/**
bubble emmiter by <a href="http://www.local-guru.net/blog">guru</a>

*/

PVector pos[];
PVector dir[];
int[] age;

void setup() {
  size(300,300);
  smooth();
  
  pos = new PVector[30];
  dir = new PVector[30];
  age = new int[30];
  
  for( int i=0; i<30; i++) {
    pos[i]=new PVector(150,150);
    PVector v = new PVector( random(width)-150, random(height)-150);
    v.normalize();
    dir[i] = v;
    age[i] = -(int)random( 100 );
  }
}

void draw() {
  background(0);
  noFill();
  for( int i=0; i<30; i++) {

    if ( age[i] > 0 ) {
     stroke(0,0,255, 255-age[i]*2); 
     fill(0,0,100, 255-age[i]*2);

      ellipse( pos[i].x, pos[i].y, sqrt(age[i])*2, sqrt(age[i])*2);
      pos[i].add(dir[i]);
    }
    age[i]++;
    if ( age[i] > 100 ) {
      age[i] = 0;
      pos[i] = new PVector(150,150);
      PVector v = new PVector( random(width)-150, random(height)-150);
      v.normalize();
      dir[i] = v;
     
    }
    
  }  
  
}