TileStitcher.clj

(defn calculate-offset [value file s r c]
  (println "Calculating offset for" (.getName file) "at" [s r c])
  (if-let [tile (get-tile s r c)]
    (really-calculate-offset file (:file tile))
    (do (Thread/sleep 60000)
	(recur value file s r c))))

(defn make-offset [file sec row col]
  (let [->offset #(calculate-offset %1 file sec %2 %3)
        row-1 (dec row) row+1 (inc row)
	col-1 (dec col) col+1 (inc col)]
    (struct-map Offset
      :north (send (agent []) ->offset row-1 col)
      :south (send (agent []) ->offset row+1 col)
      :east  (send (agent []) ->offset row   col+1)
      :west  (send (agent []) ->offset row   col-1))))