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

public class BrownMo7 extends Applet implements Runnable {
    


    Thread runner;
    int z,w;
    int x = 250;
    int y = 200;

    public void init() {
    Label theTitle = new Label("Brownian Motion Movie");
    Label myName = new Label(" Paul Garrett   garrett@math.umn.edu");
    add(theTitle);
    add(myName);
    }

    public void start() {
	if (runner == null) {
	    runner = new Thread(this);
	    runner.start();
	}
    }

    public void stop() {
	if (runner != null) {
	    runner.stop();
	    runner = null;
	}
    }

    void pause(int time) {
	try { Thread.sleep(time); }
	catch ( InterruptedException e) { }
    }

    public void update(Graphics g) { // don't clear the screen
	paint(g);
    }

    public void run() {
	    setBackground(Color.darkGray);
	    setForeground(Color.red);

	    for (int i=0 ; i < 2000 ; i++ ) {
	        twoConsecutivePoints(i);
		repaint();
		pause(150);
	}
    }	

    public void paint(Graphics g) {
	g.drawLine(x,y,z,w);
    }

    public void twoConsecutivePoints(int j) {
	int angle = (int) Math.floor(Math.random()*360);
	z = x;
	w = y;
	x = z + (int) (14 * Math.cos(angle));
	y = w + (int) (14 * Math.sin(angle));
    }

}