Scrolling images and text

import java.applet.*; 
import java.awt.*; 
import java.awt.image.PixelGrabber; 
import java.awt.image.MemoryImageSource; 

public class CoolScroll extends Applet implements Runnable 
{ 
private Thread m_CoolScroll = null; 
boolean asodreadisegna = false; 
private double rad = 20.0, 
rad_inc = 0.5, 
RAD = 3.1415926535 / 180, 
ang_x = 0.0, 
angolo_x = 0.0, 
inc_factor = 1.5; 

int asciioffset = 0; 
int veloce; 
char msg[]; 
int msgbounceindex []; 
int lametable[]; 
int xadd = 0; 
int scrollpos = 0; 
int mirrorpic[], 
swappic[]; 
int startx = 0, 
starty = 0, 
msglenght; 
Color forecolor, 
backcolor; 
Image backdrop; 
Image appletimage; 
Image cropfont, 
upperimage, 
lowerimage; 
int redmaskadd = 90, 
greenmaskadd = 120, 
bluemaskadd = 140; 
int redadd = 5, 
greenadd = 5, 
blueadd = 5; 
Image letter; 
int extent_x, 
extent_y; 
int letterwidth = 0, 
letterheight = 0; 
private MemoryImageSource screenMem; 
Graphics gfx, 
lettergfx, 
appletgfx; 
public void init() 
{ 
String messaggio; 
messaggio = getParameter("scrolltext"); 
if(messaggio == null) 
{ 
messaggio="SAY SOMETHING TO THE WORLD...WRITE IT!"; 
} 
veloce = Integer.parseInt(getParameter("scrollspeed")); 
asciioffset = Integer.parseInt(getParameter("asciioffset")); 
//Single letter build 
letterwidth = Integer.parseInt(getParameter("fontx")); 
letterheight = Integer.parseInt(getParameter("fonty")); 
letter = createImage(letterwidth , letterheight ); 
lettergfx = letter.getGraphics(); 
//Single letter build 
appletimage = createImage(size().width , size().height); 
appletgfx = appletimage.getGraphics(); 
//Half scroll build 
extent_x = size().width / 2; 
extent_y = size().height / 4; 
upperimage = createImage( extent_x , extent_y ); 
gfx = upperimage.getGraphics(); 
scrollpos = extent_x; 
swappic = new int[extent_x * extent_y + extent_x]; 
mirrorpic = new int[extent_x * extent_y + extent_x]; 
//Half scroll build 
//ScrollText build 
msglenght = messaggio.length(); 
msg = new char[msglenght+1]; 
//Get ready to bounce... 
msgbounceindex = new int[msglenght+1]; 
lametable = new int[16]; 
loadlameBounce(); 
int nowind = 0; 
for (int loop=0; loop < msglenght; loop++) 
{ 
msgbounceindex[loop] = nowind; 
if(++nowind>15) 
nowind = 0; 
} 


msg = messaggio.toCharArray(); 
//ScrollText build 
MediaTracker tracker = new MediaTracker(this); 
cropfont = getImage(getDocumentBase(), getParameter("fontimage")); 
tracker.addImage(cropfont, 0); 
try 
{ 
tracker.waitForID(0); 
} 
catch (InterruptedException e) 
{ 
} 
MediaTracker tracker2 = new MediaTracker(this); 
backdrop = getImage(getDocumentBase(), getParameter("backimage")); 
tracker2.addImage(backdrop, 1); 
try 
{ 
tracker2.waitForID(1); 
} 
catch (InterruptedException e) 
{ 
} 
forecolor = new Color(255,0,0); 
backcolor = new Color(0,0,0); 
screenMem = new MemoryImageSource(extent_x, 
extent_y, 
mirrorpic, 
0, 
extent_x); 

} 
public void update(Graphics g) 
{ 
gfx.drawImage(backdrop,0,0,this); 
BounceScroll(); 
loadPix(); 
renderPix(); 
appletgfx.drawImage(upperimage,0,0, extent_x * 2, extent_y * 2, this); 
appletgfx.drawImage(lowerimage,0,extent_y*2, extent_x * 2, (extent_y * 2)+xadd, this); 
paint(g); 
} 

public void paint(Graphics g) 
{ 
if (appletgfx != null) 
{ 
g.drawImage(appletimage ,0,0, this); 
} 
} 
public void start() 
{ 
if (m_CoolScroll == null) 
{ 
m_CoolScroll = new Thread(this); 
m_CoolScroll.start(); 
} 
} 
public void stop() 
{ 
if (m_CoolScroll != null) 
{ 
m_CoolScroll.stop(); 
m_CoolScroll = null; 
} 
} 
public void run() 
{ 
while (true) 
{ 
try 
{ 
repaint(); 
Thread.sleep(50); 
System.gc(); 
} 
catch (InterruptedException e) 
{ 
stop(); 
} 
} 
} 

private void loadPix() 
{ 
int punto = 0; 
int themask = 0; 
asodreadisegna = true; 
PixelGrabber grabber = new PixelGrabber( upperimage, 
0, 
0, 
extent_x, 
extent_y, 
swappic , 
0, 
extent_x); 
boolean done = false; 
do 
{ 
try 
{ 
done = grabber.grabPixels( 500 ); 
} 
catch ( InterruptedException e ) {} 
} 
while( !done ); 

asodreadisegna = false; 
} 
private void renderPix() 
{ 
int punto = 0; 
int themask = 0; 
int red = 0; 
int green = 0; 
int blue = 0; 
int yindex = extent_y-1; 
redmaskadd += redadd; 
greenmaskadd += greenadd; 
bluemaskadd += blueadd; 
if(redmaskadd == 255 || redmaskadd == 90 ) 
redadd = redadd * -1; 
if(greenmaskadd == 255 || greenmaskadd == 90 ) 
greenadd = greenadd * -1; 
if(bluemaskadd == 255 || bluemaskadd == 90 ) 
blueadd = blueadd * -1; 
for(int loopy = 0; loopy < extent_y; loopy++) 
{ 
for(int loopx = 0; loopx < extent_x; loopx++) 
{ 
punto = swappic[extent_x * yindex + loopx]; 
themask = punto & 0x00ff0000; 
red = themask >> 16; 
themask = punto & 0x0000ff00; 
green = themask >> 8; 
themask = punto & 0x000000ff; 
blue = themask; 
//red = blue; 
//green = blue; 
red = red; 
green = green; 
red = (int)((red * redmaskadd)<<8); 
green = (int)((green * greenmaskadd)); 
blue = (int)((blue * bluemaskadd)>>8); 


mirrorpic[extent_x * loopy + loopx] = 0xff000000 |(red & 0x00ff0000) | (green & 0x0000ff00) | (blue & 0xff); 
} 
yindex--; 
} 
lowerimage = createImage(screenMem); 
} 
// Lame Pre-Calc bounce table.... 
private void loadlameBounce() 
{ 
lametable[0] = 0; 
lametable[1] = 0; 
lametable[2] = 0; 
lametable[3] = 1; 
lametable[4] = 1; 
lametable[5] = 2; 
lametable[6] = 4; 
lametable[7] = 6; 
lametable[8] = 10; 
lametable[9] = 15; 
lametable[10] = 10; 
lametable[11] = 6; 
lametable[12] = 4; 
lametable[13] = 2; 
lametable[14] = 1; 
lametable[15] = 1; 
} 
private void BounceScroll() 
{ 
int retval = 0; 
double CX; 

for (int loopx = 0; loopx < msglenght; loopx++) 
{ 
if( scrollpos + (loopx * letterwidth ) < extent_x && scrollpos + (loopx * letterwidth ) > letterwidth * -1) 
{ 
getletterIndex((int)msg[loopx]); 
//Simulating transparent color.... 
lettergfx.drawImage(backdrop, -(scrollpos + (loopx * letterwidth)), -(1+lametable [msgbounceindex[loopx]]),this); 
lettergfx.drawImage(cropfont, -(startx * letterwidth), -(starty * letterheight),this); 
gfx.drawImage(letter,scrollpos + (loopx * letterwidth),1+lametable [msgbounceindex[loopx]],this); 
lettergfx.fillRect(0,0,letterwidth, letterheight); 
} 
if(++msgbounceindex[loopx] > 15) 
msgbounceindex[loopx] = 0; 
} 
scrollpos -= veloce; 
if(scrollpos * -1 > msglenght * letterwidth) 
scrollpos = extent_x; 
//sinus stuff 
angolo_x += inc_factor; 
if (angolo_x > 90 || angolo_x < 0) 
{ 
inc_factor = inc_factor * -1; 
} 
CX = Math.cos((angolo_x ) * RAD); 
xadd = (int)(angolo_x * CX); 
//end of sinus stuff 
} 
private void getletterIndex(int ASCIIcode) 
{ 
int retval = 0; 
retval = ((int)ASCIIcode)-asciioffset; 
if(retval<=0) 
{ 
startx = 0; 
starty = 0; 
} 
else 
{ 
starty = ((int)(retval / 10)); 
startx = (retval%10); 
} 
} 
}