import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;
import java.applet.*;

public class LifeGame2002 extends Applet implements Runnable {
    boolean running=false;
    int width,length,height;
    int[][] current,next;
    int[] pix;
    MemoryImageSource mis;
    Image image,offscreen;
    int count0,count1,count2,count3;

    public void init() {
        width=getSize().width;
        length=width/32+1;
        height=getSize().height;
        current=new int[height][length];
        next=new int[height][length];
        pix=new int[height*width];
        mis=new MemoryImageSource(width,height,pix,0,width);
        mis.setAnimated(true);
        image=Toolkit.getDefaultToolkit().createImage(mis);
        Random random=new Random();
        for (int y=0;y<height;y++) for (int i=0;i<length;i++)
            current[y][i]=random.nextInt();
        addMouseListener(new MouseAdapter(){
            public void mouseClicked(MouseEvent e) {
                if (running) stop();
                else start();
            }
        });
    }
    
    public synchronized void start() {
        if (!running) {
            running=true;
            new Thread(this).start();
        }
    }
    
    public synchronized void stop() {
        running=false;
    }
    
    public void run() {
        while(running) {
            synchronized (this) {
                for (int y=0;y<height;y++) for (int i=0;i<length;i++) {

                    count0=~0;
                    count1=0;
                    count2=0;
                    count3=0;

                    int y_u=(y-1+height)%height, y_d=(y+1)%height;
                    int i_l=(i-1+length)%length, i_r=(i+1)%length;

                    add(current[y_u][i]<<1 | current[y_u][i_l]>>>31 );
                    add(current[y_u][i] );
                    add(current[y_u][i]>>>1 | current[y_u][i_r]<<31 );
                    add(current[y][i]<<1 | current[y][i_l]>>>31 );
                    add(current[y][i]>>>1 | current[y][i_r]<<31 );
                    add(current[y_d][i]<<1 | current[y_d][i_l]>>>31 );
                    add(current[y_d][i] );
                    add(current[y_d][i]>>>1 | current[y_d][i_r]<<31 );

                    next[y][i]=count2&current[y][i]|count3;
                }
                int[][] temp=next;
                next=current;
                current=temp;
                for (int i=0,y=0;y<height;y++) for (int x=0;x<width;x++,i++)
                    pix[i]=(current[y][x/32]&1<<x%32)==0?0xffffffff:0xff000000;
                mis.newPixels();
            }
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
            }
        }
    }

    private void add(int bits) {
        count3&=~bits;
        count3|=count2&bits;
        count2&=~bits;
        count2|=count1&bits;
        count1&=~bits;
        count1|=count0&bits;
        count0&=~bits;
    }

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

    public synchronized void paint(Graphics g) {
        if (offscreen==null) offscreen=createImage(width,height);
        Graphics og=offscreen.getGraphics();
        og.drawImage(image,0,0,this);
        g.drawImage(offscreen,0,0,this);
    }
}