RosettaCodeData/Task/Maze-generation/TXR/maze-generation-2.txr
2019-09-12 10:33:56 -07:00

80 lines
2.1 KiB
Text

(defvar vi) ;; visited hash
(defvar pa) ;; path connectivity hash
(defvar sc) ;; count, derived from straightness fator
(defun rnd-pick (list)
(if list [list (rand (length list))]))
(defun neigh (loc)
(let ((x (from loc))
(y (to loc)))
(list (- x 1)..y (+ x 1)..y
x..(- y 1) x..(+ y 1))))
(defun make-maze-impl (cu)
(let ((q (list cu))
(c sc))
(set [vi cu] t)
(while q
(let* ((cu (first q))
(ne (rnd-pick (remove-if vi (neigh cu)))))
(cond (ne (set [vi ne] t)
(push ne [pa cu])
(push cu [pa ne])
(push ne q)
(cond ((<= (dec c) 0)
(set q (shuffle q))
(set c sc))))
(t (pop q)))))))
(defun make-maze (w h sf)
(let ((vi (hash :equal-based))
(pa (hash :equal-based))
(sc (max 1 (trunc (* sf w h) 100))))
(each ((x (range -1 w)))
(set [vi x..-1] t)
(set [vi x..h] t))
(each ((y (range* 0 h)))
(set [vi -1..y] t)
(set [vi w..y] t))
(make-maze-impl 0..0)
pa))
(defun print-tops (pa w j)
(each ((i (range* 0 w)))
(if (memqual i..(- j 1) [pa i..j])
(put-string "+ ")
(put-string "+----")))
(put-line "+"))
(defun print-sides (pa w j)
(let ((str ""))
(each ((i (range* 0 w)))
(if (memqual (- i 1)..j [pa i..j])
(set str `@str `)
(set str `@str| `)))
(put-line `@str|\n@str|`)))
(defun print-maze (pa w h)
(each ((j (range* 0 h)))
(print-tops pa w j)
(print-sides pa w j))
(print-tops pa w h))
(defun usage ()
(let ((invocation (ldiff *full-args* *args*)))
(put-line "usage: ")
(put-line `@invocation <width> <height> [<straightness>]`)
(put-line "straightness-factor is a percentage, defaulting to 15")
(exit 1)))
(let ((args [mapcar int-str *args*])
(*random-state* (make-random-state nil)))
(if (memq nil args)
(usage))
(tree-case args
((w h s ju . nk) (usage))
((w h : (s 15)) (set w (max 1 w))
(set h (max 1 h))
(print-maze (make-maze w h s) w h))
(else (usage))))