Commit | Line | Data |
---|---|---|
6594deb0 ER |
1 | ;;; life.el --- John Horton Conway's `Life' game for GNU Emacs |
2 | ||
80a677d9 JA |
3 | ;; Copyright (C) 1988 Free Software Foundation, Inc. |
4 | ;; Contributed by Kyle Jones, talos!kjones@uunet.uu.net | |
5 | ||
6 | ;; This file is part of GNU Emacs. | |
7 | ||
8 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
9 | ;; it under the terms of the GNU General Public License as published by | |
10 | ;; the Free Software Foundation; either version 1, or (at your option) | |
11 | ;; any later version. | |
12 | ||
13 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
14 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | ;; GNU General Public License for more details. | |
17 | ||
18 | ;; You should have received a copy of the GNU General Public License | |
19 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
20 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | ||
80a677d9 JA |
22 | (defconst life-patterns |
23 | [("@@@" " @@" "@@@") | |
24 | ("@@@ @@@" "@@ @@ " "@@@ @@@") | |
25 | ("@@@ @@@" "@@ @@" "@@@ @@@") | |
26 | ("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@") | |
27 | ("@@@@@@@@@@") | |
28 | (" @@@@@@@@@@ " | |
29 | " @@@@@@@@@@ " | |
30 | " @@@@@@@@@@ " | |
31 | "@@@@@@@@@@ " | |
32 | "@@@@@@@@@@ ") | |
33 | ("@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@") | |
34 | ("@ @" "@ @" "@ @" | |
35 | "@ @" "@ @" "@ @" | |
36 | "@ @" "@ @" "@ @" | |
37 | "@ @" "@ @" "@ @" | |
38 | "@ @" "@ @" "@ @") | |
39 | ("@@ " " @@ " " @@ " | |
40 | " @@ " " @@ " " @@ " | |
41 | " @@ " " @@ " " @@ " | |
42 | " @@ " " @@ " " @@ " | |
43 | " @@ " " @@ " " @@ " | |
44 | " @@") | |
45 | ("@@@@@@@@@" "@ @ @" "@ @@@@@ @" "@ @ @ @" "@@@ @@@" | |
46 | "@ @ @ @" "@ @@@@@ @" "@ @ @" "@@@@@@@@@")] | |
47 | "Vector of rectangles containing some Life startup patterns.") | |
48 | ||
49 | ;; Macros are used macros for manifest constants instead of variables | |
50 | ;; because the compiler will convert them to constants, which should | |
51 | ;; eval faster than symbols. | |
52 | ;; | |
53 | ;; The (require) wrapping forces the compiler to eval these macros at | |
54 | ;; compile time. This would not be necessary if we did not use macros | |
55 | ;; inside of macros, which the compiler doesn't seem to check for. | |
56 | ;; | |
57 | ;; Don't change any of the life-* macro constants unless you thoroughly | |
58 | ;; understand the `life-grim-reaper' function. | |
59 | (require | |
60 | (progn | |
61 | (defmacro life-life-char () ?@) | |
62 | (defmacro life-death-char () (1+ (life-life-char))) | |
63 | (defmacro life-birth-char () 3) | |
64 | (defmacro life-void-char () ?\ ) | |
65 | ||
66 | (defmacro life-life-string () (char-to-string (life-life-char))) | |
67 | (defmacro life-death-string () (char-to-string (life-death-char))) | |
68 | (defmacro life-birth-string () (char-to-string (life-birth-char))) | |
69 | (defmacro life-void-string () (char-to-string (life-void-char))) | |
70 | (defmacro life-not-void-regexp () (concat "[^" (life-void-string) "\n]")) | |
71 | ||
72 | ;; try to optimize the (goto-char (point-min)) & (goto-char (point-max)) | |
73 | ;; idioms. This depends on goto-char's not griping if we underrshoot | |
74 | ;; or overshoot beginning or end of buffer. | |
75 | (defmacro goto-beginning-of-buffer () '(goto-char 1)) | |
76 | (defmacro maxint () (lsh (lsh (lognot 0) 1) -1)) | |
77 | (defmacro goto-end-of-buffer () '(goto-char (maxint))) | |
78 | ||
79 | (defmacro increment (variable) (list 'setq variable (list '1+ variable))) | |
80 | 'life)) | |
81 | ||
82 | ;; list of numbers that tell how many characters to move to get to | |
83 | ;; each of a cell's eight neighbors. | |
84 | (defconst life-neighbor-deltas nil) | |
85 | ||
86 | ;; window display always starts here. Easier to deal with than | |
87 | ;; (scroll-up) and (scroll-down) when trying to center the display. | |
88 | (defconst life-window-start nil) | |
89 | ||
90 | ;; For mode line | |
91 | (defconst life-current-generation nil) | |
92 | ;; Sadly, mode-line-format won't display numbers. | |
93 | (defconst life-generation-string nil) | |
94 | ||
95 | (defun abs (n) (if (< n 0) (- n) n)) | |
96 | ||
97 | (defun life (&optional sleeptime) | |
98 | "Run Conway's Life simulation. | |
e3f99b91 JB |
99 | The starting pattern is randomly selected. Prefix arg (optional first |
100 | arg non-nil from a program) is the number of seconds to sleep between | |
80a677d9 JA |
101 | generations (this defaults to 1)." |
102 | (interactive "p") | |
103 | (or sleeptime (setq sleeptime 1)) | |
104 | (life-setup) | |
105 | (life-display-generation sleeptime) | |
106 | (while t | |
107 | (let ((inhibit-quit t)) | |
108 | (life-grim-reaper) | |
109 | (life-expand-plane-if-needed) | |
110 | (life-increment-generation) | |
111 | (life-display-generation sleeptime)))) | |
112 | ||
113 | (fset 'life-mode 'life) | |
114 | (put 'life-mode 'mode-class 'special) | |
115 | ||
116 | (random t) | |
117 | ||
118 | (defun life-setup () | |
119 | (let (n) | |
120 | (switch-to-buffer (get-buffer-create "*Life*") t) | |
121 | (erase-buffer) | |
122 | (kill-all-local-variables) | |
123 | (setq case-fold-search nil | |
124 | mode-name "Life" | |
125 | major-mode 'life-mode | |
126 | truncate-lines t | |
127 | life-current-generation 0 | |
128 | life-generation-string "0" | |
129 | mode-line-buffer-identification '("Life: generation " | |
130 | life-generation-string) | |
131 | fill-column (1- (window-width)) | |
132 | life-window-start 1) | |
133 | (buffer-disable-undo (current-buffer)) | |
134 | ;; stuff in the random pattern | |
135 | (life-insert-random-pattern) | |
136 | ;; make sure (life-life-char) is used throughout | |
137 | (goto-beginning-of-buffer) | |
138 | (while (re-search-forward (life-not-void-regexp) nil t) | |
139 | (replace-match (life-life-string) t t)) | |
140 | ;; center the pattern horizontally | |
141 | (goto-beginning-of-buffer) | |
142 | (setq n (/ (- fill-column (save-excursion (end-of-line) (point))) 2)) | |
143 | (while (not (eobp)) | |
144 | (indent-to n) | |
145 | (forward-line)) | |
146 | ;; center the pattern vertically | |
147 | (setq n (/ (- (1- (window-height)) | |
148 | (count-lines (point-min) (point-max))) | |
149 | 2)) | |
150 | (goto-beginning-of-buffer) | |
151 | (newline n) | |
152 | (goto-end-of-buffer) | |
153 | (newline n) | |
154 | ;; pad lines out to fill-column | |
155 | (goto-beginning-of-buffer) | |
156 | (while (not (eobp)) | |
157 | (end-of-line) | |
158 | (indent-to fill-column) | |
159 | (move-to-column fill-column) | |
160 | (delete-region (point) (progn (end-of-line) (point))) | |
161 | (forward-line)) | |
162 | ;; expand tabs to spaces | |
163 | (untabify (point-min) (point-max)) | |
164 | ;; before starting be sure the automaton has room to grow | |
165 | (life-expand-plane-if-needed) | |
166 | ;; compute initial neighbor deltas | |
167 | (life-compute-neighbor-deltas))) | |
168 | ||
169 | (defun life-compute-neighbor-deltas () | |
170 | (setq life-neighbor-deltas | |
171 | (list -1 (- fill-column) | |
172 | (- (1+ fill-column)) (- (+ 2 fill-column)) | |
173 | 1 fill-column (1+ fill-column) | |
174 | (+ 2 fill-column)))) | |
175 | ||
176 | (defun life-insert-random-pattern () | |
177 | (insert-rectangle | |
178 | (elt life-patterns (% (abs (random)) (length life-patterns)))) | |
179 | (insert ?\n)) | |
180 | ||
181 | (defun life-increment-generation () | |
182 | (increment life-current-generation) | |
183 | (setq life-generation-string (int-to-string life-current-generation))) | |
184 | ||
185 | (defun life-grim-reaper () | |
186 | ;; Clear the match information. Later we check to see if it | |
187 | ;; is still clear, if so then all the cells have died. | |
188 | (store-match-data nil) | |
189 | (goto-beginning-of-buffer) | |
190 | ;; For speed declare all local variable outside the loop. | |
191 | (let (point char pivot living-neighbors list) | |
192 | (while (search-forward (life-life-string) nil t) | |
193 | (setq list life-neighbor-deltas | |
194 | living-neighbors 0 | |
195 | pivot (1- (point))) | |
196 | (while list | |
197 | (setq point (+ pivot (car list)) | |
198 | char (char-after point)) | |
199 | (cond ((eq char (life-void-char)) | |
200 | (subst-char-in-region point (1+ point) | |
201 | (life-void-char) 1 t)) | |
202 | ((< char 3) | |
203 | (subst-char-in-region point (1+ point) char (1+ char) t)) | |
204 | ((< char 9) | |
205 | (subst-char-in-region point (1+ point) char 9 t)) | |
206 | ((>= char (life-life-char)) | |
207 | (increment living-neighbors))) | |
208 | (setq list (cdr list))) | |
209 | (if (memq living-neighbors '(2 3)) | |
210 | () | |
211 | (subst-char-in-region pivot (1+ pivot) | |
212 | (life-life-char) (life-death-char) t)))) | |
213 | (if (null (match-beginning 0)) | |
214 | (life-extinct-quit)) | |
215 | (subst-char-in-region 1 (point-max) 9 (life-void-char) t) | |
216 | (subst-char-in-region 1 (point-max) 1 (life-void-char) t) | |
217 | (subst-char-in-region 1 (point-max) 2 (life-void-char) t) | |
218 | (subst-char-in-region 1 (point-max) (life-birth-char) (life-life-char) t) | |
219 | (subst-char-in-region 1 (point-max) (life-death-char) (life-void-char) t)) | |
220 | ||
221 | (defun life-expand-plane-if-needed () | |
222 | (catch 'done | |
223 | (goto-beginning-of-buffer) | |
224 | (while (not (eobp)) | |
225 | ;; check for life at beginning or end of line. If found at | |
226 | ;; either end, expand at both ends, | |
227 | (cond ((or (eq (following-char) (life-life-char)) | |
228 | (eq (progn (end-of-line) (preceding-char)) (life-life-char))) | |
229 | (goto-beginning-of-buffer) | |
230 | (while (not (eobp)) | |
231 | (insert (life-void-char)) | |
232 | (end-of-line) | |
233 | (insert (life-void-char)) | |
234 | (forward-char)) | |
235 | (setq fill-column (+ 2 fill-column)) | |
236 | (scroll-left 1) | |
237 | (life-compute-neighbor-deltas) | |
238 | (throw 'done t))) | |
239 | (forward-line))) | |
240 | (goto-beginning-of-buffer) | |
241 | ;; check for life within the first two lines of the buffer. | |
242 | ;; If present insert two lifeless lines at the beginning.. | |
243 | (cond ((search-forward (life-life-string) | |
244 | (+ (point) fill-column fill-column 2) t) | |
245 | (goto-beginning-of-buffer) | |
246 | (insert-char (life-void-char) fill-column) | |
247 | (insert ?\n) | |
248 | (insert-char (life-void-char) fill-column) | |
249 | (insert ?\n) | |
250 | (setq life-window-start (+ life-window-start fill-column 1)))) | |
251 | (goto-end-of-buffer) | |
252 | ;; check for life within the last two lines of the buffer. | |
253 | ;; If present insert two lifeless lines at the end. | |
254 | (cond ((search-backward (life-life-string) | |
255 | (- (point) fill-column fill-column 2) t) | |
256 | (goto-end-of-buffer) | |
257 | (insert-char (life-void-char) fill-column) | |
258 | (insert ?\n) | |
259 | (insert-char (life-void-char) fill-column) | |
260 | (insert ?\n) | |
261 | (setq life-window-start (+ life-window-start fill-column 1))))) | |
262 | ||
263 | (defun life-display-generation (sleeptime) | |
264 | (goto-char life-window-start) | |
265 | (recenter 0) | |
266 | (sit-for sleeptime)) | |
267 | ||
268 | (defun life-extinct-quit () | |
269 | (life-display-generation 0) | |
270 | (signal 'life-extinct nil)) | |
271 | ||
272 | (put 'life-extinct 'error-conditions '(life-extinct quit)) | |
273 | (put 'life-extinct 'error-message "All life has perished") | |
49116ac0 JB |
274 | |
275 | (provide 'life) | |
276 | ||
6594deb0 | 277 | ;;; life.el ends here |