/**
        Program:        Pascal5
        Purpose:        Generator's figure
        @author:        Sanae.Masasi
        @version:       1.00; 20.June.96
*/


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

public class Pascal5 extends Applet{

    Control5 controls;
    public void init(){
	setLayout(new BorderLayout());
	Canvas5 c = new Canvas5();
	add("Center",c);
	add("South",controls = new Control5(c));
	c.setBackground(Color.white);

    }

    public void start(){
	controls.enable();
    }

    public void stop(){
	controls.disable();
    }

    public boolean handleEvent(Event e){
	if(e.id == Event.WINDOW_DESTROY){
	    System.exit(0);
	}
	return false;
    }

}

class Canvas5 extends Canvas{
    
    public static final double PI = 3.1415927d;
    double LPX, LPY, ANGLE;

    int N = 1;
    double sx,sy;
    double leng0,ang0;
    public double gene[][] = new double[3][2];
    double a,b,c,s,t;
    int n_gene = 3;
    boolean drawflag = true;
    
    Rectangle rect;
    Font font = new Font("TimesRoman",Font.ITALIC,16);

    public void paint(Graphics g) {

	gene[0][0] = 60d;
	gene[0][1] = -1d;
	gene[1][0] = -60d;
	gene[1][1] = 1d;
	gene[2][0] = -60d;
	gene[2][1] = -1d;

    }

    public void update(Graphics g) {

	rect = bounds();
	sx = rect.width * 0.1;
	sy = rect.height * 0.9;

    	LPX = 0d;LPY = 0d;ANGLE = 0d;
	ang0 = 0d;leng0 = rect.width * 0.8d;
	a = 0.0d;b = 0;c = 0.0d;
	for(int i = 0;i < n_gene;i++){
	    turn(gene[i][0]);
	    a =  a + Math.abs(gene[i][1])
		 * Math.cos(ANGLE * PI / 180d);
	    c =  c + Math.abs(gene[i][1])
		 * Math.sin(ANGLE * PI / 180d);
	}
	s = ANGLE;
	t = Math.atan(c / a);
	a = a / Math.cos(t);

	g.setColor(Color.white);
	g.fillRect(0,0,rect.width,rect.height);
	g.setColor(Color.black);
	setlp(sx,sy);
	setangle(ang0);
	fractal(g,leng0,0);
	g.setColor(Color.red);
	g.setFont(font);
    }

    public void redraw(int N){
	this.N = N;
	repaint();
    }

    private void fractal(Graphics g,double leng,int n){

	if(n >= N){
	    move(g,leng);
	}else{
	    turn(-180.0d * t /PI);
	    for(int i=0;i < n_gene;i++){
		turn(gene[i][0]);
		if(gene[i][0] != -180.0d){
		    if(gene[i][1] < 0){
			warp(Math.abs(gene[i][1] * leng /a));
			turn(180.0d);
			fractal(g,Math.abs(gene[i][1]) * leng / a,
				n + 1);
			turn(180.0d);
			warp(Math.abs(gene[i][1] * leng /a));
		    }else{
			fractal(g,Math.abs(gene[i][1]) * leng / a,
				n + 1);
		    }
		}else{
		    warp(Math.abs(gene[i][1]) * leng / a);
		}
	    }
	    turn(-s + 180d * t / PI);
	}
    }

    public void setlp(double lpx,double lpy){
	LPX = lpx;
	LPY = lpy;
    }

    public void setangle(double ang){
	ANGLE = ang;
    }

    public void turn(double ang){
	ANGLE = ANGLE + ang;
	ANGLE = ANGLE - (int)ANGLE + (int)ANGLE%360;
    }

    public void warp(double leng){
	LPX = LPX + leng * Math.cos(ANGLE * PI /180d);
	LPY = LPY - leng * Math.sin(ANGLE * PI /180d);
    }

    public void move(Graphics g,double leng){
	double x,y;
	x = LPX + leng * Math.cos(ANGLE * PI /180d);
	y = LPY - leng * Math.sin(ANGLE * PI /180d);
	g.drawLine((int)LPX,(int)LPY,(int)x,(int)y);
	LPX = x;
	LPY = y;
    }
}

class Control5 extends Panel{

    Canvas5 canvas;
    Font font = new Font("TimesRoman",Font.ITALIC,12);
    Choice Num;
    Label labelN;

    public Control5(Canvas5 canvas){

	this.canvas = canvas;
	setLayout(new FlowLayout());

	labelN = new Label("count  ",Label.LEFT);
	labelN.setFont(font);
	add(labelN);
	Num = new Choice();
	for(int a = 1;a <=15;a ++){
	    Num.addItem(""+a);
	}
	Num.select(String.valueOf(canvas.N));
	add(Num);
	
	add(new Button("DRAW"));

    }

    public boolean action(Event ev, Object arg) {

	if (ev.target instanceof Button) {
	    canvas.redraw(Integer.parseInt(Num.getSelectedItem()));
	}
	return false;
    }
}