CoolScroll

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);
		}

	}
}

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