code: function(height, angle, dist) {
      var z = dist * Math.cos(angle);
      var wallH = this.height * height / z;
      var bottom = this.height / 2 * (1 + 1 / z);
  
      return {
        top: bottom - wallH,
        height: wallH
      };
    }
docs: Based on the angle and distance, determine how we are going to project the image.
  @param  {Number} height Wall piece height.
  @param  {Number} angle  Angle of the ray.
  @param  {Number} dist   Distnace from the player.
  @return {Object}        top and height