//<pre>
/* munch.java    --- rrs@isi.edu ---   05-28-96   */
/* Munching Squares is a neat display hack!!! this applet should provide about
   12 hours  of different displays before repeating. This version is for bitmap
   displays and Xor¼s the pixels for a multi-pas display. Originally this
   was five machine language instructions on the Dec PDP-1	*/

import java.awt.*;
import java.applet.*;

public class munch9bw extends Applet  implements Runnable
{
	int wx, wy;			// window width and heigth
	int x, y, t;
	int lim = 255;
	Thread munchThread;
	int delay = 10;
	static boolean keepRunning;
	Graphics myG;
	Color frgclr, bkgclr, xorclr;

	 public void init( )
		{
			wx = 256;
			wy = 256;
			myG = this.getGraphics( );
			Dimension d = size();
			if (( d.width != wx ) || ( d.height != wy))  { resize( wx, wy); }
			frgclr = Color.white;
			bkgclr = Color.black;
			xorclr = Color.blue;
			setBackground( bkgclr );
			setForeground( frgclr );
			keepRunning = true;
			String spdstr =  "10";
			delay = Integer.parseInt( spdstr );
	   	}

	public void start( )
		{
			keepRunning = true;
			munchThread = new Thread(this);
			myG.setColor( frgclr );
			myG.fillRect( 0, 0,   wx-1, wy-1);
			try {Thread.currentThread().sleep(2*delay);}
			      catch (InterruptedException e){}

			munchThread.start();
		}


	public void stop()
		{
			keepRunning = false;
			munchThread.stop();
		}



	public void run (  )
		{
			int sw = 1, sdel = 300;
			int x, y;
			boolean fullcycle = true;
			t=0;
			try {Thread.currentThread().sleep(sdel);}
			   catch (InterruptedException e){}
			while( keepRunning )
			   {
				showStatus( "" + sw );
				t = ( t + sw ) & 255;

				if( t == 0 )
					{
						fullcycle = ! fullcycle;
						if ( fullcycle ) { sw++; sw &= 255; }
					}
				update( myG );
				Thread.currentThread().yield();
			  }
		}


	public void update( Graphics g )
		{
			paint( g );
		}

	public void paint ( Graphics g )
		{
			int lim = 255;
			g.setXORMode( xorclr );
			for( int x = 0; x <= lim; x++)
	 		   {
				g.drawLine( x, x^t,  x, x^t );
			   }
			g.setPaintMode();
		}


}
//</pre>