f1010613 |
1 | /* |
2 | * slant.c: Puzzle from nikoli.co.jp involving drawing a diagonal |
3 | * line through each square of a grid. |
4 | */ |
5 | |
6 | /* |
7 | * In this puzzle you have a grid of squares, each of which must |
8 | * contain a diagonal line; you also have clue numbers placed at |
9 | * _points_ of that grid, which means there's a (w+1) x (h+1) array |
10 | * of possible clue positions. |
11 | * |
12 | * I'm therefore going to adopt a rigid convention throughout this |
13 | * source file of using w and h for the dimensions of the grid of |
14 | * squares, and W and H for the dimensions of the grid of points. |
15 | * Thus, W == w+1 and H == h+1 always. |
16 | * |
17 | * Clue arrays will be W*H `signed char's, and the clue at each |
18 | * point will be a number from 0 to 4, or -1 if there's no clue. |
19 | * |
20 | * Solution arrays will be W*H `signed char's, and the number at |
21 | * each point will be +1 for a forward slash (/), -1 for a |
22 | * backslash (\), and 0 for unknown. |
23 | */ |
24 | |
25 | #include <stdio.h> |
26 | #include <stdlib.h> |
27 | #include <string.h> |
28 | #include <assert.h> |
29 | #include <ctype.h> |
30 | #include <math.h> |
31 | |
32 | #include "puzzles.h" |
33 | |
34 | enum { |
35 | COL_BACKGROUND, |
36 | COL_GRID, |
37 | COL_INK, |
e3478a4b |
38 | COL_SLANT1, |
39 | COL_SLANT2, |
9dc3c55b |
40 | COL_ERROR, |
f1010613 |
41 | NCOLOURS |
42 | }; |
43 | |
b926ba00 |
44 | /* |
45 | * In standalone solver mode, `verbose' is a variable which can be |
46 | * set by command-line option; in debugging mode it's simply always |
47 | * true. |
48 | */ |
49 | #if defined STANDALONE_SOLVER |
50 | #define SOLVER_DIAGNOSTICS |
51 | int verbose = FALSE; |
52 | #elif defined SOLVER_DIAGNOSTICS |
53 | #define verbose TRUE |
54 | #endif |
55 | |
56 | /* |
57 | * Difficulty levels. I do some macro ickery here to ensure that my |
58 | * enum and the various forms of my name list always match up. |
59 | */ |
60 | #define DIFFLIST(A) \ |
61 | A(EASY,Easy,e) \ |
62 | A(HARD,Hard,h) |
63 | #define ENUM(upper,title,lower) DIFF_ ## upper, |
64 | #define TITLE(upper,title,lower) #title, |
65 | #define ENCODE(upper,title,lower) #lower |
66 | #define CONFIG(upper,title,lower) ":" #title |
67 | enum { DIFFLIST(ENUM) DIFFCOUNT }; |
68 | static char const *const slant_diffnames[] = { DIFFLIST(TITLE) }; |
69 | static char const slant_diffchars[] = DIFFLIST(ENCODE); |
70 | #define DIFFCONFIG DIFFLIST(CONFIG) |
71 | |
f1010613 |
72 | struct game_params { |
b926ba00 |
73 | int w, h, diff; |
f1010613 |
74 | }; |
75 | |
76 | typedef struct game_clues { |
77 | int w, h; |
78 | signed char *clues; |
9dc3c55b |
79 | signed char *tmpsoln; |
f1010613 |
80 | int refcount; |
81 | } game_clues; |
82 | |
9dc3c55b |
83 | #define ERR_VERTEX 1 |
84 | #define ERR_SQUARE 2 |
85 | |
f1010613 |
86 | struct game_state { |
87 | struct game_params p; |
88 | game_clues *clues; |
89 | signed char *soln; |
9dc3c55b |
90 | unsigned char *errors; |
f1010613 |
91 | int completed; |
92 | int used_solve; /* used to suppress completion flash */ |
93 | }; |
94 | |
95 | static game_params *default_params(void) |
96 | { |
97 | game_params *ret = snew(game_params); |
98 | |
99 | ret->w = ret->h = 8; |
b926ba00 |
100 | ret->diff = DIFF_EASY; |
f1010613 |
101 | |
102 | return ret; |
103 | } |
104 | |
105 | static const struct game_params slant_presets[] = { |
b926ba00 |
106 | {5, 5, DIFF_EASY}, |
107 | {5, 5, DIFF_HARD}, |
108 | {8, 8, DIFF_EASY}, |
109 | {8, 8, DIFF_HARD}, |
110 | {12, 10, DIFF_EASY}, |
111 | {12, 10, DIFF_HARD}, |
f1010613 |
112 | }; |
113 | |
114 | static int game_fetch_preset(int i, char **name, game_params **params) |
115 | { |
116 | game_params *ret; |
117 | char str[80]; |
118 | |
119 | if (i < 0 || i >= lenof(slant_presets)) |
120 | return FALSE; |
121 | |
122 | ret = snew(game_params); |
123 | *ret = slant_presets[i]; |
124 | |
b926ba00 |
125 | sprintf(str, "%dx%d %s", ret->w, ret->h, slant_diffnames[ret->diff]); |
f1010613 |
126 | |
127 | *name = dupstr(str); |
128 | *params = ret; |
129 | return TRUE; |
130 | } |
131 | |
132 | static void free_params(game_params *params) |
133 | { |
134 | sfree(params); |
135 | } |
136 | |
137 | static game_params *dup_params(game_params *params) |
138 | { |
139 | game_params *ret = snew(game_params); |
140 | *ret = *params; /* structure copy */ |
141 | return ret; |
142 | } |
143 | |
144 | static void decode_params(game_params *ret, char const *string) |
145 | { |
146 | ret->w = ret->h = atoi(string); |
147 | while (*string && isdigit((unsigned char)*string)) string++; |
148 | if (*string == 'x') { |
149 | string++; |
150 | ret->h = atoi(string); |
b926ba00 |
151 | while (*string && isdigit((unsigned char)*string)) string++; |
152 | } |
153 | if (*string == 'd') { |
154 | int i; |
155 | string++; |
156 | for (i = 0; i < DIFFCOUNT; i++) |
157 | if (*string == slant_diffchars[i]) |
158 | ret->diff = i; |
159 | if (*string) string++; |
f1010613 |
160 | } |
161 | } |
162 | |
163 | static char *encode_params(game_params *params, int full) |
164 | { |
165 | char data[256]; |
166 | |
167 | sprintf(data, "%dx%d", params->w, params->h); |
b926ba00 |
168 | if (full) |
169 | sprintf(data + strlen(data), "d%c", slant_diffchars[params->diff]); |
f1010613 |
170 | |
171 | return dupstr(data); |
172 | } |
173 | |
174 | static config_item *game_configure(game_params *params) |
175 | { |
176 | config_item *ret; |
177 | char buf[80]; |
178 | |
15164c74 |
179 | ret = snewn(4, config_item); |
f1010613 |
180 | |
181 | ret[0].name = "Width"; |
182 | ret[0].type = C_STRING; |
183 | sprintf(buf, "%d", params->w); |
184 | ret[0].sval = dupstr(buf); |
185 | ret[0].ival = 0; |
186 | |
187 | ret[1].name = "Height"; |
188 | ret[1].type = C_STRING; |
189 | sprintf(buf, "%d", params->h); |
190 | ret[1].sval = dupstr(buf); |
191 | ret[1].ival = 0; |
192 | |
b926ba00 |
193 | ret[2].name = "Difficulty"; |
194 | ret[2].type = C_CHOICES; |
195 | ret[2].sval = DIFFCONFIG; |
196 | ret[2].ival = params->diff; |
197 | |
198 | ret[3].name = NULL; |
199 | ret[3].type = C_END; |
200 | ret[3].sval = NULL; |
201 | ret[3].ival = 0; |
f1010613 |
202 | |
203 | return ret; |
204 | } |
205 | |
206 | static game_params *custom_params(config_item *cfg) |
207 | { |
208 | game_params *ret = snew(game_params); |
209 | |
210 | ret->w = atoi(cfg[0].sval); |
211 | ret->h = atoi(cfg[1].sval); |
b926ba00 |
212 | ret->diff = cfg[2].ival; |
f1010613 |
213 | |
214 | return ret; |
215 | } |
216 | |
217 | static char *validate_params(game_params *params, int full) |
218 | { |
219 | /* |
220 | * (At least at the time of writing this comment) The grid |
221 | * generator is actually capable of handling even zero grid |
222 | * dimensions without crashing. Puzzles with a zero-area grid |
223 | * are a bit boring, though, because they're already solved :-) |
b926ba00 |
224 | * And puzzles with a dimension of 1 can't be made Hard, which |
225 | * means the simplest thing is to forbid them altogether. |
f1010613 |
226 | */ |
227 | |
b926ba00 |
228 | if (params->w < 2 || params->h < 2) |
229 | return "Width and height must both be at least two"; |
f1010613 |
230 | |
231 | return NULL; |
232 | } |
233 | |
234 | /* |
b926ba00 |
235 | * Scratch space for solver. |
f1010613 |
236 | */ |
b926ba00 |
237 | struct solver_scratch { |
238 | /* |
239 | * Disjoint set forest which tracks the connected sets of |
240 | * points. |
241 | */ |
242 | int *connected; |
f1010613 |
243 | |
b926ba00 |
244 | /* |
245 | * Counts the number of possible exits from each connected set |
246 | * of points. (That is, the number of possible _simultaneous_ |
247 | * exits: an unconnected point labelled 2 has an exit count of |
248 | * 2 even if all four possible edges are still under |
249 | * consideration.) |
250 | */ |
251 | int *exits; |
f1010613 |
252 | |
b926ba00 |
253 | /* |
254 | * Tracks whether each connected set of points includes a |
255 | * border point. |
256 | */ |
257 | unsigned char *border; |
f1010613 |
258 | |
b926ba00 |
259 | /* |
260 | * Another disjoint set forest. This one tracks _squares_ which |
261 | * are known to slant in the same direction. |
262 | */ |
263 | int *equiv; |
f1010613 |
264 | |
b926ba00 |
265 | /* |
266 | * Stores slash values which we know for an equivalence class. |
267 | * When we fill in a square, we set slashval[canonify(x)] to |
268 | * the same value as soln[x], so that we can then spot other |
269 | * squares equivalent to it and fill them in immediately via |
270 | * their known equivalence. |
271 | */ |
272 | signed char *slashval; |
273 | |
274 | /* |
275 | * Useful to have this information automatically passed to |
276 | * solver subroutines. (This pointer is not dynamically |
277 | * allocated by new_scratch and free_scratch.) |
278 | */ |
279 | const signed char *clues; |
f1010613 |
280 | }; |
281 | |
986cc2de |
282 | static struct solver_scratch *new_scratch(int w, int h) |
f1010613 |
283 | { |
284 | int W = w+1, H = h+1; |
285 | struct solver_scratch *ret = snew(struct solver_scratch); |
b926ba00 |
286 | ret->connected = snewn(W*H, int); |
287 | ret->exits = snewn(W*H, int); |
288 | ret->border = snewn(W*H, unsigned char); |
289 | ret->equiv = snewn(w*h, int); |
290 | ret->slashval = snewn(w*h, signed char); |
f1010613 |
291 | return ret; |
292 | } |
293 | |
986cc2de |
294 | static void free_scratch(struct solver_scratch *sc) |
f1010613 |
295 | { |
b926ba00 |
296 | sfree(sc->slashval); |
297 | sfree(sc->equiv); |
298 | sfree(sc->border); |
299 | sfree(sc->exits); |
300 | sfree(sc->connected); |
f1010613 |
301 | sfree(sc); |
302 | } |
303 | |
304 | /* |
b926ba00 |
305 | * Wrapper on dsf_merge() which updates the `exits' and `border' |
306 | * arrays. |
307 | */ |
308 | static void merge_vertices(int *connected, |
309 | struct solver_scratch *sc, int i, int j) |
310 | { |
311 | int exits = -1, border = FALSE; /* initialise to placate optimiser */ |
312 | |
313 | if (sc) { |
314 | i = dsf_canonify(connected, i); |
315 | j = dsf_canonify(connected, j); |
316 | |
317 | /* |
318 | * We have used one possible exit from each of the two |
319 | * classes. Thus, the viable exit count of the new class is |
320 | * the sum of the old exit counts minus two. |
321 | */ |
322 | exits = sc->exits[i] + sc->exits[j] - 2; |
323 | |
324 | border = sc->border[i] || sc->border[j]; |
325 | } |
326 | |
327 | dsf_merge(connected, i, j); |
328 | |
329 | if (sc) { |
330 | i = dsf_canonify(connected, i); |
331 | sc->exits[i] = exits; |
332 | sc->border[i] = border; |
333 | } |
334 | } |
335 | |
336 | /* |
337 | * Called when we have just blocked one way out of a particular |
338 | * point. If that point is a non-clue point (thus has a variable |
339 | * number of exits), we have therefore decreased its potential exit |
340 | * count, so we must decrement the exit count for the group as a |
341 | * whole. |
342 | */ |
343 | static void decr_exits(struct solver_scratch *sc, int i) |
344 | { |
345 | if (sc->clues[i] < 0) { |
346 | i = dsf_canonify(sc->connected, i); |
347 | sc->exits[i]--; |
348 | } |
349 | } |
350 | |
351 | static void fill_square(int w, int h, int x, int y, int v, |
352 | signed char *soln, |
353 | int *connected, struct solver_scratch *sc) |
354 | { |
355 | int W = w+1 /*, H = h+1 */; |
356 | |
357 | assert(x >= 0 && x < w && y >= 0 && y < h); |
358 | |
359 | if (soln[y*w+x] != 0) { |
360 | return; /* do nothing */ |
361 | } |
362 | |
363 | #ifdef SOLVER_DIAGNOSTICS |
364 | if (verbose) |
365 | printf(" placing %c in %d,%d\n", v == -1 ? '\\' : '/', x, y); |
366 | #endif |
367 | |
368 | soln[y*w+x] = v; |
369 | |
370 | if (sc) { |
371 | int c = dsf_canonify(sc->equiv, y*w+x); |
372 | sc->slashval[c] = v; |
373 | } |
374 | |
375 | if (v < 0) { |
376 | merge_vertices(connected, sc, y*W+x, (y+1)*W+(x+1)); |
377 | if (sc) { |
378 | decr_exits(sc, y*W+(x+1)); |
379 | decr_exits(sc, (y+1)*W+x); |
380 | } |
381 | } else { |
382 | merge_vertices(connected, sc, y*W+(x+1), (y+1)*W+x); |
383 | if (sc) { |
384 | decr_exits(sc, y*W+x); |
385 | decr_exits(sc, (y+1)*W+(x+1)); |
386 | } |
387 | } |
388 | } |
389 | |
390 | /* |
f1010613 |
391 | * Solver. Returns 0 for impossibility, 1 for success, 2 for |
392 | * ambiguity or failure to converge. |
393 | */ |
394 | static int slant_solve(int w, int h, const signed char *clues, |
b926ba00 |
395 | signed char *soln, struct solver_scratch *sc, |
396 | int difficulty) |
f1010613 |
397 | { |
398 | int W = w+1, H = h+1; |
b926ba00 |
399 | int x, y, i, j; |
f1010613 |
400 | int done_something; |
401 | |
402 | /* |
403 | * Clear the output. |
404 | */ |
405 | memset(soln, 0, w*h); |
406 | |
b926ba00 |
407 | sc->clues = clues; |
408 | |
f1010613 |
409 | /* |
410 | * Establish a disjoint set forest for tracking connectedness |
411 | * between grid points. |
412 | */ |
413 | for (i = 0; i < W*H; i++) |
b926ba00 |
414 | sc->connected[i] = i; /* initially all distinct */ |
415 | |
416 | /* |
417 | * Establish a disjoint set forest for tracking which squares |
418 | * are known to slant in the same direction. |
419 | */ |
420 | for (i = 0; i < w*h; i++) |
421 | sc->equiv[i] = i; /* initially all distinct */ |
422 | |
423 | /* |
424 | * Clear the slashval array. |
425 | */ |
426 | memset(sc->slashval, 0, w*h); |
427 | |
428 | /* |
429 | * Initialise the `exits' and `border' arrays. Theses is used |
430 | * to do second-order loop avoidance: the dual of the no loops |
431 | * constraint is that every point must be somehow connected to |
432 | * the border of the grid (otherwise there would be a solid |
433 | * loop around it which prevented this). |
434 | * |
435 | * I define a `dead end' to be a connected group of points |
436 | * which contains no border point, and which can form at most |
437 | * one new connection outside itself. Then I forbid placing an |
438 | * edge so that it connects together two dead-end groups, since |
439 | * this would yield a non-border-connected isolated subgraph |
440 | * with no further scope to extend it. |
441 | */ |
442 | for (y = 0; y < H; y++) |
443 | for (x = 0; x < W; x++) { |
444 | if (y == 0 || y == H-1 || x == 0 || x == W-1) |
445 | sc->border[y*W+x] = TRUE; |
446 | else |
447 | sc->border[y*W+x] = FALSE; |
448 | |
449 | if (clues[y*W+x] < 0) |
450 | sc->exits[y*W+x] = 4; |
451 | else |
452 | sc->exits[y*W+x] = clues[y*W+x]; |
453 | } |
454 | |
455 | /* |
456 | * Make a one-off preliminary pass over the grid looking for |
457 | * starting-point arrangements. The ones we need to spot are: |
458 | * |
459 | * - two adjacent 1s in the centre of the grid imply that each |
460 | * one's single line points towards the other. (If either 1 |
461 | * were connected on the far side, the two squares shared |
462 | * between the 1s would both link to the other 1 as a |
463 | * consequence of neither linking to the first.) Thus, we |
464 | * can fill in the four squares around them. |
465 | * |
466 | * - dually, two adjacent 3s imply that each one's _non_-line |
467 | * points towards the other. |
468 | * |
469 | * - if the pair of 1s and 3s is not _adjacent_ but is |
470 | * separated by one or more 2s, the reasoning still applies. |
471 | * |
472 | * This is more advanced than just spotting obvious starting |
473 | * squares such as central 4s and edge 2s, so we disable it on |
474 | * DIFF_EASY. |
475 | * |
476 | * (I don't like this loop; it feels grubby to me. My |
477 | * mathematical intuition feels there ought to be some more |
478 | * general deductive form which contains this loop as a special |
479 | * case, but I can't bring it to mind right now.) |
480 | */ |
481 | if (difficulty > DIFF_EASY) { |
482 | for (y = 1; y+1 < H; y++) |
483 | for (x = 1; x+1 < W; x++) { |
484 | int v = clues[y*W+x], s, x2, y2, dx, dy; |
485 | if (v != 1 && v != 3) |
486 | continue; |
487 | /* Slash value of the square up and left of (x,y). */ |
488 | s = (v == 1 ? +1 : -1); |
489 | |
490 | /* Look in each direction once. */ |
491 | for (dy = 0; dy < 2; dy++) { |
492 | dx = 1 - dy; |
493 | x2 = x+dx; |
494 | y2 = y+dy; |
495 | if (x2+1 >= W || y2+1 >= H) |
496 | continue; /* too close to the border */ |
497 | while (x2+dx+1 < W && y2+dy+1 < H && clues[y2*W+x2] == 2) |
498 | x2 += dx, y2 += dy; |
499 | if (clues[y2*W+x2] == v) { |
500 | #ifdef SOLVER_DIAGNOSTICS |
501 | if (verbose) |
502 | printf("found adjacent %ds at %d,%d and %d,%d\n", |
503 | v, x, y, x2, y2); |
504 | #endif |
505 | fill_square(w, h, x-1, y-1, s, soln, |
506 | sc->connected, sc); |
507 | fill_square(w, h, x-1+dy, y-1+dx, -s, soln, |
508 | sc->connected, sc); |
509 | fill_square(w, h, x2, y2, s, soln, |
510 | sc->connected, sc); |
511 | fill_square(w, h, x2-dy, y2-dx, -s, soln, |
512 | sc->connected, sc); |
513 | } |
514 | } |
515 | } |
516 | } |
f1010613 |
517 | |
518 | /* |
519 | * Repeatedly try to deduce something until we can't. |
520 | */ |
521 | do { |
522 | done_something = FALSE; |
523 | |
524 | /* |
525 | * Any clue point with the number of remaining lines equal |
526 | * to zero or to the number of remaining undecided |
527 | * neighbouring squares can be filled in completely. |
528 | */ |
529 | for (y = 0; y < H; y++) |
530 | for (x = 0; x < W; x++) { |
b926ba00 |
531 | struct { |
532 | int pos, slash; |
533 | } neighbours[4]; |
534 | int nneighbours; |
535 | int nu, nl, c, s, eq, eq2, last, meq, mj1, mj2; |
f1010613 |
536 | |
537 | if ((c = clues[y*W+x]) < 0) |
538 | continue; |
539 | |
540 | /* |
b926ba00 |
541 | * We have a clue point. Start by listing its |
542 | * neighbouring squares, in order around the point, |
543 | * together with the type of slash that would be |
544 | * required in that square to connect to the point. |
545 | */ |
546 | nneighbours = 0; |
547 | if (x > 0 && y > 0) { |
548 | neighbours[nneighbours].pos = (y-1)*w+(x-1); |
549 | neighbours[nneighbours].slash = -1; |
550 | nneighbours++; |
551 | } |
552 | if (x > 0 && y < h) { |
553 | neighbours[nneighbours].pos = y*w+(x-1); |
554 | neighbours[nneighbours].slash = +1; |
555 | nneighbours++; |
556 | } |
557 | if (x < w && y < h) { |
558 | neighbours[nneighbours].pos = y*w+x; |
559 | neighbours[nneighbours].slash = -1; |
560 | nneighbours++; |
561 | } |
562 | if (x < w && y > 0) { |
563 | neighbours[nneighbours].pos = (y-1)*w+x; |
564 | neighbours[nneighbours].slash = +1; |
565 | nneighbours++; |
566 | } |
567 | |
568 | /* |
569 | * Count up the number of undecided neighbours, and |
570 | * also the number of lines already present. |
571 | * |
572 | * If we're not on DIFF_EASY, then in this loop we |
573 | * also track whether we've seen two adjacent empty |
574 | * squares belonging to the same equivalence class |
575 | * (meaning they have the same type of slash). If |
576 | * so, we count them jointly as one line. |
f1010613 |
577 | */ |
578 | nu = 0; |
579 | nl = c; |
b926ba00 |
580 | last = neighbours[nneighbours-1].pos; |
581 | if (soln[last] == 0) |
582 | eq = dsf_canonify(sc->equiv, last); |
583 | else |
584 | eq = -1; |
585 | meq = mj1 = mj2 = -1; |
586 | for (i = 0; i < nneighbours; i++) { |
587 | j = neighbours[i].pos; |
588 | s = neighbours[i].slash; |
589 | if (soln[j] == 0) { |
590 | nu++; /* undecided */ |
591 | if (meq < 0 && difficulty > DIFF_EASY) { |
592 | eq2 = dsf_canonify(sc->equiv, j); |
593 | if (eq == eq2 && last != j) { |
594 | /* |
595 | * We've found an equivalent pair. |
596 | * Mark it. This also inhibits any |
597 | * further equivalence tracking |
598 | * around this square, since we can |
599 | * only handle one pair (and in |
600 | * particular we want to avoid |
601 | * being misled by two overlapping |
602 | * equivalence pairs). |
603 | */ |
604 | meq = eq; |
605 | mj1 = last; |
606 | mj2 = j; |
607 | nl--; /* count one line */ |
608 | nu -= 2; /* and lose two undecideds */ |
609 | } else |
610 | eq = eq2; |
611 | } |
612 | } else { |
613 | eq = -1; |
614 | if (soln[j] == s) |
615 | nl--; /* here's a line */ |
616 | } |
617 | last = j; |
618 | } |
f1010613 |
619 | |
620 | /* |
621 | * Check the counts. |
622 | */ |
623 | if (nl < 0 || nl > nu) { |
624 | /* |
625 | * No consistent value for this at all! |
626 | */ |
b926ba00 |
627 | #ifdef SOLVER_DIAGNOSTICS |
628 | if (verbose) |
629 | printf("need %d / %d lines around clue point at %d,%d!\n", |
630 | nl, nu, x, y); |
631 | #endif |
f1010613 |
632 | return 0; /* impossible */ |
633 | } |
634 | |
635 | if (nu > 0 && (nl == 0 || nl == nu)) { |
636 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
637 | if (verbose) { |
638 | if (meq >= 0) |
639 | printf("partially (since %d,%d == %d,%d) ", |
640 | mj1%w, mj1/w, mj2%w, mj2/w); |
641 | printf("%s around clue point at %d,%d\n", |
642 | nl ? "filling" : "emptying", x, y); |
643 | } |
f1010613 |
644 | #endif |
b926ba00 |
645 | for (i = 0; i < nneighbours; i++) { |
646 | j = neighbours[i].pos; |
647 | s = neighbours[i].slash; |
648 | if (soln[j] == 0 && j != mj1 && j != mj2) |
649 | fill_square(w, h, j%w, j/w, (nl ? s : -s), soln, |
650 | sc->connected, sc); |
651 | } |
f1010613 |
652 | |
653 | done_something = TRUE; |
b926ba00 |
654 | } else if (nu == 2 && nl == 1 && difficulty > DIFF_EASY) { |
655 | /* |
656 | * If we have precisely two undecided squares |
657 | * and precisely one line to place between |
658 | * them, _and_ those squares are adjacent, then |
659 | * we can mark them as equivalent to one |
660 | * another. |
661 | * |
662 | * This even applies if meq >= 0: if we have a |
663 | * 2 clue point and two of its neighbours are |
664 | * already marked equivalent, we can indeed |
665 | * mark the other two as equivalent. |
666 | * |
667 | * We don't bother with this on DIFF_EASY, |
668 | * since we wouldn't have used the results |
669 | * anyway. |
670 | */ |
671 | last = -1; |
672 | for (i = 0; i < nneighbours; i++) { |
673 | j = neighbours[i].pos; |
674 | if (soln[j] == 0 && j != mj1 && j != mj2) { |
675 | if (last < 0) |
676 | last = i; |
677 | else if (last == i-1 || (last == 0 && i == 3)) |
678 | break; /* found a pair */ |
679 | } |
680 | } |
681 | if (i < nneighbours) { |
682 | int sv1, sv2; |
683 | |
684 | assert(last >= 0); |
685 | /* |
686 | * neighbours[last] and neighbours[i] are |
687 | * the pair. Mark them equivalent. |
688 | */ |
689 | #ifdef SOLVER_DIAGNOSTICS |
690 | if (verbose) { |
691 | if (meq >= 0) |
692 | printf("since %d,%d == %d,%d, ", |
693 | mj1%w, mj1/w, mj2%w, mj2/w); |
694 | } |
695 | #endif |
696 | mj1 = neighbours[last].pos; |
697 | mj2 = neighbours[i].pos; |
698 | #ifdef SOLVER_DIAGNOSTICS |
699 | if (verbose) |
700 | printf("clue point at %d,%d implies %d,%d == %d," |
701 | "%d\n", x, y, mj1%w, mj1/w, mj2%w, mj2/w); |
702 | #endif |
703 | mj1 = dsf_canonify(sc->equiv, mj1); |
704 | sv1 = sc->slashval[mj1]; |
705 | mj2 = dsf_canonify(sc->equiv, mj2); |
706 | sv2 = sc->slashval[mj2]; |
707 | if (sv1 != 0 && sv2 != 0 && sv1 != sv2) { |
708 | #ifdef SOLVER_DIAGNOSTICS |
709 | if (verbose) |
710 | printf("merged two equivalence classes with" |
711 | " different slash values!\n"); |
712 | #endif |
713 | return 0; |
714 | } |
715 | sv1 = sv1 ? sv1 : sv2; |
716 | dsf_merge(sc->equiv, mj1, mj2); |
717 | mj1 = dsf_canonify(sc->equiv, mj1); |
718 | sc->slashval[mj1] = sv1; |
719 | } |
f1010613 |
720 | } |
721 | } |
722 | |
723 | if (done_something) |
724 | continue; |
725 | |
726 | /* |
727 | * Failing that, we now apply the second condition, which |
728 | * is that no square may be filled in such a way as to form |
b926ba00 |
729 | * a loop. Also in this loop (since it's over squares |
730 | * rather than points), we check slashval to see if we've |
731 | * already filled in another square in the same equivalence |
732 | * class. |
733 | * |
734 | * The slashval check is disabled on DIFF_EASY, as is dead |
735 | * end avoidance. Only _immediate_ loop avoidance remains. |
f1010613 |
736 | */ |
737 | for (y = 0; y < h; y++) |
738 | for (x = 0; x < w; x++) { |
b926ba00 |
739 | int fs, bs, v; |
740 | int c1, c2; |
741 | #ifdef SOLVER_DIAGNOSTICS |
742 | char *reason = "<internal error>"; |
743 | #endif |
f1010613 |
744 | |
745 | if (soln[y*w+x]) |
746 | continue; /* got this one already */ |
747 | |
b926ba00 |
748 | fs = FALSE; |
749 | bs = FALSE; |
750 | |
751 | if (difficulty > DIFF_EASY) |
752 | v = sc->slashval[dsf_canonify(sc->equiv, y*w+x)]; |
753 | else |
754 | v = 0; |
755 | |
756 | /* |
757 | * Try to rule out connectivity between (x,y) and |
758 | * (x+1,y+1); if successful, we will deduce that we |
759 | * must have a forward slash. |
760 | */ |
761 | c1 = dsf_canonify(sc->connected, y*W+x); |
762 | c2 = dsf_canonify(sc->connected, (y+1)*W+(x+1)); |
763 | if (c1 == c2) { |
764 | fs = TRUE; |
765 | #ifdef SOLVER_DIAGNOSTICS |
766 | reason = "simple loop avoidance"; |
767 | #endif |
768 | } |
769 | if (difficulty > DIFF_EASY && |
770 | !sc->border[c1] && !sc->border[c2] && |
771 | sc->exits[c1] <= 1 && sc->exits[c2] <= 1) { |
772 | fs = TRUE; |
773 | #ifdef SOLVER_DIAGNOSTICS |
774 | reason = "dead end avoidance"; |
775 | #endif |
776 | } |
777 | if (v == +1) { |
778 | fs = TRUE; |
779 | #ifdef SOLVER_DIAGNOSTICS |
780 | reason = "equivalence to an already filled square"; |
781 | #endif |
782 | } |
783 | |
784 | /* |
785 | * Now do the same between (x+1,y) and (x,y+1), to |
786 | * see if we are required to have a backslash. |
787 | */ |
788 | c1 = dsf_canonify(sc->connected, y*W+(x+1)); |
789 | c2 = dsf_canonify(sc->connected, (y+1)*W+x); |
790 | if (c1 == c2) { |
791 | bs = TRUE; |
792 | #ifdef SOLVER_DIAGNOSTICS |
793 | reason = "simple loop avoidance"; |
794 | #endif |
795 | } |
796 | if (difficulty > DIFF_EASY && |
797 | !sc->border[c1] && !sc->border[c2] && |
798 | sc->exits[c1] <= 1 && sc->exits[c2] <= 1) { |
799 | bs = TRUE; |
800 | #ifdef SOLVER_DIAGNOSTICS |
801 | reason = "dead end avoidance"; |
802 | #endif |
803 | } |
804 | if (v == -1) { |
805 | bs = TRUE; |
806 | #ifdef SOLVER_DIAGNOSTICS |
807 | reason = "equivalence to an already filled square"; |
808 | #endif |
809 | } |
f1010613 |
810 | |
811 | if (fs && bs) { |
812 | /* |
b926ba00 |
813 | * No consistent value for this at all! |
f1010613 |
814 | */ |
b926ba00 |
815 | #ifdef SOLVER_DIAGNOSTICS |
816 | if (verbose) |
817 | printf("%d,%d has no consistent slash!\n", x, y); |
818 | #endif |
f1010613 |
819 | return 0; /* impossible */ |
820 | } |
821 | |
822 | if (fs) { |
f1010613 |
823 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
824 | if (verbose) |
825 | printf("employing %s\n", reason); |
f1010613 |
826 | #endif |
b926ba00 |
827 | fill_square(w, h, x, y, +1, soln, sc->connected, sc); |
f1010613 |
828 | done_something = TRUE; |
829 | } else if (bs) { |
f1010613 |
830 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
831 | if (verbose) |
832 | printf("employing %s\n", reason); |
f1010613 |
833 | #endif |
b926ba00 |
834 | fill_square(w, h, x, y, -1, soln, sc->connected, sc); |
f1010613 |
835 | done_something = TRUE; |
836 | } |
837 | } |
838 | |
839 | } while (done_something); |
840 | |
841 | /* |
842 | * Solver can make no more progress. See if the grid is full. |
843 | */ |
844 | for (i = 0; i < w*h; i++) |
845 | if (!soln[i]) |
846 | return 2; /* failed to converge */ |
847 | return 1; /* success */ |
848 | } |
849 | |
850 | /* |
851 | * Filled-grid generator. |
852 | */ |
853 | static void slant_generate(int w, int h, signed char *soln, random_state *rs) |
854 | { |
855 | int W = w+1, H = h+1; |
856 | int x, y, i; |
b926ba00 |
857 | int *connected, *indices; |
f1010613 |
858 | |
859 | /* |
860 | * Clear the output. |
861 | */ |
862 | memset(soln, 0, w*h); |
863 | |
864 | /* |
865 | * Establish a disjoint set forest for tracking connectedness |
866 | * between grid points. |
867 | */ |
b926ba00 |
868 | connected = snewn(W*H, int); |
f1010613 |
869 | for (i = 0; i < W*H; i++) |
b926ba00 |
870 | connected[i] = i; /* initially all distinct */ |
f1010613 |
871 | |
872 | /* |
873 | * Prepare a list of the squares in the grid, and fill them in |
874 | * in a random order. |
875 | */ |
876 | indices = snewn(w*h, int); |
877 | for (i = 0; i < w*h; i++) |
878 | indices[i] = i; |
879 | shuffle(indices, w*h, sizeof(*indices), rs); |
880 | |
881 | /* |
882 | * Fill in each one in turn. |
883 | */ |
884 | for (i = 0; i < w*h; i++) { |
885 | int fs, bs, v; |
886 | |
887 | y = indices[i] / w; |
888 | x = indices[i] % w; |
889 | |
b926ba00 |
890 | fs = (dsf_canonify(connected, y*W+x) == |
891 | dsf_canonify(connected, (y+1)*W+(x+1))); |
892 | bs = (dsf_canonify(connected, (y+1)*W+x) == |
893 | dsf_canonify(connected, y*W+(x+1))); |
f1010613 |
894 | |
895 | /* |
896 | * It isn't possible to get into a situation where we |
897 | * aren't allowed to place _either_ type of slash in a |
b926ba00 |
898 | * square. Thus, filled-grid generation never has to |
899 | * backtrack. |
f1010613 |
900 | * |
901 | * Proof (thanks to Gareth Taylor): |
902 | * |
903 | * If it were possible, it would have to be because there |
904 | * was an existing path (not using this square) between the |
905 | * top-left and bottom-right corners of this square, and |
906 | * another between the other two. These two paths would |
907 | * have to cross at some point. |
908 | * |
909 | * Obviously they can't cross in the middle of a square, so |
910 | * they must cross by sharing a point in common. But this |
911 | * isn't possible either: if you chessboard-colour all the |
912 | * points on the grid, you find that any continuous |
913 | * diagonal path is entirely composed of points of the same |
914 | * colour. And one of our two hypothetical paths is between |
915 | * two black points, and the other is between two white |
916 | * points - therefore they can have no point in common. [] |
917 | */ |
918 | assert(!(fs && bs)); |
919 | |
920 | v = fs ? +1 : bs ? -1 : 2 * random_upto(rs, 2) - 1; |
b926ba00 |
921 | fill_square(w, h, x, y, v, soln, connected, NULL); |
f1010613 |
922 | } |
923 | |
924 | sfree(indices); |
b926ba00 |
925 | sfree(connected); |
f1010613 |
926 | } |
927 | |
928 | static char *new_game_desc(game_params *params, random_state *rs, |
929 | char **aux, int interactive) |
930 | { |
931 | int w = params->w, h = params->h, W = w+1, H = h+1; |
932 | signed char *soln, *tmpsoln, *clues; |
933 | int *clueindices; |
934 | struct solver_scratch *sc; |
b926ba00 |
935 | int x, y, v, i, j; |
f1010613 |
936 | char *desc; |
937 | |
938 | soln = snewn(w*h, signed char); |
939 | tmpsoln = snewn(w*h, signed char); |
940 | clues = snewn(W*H, signed char); |
941 | clueindices = snewn(W*H, int); |
942 | sc = new_scratch(w, h); |
943 | |
944 | do { |
945 | /* |
946 | * Create the filled grid. |
947 | */ |
948 | slant_generate(w, h, soln, rs); |
949 | |
950 | /* |
951 | * Fill in the complete set of clues. |
952 | */ |
953 | for (y = 0; y < H; y++) |
954 | for (x = 0; x < W; x++) { |
955 | v = 0; |
956 | |
957 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == -1) v++; |
958 | if (x > 0 && y < h && soln[y*w+(x-1)] == +1) v++; |
959 | if (x < w && y > 0 && soln[(y-1)*w+x] == +1) v++; |
960 | if (x < w && y < h && soln[y*w+x] == -1) v++; |
961 | |
962 | clues[y*W+x] = v; |
963 | } |
f1010613 |
964 | |
b926ba00 |
965 | /* |
966 | * With all clue points filled in, all puzzles are easy: we can |
967 | * simply process the clue points in lexicographic order, and |
968 | * at each clue point we will always have at most one square |
969 | * undecided, which we can then fill in uniquely. |
970 | */ |
971 | assert(slant_solve(w, h, clues, tmpsoln, sc, DIFF_EASY) == 1); |
972 | |
973 | /* |
974 | * Remove as many clues as possible while retaining solubility. |
975 | * |
976 | * In DIFF_HARD mode, we prioritise the removal of obvious |
977 | * starting points (4s, 0s, border 2s and corner 1s), on |
978 | * the grounds that having as few of these as possible |
979 | * seems like a good thing. In particular, we can often get |
980 | * away without _any_ completely obvious starting points, |
981 | * which is even better. |
982 | */ |
983 | for (i = 0; i < W*H; i++) |
984 | clueindices[i] = i; |
985 | shuffle(clueindices, W*H, sizeof(*clueindices), rs); |
986 | for (j = 0; j < 2; j++) { |
987 | for (i = 0; i < W*H; i++) { |
988 | int pass, yb, xb; |
989 | |
990 | y = clueindices[i] / W; |
991 | x = clueindices[i] % W; |
992 | v = clues[y*W+x]; |
993 | |
994 | /* |
995 | * Identify which pass we should process this point |
996 | * in. If it's an obvious start point, _or_ we're |
997 | * in DIFF_EASY, then it goes in pass 0; otherwise |
998 | * pass 1. |
999 | */ |
1000 | xb = (x == 0 || x == W-1); |
1001 | yb = (y == 0 || y == H-1); |
1002 | if (params->diff == DIFF_EASY || v == 4 || v == 0 || |
1003 | (v == 2 && (xb||yb)) || (v == 1 && xb && yb)) |
1004 | pass = 0; |
1005 | else |
1006 | pass = 1; |
1007 | |
1008 | if (pass == j) { |
1009 | clues[y*W+x] = -1; |
1010 | if (slant_solve(w, h, clues, tmpsoln, sc, |
1011 | params->diff) != 1) |
1012 | clues[y*W+x] = v; /* put it back */ |
1013 | } |
1014 | } |
1015 | } |
1016 | |
1017 | /* |
1018 | * And finally, verify that the grid is of _at least_ the |
1019 | * requested difficulty, by running the solver one level |
1020 | * down and verifying that it can't manage it. |
1021 | */ |
1022 | } while (params->diff > 0 && |
1023 | slant_solve(w, h, clues, tmpsoln, sc, params->diff - 1) <= 1); |
f1010613 |
1024 | |
1025 | /* |
1026 | * Now we have the clue set as it will be presented to the |
1027 | * user. Encode it in a game desc. |
1028 | */ |
1029 | { |
1030 | char *p; |
1031 | int run, i; |
1032 | |
1033 | desc = snewn(W*H+1, char); |
1034 | p = desc; |
1035 | run = 0; |
1036 | for (i = 0; i <= W*H; i++) { |
1037 | int n = (i < W*H ? clues[i] : -2); |
1038 | |
1039 | if (n == -1) |
1040 | run++; |
1041 | else { |
1042 | if (run) { |
1043 | while (run > 0) { |
1044 | int c = 'a' - 1 + run; |
1045 | if (run > 26) |
1046 | c = 'z'; |
1047 | *p++ = c; |
1048 | run -= c - ('a' - 1); |
1049 | } |
1050 | } |
1051 | if (n >= 0) |
1052 | *p++ = '0' + n; |
1053 | run = 0; |
1054 | } |
1055 | } |
1056 | assert(p - desc <= W*H); |
1057 | *p++ = '\0'; |
1058 | desc = sresize(desc, p - desc, char); |
1059 | } |
1060 | |
1061 | /* |
1062 | * Encode the solution as an aux_info. |
1063 | */ |
1064 | { |
1065 | char *auxbuf; |
1066 | *aux = auxbuf = snewn(w*h+1, char); |
1067 | for (i = 0; i < w*h; i++) |
1068 | auxbuf[i] = soln[i] < 0 ? '\\' : '/'; |
1069 | auxbuf[w*h] = '\0'; |
1070 | } |
1071 | |
1072 | free_scratch(sc); |
1073 | sfree(clueindices); |
1074 | sfree(clues); |
1075 | sfree(tmpsoln); |
1076 | sfree(soln); |
1077 | |
1078 | return desc; |
1079 | } |
1080 | |
1081 | static char *validate_desc(game_params *params, char *desc) |
1082 | { |
1083 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1084 | int area = W*H; |
1085 | int squares = 0; |
1086 | |
1087 | while (*desc) { |
1088 | int n = *desc++; |
1089 | if (n >= 'a' && n <= 'z') { |
1090 | squares += n - 'a' + 1; |
1091 | } else if (n >= '0' && n <= '4') { |
1092 | squares++; |
1093 | } else |
1094 | return "Invalid character in game description"; |
1095 | } |
1096 | |
1097 | if (squares < area) |
1098 | return "Not enough data to fill grid"; |
1099 | |
1100 | if (squares > area) |
1101 | return "Too much data to fit in grid"; |
1102 | |
1103 | return NULL; |
1104 | } |
1105 | |
dafd6cf6 |
1106 | static game_state *new_game(midend *me, game_params *params, char *desc) |
f1010613 |
1107 | { |
1108 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1109 | game_state *state = snew(game_state); |
1110 | int area = W*H; |
1111 | int squares = 0; |
1112 | |
1113 | state->p = *params; |
1114 | state->soln = snewn(w*h, signed char); |
1115 | memset(state->soln, 0, w*h); |
1116 | state->completed = state->used_solve = FALSE; |
9dc3c55b |
1117 | state->errors = snewn(W*H, unsigned char); |
1118 | memset(state->errors, 0, W*H); |
f1010613 |
1119 | |
1120 | state->clues = snew(game_clues); |
1121 | state->clues->w = w; |
1122 | state->clues->h = h; |
1123 | state->clues->clues = snewn(W*H, signed char); |
1124 | state->clues->refcount = 1; |
9dc3c55b |
1125 | state->clues->tmpsoln = snewn(w*h, signed char); |
f1010613 |
1126 | memset(state->clues->clues, -1, W*H); |
1127 | while (*desc) { |
1128 | int n = *desc++; |
1129 | if (n >= 'a' && n <= 'z') { |
1130 | squares += n - 'a' + 1; |
1131 | } else if (n >= '0' && n <= '4') { |
1132 | state->clues->clues[squares++] = n - '0'; |
1133 | } else |
1134 | assert(!"can't get here"); |
1135 | } |
1136 | assert(squares == area); |
1137 | |
1138 | return state; |
1139 | } |
1140 | |
1141 | static game_state *dup_game(game_state *state) |
1142 | { |
9dc3c55b |
1143 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1144 | game_state *ret = snew(game_state); |
1145 | |
1146 | ret->p = state->p; |
1147 | ret->clues = state->clues; |
1148 | ret->clues->refcount++; |
1149 | ret->completed = state->completed; |
1150 | ret->used_solve = state->used_solve; |
1151 | |
1152 | ret->soln = snewn(w*h, signed char); |
1153 | memcpy(ret->soln, state->soln, w*h); |
1154 | |
9dc3c55b |
1155 | ret->errors = snewn(W*H, unsigned char); |
1156 | memcpy(ret->errors, state->errors, W*H); |
1157 | |
f1010613 |
1158 | return ret; |
1159 | } |
1160 | |
1161 | static void free_game(game_state *state) |
1162 | { |
9dc3c55b |
1163 | sfree(state->errors); |
986cc2de |
1164 | sfree(state->soln); |
1165 | assert(state->clues); |
1166 | if (--state->clues->refcount <= 0) { |
1167 | sfree(state->clues->clues); |
9dc3c55b |
1168 | sfree(state->clues->tmpsoln); |
986cc2de |
1169 | sfree(state->clues); |
1170 | } |
f1010613 |
1171 | sfree(state); |
1172 | } |
1173 | |
9dc3c55b |
1174 | /* |
1175 | * Utility function to return the current degree of a vertex. If |
1176 | * `anti' is set, it returns the number of filled-in edges |
1177 | * surrounding the point which _don't_ connect to it; thus 4 minus |
1178 | * its anti-degree is the maximum degree it could have if all the |
1179 | * empty spaces around it were filled in. |
1180 | * |
1181 | * (Yes, _4_ minus its anti-degree even if it's a border vertex.) |
1182 | * |
1183 | * If ret > 0, *sx and *sy are set to the coordinates of one of the |
1184 | * squares that contributed to it. |
1185 | */ |
1186 | static int vertex_degree(int w, int h, signed char *soln, int x, int y, |
1187 | int anti, int *sx, int *sy) |
1188 | { |
1189 | int ret = 0; |
1190 | |
1191 | assert(x >= 0 && x <= w && y >= 0 && y <= h); |
1192 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] - anti < 0) { |
1193 | if (sx) *sx = x-1; |
1194 | if (sy) *sy = y-1; |
1195 | ret++; |
1196 | } |
1197 | if (x > 0 && y < h && soln[y*w+(x-1)] + anti > 0) { |
1198 | if (sx) *sx = x-1; |
1199 | if (sy) *sy = y; |
1200 | ret++; |
1201 | } |
1202 | if (x < w && y > 0 && soln[(y-1)*w+x] + anti > 0) { |
1203 | if (sx) *sx = x; |
1204 | if (sy) *sy = y-1; |
1205 | ret++; |
1206 | } |
1207 | if (x < w && y < h && soln[y*w+x] - anti < 0) { |
1208 | if (sx) *sx = x; |
1209 | if (sy) *sy = y; |
1210 | ret++; |
1211 | } |
1212 | |
1213 | return anti ? 4 - ret : ret; |
1214 | } |
1215 | |
f1010613 |
1216 | static int check_completion(game_state *state) |
1217 | { |
1218 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
9dc3c55b |
1219 | int x, y, err = FALSE; |
1220 | signed char *ts; |
1221 | |
1222 | memset(state->errors, 0, W*H); |
f1010613 |
1223 | |
1224 | /* |
9dc3c55b |
1225 | * An easy way to do loop checking would be by means of the |
1226 | * same dsf technique we've used elsewhere (loop over all edges |
1227 | * in the grid, joining vertices together into equivalence |
1228 | * classes when connected by an edge, and raise the alarm when |
1229 | * an edge joins two already-equivalent vertices). However, a |
1230 | * better approach is to repeatedly remove the single edge |
1231 | * connecting to any degree-1 vertex, and then see if there are |
1232 | * any edges left over; if so, precisely those edges are part |
1233 | * of loops, which means we can highlight them as errors for |
1234 | * the user. |
1235 | * |
1236 | * We use the `tmpsoln' scratch space in the shared clues |
1237 | * structure, to avoid mallocing too often. |
f1010613 |
1238 | */ |
9dc3c55b |
1239 | ts = state->clues->tmpsoln; |
1240 | memcpy(ts, state->soln, w*h); |
1241 | for (y = 0; y < H; y++) |
1242 | for (x = 0; x < W; x++) { |
1243 | int vx = x, vy = y; |
1244 | int sx, sy; |
1245 | /* |
1246 | * Every time we disconnect a vertex like this, there |
1247 | * is precisely one other vertex which might have |
1248 | * become degree 1; so we follow the trail as far as it |
1249 | * leads. This ensures that we don't have to make more |
1250 | * than one loop over the grid, because whenever a |
1251 | * degree-1 vertex comes into existence somewhere we've |
1252 | * already looked, we immediately remove it again. |
1253 | * Hence one loop over the grid is adequate; and |
1254 | * moreover, this algorithm visits every vertex at most |
1255 | * twice (once in the loop and possibly once more as a |
1256 | * result of following a trail) so it has linear time |
1257 | * in the area of the grid. |
1258 | */ |
1259 | while (vertex_degree(w, h, ts, vx, vy, FALSE, &sx, &sy) == 1) { |
1260 | ts[sy*w+sx] = 0; |
1261 | vx = vx + 1 + (sx - vx) * 2; |
1262 | vy = vy + 1 + (sy - vy) * 2; |
1263 | } |
1264 | } |
f1010613 |
1265 | |
1266 | /* |
9dc3c55b |
1267 | * Now mark any remaining edges with ERR_SQUARE. |
f1010613 |
1268 | */ |
1269 | for (y = 0; y < h; y++) |
9dc3c55b |
1270 | for (x = 0; x < w; x++) |
1271 | if (ts[y*w+x]) { |
1272 | state->errors[y*W+x] |= ERR_SQUARE; |
1273 | err = TRUE; |
1274 | } |
f1010613 |
1275 | |
1276 | /* |
9dc3c55b |
1277 | * Now go through and check the degree of each clue vertex, and |
1278 | * mark it with ERR_VERTEX if it cannot be fulfilled. |
f1010613 |
1279 | */ |
1280 | for (y = 0; y < H; y++) |
9dc3c55b |
1281 | for (x = 0; x < W; x++) { |
1282 | int c; |
f1010613 |
1283 | |
1284 | if ((c = state->clues->clues[y*W+x]) < 0) |
1285 | continue; |
1286 | |
9dc3c55b |
1287 | /* |
1288 | * Check to see if there are too many connections to |
1289 | * this vertex _or_ too many non-connections. Either is |
1290 | * grounds for marking the vertex as erroneous. |
1291 | */ |
1292 | if (vertex_degree(w, h, state->soln, x, y, |
1293 | FALSE, NULL, NULL) > c || |
1294 | vertex_degree(w, h, state->soln, x, y, |
1295 | TRUE, NULL, NULL) > 4-c) { |
1296 | state->errors[y*W+x] |= ERR_VERTEX; |
1297 | err = TRUE; |
1298 | } |
1299 | } |
1300 | |
1301 | /* |
1302 | * Now our actual victory condition is that (a) none of the |
1303 | * above code marked anything as erroneous, and (b) every |
1304 | * square has an edge in it. |
1305 | */ |
f1010613 |
1306 | |
9dc3c55b |
1307 | if (err) |
1308 | return FALSE; |
f1010613 |
1309 | |
9dc3c55b |
1310 | for (y = 0; y < h; y++) |
1311 | for (x = 0; x < w; x++) |
1312 | if (state->soln[y*w+x] == 0) |
f1010613 |
1313 | return FALSE; |
f1010613 |
1314 | |
1315 | return TRUE; |
1316 | } |
1317 | |
1318 | static char *solve_game(game_state *state, game_state *currstate, |
1319 | char *aux, char **error) |
1320 | { |
1321 | int w = state->p.w, h = state->p.h; |
1322 | signed char *soln; |
1323 | int bs, ret; |
1324 | int free_soln = FALSE; |
1325 | char *move, buf[80]; |
1326 | int movelen, movesize; |
1327 | int x, y; |
1328 | |
1329 | if (aux) { |
1330 | /* |
1331 | * If we already have the solution, save ourselves some |
1332 | * time. |
1333 | */ |
1334 | soln = (signed char *)aux; |
1335 | bs = (signed char)'\\'; |
1336 | free_soln = FALSE; |
1337 | } else { |
1338 | struct solver_scratch *sc = new_scratch(w, h); |
1339 | soln = snewn(w*h, signed char); |
1340 | bs = -1; |
b926ba00 |
1341 | ret = slant_solve(w, h, state->clues->clues, soln, sc, DIFF_HARD); |
f1010613 |
1342 | free_scratch(sc); |
1343 | if (ret != 1) { |
1344 | sfree(soln); |
1345 | if (ret == 0) |
8349ac38 |
1346 | *error = "This puzzle is not self-consistent"; |
f1010613 |
1347 | else |
8349ac38 |
1348 | *error = "Unable to find a unique solution for this puzzle"; |
1349 | return NULL; |
f1010613 |
1350 | } |
1351 | free_soln = TRUE; |
1352 | } |
1353 | |
1354 | /* |
1355 | * Construct a move string which turns the current state into |
1356 | * the solved state. |
1357 | */ |
1358 | movesize = 256; |
1359 | move = snewn(movesize, char); |
1360 | movelen = 0; |
1361 | move[movelen++] = 'S'; |
1362 | move[movelen] = '\0'; |
1363 | for (y = 0; y < h; y++) |
1364 | for (x = 0; x < w; x++) { |
1365 | int v = (soln[y*w+x] == bs ? -1 : +1); |
1366 | if (state->soln[y*w+x] != v) { |
986cc2de |
1367 | int len = sprintf(buf, ";%c%d,%d", (int)(v < 0 ? '\\' : '/'), x, y); |
f1010613 |
1368 | if (movelen + len >= movesize) { |
1369 | movesize = movelen + len + 256; |
1370 | move = sresize(move, movesize, char); |
1371 | } |
1372 | strcpy(move + movelen, buf); |
1373 | movelen += len; |
1374 | } |
1375 | } |
1376 | |
1377 | if (free_soln) |
1378 | sfree(soln); |
1379 | |
1380 | return move; |
1381 | } |
1382 | |
1383 | static char *game_text_format(game_state *state) |
1384 | { |
1385 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
1386 | int x, y, len; |
1387 | char *ret, *p; |
1388 | |
1389 | /* |
1390 | * There are h+H rows of w+W columns. |
1391 | */ |
1392 | len = (h+H) * (w+W+1) + 1; |
1393 | ret = snewn(len, char); |
1394 | p = ret; |
1395 | |
1396 | for (y = 0; y < H; y++) { |
1397 | for (x = 0; x < W; x++) { |
1398 | if (state->clues->clues[y*W+x] >= 0) |
1399 | *p++ = state->clues->clues[y*W+x] + '0'; |
1400 | else |
1401 | *p++ = '+'; |
1402 | if (x < w) |
1403 | *p++ = '-'; |
1404 | } |
1405 | *p++ = '\n'; |
1406 | if (y < h) { |
1407 | for (x = 0; x < W; x++) { |
1408 | *p++ = '|'; |
1409 | if (x < w) { |
1410 | if (state->soln[y*w+x] != 0) |
1411 | *p++ = (state->soln[y*w+x] < 0 ? '\\' : '/'); |
1412 | else |
1413 | *p++ = ' '; |
1414 | } |
1415 | } |
1416 | *p++ = '\n'; |
1417 | } |
1418 | } |
1419 | *p++ = '\0'; |
1420 | |
1421 | assert(p - ret == len); |
1422 | return ret; |
1423 | } |
1424 | |
1425 | static game_ui *new_ui(game_state *state) |
1426 | { |
1427 | return NULL; |
1428 | } |
1429 | |
1430 | static void free_ui(game_ui *ui) |
1431 | { |
1432 | } |
1433 | |
1434 | static char *encode_ui(game_ui *ui) |
1435 | { |
1436 | return NULL; |
1437 | } |
1438 | |
1439 | static void decode_ui(game_ui *ui, char *encoding) |
1440 | { |
1441 | } |
1442 | |
1443 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
1444 | game_state *newstate) |
1445 | { |
1446 | } |
1447 | |
1448 | #define PREFERRED_TILESIZE 32 |
1449 | #define TILESIZE (ds->tilesize) |
1450 | #define BORDER TILESIZE |
1451 | #define CLUE_RADIUS (TILESIZE / 3) |
1452 | #define CLUE_TEXTSIZE (TILESIZE / 2) |
1453 | #define COORD(x) ( (x) * TILESIZE + BORDER ) |
1454 | #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 ) |
1455 | |
1456 | #define FLASH_TIME 0.30F |
1457 | |
1458 | /* |
1459 | * Bit fields in the `grid' and `todraw' elements of the drawstate. |
1460 | */ |
9dc3c55b |
1461 | #define BACKSLASH 0x00000001L |
1462 | #define FORWSLASH 0x00000002L |
1463 | #define L_T 0x00000004L |
1464 | #define ERR_L_T 0x00000008L |
1465 | #define L_B 0x00000010L |
1466 | #define ERR_L_B 0x00000020L |
1467 | #define T_L 0x00000040L |
1468 | #define ERR_T_L 0x00000080L |
1469 | #define T_R 0x00000100L |
1470 | #define ERR_T_R 0x00000200L |
1471 | #define C_TL 0x00000400L |
1472 | #define ERR_C_TL 0x00000800L |
1473 | #define FLASH 0x00001000L |
1474 | #define ERRSLASH 0x00002000L |
1475 | #define ERR_TL 0x00004000L |
1476 | #define ERR_TR 0x00008000L |
1477 | #define ERR_BL 0x00010000L |
1478 | #define ERR_BR 0x00020000L |
f1010613 |
1479 | |
1480 | struct game_drawstate { |
1481 | int tilesize; |
1482 | int started; |
9dc3c55b |
1483 | long *grid; |
1484 | long *todraw; |
f1010613 |
1485 | }; |
1486 | |
1487 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
1488 | int x, int y, int button) |
1489 | { |
1490 | int w = state->p.w, h = state->p.h; |
1491 | |
1492 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
1493 | int v; |
1494 | char buf[80]; |
1495 | |
68bf6206 |
1496 | /* |
1497 | * This is an utterly awful hack which I should really sort out |
1498 | * by means of a proper configuration mechanism. One Slant |
1499 | * player has observed that they prefer the mouse buttons to |
1500 | * function exactly the opposite way round, so here's a |
1501 | * mechanism for environment-based configuration. I cache the |
1502 | * result in a global variable - yuck! - to avoid repeated |
1503 | * lookups. |
1504 | */ |
1505 | { |
1506 | static int swap_buttons = -1; |
1507 | if (swap_buttons < 0) { |
1508 | char *env = getenv("SLANT_SWAP_BUTTONS"); |
1509 | swap_buttons = (env && (env[0] == 'y' || env[0] == 'Y')); |
1510 | } |
1511 | if (swap_buttons) { |
1512 | if (button == LEFT_BUTTON) |
1513 | button = RIGHT_BUTTON; |
1514 | else |
1515 | button = LEFT_BUTTON; |
1516 | } |
1517 | } |
1518 | |
f1010613 |
1519 | x = FROMCOORD(x); |
1520 | y = FROMCOORD(y); |
1521 | if (x < 0 || y < 0 || x >= w || y >= h) |
1522 | return NULL; |
1523 | |
1524 | if (button == LEFT_BUTTON) { |
1525 | /* |
1526 | * Left-clicking cycles blank -> \ -> / -> blank. |
1527 | */ |
1528 | v = state->soln[y*w+x] - 1; |
1529 | if (v == -2) |
1530 | v = +1; |
1531 | } else { |
1532 | /* |
1533 | * Right-clicking cycles blank -> / -> \ -> blank. |
1534 | */ |
1535 | v = state->soln[y*w+x] + 1; |
1536 | if (v == +2) |
1537 | v = -1; |
1538 | } |
1539 | |
986cc2de |
1540 | sprintf(buf, "%c%d,%d", (int)(v==-1 ? '\\' : v==+1 ? '/' : 'C'), x, y); |
f1010613 |
1541 | return dupstr(buf); |
1542 | } |
1543 | |
1544 | return NULL; |
1545 | } |
1546 | |
1547 | static game_state *execute_move(game_state *state, char *move) |
1548 | { |
1549 | int w = state->p.w, h = state->p.h; |
1550 | char c; |
1551 | int x, y, n; |
1552 | game_state *ret = dup_game(state); |
1553 | |
1554 | while (*move) { |
1555 | c = *move; |
1556 | if (c == 'S') { |
1557 | ret->used_solve = TRUE; |
1558 | move++; |
1559 | } else if (c == '\\' || c == '/' || c == 'C') { |
1560 | move++; |
1561 | if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || |
1562 | x < 0 || y < 0 || x >= w || y >= h) { |
1563 | free_game(ret); |
1564 | return NULL; |
1565 | } |
1566 | ret->soln[y*w+x] = (c == '\\' ? -1 : c == '/' ? +1 : 0); |
1567 | move += n; |
1568 | } else { |
1569 | free_game(ret); |
1570 | return NULL; |
1571 | } |
1572 | if (*move == ';') |
1573 | move++; |
1574 | else if (*move) { |
1575 | free_game(ret); |
1576 | return NULL; |
1577 | } |
1578 | } |
1579 | |
9dc3c55b |
1580 | /* |
1581 | * We never clear the `completed' flag, but we must always |
1582 | * re-run the completion check because it also highlights |
1583 | * errors in the grid. |
1584 | */ |
1585 | ret->completed = check_completion(ret) || ret->completed; |
f1010613 |
1586 | |
1587 | return ret; |
1588 | } |
1589 | |
1590 | /* ---------------------------------------------------------------------- |
1591 | * Drawing routines. |
1592 | */ |
1593 | |
1594 | static void game_compute_size(game_params *params, int tilesize, |
1595 | int *x, int *y) |
1596 | { |
1597 | /* fool the macros */ |
1598 | struct dummy { int tilesize; } dummy = { tilesize }, *ds = &dummy; |
1599 | |
1600 | *x = 2 * BORDER + params->w * TILESIZE + 1; |
1601 | *y = 2 * BORDER + params->h * TILESIZE + 1; |
1602 | } |
1603 | |
dafd6cf6 |
1604 | static void game_set_size(drawing *dr, game_drawstate *ds, |
1605 | game_params *params, int tilesize) |
f1010613 |
1606 | { |
1607 | ds->tilesize = tilesize; |
1608 | } |
1609 | |
1610 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
1611 | { |
1612 | float *ret = snewn(3 * NCOLOURS, float); |
1613 | |
1614 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
1615 | |
1616 | ret[COL_GRID * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.7F; |
1617 | ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.7F; |
1618 | ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.7F; |
1619 | |
1620 | ret[COL_INK * 3 + 0] = 0.0F; |
1621 | ret[COL_INK * 3 + 1] = 0.0F; |
1622 | ret[COL_INK * 3 + 2] = 0.0F; |
1623 | |
e3478a4b |
1624 | ret[COL_SLANT1 * 3 + 0] = 0.0F; |
1625 | ret[COL_SLANT1 * 3 + 1] = 0.0F; |
1626 | ret[COL_SLANT1 * 3 + 2] = 0.0F; |
1627 | |
1628 | ret[COL_SLANT2 * 3 + 0] = 0.0F; |
1629 | ret[COL_SLANT2 * 3 + 1] = 0.0F; |
1630 | ret[COL_SLANT2 * 3 + 2] = 0.0F; |
1631 | |
9dc3c55b |
1632 | ret[COL_ERROR * 3 + 0] = 1.0F; |
1633 | ret[COL_ERROR * 3 + 1] = 0.0F; |
1634 | ret[COL_ERROR * 3 + 2] = 0.0F; |
1635 | |
f1010613 |
1636 | *ncolours = NCOLOURS; |
1637 | return ret; |
1638 | } |
1639 | |
dafd6cf6 |
1640 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
f1010613 |
1641 | { |
1642 | int w = state->p.w, h = state->p.h; |
1643 | int i; |
1644 | struct game_drawstate *ds = snew(struct game_drawstate); |
1645 | |
1646 | ds->tilesize = 0; |
1647 | ds->started = FALSE; |
9dc3c55b |
1648 | ds->grid = snewn((w+2)*(h+2), long); |
1649 | ds->todraw = snewn((w+2)*(h+2), long); |
1650 | for (i = 0; i < (w+2)*(h+2); i++) |
f1010613 |
1651 | ds->grid[i] = ds->todraw[i] = -1; |
1652 | |
1653 | return ds; |
1654 | } |
1655 | |
dafd6cf6 |
1656 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
f1010613 |
1657 | { |
986cc2de |
1658 | sfree(ds->todraw); |
f1010613 |
1659 | sfree(ds->grid); |
1660 | sfree(ds); |
1661 | } |
1662 | |
dafd6cf6 |
1663 | static void draw_clue(drawing *dr, game_drawstate *ds, |
1664 | int x, int y, long v, long err, int bg, int colour) |
f1010613 |
1665 | { |
1666 | char p[2]; |
dafd6cf6 |
1667 | int ccol = colour >= 0 ? colour : ((x ^ y) & 1) ? COL_SLANT1 : COL_SLANT2; |
1668 | int tcol = colour >= 0 ? colour : err ? COL_ERROR : COL_INK; |
f1010613 |
1669 | |
1670 | if (v < 0) |
1671 | return; |
1672 | |
1673 | p[0] = v + '0'; |
1674 | p[1] = '\0'; |
dafd6cf6 |
1675 | draw_circle(dr, COORD(x), COORD(y), CLUE_RADIUS, |
1676 | bg >= 0 ? bg : COL_BACKGROUND, ccol); |
1677 | draw_text(dr, COORD(x), COORD(y), FONT_VARIABLE, |
9dc3c55b |
1678 | CLUE_TEXTSIZE, ALIGN_VCENTRE|ALIGN_HCENTRE, tcol, p); |
f1010613 |
1679 | } |
1680 | |
dafd6cf6 |
1681 | static void draw_tile(drawing *dr, game_drawstate *ds, game_clues *clues, |
5788a57e |
1682 | int x, int y, long v) |
f1010613 |
1683 | { |
9dc3c55b |
1684 | int w = clues->w, h = clues->h, W = w+1 /*, H = h+1 */; |
e3478a4b |
1685 | int chesscolour = (x ^ y) & 1; |
1686 | int fscol = chesscolour ? COL_SLANT2 : COL_SLANT1; |
1687 | int bscol = chesscolour ? COL_SLANT1 : COL_SLANT2; |
f1010613 |
1688 | |
dafd6cf6 |
1689 | clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
f1010613 |
1690 | |
dafd6cf6 |
1691 | draw_rect(dr, COORD(x), COORD(y), TILESIZE, TILESIZE, |
f1010613 |
1692 | (v & FLASH) ? COL_GRID : COL_BACKGROUND); |
1693 | |
1694 | /* |
1695 | * Draw the grid lines. |
1696 | */ |
9dc3c55b |
1697 | if (x >= 0 && x < w && y >= 0) |
dafd6cf6 |
1698 | draw_rect(dr, COORD(x), COORD(y), TILESIZE+1, 1, COL_GRID); |
9dc3c55b |
1699 | if (x >= 0 && x < w && y < h) |
dafd6cf6 |
1700 | draw_rect(dr, COORD(x), COORD(y+1), TILESIZE+1, 1, COL_GRID); |
9dc3c55b |
1701 | if (y >= 0 && y < h && x >= 0) |
dafd6cf6 |
1702 | draw_rect(dr, COORD(x), COORD(y), 1, TILESIZE+1, COL_GRID); |
9dc3c55b |
1703 | if (y >= 0 && y < h && x < w) |
dafd6cf6 |
1704 | draw_rect(dr, COORD(x+1), COORD(y), 1, TILESIZE+1, COL_GRID); |
9dc3c55b |
1705 | if (x == -1 && y == -1) |
dafd6cf6 |
1706 | draw_rect(dr, COORD(x+1), COORD(y+1), 1, 1, COL_GRID); |
9dc3c55b |
1707 | if (x == -1 && y == h) |
dafd6cf6 |
1708 | draw_rect(dr, COORD(x+1), COORD(y), 1, 1, COL_GRID); |
9dc3c55b |
1709 | if (x == w && y == -1) |
dafd6cf6 |
1710 | draw_rect(dr, COORD(x), COORD(y+1), 1, 1, COL_GRID); |
9dc3c55b |
1711 | if (x == w && y == h) |
dafd6cf6 |
1712 | draw_rect(dr, COORD(x), COORD(y), 1, 1, COL_GRID); |
f1010613 |
1713 | |
1714 | /* |
1715 | * Draw the slash. |
1716 | */ |
1717 | if (v & BACKSLASH) { |
9dc3c55b |
1718 | int scol = (v & ERRSLASH) ? COL_ERROR : bscol; |
dafd6cf6 |
1719 | draw_line(dr, COORD(x), COORD(y), COORD(x+1), COORD(y+1), scol); |
1720 | draw_line(dr, COORD(x)+1, COORD(y), COORD(x+1), COORD(y+1)-1, |
9dc3c55b |
1721 | scol); |
dafd6cf6 |
1722 | draw_line(dr, COORD(x), COORD(y)+1, COORD(x+1)-1, COORD(y+1), |
9dc3c55b |
1723 | scol); |
f1010613 |
1724 | } else if (v & FORWSLASH) { |
9dc3c55b |
1725 | int scol = (v & ERRSLASH) ? COL_ERROR : fscol; |
dafd6cf6 |
1726 | draw_line(dr, COORD(x+1), COORD(y), COORD(x), COORD(y+1), scol); |
1727 | draw_line(dr, COORD(x+1)-1, COORD(y), COORD(x), COORD(y+1)-1, |
9dc3c55b |
1728 | scol); |
dafd6cf6 |
1729 | draw_line(dr, COORD(x+1), COORD(y)+1, COORD(x)+1, COORD(y+1), |
9dc3c55b |
1730 | scol); |
f1010613 |
1731 | } |
1732 | |
1733 | /* |
1734 | * Draw dots on the grid corners that appear if a slash is in a |
1735 | * neighbouring cell. |
1736 | */ |
9dc3c55b |
1737 | if (v & (L_T | BACKSLASH)) |
dafd6cf6 |
1738 | draw_rect(dr, COORD(x), COORD(y)+1, 1, 1, |
ae4bc2cf |
1739 | (v & ERR_L_T ? COL_ERROR : bscol)); |
9dc3c55b |
1740 | if (v & (L_B | FORWSLASH)) |
dafd6cf6 |
1741 | draw_rect(dr, COORD(x), COORD(y+1)-1, 1, 1, |
ae4bc2cf |
1742 | (v & ERR_L_B ? COL_ERROR : fscol)); |
9dc3c55b |
1743 | if (v & (T_L | BACKSLASH)) |
dafd6cf6 |
1744 | draw_rect(dr, COORD(x)+1, COORD(y), 1, 1, |
ae4bc2cf |
1745 | (v & ERR_T_L ? COL_ERROR : bscol)); |
9dc3c55b |
1746 | if (v & (T_R | FORWSLASH)) |
dafd6cf6 |
1747 | draw_rect(dr, COORD(x+1)-1, COORD(y), 1, 1, |
ae4bc2cf |
1748 | (v & ERR_T_R ? COL_ERROR : fscol)); |
9dc3c55b |
1749 | if (v & (C_TL | BACKSLASH)) |
dafd6cf6 |
1750 | draw_rect(dr, COORD(x), COORD(y), 1, 1, |
ae4bc2cf |
1751 | (v & ERR_C_TL ? COL_ERROR : bscol)); |
f1010613 |
1752 | |
1753 | /* |
1754 | * And finally the clues at the corners. |
1755 | */ |
9dc3c55b |
1756 | if (x >= 0 && y >= 0) |
dafd6cf6 |
1757 | draw_clue(dr, ds, x, y, clues->clues[y*W+x], v & ERR_TL, -1, -1); |
9dc3c55b |
1758 | if (x < w && y >= 0) |
dafd6cf6 |
1759 | draw_clue(dr, ds, x+1, y, clues->clues[y*W+(x+1)], v & ERR_TR, -1, -1); |
9dc3c55b |
1760 | if (x >= 0 && y < h) |
dafd6cf6 |
1761 | draw_clue(dr, ds, x, y+1, clues->clues[(y+1)*W+x], v & ERR_BL, -1, -1); |
9dc3c55b |
1762 | if (x < w && y < h) |
dafd6cf6 |
1763 | draw_clue(dr, ds, x+1, y+1, clues->clues[(y+1)*W+(x+1)], v & ERR_BR, |
1764 | -1, -1); |
f1010613 |
1765 | |
dafd6cf6 |
1766 | unclip(dr); |
1767 | draw_update(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
f1010613 |
1768 | } |
1769 | |
dafd6cf6 |
1770 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
f1010613 |
1771 | game_state *state, int dir, game_ui *ui, |
1772 | float animtime, float flashtime) |
1773 | { |
6c48bdb7 |
1774 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1775 | int x, y; |
1776 | int flashing; |
1777 | |
1778 | if (flashtime > 0) |
1779 | flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; |
1780 | else |
1781 | flashing = FALSE; |
1782 | |
1783 | if (!ds->started) { |
1784 | int ww, wh; |
1785 | game_compute_size(&state->p, TILESIZE, &ww, &wh); |
dafd6cf6 |
1786 | draw_rect(dr, 0, 0, ww, wh, COL_BACKGROUND); |
1787 | draw_update(dr, 0, 0, ww, wh); |
f1010613 |
1788 | ds->started = TRUE; |
1789 | } |
1790 | |
1791 | /* |
1792 | * Loop over the grid and work out where all the slashes are. |
1793 | * We need to do this because a slash in one square affects the |
1794 | * drawing of the next one along. |
1795 | */ |
9dc3c55b |
1796 | for (y = -1; y <= h; y++) |
1797 | for (x = -1; x <= w; x++) { |
1798 | if (x >= 0 && x < w && y >= 0 && y < h) |
1799 | ds->todraw[(y+1)*(w+2)+(x+1)] = flashing ? FLASH : 0; |
1800 | else |
1801 | ds->todraw[(y+1)*(w+2)+(x+1)] = 0; |
1802 | } |
f1010613 |
1803 | |
1804 | for (y = 0; y < h; y++) { |
1805 | for (x = 0; x < w; x++) { |
9dc3c55b |
1806 | int err = state->errors[y*W+x] & ERR_SQUARE; |
1807 | |
f1010613 |
1808 | if (state->soln[y*w+x] < 0) { |
9dc3c55b |
1809 | ds->todraw[(y+1)*(w+2)+(x+1)] |= BACKSLASH; |
1810 | ds->todraw[(y+2)*(w+2)+(x+1)] |= T_R; |
1811 | ds->todraw[(y+1)*(w+2)+(x+2)] |= L_B; |
1812 | ds->todraw[(y+2)*(w+2)+(x+2)] |= C_TL; |
1813 | if (err) { |
ae4bc2cf |
1814 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERRSLASH | |
1815 | ERR_T_L | ERR_L_T | ERR_C_TL; |
9dc3c55b |
1816 | ds->todraw[(y+2)*(w+2)+(x+1)] |= ERR_T_R; |
1817 | ds->todraw[(y+1)*(w+2)+(x+2)] |= ERR_L_B; |
1818 | ds->todraw[(y+2)*(w+2)+(x+2)] |= ERR_C_TL; |
1819 | } |
f1010613 |
1820 | } else if (state->soln[y*w+x] > 0) { |
9dc3c55b |
1821 | ds->todraw[(y+1)*(w+2)+(x+1)] |= FORWSLASH; |
1822 | ds->todraw[(y+1)*(w+2)+(x+2)] |= L_T | C_TL; |
1823 | ds->todraw[(y+2)*(w+2)+(x+1)] |= T_L | C_TL; |
1824 | if (err) { |
ae4bc2cf |
1825 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERRSLASH | |
1826 | ERR_L_B | ERR_T_R; |
9dc3c55b |
1827 | ds->todraw[(y+1)*(w+2)+(x+2)] |= ERR_L_T | ERR_C_TL; |
1828 | ds->todraw[(y+2)*(w+2)+(x+1)] |= ERR_T_L | ERR_C_TL; |
1829 | } |
f1010613 |
1830 | } |
1831 | } |
1832 | } |
1833 | |
9dc3c55b |
1834 | for (y = 0; y < H; y++) |
1835 | for (x = 0; x < W; x++) |
1836 | if (state->errors[y*W+x] & ERR_VERTEX) { |
1837 | ds->todraw[y*(w+2)+x] |= ERR_BR; |
1838 | ds->todraw[y*(w+2)+(x+1)] |= ERR_BL; |
1839 | ds->todraw[(y+1)*(w+2)+x] |= ERR_TR; |
1840 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERR_TL; |
1841 | } |
1842 | |
f1010613 |
1843 | /* |
1844 | * Now go through and draw the grid squares. |
1845 | */ |
9dc3c55b |
1846 | for (y = -1; y <= h; y++) { |
1847 | for (x = -1; x <= w; x++) { |
1848 | if (ds->todraw[(y+1)*(w+2)+(x+1)] != ds->grid[(y+1)*(w+2)+(x+1)]) { |
dafd6cf6 |
1849 | draw_tile(dr, ds, state->clues, x, y, |
9dc3c55b |
1850 | ds->todraw[(y+1)*(w+2)+(x+1)]); |
1851 | ds->grid[(y+1)*(w+2)+(x+1)] = ds->todraw[(y+1)*(w+2)+(x+1)]; |
f1010613 |
1852 | } |
1853 | } |
1854 | } |
1855 | } |
1856 | |
1857 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1858 | int dir, game_ui *ui) |
1859 | { |
1860 | return 0.0F; |
1861 | } |
1862 | |
1863 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
1864 | int dir, game_ui *ui) |
1865 | { |
1866 | if (!oldstate->completed && newstate->completed && |
1867 | !oldstate->used_solve && !newstate->used_solve) |
1868 | return FLASH_TIME; |
1869 | |
1870 | return 0.0F; |
1871 | } |
1872 | |
1873 | static int game_wants_statusbar(void) |
1874 | { |
1875 | return FALSE; |
1876 | } |
1877 | |
1878 | static int game_timing_state(game_state *state, game_ui *ui) |
1879 | { |
1880 | return TRUE; |
1881 | } |
1882 | |
dafd6cf6 |
1883 | static void game_print_size(game_params *params, float *x, float *y) |
1884 | { |
1885 | int pw, ph; |
1886 | |
1887 | /* |
1888 | * I'll use 6mm squares by default. |
1889 | */ |
1890 | game_compute_size(params, 600, &pw, &ph); |
1891 | *x = pw / 100.0; |
1892 | *y = ph / 100.0; |
1893 | } |
1894 | |
1895 | static void game_print(drawing *dr, game_state *state, int tilesize) |
1896 | { |
1897 | int w = state->p.w, h = state->p.h, W = w+1; |
1898 | int ink = print_mono_colour(dr, 0); |
1899 | int paper = print_mono_colour(dr, 1); |
1900 | int x, y; |
1901 | |
1902 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
1903 | game_drawstate ads, *ds = &ads; |
1904 | ads.tilesize = tilesize; |
1905 | |
1906 | /* |
1907 | * Border. |
1908 | */ |
1909 | print_line_width(dr, TILESIZE / 16); |
1910 | draw_rect_outline(dr, COORD(0), COORD(0), w*TILESIZE, h*TILESIZE, ink); |
1911 | |
1912 | /* |
1913 | * Grid. |
1914 | */ |
1915 | print_line_width(dr, TILESIZE / 24); |
1916 | for (x = 1; x < w; x++) |
1917 | draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), ink); |
1918 | for (y = 1; y < h; y++) |
1919 | draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), ink); |
1920 | |
1921 | /* |
1922 | * Solution. |
1923 | */ |
1924 | print_line_width(dr, TILESIZE / 12); |
1925 | for (y = 0; y < h; y++) |
1926 | for (x = 0; x < w; x++) |
1927 | if (state->soln[y*w+x]) { |
1928 | int ly, ry; |
1929 | /* |
1930 | * To prevent nasty line-ending artefacts at |
1931 | * corners, I'll do something slightly cunning |
1932 | * here. |
1933 | */ |
1934 | clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
1935 | if (state->soln[y*w+x] < 0) |
1936 | ly = y-1, ry = y+2; |
1937 | else |
1938 | ry = y-1, ly = y+2; |
1939 | draw_line(dr, COORD(x-1), COORD(ly), COORD(x+2), COORD(ry), |
1940 | ink); |
1941 | unclip(dr); |
1942 | } |
1943 | |
1944 | /* |
1945 | * Clues. |
1946 | */ |
1947 | print_line_width(dr, TILESIZE / 24); |
1948 | for (y = 0; y <= h; y++) |
1949 | for (x = 0; x <= w; x++) |
1950 | draw_clue(dr, ds, x, y, state->clues->clues[y*W+x], |
1951 | FALSE, paper, ink); |
1952 | } |
1953 | |
f1010613 |
1954 | #ifdef COMBINED |
1955 | #define thegame slant |
1956 | #endif |
1957 | |
1958 | const struct game thegame = { |
1959 | "Slant", "games.slant", |
1960 | default_params, |
1961 | game_fetch_preset, |
1962 | decode_params, |
1963 | encode_params, |
1964 | free_params, |
1965 | dup_params, |
1966 | TRUE, game_configure, custom_params, |
1967 | validate_params, |
1968 | new_game_desc, |
1969 | validate_desc, |
1970 | new_game, |
1971 | dup_game, |
1972 | free_game, |
1973 | TRUE, solve_game, |
1974 | TRUE, game_text_format, |
1975 | new_ui, |
1976 | free_ui, |
1977 | encode_ui, |
1978 | decode_ui, |
1979 | game_changed_state, |
1980 | interpret_move, |
1981 | execute_move, |
1982 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
1983 | game_colours, |
1984 | game_new_drawstate, |
1985 | game_free_drawstate, |
1986 | game_redraw, |
1987 | game_anim_length, |
1988 | game_flash_length, |
dafd6cf6 |
1989 | TRUE, FALSE, game_print_size, game_print, |
f1010613 |
1990 | game_wants_statusbar, |
1991 | FALSE, game_timing_state, |
1992 | 0, /* mouse_priorities */ |
1993 | }; |
b926ba00 |
1994 | |
1995 | #ifdef STANDALONE_SOLVER |
1996 | |
1997 | #include <stdarg.h> |
1998 | |
b926ba00 |
1999 | int main(int argc, char **argv) |
2000 | { |
2001 | game_params *p; |
2002 | game_state *s; |
2003 | char *id = NULL, *desc, *err; |
2004 | int grade = FALSE; |
ccda7394 |
2005 | int ret, diff, really_verbose = FALSE; |
b926ba00 |
2006 | struct solver_scratch *sc; |
2007 | |
2008 | while (--argc > 0) { |
2009 | char *p = *++argv; |
2010 | if (!strcmp(p, "-v")) { |
ccda7394 |
2011 | really_verbose = TRUE; |
b926ba00 |
2012 | } else if (!strcmp(p, "-g")) { |
2013 | grade = TRUE; |
2014 | } else if (*p == '-') { |
2015 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
2016 | return 1; |
2017 | } else { |
2018 | id = p; |
2019 | } |
2020 | } |
2021 | |
2022 | if (!id) { |
2023 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
2024 | return 1; |
2025 | } |
2026 | |
2027 | desc = strchr(id, ':'); |
2028 | if (!desc) { |
2029 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
2030 | return 1; |
2031 | } |
2032 | *desc++ = '\0'; |
2033 | |
2034 | p = default_params(); |
2035 | decode_params(p, id); |
2036 | err = validate_desc(p, desc); |
2037 | if (err) { |
2038 | fprintf(stderr, "%s: %s\n", argv[0], err); |
2039 | return 1; |
2040 | } |
2041 | s = new_game(NULL, p, desc); |
2042 | |
2043 | sc = new_scratch(p->w, p->h); |
2044 | |
ccda7394 |
2045 | /* |
2046 | * When solving an Easy puzzle, we don't want to bother the |
2047 | * user with Hard-level deductions. For this reason, we grade |
2048 | * the puzzle internally before doing anything else. |
2049 | */ |
8067a45b |
2050 | ret = -1; /* placate optimiser */ |
ccda7394 |
2051 | for (diff = 0; diff < DIFFCOUNT; diff++) { |
b926ba00 |
2052 | ret = slant_solve(p->w, p->h, s->clues->clues, |
ccda7394 |
2053 | s->soln, sc, diff); |
2054 | if (ret < 2) |
2055 | break; |
2056 | } |
2057 | |
2058 | if (diff == DIFFCOUNT) { |
2059 | if (grade) |
2060 | printf("Difficulty rating: harder than Hard, or ambiguous\n"); |
2061 | else |
2062 | printf("Unable to find a unique solution\n"); |
2063 | } else { |
2064 | if (grade) { |
b926ba00 |
2065 | if (ret == 0) |
2066 | printf("Difficulty rating: impossible (no solution exists)\n"); |
2067 | else if (ret == 1) |
ccda7394 |
2068 | printf("Difficulty rating: %s\n", slant_diffnames[diff]); |
2069 | } else { |
2070 | verbose = really_verbose; |
2071 | ret = slant_solve(p->w, p->h, s->clues->clues, |
2072 | s->soln, sc, diff); |
2073 | if (ret == 0) |
2074 | printf("Puzzle is inconsistent\n"); |
b926ba00 |
2075 | else |
ccda7394 |
2076 | fputs(game_text_format(s), stdout); |
b926ba00 |
2077 | } |
b926ba00 |
2078 | } |
2079 | |
2080 | return 0; |
2081 | } |
2082 | |
2083 | #endif |