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

/**
 * @author William Dubel
 * @version 01.31.2004
 */

class FractalPanel extends JPanel
{
	private String type;
	private Color foreground, background;

	public FractalPanel(String type, Color foreground, Color background)
	{
		super();
		this.type = type;
		this.foreground = foreground;
		this.background = background;
	}

	private static Coord mid(Coord a, Coord b)
	{
		return new Coord((a.x+b.x)/2, (a.y+b.y)/2);
	}

	private static Coord third(Coord a, Coord b)
	{
		return new Coord((b.x-a.x)/3+a.x, (b.y-a.y)/3+a.y);
	}

	private static double dist(Coord a, Coord b)
	{
		return Math.sqrt(Math.pow(b.x-a.x,2)+Math.pow(b.y-a.y,2));
	}

	private static void drawKochSide(Graphics2D g2, Coord a, Coord b)
	{
		//if lines are only 1 pixels in length
		if (dist(a,b)<=1)
		{
			g2.drawLine((int)a.x, (int)a.y, (int)b.x, (int)b.y);
		}
		else
		{
			Coord c = new Coord(Math.cos(Math.PI/3.0 + Math.atan2(b.y-a.y,b.x-a.x))*
				(dist(a,b)/3)+third(a,b).x,
				Math.sin(Math.PI/3.0 + Math.atan2(b.y-a.y,b.x-a.x))*
				(dist(a,b)/3)+third(a,b).y);

			drawKochSide(g2, a, third(a,b));
			drawKochSide(g2, third(a,b), c);
			drawKochSide(g2, c, mid(third(a,b), b));
			drawKochSide(g2, mid(third(a,b),b), b);
		}
	}

	private static void drawSierpinski(Graphics2D g2, Coord a, Coord b, Coord c)
	{
		if (dist(a,b)<=2)  // if lines are only 2 pixels in length
		{
			g2.drawLine((int)a.x, (int)a.y, (int)b.x, (int)b.y);
			g2.drawLine((int)b.x, (int)b.y, (int)c.x, (int)c.y);
			g2.drawLine((int)c.x, (int)c.y, (int)a.x, (int)a.y);
		}
		else
		{
			drawSierpinski(g2, a, mid(a,b), mid(a,c));
			drawSierpinski(g2, mid(a,b), b, mid(b,c));
			drawSierpinski(g2, mid(a,c), mid(b,c), c);
		}
	}

	public void paintComponent(Graphics g)
	{
		double w = getSize().getWidth();
		double h = getSize().getHeight();

		g.setColor(background);
		g.fillRect(0, 0, (int)w, (int)h);
		g.setColor(foreground);
		Graphics2D g2 = (Graphics2D)g;

		if ("Sierpinski".equalsIgnoreCase(type))
		{
			drawSierpinski(g2, new Coord(0, h), new Coord(w/2.0, 0), new Coord(w, h));
		}
		else
		{
			// Make sure that the koch snowflake is proportioned and centered correctly
			double ox = 0.0, oy = 0.0;

			if ((w*2.0*Math.sqrt(3.0))<h*3.0)
			{
				h = (w * 2.0 * Math.sqrt(3.0)) / 3.0;
				oy = (getSize().getHeight()-1 - h)/2.0;
			}
			if ((w*2.0*Math.sqrt(3.0))>h*3.0)
			{
				w = (h * 3.0) / (2 * Math.sqrt(3.0));
				ox = (getSize().getWidth()-1 - w)/2.0;
			}
			drawKochSide(g2, new Coord(w/2.0+ox, oy), new Coord(ox, h*0.75+oy));
			drawKochSide(g2, new Coord(w+ox, h*0.75+oy), new Coord(w/2.0+ox, oy));
			drawKochSide(g2, new Coord(ox, h*0.75+oy), new Coord(w+ox, h*0.75+oy));
		}
	}
}

class Coord
{
	public double x, y;
	public Coord(double x, double y)
	{
		this.x = x;
		this.y = y;
	}
}

class GraphWindow extends JFrame
{
	private Container c;
	public GraphWindow()
	{
		super("Fractal Maker");
		c = getContentPane();
		c.add(new FractalPanel("Kosh", Color.white, Color.darkGray));
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setSize(600,520);
	}
}

public class Fractal extends JApplet
{
	public void init()
	{
		Container c = getContentPane();
		c.add(new FractalPanel("Sierpinski", Color.blue, Color.white));
	}

	public static void main(String [] args)
	{
		GraphWindow app = new GraphWindow();
		Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
		Dimension frame = app.getSize();

		if (frame.height > screen.height) frame.height = screen.height;
		if (frame.width > screen.width) frame.width = screen.width;

		app.setLocation((screen.width - frame.width) / 2, (screen.height - frame.height) / 2);
		app.setVisible(true);
	}
}