import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JComponent;
import java.awt.geom.Line2D;
import java.util.ArrayList;
import java.awt.geom.GeneralPath;
import java.awt.Polygon;
import java.awt.Point;
 
public class KochComponent3 extends JComponent 
{
 
    ArrayList<Point> points = null;
 
    /** create the initial triangle */
    private void createTriangle() 
    {
        points = new ArrayList<Point>();
 
        int length = Math.min(getWidth(), getHeight())*2/3;
 
        int x1 = (getWidth()-length)/2;
        int y1 = length/2;
        points.add(new Point(x1, y1));
 
        int x2 = x1+length;
        int y2 = y1;
        points.add(new Point(x2, y2));
 
        int x3 = x1+(length/2);
        int y3 = y1+length;
        points.add(new Point(x3, y3));
 
    }
 
    public void next() 
    {
        numIterations++;
 
        ArrayList<Point> newPoints = new ArrayList<Point>();
        // generate the new points for each line segment
        for(int i = 0; i<points.size(); i++) {
            Point p1 = points.get(i);
            Point p2 = i==points.size()-1 ? 
              points.get(0) : points.get(i+1);
            newPoints.add(p1);
            newPoints.addAll(getKochPoints(p1, p2));
 
        }
        points = newPoints;
        xAngle += 30;
        yAngle += 30;
        repaint();
    }
 
    public void paintComponent(Graphics g) 
    {
        if(points==null)
        {
            createTriangle();
        }
 
        Graphics2D g2 = (Graphics2D)g;
         Polygon koch = new Polygon();
         for (Point p : points){
           koch.addPoint(p.x, p.y);
         }
         g2.draw(koch);
 
    }
 
 
 
    /** Generate the points to add for each segment
     * for each iteration.
     * I am just putting in the easy ones here.
     * You get to do the trickier one!
     */
    private ArrayList<Point> getKochPoints(Point p1, Point p2) 
    {
        ArrayList<Point> kochPoints = new ArrayList<Point>();
 
        int dx = p2.x-p1.x;
        int dy = p2.y-p1.y;
 
 
        Point kp1 = new Point(p1.x+dx/3, p1.y+dy/3);
        kochPoints.add(kp1);
 
 
 
 
        if(p1.y == p2.y)
        {
            Point kp2 = new Point();
            kp2.setLocation(kp1);
            kp2.translate((int)((dx/3)/2), (int)(-dx/3));
            kochPoints.add(kp2);
        }
        else if(p1.x > p1.y)
        {
 
 
            double v1 = Math.toRadians(30);
            double v2 = Math.toRadians(60);
            Point kp2 = new Point();
            kp2.setLocation(kp1);
            kp2.translate((int)(-Math.cos(v1)*dx/3), (int)(-Math.sin(v2)*2*dx/3 + dx/6));
            kochPoints.add(kp2); 
 
        }
        else
        {
            double v1 = Math.toRadians(xAngle);
            double v2 = Math.toRadians(yAngle);
            Point kp2 = new Point();
            kp2.setLocation(kp1);
            kp2.translate((int)(Math.cos(v2)*dx + dx/6), (int)(Math.sin(v1)*dx/3));
            kochPoints.add(kp2); 
        }
 
        Point kp3 = new Point(p1.x+2*dx/3, p1.y+2*dy/3);
        kochPoints.add(kp3);
 
 
        return kochPoints;
    }
    private int xAngle = 30;
    private int yAngle = 60;
    private int numIterations;
 
}