// An array of stripes
Stripe[] stripes = new Stripe[50];

void setup() {
  size(200,200);
  // Initialize all "stripes"
  for (int i = 0; i < stripes.length; i++) {
    stripes[i] = new Stripe();
  }
}

void draw() {
  background(100);
  // Move and display all "stripes"
  for (int i = 0; i < stripes.length; i++) {
    stripes[i].move();
    stripes[i].display();
  }
}

class Stripe {
  float x;       // horizontal location of stripe
  float speed;   // speed of stripe
  float w;       // width of stripe
  boolean mouse; // state of stripe (mouse is over or not?)

  Stripe() {
    x = 0;              // All stripes start at 0
    speed = random(1);  // All stripes have a random positive speed
    w = random(10,30);
    mouse = false;
  }

  // Draw stripe
  void display() {
    fill(255,100);
    noStroke();
    rect(x,0,w,height);
  }

  // Move stripe
  void move() {
    x += speed;
    if (x > width+20) x = -20;
  }
}