class Flying {
  PVector loc;
  PVector vel;
  PVector rand;
  int counter;
  float theta;

  Flying() {
    loc = new PVector(width/2,height/10);
    vel = new PVector(2.5,0);
  }

  void render() {
    stroke(255);
    fill(100);
    rectMode(CENTER);
    rect(loc.x,loc.y,40,40);
  }

  void fly() {
    
    float test = (sin(theta));
    theta += 0.05;
    println(test);

    rand = new PVector(0,test);

    // Constrain ----------------------------------
    if ((loc.x > width+60) || (loc.x < -60)) {
      vel.x = vel.x * -1;
      counter = counter + 1;  
    }

    if ((loc.y > height) || (loc.y < 10)) {
      vel.y = vel.y * - 1;
    }
    
    if (loc.y < 20) {
      loc.y = loc.y + 10;
      vel.y = 0;
    }
    
    // Dive --------------------------------------
    if (counter == 2 && loc.x >= width/4 && loc.x <= width/2) {
      vel.y = 20;
    }

    if (counter == 2 && loc.x >= width/2) {
      vel.y = -20;
    }
    
    if (counter == 2 && loc.x >= (width/4)*3) {
      vel.y = 0;
    }

    if (counter == 5) {
      counter = 1;
    }
    // -------------------------------------------


    loc.add(vel);
    loc.add(rand);
  }
}