) mw = -1;
else if(endw <= 300) mw = 1;
if(endh >= 900) mh = -1;
else if(endh <= 50) mh = 1;
try { Thread.sleep(1); } catch (Exception e) {}
}
}
private class keyhandler extends KeyAdapter
{
public void keyTyped(KeyEvent e)
{
System.exit(0);
}
}
// main function
public static void main(String[] args)
{
new MainWindow();
}
}
