谁来帮我？？？？？？(50分)

谁能帮忙看一下这段程序，给我讲解一下它的工程流程以及原理，好吗？？？
import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.*;
import java.awt.image.MemoryImageSource;
import java.util.Random;
public class jhanabi extends Applet
implements Runnable
{
private int m_nAppX = 0;
private int m_nAppY = 0;
private int m_centerX = 0;
private int m_centerY = 0;
private int m_mouseX = 0;
private int m_mouseY = 0;
private int m_sleepTime = 0;
private boolean isError = false;
private boolean m_isPaintFinished = false;
boolean isRunning = false;
boolean isInitialized = false;
Thread runner = null;
int pix0[] = null;
MemoryImageSource offImage = null;
Image dbImg = null;
int pixls = 0;
int pixls2 = 0;
Random rand = null;
int bits = 0;
do
uble bit_px[] = null;
do
uble bit_py[] = null;
do
uble bit_vx[] = null;
do
uble bit_vy[] = null;
int bit_sx[] = null;
int bit_sy[] = null;
int bit_l[] = null;
int bit_f[] = null;
int bit_p[] = null;
int bit_c[] = null;
int bit_max = 0;
int bit_sound = 0;
int ru = 0;
int rv = 0;
AudioClip sound1 = null;
AudioClip sound2 = null;
public jhanabi()
{
m_mouseX = 0;
m_mouseY = 0;
m_sleepTime = 5;
isError = false;
isInitialized = false;
rand = new Random();
bits = 10000;
bit_px = newdo
uble[bits];
bit_py = newdo
uble[bits];
bit_vx = newdo
uble[bits];
bit_vy = newdo
uble[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 = size().width;
m_nAppY = size().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 = 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 &amp;
0xff0000) >> 16;
int k1 = ((((l &amp;
0xff0000) >> 16) - i) * ru >> 8) + i;
i = (k &amp;
0xff00) >> 8;
int l1 = ((((l &amp;
0xff00) >> 8) - i) * ru >> 8) + i;
i = k &amp;
0xff;
int i2 = (((l &amp;
0xff) - i) * ru >> 8) + i;
i = (i1 &amp;
0xff0000) >> 16;
int j2 = ((((j1 &amp;
0xff0000) >> 16) - i) * ru >> 8) + i;
i = (i1 &amp;
0xff00) >> 8;
int k2 = ((((j1 &amp;
0xff00) >> 8) - i) * ru >> 8) + i;
i = i1 &amp;
0xff;
int l2 = (((j1 &amp;
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;
do
uble d = rand.nextDouble() * 6.2800000000000002D;
do
uble 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 &amp;&amp;
bit_sound > 0)
sound1.play();
}
void bit_set(int i, int j, int k)
{
int l = i + j * m_nAppX;
pix0[l] = k;
}
}

老兄，这一大段的Java的代码，估计够呛！

估计是生成脱屏图像并进行动画显示加配音效果的

这些我明白，我想问的是，那里面的那几个函数是在什么情况下起作用，意思就是在
什么情况下执行哪个，执行的顺序是什么？？？？

没人帮我呀？？？？？