Re: Graphics help please

From:

"Rexx Magnus" <trashcan@uk2.net>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 27 Jan 2008 11:26:32 -0000

Message-ID:

<op.t5k52iskp9vcmo@deanes-mac.local>

On Sat, 26 Jan 2008 20:31:18 -0000, Knute Johnson =

<nospam@rabbitbrush.frazmtn.com> wrote:

Actually, I don't think the code below helps me much with what I want to=
=

do (draw images pixel by pixel) as I don't want to clear the entire imag=
e =

before displaying the changes, which is effectively what happens below. =
I =

just used the circle as test code to render with pixels. How do I just a=
dd =

to the image and then display that without clearing it each time?

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;

public class test2 extends JPanel implements Runnable {
     private volatile int angle;

     public test2() {
         setPreferredSize(new Dimension(300,300));
     }

     public void run() {
         while (--angle >= -360) {
             repaint();
             try {
                 Thread.sleep(20);
             } catch (InterruptedException ie) {
                 ie.printStackTrace();
             }
         }
     }

     public void paintComponent(Graphics g2D) {
         Graphics2D g = (Graphics2D)g2D;
         g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
          RenderingHints.VALUE_ANTIALIAS_ON);
         g.setColor(Color.WHITE);
         g.fillRect(0,0,getWidth(),getHeight());
         g.setColor(Color.BLUE);
         g.drawArc(0,0,getWidth()-1,getHeight()-1,90,angle);
     }

     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new JFrame();
                 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                 test2 t2 = new test2();
                 f.add(t2);
                 f.pack();
                 f.setVisible(true);
                 new Thread(t2).start();
             }
         });
     }
}