import processing.opengl.*;
import java.util.ArrayList;


		Particle[] pArray;
		private int pNum = 600;

                PImage[] images;
                int x;
                int y;
                PImage particle;
                ArrayList galleries;
		PImage img;
		void setup(){

  
    			size (640,480,OPENGL);
			frameRate(30);
                        lights();
                        smooth();
                         galleries = new ArrayList(); 
                        x = mouseX;
                        y = mouseY;
			pArray = new Particle[pNum];

                        int pWidth = 100;
                        int pHeight = 100;
                        particle = loadImage("particle.png");
                        blend(particle, 0, 0, 50, 50, 0, 0, 50, 50, ADD);
                        image(particle,100,100);
                        

			for (int i=0;i<pNum;i++){
                                
				double vRandX = Math.random() * 10;
				double vRandY = Math.random() * 10;
				double vRandZ = Math.random() * 10;

                                //float startX = i%cols * 50;
                               // float startY = i/cols * 50;
				pArray[i] = new Particle(i, (float)Math.random()*width , height+100, 0, vRandY, 0,(float)Math.random()*1,Math.random()* 0.1);
			}
		}
		
		public void draw(){
  
                        background(0);
                        int startX = width/2;
                        int startY = height / 2;
                        
                        
                        //if(mousePressed){
                          //startX = mouseX;
                          //startY = mouseY;
                        //}
                        
                        for (int i=0;i<pArray.length;i++){
                         
				pArray[i].update();
				pArray[i].render(particle);

			}
                       
                        //smooth();
                        //stroke(255);
                        //strokeWeight(4);
                        //noFill();
                        //ellipse(width/2,height/2,100,100);
                        
                        if (frameCount <= 1000) {
                           // saveFrame("circles-####.tif");
                        }
                        
		}
	

	class Particle{
			
			double vx;
			double vy;
			double vz;

                        float emitX;
                        float emitY;
			float pSize;
			float x;
			float startX;
			float y;
			float z;
			double phaseInc;
			double phase = 1;
                        float curSize;
			color col;
                        int index;
                        float t = 0;
                        float timeInc = 0.01;
			Particle(int index,float x, float y, double vx, double vy, double vz, float pSize, double phaseInc){
				this.index = index;
                                this.vx = vx;
				this.vy = vy;
				this.vz = vz;
                                this.curSize = pSize;
                                this.startX = x;
                                this.y = y;
                                this.z = 0;                               
				this.pSize = pSize;
				this.phaseInc = phaseInc;
                                this.col = color(random(255),0,0,200);
			}
			
			public void update(){
				x = startX + (float)( 10 * pSize * Math.sin(phase));
                                y -= vy;
				//z += vz + (vz * Math.cos(phase));
				updateVelocity();

                                if (curSize < pSize){
                                   curSize *= 1.1; 
                                }
                                if (mousePressed){
                                   emitX = mouseX;
                                   emitY = mouseY; 
                                }else{
                                  emitX = width/2;
                                  emitY = height/2;                                
                                }
                                phase += phaseInc;
                                /*
                                *  If the particle has left the screen, reset its position and velocity.
                                */
                                
                                if (y > height  || y < -100){
                                   x=width/2;
                                   y=height;
                                   z= 0 ;
                                   curSize = 0.1;
                                   vx = Math.random()*5-2.5;
				   vy = Math.random()*5-2.5;
                                   vz = Math.random()*5-2.5;
                                }
			}
	
			private void updateVelocity() {
				
                                //vx *= 1.01;
				vy *= 1.01;
				//vz *= 1.01;
				phase += phaseInc;
                                //t+=timeInc;
                                
                                
                               // if (mousePressed){
                               //    t+=timeInc
                               // }
                              // if (t < 90){
                               //   phase = quadEaseOut((float)t,(float)0,(float)1,(float)90);
                               // }
                               // if (t>90 || t<0){
                               //    timeInc *=  -1;
                              //  }
                              // println(":" + phase);
			}
			
			public void render(PImage img){

                               
                               pushMatrix();
                               
                               translate(x,y,z);
                               pushMatrix();
                               translate(-25,-25,0);
                               popMatrix();
                               
                               scale(curSize);
                               image(img,50,50);
                               
                               popMatrix();
			}
		}
        /*
        * 
        *    It's the penner bounce function!
        * 
        */
	public float bounceEaseOut (float t, float b, float c, float d) {
		if ((t/=d) < (1/2.75)) {
			return c*(7.5625*t*t) + b;
		} else if (t < (2/2.75)) {
			return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;
		} else if (t < (2.5/2.75)) {
			return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
		} else {
			return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
		}
	}

        public float quadEaseIn (float t,float b,float c,float d) {
			return c*(t/=d)*t + b;
		}
	public float quadEaseOut (float t, float b,float c,float d){
			return -c *(t/=d)*(t-2) + b;
	}