import java.util.*;
ArrayList occs;

final static float PHASE = (float)(PI*Math.E);
final static int MAX_RADIUS = 250;
final static int AMP = 5;
final static int TYPE = 0;

//color constants
final static int RED_BASE = 20;
final static int RED_VARI = 30;
final static int BLUE_BASE = 156;
final static int BLUE_VARI = 100;
final static int GREEN_BASE = 50;
final static int GREEN_VARI = 50;
void setup(){
  size(500, 500);
  background(55); 
  smooth();
  ellipseMode(CENTER);
  fill(0,0,0,0);
  stroke(0);
  strokeWeight(2);
  frameRate(15);
  occs = new ArrayList();
  if(TYPE == 0){
    for(float t = 0; t < 100; t+=.25){
     float x = (float)(AMP*t*Math.cos(PHASE*t));
     float y = (float)(AMP*t*Math.sin(PHASE*t));
     x+=width/2;
     y+=height/2; 
     int radius = MAX_RADIUS - (int)sqrt(sq(x - width/2) + sq(y - height/2));
     if(radius > 1){
       occs.add( new occ( x, y, radius/3) );
     }  
    }
  }else{
    int curx = 0;
    int cury = 0;
    int multx = 20;
    int multy = 20;
    for(int i = 0; i < 1000; i++){
      curx += (multx * i);
      multx *= -1;
      for(int j = 0; j < 1000; j++){
        cury += (multy * j);
        multy *= -1;
        int posx = width/2 + curx;
        int posy = height/2 + cury;
        int radius = 450 - (int)sqrt(sq(posx - width/2f) + sq(posy - height/2f));
        if(radius > 0){
          occs.add( new occ( posx, posy, radius/2) );
        }
      }
      cury = 0;
    }
  }
}
 
void draw(){
  background(255);
  for(int i = 0; i < occs.size(); i++){
    occ o = (occ)occs.get(i);
    o.tick();
    o.render();
  }
} 

//void mousePressed(){
//  saveFrame();
//}

public class occ{
  private float x;
  private float y;
  private int maxRadius;
  private int curRadius;
  private int step;
  private color col;
  private int alph;
  public occ(float x, float y, int maxRadius){
    this(x,y,maxRadius,0);  
  }
  public occ(float x, float y, int maxRadius, int initialRadius){
    this.x = x;
    this.y = y;
    this.curRadius = initialRadius;
    this.maxRadius = maxRadius;
    this.alph = 100;
    this.step = 1;
    this.col = color( random(RED_VARI) + RED_BASE, random(BLUE_VARI)+BLUE_BASE ,random(GREEN_VARI)+GREEN_BASE);  
  }
  public void tick(){
    this.curRadius += this.step; 
    if(this.curRadius >= this.maxRadius || this.curRadius <= 0){
      this.step = -1 * this.step;
    }
  }
  
  public void render(){
    this.alph += random(5) - 2;
    fill(red(this.col), blue(this.col), green(this.col), this.alph);
    ellipse(this.x, this.y, this.curRadius, this.curRadius);
  }

}