code: function(x, y, dir, speed) {
    this.x = x;
    this.y = y;
    this.dir = dir;
    this.speed = speed || 3;
    this.steps = 0;
    this.hand = new Texture('./assets/gun.png', 512, 360);
  
    // Update the position of the audio listener.
    Howler.pos(this.x, this.y, -0.5);
  
    // Update the direction and orientation.
    this.rotate(dir);
  }
docs: The player from which we cast the rays.
  @param {Number} x     Starting x-position.
  @param {Number} y     Starting y-position.
  @param {Number} dir   Direction they are facing in radians.
  @param {Number} speed Speed they walk at.