★ I have a java applet program (yanhua.java) need help!!!

[sunlinux]

★ I have a java applet program (yanhua.java) that use mouse click a area show a fireworks, the applet program that a java fan mail me. Now i find some bug in the program, can you help me? thank in advance!
The backdrop of the question: The yanhua.java applet program works well. But one day, i install j2re 1.4.1 plugin for my microsfot Internet Explorer, i run the yanhua.java applet program again, it show difficult(i move my mouse in the area, slowness), the fireworks is not fluent. Then i try my best to find the cause , i get some information, the following: yanhua.java run in j2re 1.4.1 plugin,it will deplete 100% cpu; else yanhua.java does not run in j2re 1.4.1 plugin, it will deplete 90%--95% cpu too; but my computer c3 1G cpu and 256MB memory, without running other program at that time. So i can have the assurance to say that the yanhua.java have some bug or error. can you help me to find all bug in yanhua.java? thank you very much!!!
i want to solve the question: finding all bug in yanhua.java

NOTE:
1、fireworks show specially good effect(a yanhua.java applet) you can look at:
http://www.3ren.net/down/java/yanhua.html
2、all program you can get from http://www.3ren.net/down/java/yanhua.rar
/*************************yanhua.java*************

[big]
import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.*;
import java.awt.image.MemoryImageSource;
import java.util.Random;
public class yanhua extends Applet
    implements Runnable
{
    private int m_nAppX;
    private int m_nAppY;
    private int m_centerX;
    private int m_centerY;
    private int m_mouseX;
    private int m_mouseY;
    private int m_sleepTime;
    private boolean isError;
    private boolean m_isPaintFinished;
    boolean isRunning;
    boolean isInitialized;
    Thread runner;
    int pix0[];
    MemoryImageSource offImage;
    Image dbImg;
    int pixls;
    int pixls2;
    Random rand;
    int bits;
    double bit_px[];
    double bit_py[];
    double bit_vx[];
    double bit_vy[];
    int bit_sx[];
    int bit_sy[];
    int bit_l[];
    int bit_f[];
    int bit_p[];
    int bit_c[];
    int bit_max;
    int bit_sound;
    int ru;
    int rv;
    AudioClip sound1;
    AudioClip sound2;
    public yanhua()
    {
        m_mouseX = 0;
        m_mouseY = 0;
        m_sleepTime = 5;
        isError = false;
        isInitialized = false;
        rand = new Random();
        bits = 10000;
        bit_px = new double[bits];
        bit_py = new double[bits];
        bit_vx = new double[bits];
        bit_vy = new double[bits];
        bit_sx = new int[bits];
        bit_sy = new int[bits];
        bit_l = new int[bits];
        bit_f = new int[bits];
        bit_p = new int[bits];
        bit_c = new int[bits];
        ru = 50;
        rv = 50;
    }
    public void init()
    {
        String s = getParameter("para_bits");
        if(s != null)
            bits = Integer.parseInt(s);
        s = getParameter("para_max");
        if(s != null)
            bit_max = Integer.parseInt(s);
        s = getParameter("para_blendx");
        if(s != null)
            ru = Integer.parseInt(s);
        s = getParameter("para_blendy");
        if(s != null)
            rv = Integer.parseInt(s);
        s = getParameter("para_sound");
        if(s != null)
            bit_sound = Integer.parseInt(s);
        m_nAppX = this.getSize().width;
        m_nAppY = this.getSize().height;
        m_centerX = m_nAppX / 2;
        m_centerY = m_nAppY / 2;
        m_mouseX = m_centerX;
        m_mouseY = m_centerY;
        resize(m_nAppX, m_nAppY);
        pixls = m_nAppX * m_nAppY;
        pixls2 = pixls - m_nAppX * 2;
        pix0 = new int[pixls];
        offImage = new MemoryImageSource(m_nAppX, m_nAppY, pix0, 0, m_nAppX);
        offImage.setAnimated(true);
        dbImg = createImage(offImage);
        for(int i = 0; i < pixls; i++)
            pix0[i] = 0xff000000;
        sound1 = getAudioClip(getDocumentBase(), "firework.au");
        sound2 = getAudioClip(getDocumentBase(), "syu.au");
        for(int j = 0; j < bits; j++)
            bit_f[j] = 0;
        isInitialized = true;
        start();
    }
    public void run()
    {
        while(!isInitialized)
            try
            {
                Thread.sleep(200L);
            }
            catch(InterruptedException interruptedexception) { }
        do
        {
            for(int j = 0; j < pixls2; j++)
            {
                int k = pix0[j];
                int l = pix0[j + 1];
                int i1 = pix0[j + m_nAppX];
                int j1 = pix0[j + m_nAppX + 1];
                int i = (k & 0xff0000) >> 16;
                int k1 = ((((l & 0xff0000) >> 16) - i) * ru >> 8) + i;
                i = (k & 0xff00) >> 8;
                int l1 = ((((l & 0xff00) >> 8) - i) * ru >> 8) + i;
                i = k & 0xff;
                int i2 = (((l & 0xff) - i) * ru >> 8) + i;
                i = (i1 & 0xff0000) >> 16;
                int j2 = ((((j1 & 0xff0000) >> 16) - i) * ru >> 8) + i;
                i = (i1 & 0xff00) >> 8;
                int k2 = ((((j1 & 0xff00) >> 8) - i) * ru >> 8) + i;
                i = i1 & 0xff;
                int l2 = (((j1 & 0xff) - i) * ru >> 8) + i;
                int i3 = ((j2 - k1) * rv >> 8) + k1;
                int j3 = ((k2 - l1) * rv >> 8) + l1;
                int k3 = ((l2 - i2) * rv >> 8) + i2;
                pix0[j] = i3 << 16 | j3 << 8 | k3 | 0xff000000;
            }
            rend();
            offImage.newPixels(0, 0, m_nAppX, m_nAppY);
            try
            {
                Thread.sleep(m_sleepTime);
            }
            catch(InterruptedException interruptedexception1) { }
        } while(true);
    }
    public void update(Graphics g)
    {
        paint(g);
    }
    public void paint(Graphics g)
    {
        g.drawImage(dbImg, 0, 0, this);
    }
    public void start()
    {
        if(isError)
            return;
        isRunning = true;
        if(runner == null)
        {
            runner = new Thread(this);
            runner.start();
        }
    }
    public void stop()
    {
        if(runner != null)
        {
            runner.stop();
            runner = null;
        }
    }
    public boolean mouseMove(Event event, int i, int j)
    {
        m_mouseX = i;
        m_mouseY = j;
        return true;
    }
    public boolean mouseDown(Event event, int i, int j)
    {
        m_mouseX = i;
        m_mouseY = j;
        int k = (int)(rand.nextDouble() * 256D);
        int l = (int)(rand.nextDouble() * 256D);
        int i1 = (int)(rand.nextDouble() * 256D);
        int j1 = k << 16 | l << 8 | i1 | 0xff000000;
        int k1 = 0;
        for(int l1 = 0; l1 < bits; l1++)
        {
            if(bit_f[l1] != 0)
                continue;
            bit_px[l1] = m_mouseX;
            bit_py[l1] = m_mouseY;
            double d = rand.nextDouble() * 6.2800000000000002D;
            double d1 = rand.nextDouble();
            bit_vx[l1] = Math.sin(d) * d1;
            bit_vy[l1] = Math.cos(d) * d1;
            bit_l[l1] = (int)(rand.nextDouble() * 100D) + 100;
            bit_p[l1] = (int)(rand.nextDouble() * 3D);
            bit_c[l1] = j1;
            bit_sx[l1] = m_mouseX;
            bit_sy[l1] = m_nAppY - 5;
            bit_f[l1] = 2;
            if(++k1 == bit_max)
                break;
        }
        if(bit_sound > 1)
            sound2.play();
        return true;
    }
    public boolean mouseExit(Event event, int i, int j)
    {
        m_mouseX = i;
        m_mouseY = j;
        return true;
    }
    void rend()
    {
        boolean flag = false;
        boolean flag1 = false;
        boolean flag2 = false;
        for(int k = 0; k < bits; k++)
            switch(bit_f[k])
            {
            default:
                break;
            case 1: // '\001'
                bit_vy[k] += rand.nextDouble() / 50D;
                bit_px[k] += bit_vx[k];
                bit_py[k] += bit_vy[k];
                bit_l[k]--;
                if(bit_l[k] == 0 || bit_px[k] < 0.0D || bit_py[k] < 0.0D || bit_px[k] > (double)m_nAppX || bit_py[k] > (double)(m_nAppY - 3))
                {
                    bit_c[k] = 0xff000000;
                    bit_f[k] = 0;
                } else
                if(bit_p[k] == 0)
                {
                    if((int)(rand.nextDouble() * 2D) == 0)
                        bit_set((int)bit_px[k], (int)bit_py[k], -1);
                } else
                {
                    bit_set((int)bit_px[k], (int)bit_py[k], bit_c[k]);
                }
                break;
            case 2: // '\002'
                bit_sy[k] -= 5;
                if((double)bit_sy[k] <= bit_py[k])
                {
                    bit_f[k] = 1;
                    flag2 = true;
                }
                if((int)(rand.nextDouble() * 20D) == 0)
                {
                    int i = (int)(rand.nextDouble() * 2D);
                    int j = (int)(rand.nextDouble() * 5D);
                    bit_set(bit_sx[k] + i, bit_sy[k] + j, -1);
                }
                break;
            }
        if(flag2 && bit_sound > 0)
            sound1.play();
    }
    void bit_set(int i, int j, int k)
    {
        int l = i + j * m_nAppX;
        pix0[l] = k;
    }

}
[/big]

/*********************************end*************
[ October 10, 2002: Message edited by: sunlinux ]
[ October 10, 2002: Message edited by: sunlinux ]

[sunlinux]

no one help me???

[Dirk Schreckmann]

sunlinux,
Welcome to JavaRanch!
We ain't got many rules 'round these parts, but we do got one. Please change your display name to comply with The JavaRanch Naming Policy.
Note that you can edit your own posts. Just click on the icon that looks like a piece of paper.
Thanks Pardner! Hope to see you 'round the Ranch!
------------------
When posting code, please be sure to surround the code with the [code] and [/code] UBB Tags. This will help to preserve the formatting of the code, thus making it easier to read and understand.0

[Dirk Schreckmann]

I visited the page you referenced, and it slowed my computer (WinXP, IE6, Java 1.4.1) down as well. If you were to format the code as suggested, I'd be glad to have a look at it.

[sunlinux]

to Dirk Schreckmann : thank you very much! give me suggest

[Rob Ross]

"sunlinux,"
Java loves you too. Now please change your name.
Thank you!