code: function(x, y){
              var objects = this.game.getObjectsAtPostion(x, y);
              var range = RL.Util.getDistance(this.x, this.y, x, y);
              var _this = this;
              var filtered =  objects.filter(function(target){
                  return _this.checkValidTarget(target);
              });
  
              return filtered.map(function(target){
                  return _this.prepareTargetObject(target, x, y, range);
              });
          }
docs: Get valid target objects on a tile coord.
  @method getValidTargetsAtPosition
  @param {Number} x - Map tile coord to get valid target objects from.
  @param {Number} y - Map tile coord to get valid target objects from.
  @return {Array} mixed objects