ArrayList<Flake> flakes ;
void keyPressed(){
if(key == ' ')   reset(); 
}
void reset(){
  flakes = new ArrayList<Flake> ();
     for(int x = 0; x < SPACE; x++){
    for(int y = 0; y < SPACE; y++){
      flakes.add(new Flake((x + .5) * width / SPACE, (y+.5) * height / SPACE));  
    }
   }
}

float SPACE = 4;

void setup(){
   size(500,500); 
   reset();

     
   strokeWeight(5);
   stroke(255);
   noFill();
}

void draw(){
   background(0,0,128); 
   for(Flake f : flakes){
    f.draw(); 
   }
}

void mouseDragged(){
 mouseMoved(); 
}

void mouseMoved(){
  float dx = mouseX - pmouseX;
  float dy = mouseY - pmouseY;

 for(Flake f : flakes){
    f.blow(dx,dy,mouseX,mouseY); 
   }



}


class Flake{
   float x,y;
   float sz;
   float a,as;
   float dx,dy;
   float mx;
    Flake(float px, float py){
     x = px;
     y = py;
     sz = random(20,60);
     as = random(-.05,.05);
     
     mx = random(sz/2 + random(-sz/4,sz/4));
     dx = random(random(sz));
     dy = random(sz/2+random(sz));
     
    } 
    void draw(){
      pushMatrix();
       translate(x,y);
       rotate(a);
       a += as;
       for(int i = 0; i < 6; i++){
         pushMatrix();
         rotate((2 * PI) * (i/6));
         line(0,0,sz,0);
         line(mx,0,dx,dy);
         line(mx,0,dx,-dy);
         popMatrix();
       }
       
       popMatrix();
       as *= .99;
    }
    
    void blow(float dx,float dy,float mx,float my){
      float ds = dist(mx,my,x,y);
      if(ds>sz) return;
      if(ds == 0.0) ds = 0.001;
       float m = 1;
       if(my > y) m *= -1;
       as += m*(dx)/400; 

    }
  
}