import java.applet.Applet;
import t3d.Vector3D;
import t3d.Particle;
import t3d.Projector;
import java.awt.Graphics;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.Color;
import java.awt.Point;

public class TestParticle extends Applet implements Runnable{

Thread t;
boolean loopDone = false;
Particle points[];
Projector pj;
int max = 120;
int width;
int height;
int hWidth;
int hHeight;
int lenzLength = 200;
int bornNum = 6;
int bornNumRand = 2;
int distance = 150;
Vector3D gravity;
Graphics bg;
Image bgImage;
protected static final boolean DEBUG = false;

public void init(){
	Dimension r = size();
	width = r.width;
	height = r.height;
	hWidth = (int)(width * 0.5);
	hHeight = (int)(height * 0.5);
	gravity = new Vector3D(0.0,-0.5,0.0);
	points = new Particle[max];
	pj = new Projector(lenzLength);
	for (int i = 0 ; i < points.length ; i++){
		points[i] = new Particle(0.0,0.0,0.0,0.0,0.0,0.0);
	}
	bgImage = createImage(width, height);
	bg = bgImage.getGraphics();
}

public void start(){
	if( t == null ){
		t = new Thread(this);
		loopDone = true;
		for (int i = 0 ; i < points.length ; i++){
			points[i].kill();
		}
		t.start();
	}
}

public void stop(){
	if( t != null ){
		loopDone = false;
		t.stop();
		t=null;
	}
}

public void destroy(){
	this.stop();
}

public int searchEmptyPoint(int startnum){
	for(int i = startnum;i< points.length ; i++){
		if (!(points[i].isAlive())){
			return i;
		}
	}
	return -1;
}

public void run (){
	int i=0;
	double x,y,z;
	int px,py,px2,py2;
	int age;
	int bornNum2;
	int pCount;
	int emptyPoint;
	Point pixel;
	Point pixel2;
	Color cols[];
	
	pixel = new Point(0,0);
	pixel2 = new Point(0,0);
	
	while (loopDone){
		bg.setColor(Color.black);
		bg.fillRect(0,0,width,height);
		
		bg.setColor(Color.darkGray);
		for(i=0;i<10;i++){
			x = i*20 - 100;
			pj.translate(x,50,-100+distance,pixel);
			pj.translate(x,50,100+distance,pixel2);
			bg.drawLine(pixel.x+hWidth,pixel.y+hHeight,pixel2.x+hWidth,pixel2.y+hHeight);
		}
		for(i=0;i<10;i++){
			z = i*20 - 100;
			pj.translate(-100,50,z+distance,pixel);
			pj.translate(100,50,z+distance,pixel2);
			bg.drawLine(pixel.x+hWidth,pixel.y+hHeight,pixel2.x+hWidth,pixel2.y+hHeight);
		}
		x = 0.0 ; y = 0.0 ; z = 0.0;
		pj.translate(x,y+50,z+distance,pixel);
		bg.setColor(Color.white);
		bg.drawLine(pixel.x+hWidth,pixel.y+hHeight,pixel.x+hWidth,pixel.y+hHeight);
		
		bornNum2 = (int)(bornNum + Math.random() - 0.5 * 2 * bornNumRand);
		pCount = 0;
		for (i = 0;i<bornNum2;i++){
			emptyPoint = searchEmptyPoint(pCount);
			if (DEBUG){System.out.println("emptyPoint = "+emptyPoint);}
			if (emptyPoint < 0){break;}
			pCount = emptyPoint+1;
			points[emptyPoint].setValue(0.0,0.0,0.0,(Math.random()-0.5)*6,9.0+(Math.random()-0.5)*5,(Math.random()-0.5)*6,(int)(50+(Math.random()-0.5)*20));
		}
		for (i = 0;i<points.length;i++){
			if( points[i].isAlive() ){
				points[i].move.add(gravity);
				points[i].move();
				if (points[i].place.y < 0){
					points[i].place.y = 0;
					points[i].move.y = -points[i].move.y;
					//points[i].move.add(gravity);
				}
				x = points[i].place.x;
				y = points[i].place.y;
				z = points[i].place.z+50;
				age = points[i].age;
				pj.translate(x,-y+50,z+distance,pixel);
				bg.setColor(Color.white);
				if ( pixel.x >= -hWidth && pixel.x < hWidth && pixel.y >= -hHeight && pixel.y < hHeight){
					bg.setColor(new Color(255,255 - age*3,0));
					bg.drawLine(pixel.x+hWidth,pixel.y+hHeight,pixel.x+hWidth,pixel.y+hHeight);
				}else{
					if (DEBUG){System.out.println("x = "+pixel.x+"  y = "+pixel.y);}
				}
			}
		}
		repaint();
		try{
			t.yield();
			t.sleep(100);
		}catch ( InterruptedException e ){}

	}
}

public void update  ( Graphics g){
	paint(g);
}

public void paint(Graphics g){
	g.drawImage(bgImage, 0, 0, null);
}
}