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

public class Circle 
    extends Applet
    implements Runnable{

    private int spicchi = 12; //number of parts in which the circle is divided
    private int incr = 1; // increment at evry loop tp delta
    private double delta = 0; //distance in radians to the 2nd point of each line
    private double deltaInGrades = 1;
    private int sleep = 1000/10;

    public void init() {
	 
    }

    public void start() {
	//System.out.println("start()");
	Thread t = new Thread(this);
	t.start();
    }

    public void stop() {
    }

    public void destroy() {
    }

    public void paint(Graphics g) {
	double x1, y1, x2, y2;
	double alfa;
	alfa = (double)360/spicchi;
	alfa = toRadians(alfa);
	// now alfa is in radians
	deltaInGrades += incr;
	delta = toRadians(deltaInGrades);
	deltaInGrades = toDegrees(delta);
	if(deltaInGrades > 360) {
	    delta = toRadians(deltaInGrades);
	}
	//System.out.println("Math.toGrades(alfa) = " +  Math.toDegrees(alfa));
	//System.out.println("Math.sin(alfa) = " +  Math.sin(alfa));
	//System.out.println("150*Math.sin(alfa) = " +  150*Math.sin(alfa));
	g.drawOval(0, 0, 300, 300);
	for(int i = 0; i< spicchi; ++i) {
	    x1 = Math.cos(alfa*i); 
	    y1 = Math.sin(alfa*i);
            x2 = Math.cos(alfa*i+delta);
	    y2 = Math.sin(alfa*i+delta);
	    x1 *= 150;
	    y1 *= 150;
	    x2 *= 150;
	    y2 *= 150;
	    /*System.out.println("(2)x1 = " + x1 + " y1 = " + y1 +
			       " x2 = " + x2 + " y2 = " + y2 );
	    */
	    drawLine(g, (int)x1, (int)y1, (int)x2, (int)y2);
	}
	
    }


    private double toRadians(double angdeg) {
	double p = 3.141592654, back; 
	angdeg = angdeg % 360;
	back = (angdeg * p)/180;
	return back;
    } 

    private double toDegrees(double angrad) {
	double p = 3.141592654, back; 
	angrad = angrad % (2*p);
	back = (180*angrad) / p;
	return back;
    } 

    

    private void drawLine(Graphics g, int x1, int y1, int x2, int y2) {
	x1 += 150;
	x2 += 150;
	
	y1 = 150 - y1;
	y2 = 150 - y2;

	g.drawLine(x1, y1, x2, y2);
    }
    
    public void run() {
	while(true) {
	    repaint();
	    try {
		Thread.sleep(sleep);
	    } catch (InterruptedException e) {
	    }
	}
    }

}