ArrayList<Center> centers = new ArrayList<Center>();

void setup(){
    size(500,500);
    for(int i = 0; i < 12; i++){
       centers.add(new Center()); 
    }
}  

int PTS = 50;



void moveAway(){
  for(Center c : centers){
     c.a = atan2(c.y - mouseY, c.x - mouseX); 
  }
}
void draw(){
 
   background(200);
   
   if(mousePressed)moveAway();

   for(Center c : centers){
      c.move(); 
   }
   
   float sz = width/PTS;
   for(int i = 0; i < PTS; i++){
    for(int j = 0; j < PTS; j++){
      float min = 99999; 
      float x = i * sz;
     
       float y = j * sz;
        for(Center c : centers){
           float d = dist(x,y,c.x,c.y);
           if(d < min) {
             min = d;
         
           }
        } 
          noStroke();   
          float brite = 255 - (min*.8);
          fill(brite,brite,255);
          
          rect(x,y,sz,sz);
    }
   }

   strokeWeight(2);
   //stroke(255);
   
   for(Center c1 : centers){
     for(Center c2 : centers){
       if(c1 != c2 && dist(c1.x,c1.y,c2.x,c2.y) < 2*width/PTS){
          c1.a = random(PI*2);
          c2.a = random(PI*2);
       } 
     }
      
   }
   //fill(0);
   //text(frameRate,100,100);
}




class Center{
  float x,y,xs,ys, a;
  Center(){
      x = random(width);
      y = random(height);
      a  = random(2 * PI);

  }
  void move(){
  if(y > height) {
    a = random(PI) + PI;
    y = height; 
  }
  if(x > width){
    a = random(PI) + (PI /2);
    x = width;
  }
   if(y < 0) {
     a = random(PI)  ;
     y = 0;
   }
   if(x < 0) {

     a = random(PI) + (PI  * 3 /2);
    x = 0;
   }
      xs = (150/frameRate)*cos(a);
      ys = (150/frameRate)*sin(a);
    x += xs;
    y += ys;
   
  }
  void draw(){
     line(250,250,x,y); 
  }
}