Funny mistake in Chapter 5: class Totem

[PeterLeikauf]

Hi Guys

the original code conrtains a funny, non-reproducible, but regular bug!

Here is the original code:

class Totem extends TileSprite {

  ....

  update(dt, t) {
    if (math.randOneIn(250)) {
      this.fireIn = 1;
    }
    if (this.fireIn > 0) {
      this.fireIn -= dt;
      // Telegraph to the player
      this.frame.x = [1, 0][((t / 0.1) | 0) % 2];
      if (this.fireIn < 0) {
        this.fireAtTarget();
      }
    }
  }
}

Now here's what happens form time to time: By sheer coincidence, fireIn might end up exactly as zero after a couple of frames (around 60). In that case, no bullet will be fired (because fireIn < 0 is false) and no further subtraction will occur (because fireIn > 0 is also false). Happens regularly on my mac with Safari ;-)