import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Polygon;
import java.util.Random;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.NoninvertibleTransformException;
import javax.swing.JPanel;
import java.awt.geom.Point2D;

@SuppressWarnings("serial")
public class Board extends JPanel {

    double startx = 0;
    double starty = 0;
    double globescale = 1;
    double globex = 0;
    double globey = 0;
    double oldxstart = 0;
    double oldystart = 0;
    double done = 0;
    AffineTransform tx = new AffineTransform();
    Random generator = new Random(System.currentTimeMillis());
    Polygon p = new Polygon();

    public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2 = (Graphics2D) g;
        RenderingHints rh =
                new RenderingHints(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);

        rh.put(RenderingHints.KEY_RENDERING,
                RenderingHints.VALUE_RENDER_QUALITY);

        g2.setRenderingHints(rh);
        Dimension size = getSize();
        double w = size.getWidth();
        double h = size.getHeight();
        double num = 10000;
        double EcAn = 360 / num;
        double ang = 0;
        double len;
        if (h < w) {
            len = Math.sqrt(2 * (Math.pow((h - 20) / 2, 2))) / num * 4;
        } else {
            len = Math.sqrt(2 * (Math.pow((w - 20) / 2, 2))) / num * 4;
        }
        double orgx = w / 2;
        double orgy = 20;
        double curx = w / 2;
        double cury = 20;
        double prox = w / 2;
        double proy = 20;
        double nexx;
        double nexy;
        double lenx;
        double leny;
        if (done == 0) {
            for (double deg = 0;
                    deg < num;
                    deg++) {
                ang = ang + EcAn;
                lenx = len * Math.sin(Math.toRadians(ang + 90));
                leny = len * Math.cos(Math.toRadians(ang + 90));
                double randomnumber1 = generator.nextDouble();
                double randomnumber2 = generator.nextDouble();
                nexx = prox - lenx + randomnumber1;
                nexy = proy - leny + randomnumber2;
                //g2.draw(new Line2D.Double(curx, cury, nexx, nexy));
                p.addPoint((int) nexx, (int) nexy);
                curx = nexx;
                cury = nexy;
                prox = prox - lenx;
                proy = proy - leny;
            }
            //g2.draw(p);
        }
        g2.fill(tx.createTransformedShape(p));
        done = 1;
    }

    public Board() {
        this.addMouseWheelListener(new ZoomHandler());
        this.addMouseListener(new ClickHandler());
        this.addMouseMotionListener(new MotionHandler());
    }

    private class ClickHandler implements MouseListener {

        public void mouseClicked(MouseEvent e) {
        }

        public void mousePressed(MouseEvent e) {
            startx = e.getX();
            starty = e.getY();
        }

        public void mouseReleased(MouseEvent e) {
            oldxstart = startx;
            oldystart = starty;
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mouseExited(MouseEvent e) {
        }
    }

    private class MotionHandler implements MouseMotionListener {

        public void mouseDragged(MouseEvent e) {
            tx.setToIdentity();
            globex =  e.getX() - startx;
            globey =  e.getY() - starty;
            tx.translate(globex, globey);
            tx.scale(globescale, globescale);
            Board.this.revalidate();
            Board.this.repaint();
        }

        public void mouseMoved(MouseEvent e) {
        }
    }

    private class ZoomHandler implements MouseWheelListener {

        public void mouseWheelMoved(MouseWheelEvent e) {
            //if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {

            //Point2D p1 = e.getPoint();
            //Point2D p2 = null;
            //try {
            //    p2 = tx.inverseTransform(p1, null);
            //} catch (NoninvertibleTransformException ex) {
// should not get here
            //    ex.printStackTrace();
            //    return;
            //}

            globescale -= (0.1 * e.getWheelRotation());
            globescale = Math.max(0.1, globescale);

            tx.setToIdentity();
            tx.translate(globex, globey);
            tx.scale(globescale, globescale);

            Board.this.revalidate();
            Board.this.repaint();
            //}
        }
    }
}