(defn next-directed-cells [ mapref cell destination ]
  "Ranks all valid neighbouring cells according to their distance to the desired direction"
  (let [valid-neighbours (valid-neighbouring-cells mapref cell)
        normalised-direction (first
                              (normalise (substract-points destination cell)))
        translated-to-0 (map (fn [v] (substract-points v cell)) valid-neighbours)
        distances (map
                   (fn [v]
                     (euclidean-distance (first (normalise v))
                                         normalised-direction))
                   translated-to-0)
        zipped-distances (partition 2 (interleave valid-neighbours distances))]
    (map first
         (sort (fn [[_ d1] [_ d2]] (< d1 d2))
               zipped-distances))))