~((r.y + 50) / 100);

  if (fx < 0 || fy < 0) return;
  if (rx < 0 || ry < 0) return;
  if (fy > this.engine.map.length) return;
  if (ry > this.engine.map.length) return;
  if (fx > this.engine.map[fy].length) return;
  if (rx > this.engine.map[ry].length) return;

  if (this.engine.map[fy][fx] == 'x') {
    this.speed = -this.speed * .5;
    return true;
  }

  if (this.engine.map[ry][rx] == 'x') {
    this.speed = -this.speed * .5;
    return true;
  }

  return col;
}
            </code></pre>
         