// The copyright of this program is reserved by �N�L.
/* 
Turtle Graphics : Koch �Ȑ�(��)
*/ 

/* <applet code="Ex061013a.class" width=410 height=210> </applet> */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Ex061013a extends JApplet implements ActionListener{
	dTurtle t;
	boolean flag=false;
	double length;
	double theta=0.0;
	int order;
	JComboBox cb1,cb2;
	JButton bt;
	String cbl1[]={"n=1","n=2","n=3","n=4","n=5","n=6","n=7","n=8"};	
	String cbl2[]={"��=15��","��=30��","��=45��","��=60��","��=75��","��=80��","��=85��","��=90��"};	
	double ang[]={15.0,30.0,45.0,60.0,75.0,80.0,85.0,90.0,120.0};
	public void init(){
		Container cp = getContentPane();
		JPanel pl = new JPanel();
		pl.setBackground(Color.black);
		t = new dTurtle();
    pl.setLayout(null);
    cb1 = new JComboBox(cbl1);
    cb1.setBounds(0,0,60,20);
    cb1.setSelectedIndex(0);
    cb1.addActionListener(this);
		pl.add(cb1);		
    cb2 = new JComboBox(cbl2);
    cb2.setBounds(70,0,60,20);
    cb2.setSelectedIndex(0);
    cb2.addActionListener(this);
		pl.add(cb2);
		bt = new JButton("�`��");		
    bt.setBounds(350,0,60,20);
		bt.addActionListener(this);
		pl.add(bt);
		cp.add(pl);
	}
	
	public void actionPerformed(ActionEvent event){
		order = cb1.getSelectedIndex()+1;
		length = 400.0/(Math.pow(2.0,order)*Math.pow((1.0+Math.cos(theta/180.0*Math.PI)),order));
		theta = ang[cb2.getSelectedIndex()];
		t.setColor(Color.yellow);
		t.setPos(5.0,205.0);
		t.setAng(0.0);
		if(event.getSource()==bt){
			flag=true;
			repaint();
		}	
	}
	
	public void paint(Graphics g){
		super.paint(g);
		if(flag==true)
			koch(order,length,g);
	}
	
	public void koch(int order, double length,Graphics g){
		if(order==0)
			t.move(length,g);
		else{
			koch(order-1,length,g);
			t.turn(theta);
			koch(order-1,length,g);
			t.turn(-2*theta);
			koch(order-1,length,g);
			t.turn(theta);
			koch(order-1,length,g);
		}
	}
}