import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

// 2009.3  by K.Shindo
public class buffon extends Applet implements ActionListener
{

    Image offs;
    Graphics grf;
    int W = 450;
    int H = 360;
    double pi=3.1415926535897932;
    double pb=1.0/pi;
    double s;
    int N;
    int Nsum;
    int T;
    int Tsum;
    Button btn1;
    Button btn2;
    boolean flg;

    public void init(){
        offs = createImage(W,H);
        grf = offs.getGraphics();
        setLayout(null);
        btn1 = new Button("Trial");
        btn1.setBounds(300, 45, 50, 25);
        btn1.addActionListener(this);
        add(btn1);
        btn2 = new Button("Clear");
        btn2.setBounds(360, 45, 50, 25);
        btn2.addActionListener(this);
        add(btn2);
        flg = false;
        N = 0;
        Nsum = 0;
        T = 0;
        Tsum = 0;
    }

    public void update(Graphics g) { paint(g);}
    public void paint(Graphics g) {
        grf.setColor(new Color(180,200,180));
        grf.fillRect(0, 0, W, H);
        grf.setColor(Color.black);
        for(int  d = 1; d <= 6; d++)
            grf.drawLine(20,40+d*40, 260,40+d*40);

        if(flg){
            N = 200;
            Nsum = Nsum + N;
            T = 0;
            for(int i = 1; i <= N; i++){
                double px = 40.0+5.0*40.0 * Math.random();
                double py =80.0+5.0*40.0 * Math.random();
                double s = 2.0 * pi * Math.random();
                double qx = px + 20.0*Math.cos(s);
                double qy = py + 20.0*Math.sin(s);
                int A=(int)(py/40.0);
                int B=(int)(qy/40.0);
                if(Math.abs(A-B)==1) {
                    T = T + 1;
                    grf.setColor(Color.red);
                }
                else {
                    grf.setColor(Color.blue);
                }
                grf.drawLine((int)px,(int)py,(int)qx,(int)qy);
            }

            Tsum = Tsum + T;
            double d1 = (double)T/(double)N;
            double d2 = (double)Tsum/(double)Nsum;
            String d1S=Double.toString(d1);
            String d2S=Double.toString(d2);
            d1S=(d1S+"00000000").substring(0,8);
            d2S=(d2S+"00000000").substring(0,8);

            grf.setColor(Color.black);
            grf.drawString("j‚ͺόŠΤ‚Μ”Ό•ͺ‚̏ꍇ  yBuffon's Needle‚ζ‚θz"  , 70, 30);
            grf.setColor(Color.red);
            grf.drawString("Τ‚͐ό‚ɐG‚κ‚½j"  , 20, 60);

            String pbS=Double.toString(pb);
            pbS=pbS.substring(0,8);
            grf.setColor(Color.black);
            grf.drawString("i ˜_—’l j" ,285,95);
            grf.drawString("‚P / ƒΞ @"+pbS , 285,110);
            grf.drawString("i200–{ ŽŽsj@" , 285, 135);
            grf.drawString("N = " + N, 295, 150);
            grf.drawString("n = " + T, 295, 165);
            grf.drawString("‚Ž @/@ ‚m @= " + d1S, 295, 180);
            grf.drawString("iŽŽs—έŒvj@", 285, 215);
            grf.drawString("N = " + Nsum,295, 230);
            grf.drawString("n = " + Tsum, 295, 245);
            grf.drawString("‚Ž@ / @‚m@ = " + d2S, 295, 260);

            grf.setColor(new Color(180,50,50));
            double d=100.0*Math.abs((pb-d2)/pb);
            String dS=Double.toString(d);
            dS=(dS+"0000000").substring(0,8);
            grf.drawString("Œλ· " + dS+" %", 295, 280);
            grf.setColor(Color.black);
            grf.drawString("program  by  K.Shindo" , 295, 300);

            }
            g.drawImage(offs, 0, 0, this);
    }

    public void actionPerformed(ActionEvent actionevent) {
        if(actionevent.getActionCommand() == "Clear") {
            flg = false;
            N = 0;
            Nsum = 0;
            T = 0;
            Tsum = 0;
        } else {
            flg = true;
        }
        repaint();
    }
}