float px[] = new float[300];
float py[] = new float[300];
float pr[] = new float[360];
void setup(){
  size(300,300);
}
void draw(){
}
void mousePressed(){
  for(int i=0; i<mouseY; i++){
    px[i] = random(width);
    py[i] = random(height);
    pr[i] = random(360);
  }
}
void mouseDragged(){
  background(255);
  for(int i=0; i<mouseY; i++){
    pushMatrix();
    rectMode(CENTER);
    translate(px[i],py[i]);
    rotate(radians(pr[i] + mouseX));
    rect(0,0,5,500);
    popMatrix();
  }
}