import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Line2D;
import java.util.ArrayList;

import javax.swing.JFrame;
public class Tree extends JFrame
{
    private class Limb{
    double sx;
    double sy;
    double len;
    double angle;
    public Limb(double ssx, double ssy, double llen, double aangle)
    {
	this.sx=ssx;
	this.sy=ssy;
	this.len=llen;
	this.angle=aangle;
    }
    public double ex()
    {
	return this.sx+Math.cos(angle)*len;
    }
    public double ey()
    {
	return this.sy+Math.sin(angle)*len;
    }
    }
    
    ArrayList<Limb> ls;
    public Tree(){
	ls = new ArrayList<>();
        setSize(820, 820);
        setTitle("JFrame");
        setBackground(Color.WHITE);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    
    public void addL(double ssx, double ssy, double llen, double aangle)
    {
	System.out.println(llen);
	if (llen<1)
	{
	    repaint();
	    return;
	}
	Limb l = new Limb(ssx, ssy, llen, aangle);
	ls.add(l);
	repaint();
	try { Thread.sleep(5); } catch (Exception e) {}
	ls.add(new Limb(l.ex(), l.ey(), llen*3, aangle+Math.PI/2));
	ls.add(new Limb(l.ex(), l.ey(), llen*3, aangle-Math.PI/2));
	addL(l.ex(), l.ey(), llen-4, aangle);
	/**
	addL(l.ex(), l.ey(), llen*0.50, aangle+Math.PI/6);
	addL(l.ex(), l.ey(), llen*0.50, aangle);
	addL(l.ex(), l.ey(), llen*0.50, aangle-Math.PI/6);
	**/
    }
    
    public String toString()
    {
	return "";
    }

    public static void main(String[] args) {
         Tree m = new Tree();
         m.repaint();
         m.addL(410, 800, 40, -Math.PI/2);
    }

    public void paint(Graphics g) 
    {
        Graphics2D g2 = (Graphics2D) g;
        g2.clearRect(0, 0, 820, 800);
        g2.setStroke(new BasicStroke(1));
        for (Limb l:ls)
        {
            //System.out.println(l.sx + " " + l.sy + " " + l.ex() + " " + l.ey());
            g2.draw(new Line2D.Float((int)l.sx, (int)l.sy, (int)l.ex(), (int)l.ey()));
        }
    }

}