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

public class billard extends Applet  implements AdjustmentListener , ActionListener
{
    Panel Bouton;
    Scrollbar Scr1= new Scrollbar(Scrollbar.HORIZONTAL,60,10,0,100);
    Scrollbar Scr2= new Scrollbar(Scrollbar.HORIZONTAL,500,1,0,1000);
    Scrollbar Reflex= new Scrollbar(Scrollbar.HORIZONTAL,1,1,1,15000);
    Scrollbar Tronca= new Scrollbar(Scrollbar.HORIZONTAL,63,1,0,251);
    Label Lab1=new Label("a=");
    Label Lab2=new Label("b=");
    Label Lab0=new Label("orientation droite au départ: y=ax+b");
    Label Laba=new Label("1");
    Label Labb=new Label("0");
    Label Lab3=new Label("r=");
    Label Lab4=new Label("nombre de réflexion: r");
    Label Labr=new Label("1");
    Label Lab5=new Label("Options sur la troncature:");
    Label Labt=new Label("65");
    int x,y,xc,yc,tr,t,tr2,z,i,tx,ty,re;
    double a,b,R,l,m,n,d,xs1,xs2,ys1,ys2,x0,y0,a2,a3,a4,b4,a5,b5,p,q,xx,yx;
    double phi,theta;
    Button tronc,init;
    String Str1,Str2,Str3,Str4;
    public static  Graphics offgraphics;
    public static  Image offscreen;

    public void init()
    {
	tronc = new Button("troncature");
	init = new Button("Incidence");
	Bouton=new Panel();
	Panel P0=new Panel();
	Panel P1=new Panel();
	Panel P2=new Panel();
	Panel P3=new Panel();
	Panel P4=new Panel();
	Panel P5=new Panel();
	Panel P6=new Panel();
	Panel P7=new Panel();
	Panel P8=new Panel();
	setLayout(new BorderLayout());

	GridLayout lm=new GridLayout(9,1,10,10);
	Bouton.setLayout(lm);

	R=125.00; //rayon
	xc=225;// centre du cercle
	yc=225;
	tr=0;tr2=0;
	z=1;
	Bouton.setBounds(20,20,100,30);
	P0.add(Lab0);
	P1.add(Lab1);
	P1.add(Laba);
	P1.add(Scr1);
	P2.add(Lab2);
	P2.add(Labb);
	P2.add(Scr2);
	P3.add(Lab5);
	P4.add(tronc);
	P5.add(Labt);
	P5.add(Tronca);
	P6.add(Lab4);
	P7.add(Lab3);
	P7.add(Labr);
	P7.add(Reflex);
	P8.add(init);
	Bouton.add(P0,"East");
	Bouton.add(P1,"East");
	Bouton.add(P2,"East");
	Bouton.add(P3,"East");
	Bouton.add(P4,"East");
	Bouton.add(P5,"East");
	Bouton.add(P6,"East");
	Bouton.add(P7,"East");
	Bouton.add(P8,"East");
	add(Bouton,"East");
	Scr1.addAdjustmentListener(this);
	Scr2.addAdjustmentListener(this);
	Reflex.addAdjustmentListener(this);
	Tronca.addAdjustmentListener(this);
	tronc.addActionListener(this);
	init.addActionListener(this);
    }
 public void actionPerformed(ActionEvent ext)
    {	Object source= ext.getSource();
	if(source==tronc)
	    {tr=Math.abs(tr-1);z=1;repaint();}
	if(source==init)
	    {i=1;z=1;repaint();}
}

 public void paint(Graphics g)
    {
	update(g);
    }
    public void update(Graphics g)
    {
	//	if (z==1){g.setColor(Color.gray);g.fillRect(0,0,getSize().width,getSize().height);}
	g.setColor(Color.green);
//	g.drawString("LE BILLARD CHAOTIQUE",150,500);
	g.setColor(Color.blue);
	g.fillOval(100,100,250,250); //centre en(225,225) rayon 125
	g.setColor(Color.red);
	g.drawLine(225,100,225,350);
	g.drawLine(100,225,350,225);
	tx=Tronca.getValue();
//	ty=225+tx;
	ty=100+tx;
	g.setColor(Color.gray);
	g.fillRect(80,400,380,500);
	g.setColor(Color.lightGray);

	if(tr==1){
	g.fillRect(ty,100,280-tx,250);

	g.setColor(Color.green);
	g.drawLine(ty,117,ty,333);}
	a=(double)((Scr1.getValue()/10.0)-5);
	b=(double)(Scr2.getValue()-500);
	re=Reflex.getValue();
	xx=10*a+b;yx=500*a+b;
	if (i==1){g.setColor(Color.red);i=0;g.drawLine(10,(int)(xx),500,(int)(yx));}
	Str1=String.valueOf(a);
	Str2=String.valueOf(b);
	Str3=String.valueOf(re);
	Str4=String.valueOf(tx);
	Labr.setText(Str3);
	Labt.setText(Str4);
	Laba.setText(Str1);
	Labb.setText(Str2);
	g.setColor(Color.yellow);// l x^2+m x+n=0
	    for(t=0;t<re;t=t+1)
		{
	l=a*a+1;
	m=2*a*b-2*xc-2*yc*a;
	n=yc*yc+xc*xc-R*R-2*yc*b+b*b;
	d=m*m-4*l*n;
	if (d<=0) {}//g.drawString("erreur point hors du cercle",50,50);}
	else{//	g.setColor(Color.gray);
	    //g.fillRect(35,35,190,30);
	g.setColor(Color.yellow);}
	xs1=(-m+(Math.sqrt(d)))/(2*l);
	xs2=(-m-(Math.sqrt(d)))/(2*l);
	if(tr==1){if (xs2>ty){xs2=ty;}if (xs1>ty){xs1=ty;}}
	ys1=a*xs1+b;
	ys2=a*xs2+b;
	theta=Math.atan(a)*180.0/Math.PI;
//	System.out.println(theta);
	phi=Math.atan((ys1-225)/(xs1-225))*180.0/Math.PI;
//	System.out.println(phi);
//	System.out.println(xs1-225);
	g.drawLine((int)xs1,(int)ys1,(int)xs2,(int)ys2); //trace les rayons


	g.drawLine((int)phi+225,(int)((theta-phi)*0.5)+500,(int)phi+225,(int)((theta-phi)*0.5)+500); //trace l'espace des phase

	p=Math.abs(xs2-x0);	q=Math.abs(xs1-x0);
	if (p>q)  {x0=xs2;y0=ys2;}//if ((tr2==1)||(xs1==ty)){tr2=0;}}
	else {x0=xs1;y0=ys1;}
	if(z==1){x0=xs1;y0=ys1;z=0;}
	if (x0==ty) {tr2=1;}
	a3=(y0-yc)/(x0-xc);
	a2=-(x0-xc)/(y0-yc);// la normale et la tangente au cercle
	a4=(a-a2)/(a3-a);
    b4=(a*y0+b-y0)/(a3-a);
	a4=-a4; // passage sur réflexion grâce à la parité
	a5=(a2+a4*a3)/(1+a4);// retour à l'ancien repère a->a4
	b5=(y0-a2*x0+a4*y0-a4*a3*x0)/(1+a4);
	if(tr2==1){a4=a;b4=a*x0+b-y0;a4=-a4;a5=a4;b5=b4+y0-a4*x0;tr2=0;}
	a=a5;b=b5;}

	    }


    public void adjustmentValueChanged(AdjustmentEvent evt)
    {
	z=1;	repaint();
    }

    public void destroy()
    {
	Scr1.removeAdjustmentListener(this);
	Scr2.removeAdjustmentListener(this);
	Reflex.removeAdjustmentListener(this);
	Tronca.removeAdjustmentListener(this);
    }
}