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; |
8aa366aa |
79 | int *tmpdsf; |
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80 | int refcount; |
81 | } game_clues; |
82 | |
9dc3c55b |
83 | #define ERR_VERTEX 1 |
84 | #define ERR_SQUARE 2 |
8aa366aa |
85 | #define ERR_SQUARE_TMP 4 |
9dc3c55b |
86 | |
f1010613 |
87 | struct game_state { |
88 | struct game_params p; |
89 | game_clues *clues; |
90 | signed char *soln; |
9dc3c55b |
91 | unsigned char *errors; |
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92 | int completed; |
93 | int used_solve; /* used to suppress completion flash */ |
94 | }; |
95 | |
96 | static game_params *default_params(void) |
97 | { |
98 | game_params *ret = snew(game_params); |
99 | |
100 | ret->w = ret->h = 8; |
b926ba00 |
101 | ret->diff = DIFF_EASY; |
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102 | |
103 | return ret; |
104 | } |
105 | |
106 | static const struct game_params slant_presets[] = { |
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107 | {5, 5, DIFF_EASY}, |
108 | {5, 5, DIFF_HARD}, |
109 | {8, 8, DIFF_EASY}, |
110 | {8, 8, DIFF_HARD}, |
111 | {12, 10, DIFF_EASY}, |
112 | {12, 10, DIFF_HARD}, |
f1010613 |
113 | }; |
114 | |
115 | static int game_fetch_preset(int i, char **name, game_params **params) |
116 | { |
117 | game_params *ret; |
118 | char str[80]; |
119 | |
120 | if (i < 0 || i >= lenof(slant_presets)) |
121 | return FALSE; |
122 | |
123 | ret = snew(game_params); |
124 | *ret = slant_presets[i]; |
125 | |
b926ba00 |
126 | sprintf(str, "%dx%d %s", ret->w, ret->h, slant_diffnames[ret->diff]); |
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127 | |
128 | *name = dupstr(str); |
129 | *params = ret; |
130 | return TRUE; |
131 | } |
132 | |
133 | static void free_params(game_params *params) |
134 | { |
135 | sfree(params); |
136 | } |
137 | |
138 | static game_params *dup_params(game_params *params) |
139 | { |
140 | game_params *ret = snew(game_params); |
141 | *ret = *params; /* structure copy */ |
142 | return ret; |
143 | } |
144 | |
145 | static void decode_params(game_params *ret, char const *string) |
146 | { |
147 | ret->w = ret->h = atoi(string); |
148 | while (*string && isdigit((unsigned char)*string)) string++; |
149 | if (*string == 'x') { |
150 | string++; |
151 | ret->h = atoi(string); |
b926ba00 |
152 | while (*string && isdigit((unsigned char)*string)) string++; |
153 | } |
154 | if (*string == 'd') { |
155 | int i; |
156 | string++; |
157 | for (i = 0; i < DIFFCOUNT; i++) |
158 | if (*string == slant_diffchars[i]) |
159 | ret->diff = i; |
160 | if (*string) string++; |
f1010613 |
161 | } |
162 | } |
163 | |
164 | static char *encode_params(game_params *params, int full) |
165 | { |
166 | char data[256]; |
167 | |
168 | sprintf(data, "%dx%d", params->w, params->h); |
b926ba00 |
169 | if (full) |
170 | sprintf(data + strlen(data), "d%c", slant_diffchars[params->diff]); |
f1010613 |
171 | |
172 | return dupstr(data); |
173 | } |
174 | |
175 | static config_item *game_configure(game_params *params) |
176 | { |
177 | config_item *ret; |
178 | char buf[80]; |
179 | |
15164c74 |
180 | ret = snewn(4, config_item); |
f1010613 |
181 | |
182 | ret[0].name = "Width"; |
183 | ret[0].type = C_STRING; |
184 | sprintf(buf, "%d", params->w); |
185 | ret[0].sval = dupstr(buf); |
186 | ret[0].ival = 0; |
187 | |
188 | ret[1].name = "Height"; |
189 | ret[1].type = C_STRING; |
190 | sprintf(buf, "%d", params->h); |
191 | ret[1].sval = dupstr(buf); |
192 | ret[1].ival = 0; |
193 | |
b926ba00 |
194 | ret[2].name = "Difficulty"; |
195 | ret[2].type = C_CHOICES; |
196 | ret[2].sval = DIFFCONFIG; |
197 | ret[2].ival = params->diff; |
198 | |
199 | ret[3].name = NULL; |
200 | ret[3].type = C_END; |
201 | ret[3].sval = NULL; |
202 | ret[3].ival = 0; |
f1010613 |
203 | |
204 | return ret; |
205 | } |
206 | |
207 | static game_params *custom_params(config_item *cfg) |
208 | { |
209 | game_params *ret = snew(game_params); |
210 | |
211 | ret->w = atoi(cfg[0].sval); |
212 | ret->h = atoi(cfg[1].sval); |
b926ba00 |
213 | ret->diff = cfg[2].ival; |
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214 | |
215 | return ret; |
216 | } |
217 | |
218 | static char *validate_params(game_params *params, int full) |
219 | { |
220 | /* |
221 | * (At least at the time of writing this comment) The grid |
222 | * generator is actually capable of handling even zero grid |
223 | * dimensions without crashing. Puzzles with a zero-area grid |
224 | * are a bit boring, though, because they're already solved :-) |
b926ba00 |
225 | * And puzzles with a dimension of 1 can't be made Hard, which |
226 | * means the simplest thing is to forbid them altogether. |
f1010613 |
227 | */ |
228 | |
b926ba00 |
229 | if (params->w < 2 || params->h < 2) |
230 | return "Width and height must both be at least two"; |
f1010613 |
231 | |
232 | return NULL; |
233 | } |
234 | |
235 | /* |
b926ba00 |
236 | * Scratch space for solver. |
f1010613 |
237 | */ |
b926ba00 |
238 | struct solver_scratch { |
239 | /* |
240 | * Disjoint set forest which tracks the connected sets of |
241 | * points. |
242 | */ |
243 | int *connected; |
f1010613 |
244 | |
b926ba00 |
245 | /* |
246 | * Counts the number of possible exits from each connected set |
247 | * of points. (That is, the number of possible _simultaneous_ |
248 | * exits: an unconnected point labelled 2 has an exit count of |
249 | * 2 even if all four possible edges are still under |
250 | * consideration.) |
251 | */ |
252 | int *exits; |
f1010613 |
253 | |
b926ba00 |
254 | /* |
255 | * Tracks whether each connected set of points includes a |
256 | * border point. |
257 | */ |
258 | unsigned char *border; |
f1010613 |
259 | |
b926ba00 |
260 | /* |
261 | * Another disjoint set forest. This one tracks _squares_ which |
262 | * are known to slant in the same direction. |
263 | */ |
264 | int *equiv; |
f1010613 |
265 | |
b926ba00 |
266 | /* |
267 | * Stores slash values which we know for an equivalence class. |
268 | * When we fill in a square, we set slashval[canonify(x)] to |
269 | * the same value as soln[x], so that we can then spot other |
270 | * squares equivalent to it and fill them in immediately via |
271 | * their known equivalence. |
272 | */ |
273 | signed char *slashval; |
274 | |
275 | /* |
276 | * Useful to have this information automatically passed to |
277 | * solver subroutines. (This pointer is not dynamically |
278 | * allocated by new_scratch and free_scratch.) |
279 | */ |
280 | const signed char *clues; |
f1010613 |
281 | }; |
282 | |
986cc2de |
283 | static struct solver_scratch *new_scratch(int w, int h) |
f1010613 |
284 | { |
285 | int W = w+1, H = h+1; |
286 | struct solver_scratch *ret = snew(struct solver_scratch); |
b926ba00 |
287 | ret->connected = snewn(W*H, int); |
288 | ret->exits = snewn(W*H, int); |
289 | ret->border = snewn(W*H, unsigned char); |
290 | ret->equiv = snewn(w*h, int); |
291 | ret->slashval = snewn(w*h, signed char); |
f1010613 |
292 | return ret; |
293 | } |
294 | |
986cc2de |
295 | static void free_scratch(struct solver_scratch *sc) |
f1010613 |
296 | { |
b926ba00 |
297 | sfree(sc->slashval); |
298 | sfree(sc->equiv); |
299 | sfree(sc->border); |
300 | sfree(sc->exits); |
301 | sfree(sc->connected); |
f1010613 |
302 | sfree(sc); |
303 | } |
304 | |
305 | /* |
b926ba00 |
306 | * Wrapper on dsf_merge() which updates the `exits' and `border' |
307 | * arrays. |
308 | */ |
309 | static void merge_vertices(int *connected, |
310 | struct solver_scratch *sc, int i, int j) |
311 | { |
312 | int exits = -1, border = FALSE; /* initialise to placate optimiser */ |
313 | |
314 | if (sc) { |
315 | i = dsf_canonify(connected, i); |
316 | j = dsf_canonify(connected, j); |
317 | |
318 | /* |
319 | * We have used one possible exit from each of the two |
320 | * classes. Thus, the viable exit count of the new class is |
321 | * the sum of the old exit counts minus two. |
322 | */ |
323 | exits = sc->exits[i] + sc->exits[j] - 2; |
324 | |
325 | border = sc->border[i] || sc->border[j]; |
326 | } |
327 | |
328 | dsf_merge(connected, i, j); |
329 | |
330 | if (sc) { |
331 | i = dsf_canonify(connected, i); |
332 | sc->exits[i] = exits; |
333 | sc->border[i] = border; |
334 | } |
335 | } |
336 | |
337 | /* |
338 | * Called when we have just blocked one way out of a particular |
339 | * point. If that point is a non-clue point (thus has a variable |
340 | * number of exits), we have therefore decreased its potential exit |
341 | * count, so we must decrement the exit count for the group as a |
342 | * whole. |
343 | */ |
344 | static void decr_exits(struct solver_scratch *sc, int i) |
345 | { |
346 | if (sc->clues[i] < 0) { |
347 | i = dsf_canonify(sc->connected, i); |
348 | sc->exits[i]--; |
349 | } |
350 | } |
351 | |
352 | static void fill_square(int w, int h, int x, int y, int v, |
353 | signed char *soln, |
354 | int *connected, struct solver_scratch *sc) |
355 | { |
356 | int W = w+1 /*, H = h+1 */; |
357 | |
358 | assert(x >= 0 && x < w && y >= 0 && y < h); |
359 | |
360 | if (soln[y*w+x] != 0) { |
361 | return; /* do nothing */ |
362 | } |
363 | |
364 | #ifdef SOLVER_DIAGNOSTICS |
365 | if (verbose) |
366 | printf(" placing %c in %d,%d\n", v == -1 ? '\\' : '/', x, y); |
367 | #endif |
368 | |
369 | soln[y*w+x] = v; |
370 | |
371 | if (sc) { |
372 | int c = dsf_canonify(sc->equiv, y*w+x); |
373 | sc->slashval[c] = v; |
374 | } |
375 | |
376 | if (v < 0) { |
377 | merge_vertices(connected, sc, y*W+x, (y+1)*W+(x+1)); |
378 | if (sc) { |
379 | decr_exits(sc, y*W+(x+1)); |
380 | decr_exits(sc, (y+1)*W+x); |
381 | } |
382 | } else { |
383 | merge_vertices(connected, sc, y*W+(x+1), (y+1)*W+x); |
384 | if (sc) { |
385 | decr_exits(sc, y*W+x); |
386 | decr_exits(sc, (y+1)*W+(x+1)); |
387 | } |
388 | } |
389 | } |
390 | |
391 | /* |
f1010613 |
392 | * Solver. Returns 0 for impossibility, 1 for success, 2 for |
393 | * ambiguity or failure to converge. |
394 | */ |
395 | static int slant_solve(int w, int h, const signed char *clues, |
b926ba00 |
396 | signed char *soln, struct solver_scratch *sc, |
397 | int difficulty) |
f1010613 |
398 | { |
399 | int W = w+1, H = h+1; |
b926ba00 |
400 | int x, y, i, j; |
f1010613 |
401 | int done_something; |
402 | |
403 | /* |
404 | * Clear the output. |
405 | */ |
406 | memset(soln, 0, w*h); |
407 | |
b926ba00 |
408 | sc->clues = clues; |
409 | |
f1010613 |
410 | /* |
411 | * Establish a disjoint set forest for tracking connectedness |
412 | * between grid points. |
413 | */ |
414 | for (i = 0; i < W*H; i++) |
b926ba00 |
415 | sc->connected[i] = i; /* initially all distinct */ |
416 | |
417 | /* |
418 | * Establish a disjoint set forest for tracking which squares |
419 | * are known to slant in the same direction. |
420 | */ |
421 | for (i = 0; i < w*h; i++) |
422 | sc->equiv[i] = i; /* initially all distinct */ |
423 | |
424 | /* |
425 | * Clear the slashval array. |
426 | */ |
427 | memset(sc->slashval, 0, w*h); |
428 | |
429 | /* |
430 | * Initialise the `exits' and `border' arrays. Theses is used |
431 | * to do second-order loop avoidance: the dual of the no loops |
432 | * constraint is that every point must be somehow connected to |
433 | * the border of the grid (otherwise there would be a solid |
434 | * loop around it which prevented this). |
435 | * |
436 | * I define a `dead end' to be a connected group of points |
437 | * which contains no border point, and which can form at most |
438 | * one new connection outside itself. Then I forbid placing an |
439 | * edge so that it connects together two dead-end groups, since |
440 | * this would yield a non-border-connected isolated subgraph |
441 | * with no further scope to extend it. |
442 | */ |
443 | for (y = 0; y < H; y++) |
444 | for (x = 0; x < W; x++) { |
445 | if (y == 0 || y == H-1 || x == 0 || x == W-1) |
446 | sc->border[y*W+x] = TRUE; |
447 | else |
448 | sc->border[y*W+x] = FALSE; |
449 | |
450 | if (clues[y*W+x] < 0) |
451 | sc->exits[y*W+x] = 4; |
452 | else |
453 | sc->exits[y*W+x] = clues[y*W+x]; |
454 | } |
455 | |
456 | /* |
457 | * Make a one-off preliminary pass over the grid looking for |
458 | * starting-point arrangements. The ones we need to spot are: |
459 | * |
460 | * - two adjacent 1s in the centre of the grid imply that each |
461 | * one's single line points towards the other. (If either 1 |
462 | * were connected on the far side, the two squares shared |
463 | * between the 1s would both link to the other 1 as a |
464 | * consequence of neither linking to the first.) Thus, we |
465 | * can fill in the four squares around them. |
466 | * |
467 | * - dually, two adjacent 3s imply that each one's _non_-line |
468 | * points towards the other. |
469 | * |
470 | * - if the pair of 1s and 3s is not _adjacent_ but is |
471 | * separated by one or more 2s, the reasoning still applies. |
472 | * |
473 | * This is more advanced than just spotting obvious starting |
474 | * squares such as central 4s and edge 2s, so we disable it on |
475 | * DIFF_EASY. |
476 | * |
477 | * (I don't like this loop; it feels grubby to me. My |
478 | * mathematical intuition feels there ought to be some more |
479 | * general deductive form which contains this loop as a special |
480 | * case, but I can't bring it to mind right now.) |
481 | */ |
482 | if (difficulty > DIFF_EASY) { |
483 | for (y = 1; y+1 < H; y++) |
484 | for (x = 1; x+1 < W; x++) { |
485 | int v = clues[y*W+x], s, x2, y2, dx, dy; |
486 | if (v != 1 && v != 3) |
487 | continue; |
488 | /* Slash value of the square up and left of (x,y). */ |
489 | s = (v == 1 ? +1 : -1); |
490 | |
491 | /* Look in each direction once. */ |
492 | for (dy = 0; dy < 2; dy++) { |
493 | dx = 1 - dy; |
494 | x2 = x+dx; |
495 | y2 = y+dy; |
496 | if (x2+1 >= W || y2+1 >= H) |
497 | continue; /* too close to the border */ |
498 | while (x2+dx+1 < W && y2+dy+1 < H && clues[y2*W+x2] == 2) |
499 | x2 += dx, y2 += dy; |
500 | if (clues[y2*W+x2] == v) { |
501 | #ifdef SOLVER_DIAGNOSTICS |
502 | if (verbose) |
503 | printf("found adjacent %ds at %d,%d and %d,%d\n", |
504 | v, x, y, x2, y2); |
505 | #endif |
506 | fill_square(w, h, x-1, y-1, s, soln, |
507 | sc->connected, sc); |
508 | fill_square(w, h, x-1+dy, y-1+dx, -s, soln, |
509 | sc->connected, sc); |
510 | fill_square(w, h, x2, y2, s, soln, |
511 | sc->connected, sc); |
512 | fill_square(w, h, x2-dy, y2-dx, -s, soln, |
513 | sc->connected, sc); |
514 | } |
515 | } |
516 | } |
517 | } |
f1010613 |
518 | |
519 | /* |
520 | * Repeatedly try to deduce something until we can't. |
521 | */ |
522 | do { |
523 | done_something = FALSE; |
524 | |
525 | /* |
526 | * Any clue point with the number of remaining lines equal |
527 | * to zero or to the number of remaining undecided |
528 | * neighbouring squares can be filled in completely. |
529 | */ |
530 | for (y = 0; y < H; y++) |
531 | for (x = 0; x < W; x++) { |
b926ba00 |
532 | struct { |
533 | int pos, slash; |
534 | } neighbours[4]; |
535 | int nneighbours; |
536 | int nu, nl, c, s, eq, eq2, last, meq, mj1, mj2; |
f1010613 |
537 | |
538 | if ((c = clues[y*W+x]) < 0) |
539 | continue; |
540 | |
541 | /* |
b926ba00 |
542 | * We have a clue point. Start by listing its |
543 | * neighbouring squares, in order around the point, |
544 | * together with the type of slash that would be |
545 | * required in that square to connect to the point. |
546 | */ |
547 | nneighbours = 0; |
548 | if (x > 0 && y > 0) { |
549 | neighbours[nneighbours].pos = (y-1)*w+(x-1); |
550 | neighbours[nneighbours].slash = -1; |
551 | nneighbours++; |
552 | } |
553 | if (x > 0 && y < h) { |
554 | neighbours[nneighbours].pos = y*w+(x-1); |
555 | neighbours[nneighbours].slash = +1; |
556 | nneighbours++; |
557 | } |
558 | if (x < w && y < h) { |
559 | neighbours[nneighbours].pos = y*w+x; |
560 | neighbours[nneighbours].slash = -1; |
561 | nneighbours++; |
562 | } |
563 | if (x < w && y > 0) { |
564 | neighbours[nneighbours].pos = (y-1)*w+x; |
565 | neighbours[nneighbours].slash = +1; |
566 | nneighbours++; |
567 | } |
568 | |
569 | /* |
570 | * Count up the number of undecided neighbours, and |
571 | * also the number of lines already present. |
572 | * |
573 | * If we're not on DIFF_EASY, then in this loop we |
574 | * also track whether we've seen two adjacent empty |
575 | * squares belonging to the same equivalence class |
576 | * (meaning they have the same type of slash). If |
577 | * so, we count them jointly as one line. |
f1010613 |
578 | */ |
579 | nu = 0; |
580 | nl = c; |
b926ba00 |
581 | last = neighbours[nneighbours-1].pos; |
582 | if (soln[last] == 0) |
583 | eq = dsf_canonify(sc->equiv, last); |
584 | else |
585 | eq = -1; |
586 | meq = mj1 = mj2 = -1; |
587 | for (i = 0; i < nneighbours; i++) { |
588 | j = neighbours[i].pos; |
589 | s = neighbours[i].slash; |
590 | if (soln[j] == 0) { |
591 | nu++; /* undecided */ |
592 | if (meq < 0 && difficulty > DIFF_EASY) { |
593 | eq2 = dsf_canonify(sc->equiv, j); |
594 | if (eq == eq2 && last != j) { |
595 | /* |
596 | * We've found an equivalent pair. |
597 | * Mark it. This also inhibits any |
598 | * further equivalence tracking |
599 | * around this square, since we can |
600 | * only handle one pair (and in |
601 | * particular we want to avoid |
602 | * being misled by two overlapping |
603 | * equivalence pairs). |
604 | */ |
605 | meq = eq; |
606 | mj1 = last; |
607 | mj2 = j; |
608 | nl--; /* count one line */ |
609 | nu -= 2; /* and lose two undecideds */ |
610 | } else |
611 | eq = eq2; |
612 | } |
613 | } else { |
614 | eq = -1; |
615 | if (soln[j] == s) |
616 | nl--; /* here's a line */ |
617 | } |
618 | last = j; |
619 | } |
f1010613 |
620 | |
621 | /* |
622 | * Check the counts. |
623 | */ |
624 | if (nl < 0 || nl > nu) { |
625 | /* |
626 | * No consistent value for this at all! |
627 | */ |
b926ba00 |
628 | #ifdef SOLVER_DIAGNOSTICS |
629 | if (verbose) |
630 | printf("need %d / %d lines around clue point at %d,%d!\n", |
631 | nl, nu, x, y); |
632 | #endif |
f1010613 |
633 | return 0; /* impossible */ |
634 | } |
635 | |
636 | if (nu > 0 && (nl == 0 || nl == nu)) { |
637 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
638 | if (verbose) { |
639 | if (meq >= 0) |
640 | printf("partially (since %d,%d == %d,%d) ", |
641 | mj1%w, mj1/w, mj2%w, mj2/w); |
642 | printf("%s around clue point at %d,%d\n", |
643 | nl ? "filling" : "emptying", x, y); |
644 | } |
f1010613 |
645 | #endif |
b926ba00 |
646 | for (i = 0; i < nneighbours; i++) { |
647 | j = neighbours[i].pos; |
648 | s = neighbours[i].slash; |
649 | if (soln[j] == 0 && j != mj1 && j != mj2) |
650 | fill_square(w, h, j%w, j/w, (nl ? s : -s), soln, |
651 | sc->connected, sc); |
652 | } |
f1010613 |
653 | |
654 | done_something = TRUE; |
b926ba00 |
655 | } else if (nu == 2 && nl == 1 && difficulty > DIFF_EASY) { |
656 | /* |
657 | * If we have precisely two undecided squares |
658 | * and precisely one line to place between |
659 | * them, _and_ those squares are adjacent, then |
660 | * we can mark them as equivalent to one |
661 | * another. |
662 | * |
663 | * This even applies if meq >= 0: if we have a |
664 | * 2 clue point and two of its neighbours are |
665 | * already marked equivalent, we can indeed |
666 | * mark the other two as equivalent. |
667 | * |
668 | * We don't bother with this on DIFF_EASY, |
669 | * since we wouldn't have used the results |
670 | * anyway. |
671 | */ |
672 | last = -1; |
673 | for (i = 0; i < nneighbours; i++) { |
674 | j = neighbours[i].pos; |
675 | if (soln[j] == 0 && j != mj1 && j != mj2) { |
676 | if (last < 0) |
677 | last = i; |
678 | else if (last == i-1 || (last == 0 && i == 3)) |
679 | break; /* found a pair */ |
680 | } |
681 | } |
682 | if (i < nneighbours) { |
683 | int sv1, sv2; |
684 | |
685 | assert(last >= 0); |
686 | /* |
687 | * neighbours[last] and neighbours[i] are |
688 | * the pair. Mark them equivalent. |
689 | */ |
690 | #ifdef SOLVER_DIAGNOSTICS |
691 | if (verbose) { |
692 | if (meq >= 0) |
693 | printf("since %d,%d == %d,%d, ", |
694 | mj1%w, mj1/w, mj2%w, mj2/w); |
695 | } |
696 | #endif |
697 | mj1 = neighbours[last].pos; |
698 | mj2 = neighbours[i].pos; |
699 | #ifdef SOLVER_DIAGNOSTICS |
700 | if (verbose) |
701 | printf("clue point at %d,%d implies %d,%d == %d," |
702 | "%d\n", x, y, mj1%w, mj1/w, mj2%w, mj2/w); |
703 | #endif |
704 | mj1 = dsf_canonify(sc->equiv, mj1); |
705 | sv1 = sc->slashval[mj1]; |
706 | mj2 = dsf_canonify(sc->equiv, mj2); |
707 | sv2 = sc->slashval[mj2]; |
708 | if (sv1 != 0 && sv2 != 0 && sv1 != sv2) { |
709 | #ifdef SOLVER_DIAGNOSTICS |
710 | if (verbose) |
711 | printf("merged two equivalence classes with" |
712 | " different slash values!\n"); |
713 | #endif |
714 | return 0; |
715 | } |
716 | sv1 = sv1 ? sv1 : sv2; |
717 | dsf_merge(sc->equiv, mj1, mj2); |
718 | mj1 = dsf_canonify(sc->equiv, mj1); |
719 | sc->slashval[mj1] = sv1; |
720 | } |
f1010613 |
721 | } |
722 | } |
723 | |
724 | if (done_something) |
725 | continue; |
726 | |
727 | /* |
728 | * Failing that, we now apply the second condition, which |
729 | * is that no square may be filled in such a way as to form |
b926ba00 |
730 | * a loop. Also in this loop (since it's over squares |
731 | * rather than points), we check slashval to see if we've |
732 | * already filled in another square in the same equivalence |
733 | * class. |
734 | * |
735 | * The slashval check is disabled on DIFF_EASY, as is dead |
736 | * end avoidance. Only _immediate_ loop avoidance remains. |
f1010613 |
737 | */ |
738 | for (y = 0; y < h; y++) |
739 | for (x = 0; x < w; x++) { |
b926ba00 |
740 | int fs, bs, v; |
741 | int c1, c2; |
742 | #ifdef SOLVER_DIAGNOSTICS |
743 | char *reason = "<internal error>"; |
744 | #endif |
f1010613 |
745 | |
746 | if (soln[y*w+x]) |
747 | continue; /* got this one already */ |
748 | |
b926ba00 |
749 | fs = FALSE; |
750 | bs = FALSE; |
751 | |
752 | if (difficulty > DIFF_EASY) |
753 | v = sc->slashval[dsf_canonify(sc->equiv, y*w+x)]; |
754 | else |
755 | v = 0; |
756 | |
757 | /* |
758 | * Try to rule out connectivity between (x,y) and |
759 | * (x+1,y+1); if successful, we will deduce that we |
760 | * must have a forward slash. |
761 | */ |
762 | c1 = dsf_canonify(sc->connected, y*W+x); |
763 | c2 = dsf_canonify(sc->connected, (y+1)*W+(x+1)); |
764 | if (c1 == c2) { |
765 | fs = TRUE; |
766 | #ifdef SOLVER_DIAGNOSTICS |
767 | reason = "simple loop avoidance"; |
768 | #endif |
769 | } |
770 | if (difficulty > DIFF_EASY && |
771 | !sc->border[c1] && !sc->border[c2] && |
772 | sc->exits[c1] <= 1 && sc->exits[c2] <= 1) { |
773 | fs = TRUE; |
774 | #ifdef SOLVER_DIAGNOSTICS |
775 | reason = "dead end avoidance"; |
776 | #endif |
777 | } |
778 | if (v == +1) { |
779 | fs = TRUE; |
780 | #ifdef SOLVER_DIAGNOSTICS |
781 | reason = "equivalence to an already filled square"; |
782 | #endif |
783 | } |
784 | |
785 | /* |
786 | * Now do the same between (x+1,y) and (x,y+1), to |
787 | * see if we are required to have a backslash. |
788 | */ |
789 | c1 = dsf_canonify(sc->connected, y*W+(x+1)); |
790 | c2 = dsf_canonify(sc->connected, (y+1)*W+x); |
791 | if (c1 == c2) { |
792 | bs = TRUE; |
793 | #ifdef SOLVER_DIAGNOSTICS |
794 | reason = "simple loop avoidance"; |
795 | #endif |
796 | } |
797 | if (difficulty > DIFF_EASY && |
798 | !sc->border[c1] && !sc->border[c2] && |
799 | sc->exits[c1] <= 1 && sc->exits[c2] <= 1) { |
800 | bs = TRUE; |
801 | #ifdef SOLVER_DIAGNOSTICS |
802 | reason = "dead end avoidance"; |
803 | #endif |
804 | } |
805 | if (v == -1) { |
806 | bs = TRUE; |
807 | #ifdef SOLVER_DIAGNOSTICS |
808 | reason = "equivalence to an already filled square"; |
809 | #endif |
810 | } |
f1010613 |
811 | |
812 | if (fs && bs) { |
813 | /* |
b926ba00 |
814 | * No consistent value for this at all! |
f1010613 |
815 | */ |
b926ba00 |
816 | #ifdef SOLVER_DIAGNOSTICS |
817 | if (verbose) |
818 | printf("%d,%d has no consistent slash!\n", x, y); |
819 | #endif |
f1010613 |
820 | return 0; /* impossible */ |
821 | } |
822 | |
823 | if (fs) { |
f1010613 |
824 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
825 | if (verbose) |
826 | printf("employing %s\n", reason); |
f1010613 |
827 | #endif |
b926ba00 |
828 | fill_square(w, h, x, y, +1, soln, sc->connected, sc); |
f1010613 |
829 | done_something = TRUE; |
830 | } else if (bs) { |
f1010613 |
831 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
832 | if (verbose) |
833 | printf("employing %s\n", reason); |
f1010613 |
834 | #endif |
b926ba00 |
835 | fill_square(w, h, x, y, -1, soln, sc->connected, sc); |
f1010613 |
836 | done_something = TRUE; |
837 | } |
838 | } |
839 | |
840 | } while (done_something); |
841 | |
842 | /* |
843 | * Solver can make no more progress. See if the grid is full. |
844 | */ |
845 | for (i = 0; i < w*h; i++) |
846 | if (!soln[i]) |
847 | return 2; /* failed to converge */ |
848 | return 1; /* success */ |
849 | } |
850 | |
851 | /* |
852 | * Filled-grid generator. |
853 | */ |
854 | static void slant_generate(int w, int h, signed char *soln, random_state *rs) |
855 | { |
856 | int W = w+1, H = h+1; |
857 | int x, y, i; |
b926ba00 |
858 | int *connected, *indices; |
f1010613 |
859 | |
860 | /* |
861 | * Clear the output. |
862 | */ |
863 | memset(soln, 0, w*h); |
864 | |
865 | /* |
866 | * Establish a disjoint set forest for tracking connectedness |
867 | * between grid points. |
868 | */ |
b926ba00 |
869 | connected = snewn(W*H, int); |
f1010613 |
870 | for (i = 0; i < W*H; i++) |
b926ba00 |
871 | connected[i] = i; /* initially all distinct */ |
f1010613 |
872 | |
873 | /* |
874 | * Prepare a list of the squares in the grid, and fill them in |
875 | * in a random order. |
876 | */ |
877 | indices = snewn(w*h, int); |
878 | for (i = 0; i < w*h; i++) |
879 | indices[i] = i; |
880 | shuffle(indices, w*h, sizeof(*indices), rs); |
881 | |
882 | /* |
883 | * Fill in each one in turn. |
884 | */ |
885 | for (i = 0; i < w*h; i++) { |
886 | int fs, bs, v; |
887 | |
888 | y = indices[i] / w; |
889 | x = indices[i] % w; |
890 | |
b926ba00 |
891 | fs = (dsf_canonify(connected, y*W+x) == |
892 | dsf_canonify(connected, (y+1)*W+(x+1))); |
893 | bs = (dsf_canonify(connected, (y+1)*W+x) == |
894 | dsf_canonify(connected, y*W+(x+1))); |
f1010613 |
895 | |
896 | /* |
897 | * It isn't possible to get into a situation where we |
898 | * aren't allowed to place _either_ type of slash in a |
b926ba00 |
899 | * square. Thus, filled-grid generation never has to |
900 | * backtrack. |
f1010613 |
901 | * |
902 | * Proof (thanks to Gareth Taylor): |
903 | * |
904 | * If it were possible, it would have to be because there |
905 | * was an existing path (not using this square) between the |
906 | * top-left and bottom-right corners of this square, and |
907 | * another between the other two. These two paths would |
908 | * have to cross at some point. |
909 | * |
910 | * Obviously they can't cross in the middle of a square, so |
911 | * they must cross by sharing a point in common. But this |
912 | * isn't possible either: if you chessboard-colour all the |
913 | * points on the grid, you find that any continuous |
914 | * diagonal path is entirely composed of points of the same |
915 | * colour. And one of our two hypothetical paths is between |
916 | * two black points, and the other is between two white |
917 | * points - therefore they can have no point in common. [] |
918 | */ |
919 | assert(!(fs && bs)); |
920 | |
921 | v = fs ? +1 : bs ? -1 : 2 * random_upto(rs, 2) - 1; |
b926ba00 |
922 | fill_square(w, h, x, y, v, soln, connected, NULL); |
f1010613 |
923 | } |
924 | |
925 | sfree(indices); |
b926ba00 |
926 | sfree(connected); |
f1010613 |
927 | } |
928 | |
929 | static char *new_game_desc(game_params *params, random_state *rs, |
930 | char **aux, int interactive) |
931 | { |
932 | int w = params->w, h = params->h, W = w+1, H = h+1; |
933 | signed char *soln, *tmpsoln, *clues; |
934 | int *clueindices; |
935 | struct solver_scratch *sc; |
b926ba00 |
936 | int x, y, v, i, j; |
f1010613 |
937 | char *desc; |
938 | |
939 | soln = snewn(w*h, signed char); |
940 | tmpsoln = snewn(w*h, signed char); |
941 | clues = snewn(W*H, signed char); |
942 | clueindices = snewn(W*H, int); |
943 | sc = new_scratch(w, h); |
944 | |
945 | do { |
946 | /* |
947 | * Create the filled grid. |
948 | */ |
949 | slant_generate(w, h, soln, rs); |
950 | |
951 | /* |
952 | * Fill in the complete set of clues. |
953 | */ |
954 | for (y = 0; y < H; y++) |
955 | for (x = 0; x < W; x++) { |
956 | v = 0; |
957 | |
958 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == -1) v++; |
959 | if (x > 0 && y < h && soln[y*w+(x-1)] == +1) v++; |
960 | if (x < w && y > 0 && soln[(y-1)*w+x] == +1) v++; |
961 | if (x < w && y < h && soln[y*w+x] == -1) v++; |
962 | |
963 | clues[y*W+x] = v; |
964 | } |
f1010613 |
965 | |
b926ba00 |
966 | /* |
967 | * With all clue points filled in, all puzzles are easy: we can |
968 | * simply process the clue points in lexicographic order, and |
969 | * at each clue point we will always have at most one square |
970 | * undecided, which we can then fill in uniquely. |
971 | */ |
972 | assert(slant_solve(w, h, clues, tmpsoln, sc, DIFF_EASY) == 1); |
973 | |
974 | /* |
975 | * Remove as many clues as possible while retaining solubility. |
976 | * |
977 | * In DIFF_HARD mode, we prioritise the removal of obvious |
978 | * starting points (4s, 0s, border 2s and corner 1s), on |
979 | * the grounds that having as few of these as possible |
980 | * seems like a good thing. In particular, we can often get |
981 | * away without _any_ completely obvious starting points, |
982 | * which is even better. |
983 | */ |
984 | for (i = 0; i < W*H; i++) |
985 | clueindices[i] = i; |
986 | shuffle(clueindices, W*H, sizeof(*clueindices), rs); |
987 | for (j = 0; j < 2; j++) { |
988 | for (i = 0; i < W*H; i++) { |
989 | int pass, yb, xb; |
990 | |
991 | y = clueindices[i] / W; |
992 | x = clueindices[i] % W; |
993 | v = clues[y*W+x]; |
994 | |
995 | /* |
996 | * Identify which pass we should process this point |
997 | * in. If it's an obvious start point, _or_ we're |
998 | * in DIFF_EASY, then it goes in pass 0; otherwise |
999 | * pass 1. |
1000 | */ |
1001 | xb = (x == 0 || x == W-1); |
1002 | yb = (y == 0 || y == H-1); |
1003 | if (params->diff == DIFF_EASY || v == 4 || v == 0 || |
1004 | (v == 2 && (xb||yb)) || (v == 1 && xb && yb)) |
1005 | pass = 0; |
1006 | else |
1007 | pass = 1; |
1008 | |
1009 | if (pass == j) { |
1010 | clues[y*W+x] = -1; |
1011 | if (slant_solve(w, h, clues, tmpsoln, sc, |
1012 | params->diff) != 1) |
1013 | clues[y*W+x] = v; /* put it back */ |
1014 | } |
1015 | } |
1016 | } |
1017 | |
1018 | /* |
1019 | * And finally, verify that the grid is of _at least_ the |
1020 | * requested difficulty, by running the solver one level |
1021 | * down and verifying that it can't manage it. |
1022 | */ |
1023 | } while (params->diff > 0 && |
1024 | slant_solve(w, h, clues, tmpsoln, sc, params->diff - 1) <= 1); |
f1010613 |
1025 | |
1026 | /* |
1027 | * Now we have the clue set as it will be presented to the |
1028 | * user. Encode it in a game desc. |
1029 | */ |
1030 | { |
1031 | char *p; |
1032 | int run, i; |
1033 | |
1034 | desc = snewn(W*H+1, char); |
1035 | p = desc; |
1036 | run = 0; |
1037 | for (i = 0; i <= W*H; i++) { |
1038 | int n = (i < W*H ? clues[i] : -2); |
1039 | |
1040 | if (n == -1) |
1041 | run++; |
1042 | else { |
1043 | if (run) { |
1044 | while (run > 0) { |
1045 | int c = 'a' - 1 + run; |
1046 | if (run > 26) |
1047 | c = 'z'; |
1048 | *p++ = c; |
1049 | run -= c - ('a' - 1); |
1050 | } |
1051 | } |
1052 | if (n >= 0) |
1053 | *p++ = '0' + n; |
1054 | run = 0; |
1055 | } |
1056 | } |
1057 | assert(p - desc <= W*H); |
1058 | *p++ = '\0'; |
1059 | desc = sresize(desc, p - desc, char); |
1060 | } |
1061 | |
1062 | /* |
1063 | * Encode the solution as an aux_info. |
1064 | */ |
1065 | { |
1066 | char *auxbuf; |
1067 | *aux = auxbuf = snewn(w*h+1, char); |
1068 | for (i = 0; i < w*h; i++) |
1069 | auxbuf[i] = soln[i] < 0 ? '\\' : '/'; |
1070 | auxbuf[w*h] = '\0'; |
1071 | } |
1072 | |
1073 | free_scratch(sc); |
1074 | sfree(clueindices); |
1075 | sfree(clues); |
1076 | sfree(tmpsoln); |
1077 | sfree(soln); |
1078 | |
1079 | return desc; |
1080 | } |
1081 | |
1082 | static char *validate_desc(game_params *params, char *desc) |
1083 | { |
1084 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1085 | int area = W*H; |
1086 | int squares = 0; |
1087 | |
1088 | while (*desc) { |
1089 | int n = *desc++; |
1090 | if (n >= 'a' && n <= 'z') { |
1091 | squares += n - 'a' + 1; |
1092 | } else if (n >= '0' && n <= '4') { |
1093 | squares++; |
1094 | } else |
1095 | return "Invalid character in game description"; |
1096 | } |
1097 | |
1098 | if (squares < area) |
1099 | return "Not enough data to fill grid"; |
1100 | |
1101 | if (squares > area) |
1102 | return "Too much data to fit in grid"; |
1103 | |
1104 | return NULL; |
1105 | } |
1106 | |
dafd6cf6 |
1107 | static game_state *new_game(midend *me, game_params *params, char *desc) |
f1010613 |
1108 | { |
1109 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1110 | game_state *state = snew(game_state); |
1111 | int area = W*H; |
1112 | int squares = 0; |
1113 | |
1114 | state->p = *params; |
1115 | state->soln = snewn(w*h, signed char); |
1116 | memset(state->soln, 0, w*h); |
1117 | state->completed = state->used_solve = FALSE; |
9dc3c55b |
1118 | state->errors = snewn(W*H, unsigned char); |
1119 | memset(state->errors, 0, W*H); |
f1010613 |
1120 | |
1121 | state->clues = snew(game_clues); |
1122 | state->clues->w = w; |
1123 | state->clues->h = h; |
1124 | state->clues->clues = snewn(W*H, signed char); |
1125 | state->clues->refcount = 1; |
8aa366aa |
1126 | state->clues->tmpdsf = snewn(W*H, int); |
f1010613 |
1127 | memset(state->clues->clues, -1, W*H); |
1128 | while (*desc) { |
1129 | int n = *desc++; |
1130 | if (n >= 'a' && n <= 'z') { |
1131 | squares += n - 'a' + 1; |
1132 | } else if (n >= '0' && n <= '4') { |
1133 | state->clues->clues[squares++] = n - '0'; |
1134 | } else |
1135 | assert(!"can't get here"); |
1136 | } |
1137 | assert(squares == area); |
1138 | |
1139 | return state; |
1140 | } |
1141 | |
1142 | static game_state *dup_game(game_state *state) |
1143 | { |
9dc3c55b |
1144 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1145 | game_state *ret = snew(game_state); |
1146 | |
1147 | ret->p = state->p; |
1148 | ret->clues = state->clues; |
1149 | ret->clues->refcount++; |
1150 | ret->completed = state->completed; |
1151 | ret->used_solve = state->used_solve; |
1152 | |
1153 | ret->soln = snewn(w*h, signed char); |
1154 | memcpy(ret->soln, state->soln, w*h); |
1155 | |
9dc3c55b |
1156 | ret->errors = snewn(W*H, unsigned char); |
1157 | memcpy(ret->errors, state->errors, W*H); |
1158 | |
f1010613 |
1159 | return ret; |
1160 | } |
1161 | |
1162 | static void free_game(game_state *state) |
1163 | { |
9dc3c55b |
1164 | sfree(state->errors); |
986cc2de |
1165 | sfree(state->soln); |
1166 | assert(state->clues); |
1167 | if (--state->clues->refcount <= 0) { |
1168 | sfree(state->clues->clues); |
8aa366aa |
1169 | sfree(state->clues->tmpdsf); |
986cc2de |
1170 | sfree(state->clues); |
1171 | } |
f1010613 |
1172 | sfree(state); |
1173 | } |
1174 | |
9dc3c55b |
1175 | /* |
1176 | * Utility function to return the current degree of a vertex. If |
1177 | * `anti' is set, it returns the number of filled-in edges |
1178 | * surrounding the point which _don't_ connect to it; thus 4 minus |
1179 | * its anti-degree is the maximum degree it could have if all the |
1180 | * empty spaces around it were filled in. |
1181 | * |
1182 | * (Yes, _4_ minus its anti-degree even if it's a border vertex.) |
1183 | * |
1184 | * If ret > 0, *sx and *sy are set to the coordinates of one of the |
1185 | * squares that contributed to it. |
1186 | */ |
1187 | static int vertex_degree(int w, int h, signed char *soln, int x, int y, |
1188 | int anti, int *sx, int *sy) |
1189 | { |
1190 | int ret = 0; |
1191 | |
1192 | assert(x >= 0 && x <= w && y >= 0 && y <= h); |
1193 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] - anti < 0) { |
1194 | if (sx) *sx = x-1; |
1195 | if (sy) *sy = y-1; |
1196 | ret++; |
1197 | } |
1198 | if (x > 0 && y < h && soln[y*w+(x-1)] + anti > 0) { |
1199 | if (sx) *sx = x-1; |
1200 | if (sy) *sy = y; |
1201 | ret++; |
1202 | } |
1203 | if (x < w && y > 0 && soln[(y-1)*w+x] + anti > 0) { |
1204 | if (sx) *sx = x; |
1205 | if (sy) *sy = y-1; |
1206 | ret++; |
1207 | } |
1208 | if (x < w && y < h && soln[y*w+x] - anti < 0) { |
1209 | if (sx) *sx = x; |
1210 | if (sy) *sy = y; |
1211 | ret++; |
1212 | } |
1213 | |
1214 | return anti ? 4 - ret : ret; |
1215 | } |
1216 | |
f1010613 |
1217 | static int check_completion(game_state *state) |
1218 | { |
1219 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
8aa366aa |
1220 | int i, x, y, err = FALSE; |
1221 | int *dsf; |
9dc3c55b |
1222 | |
1223 | memset(state->errors, 0, W*H); |
f1010613 |
1224 | |
1225 | /* |
8aa366aa |
1226 | * To detect loops in the grid, we iterate through each edge |
1227 | * building up a dsf of connected components, and raise the |
1228 | * alarm whenever we find an edge that connects two |
1229 | * already-connected vertices. |
9dc3c55b |
1230 | * |
8aa366aa |
1231 | * We use the `tmpdsf' scratch space in the shared clues |
9dc3c55b |
1232 | * structure, to avoid mallocing too often. |
8aa366aa |
1233 | * |
1234 | * When we find such an edge, we then search around the grid to |
1235 | * find the loop it is a part of, so that we can highlight it |
1236 | * as an error for the user. We do this by the hand-on-one-wall |
1237 | * technique: the search will follow branches off the inside of |
1238 | * the loop, discover they're dead ends, and unhighlight them |
1239 | * again when returning to the actual loop. |
1240 | * |
1241 | * This technique guarantees that every loop it tracks will |
1242 | * surround a disjoint area of the grid (since if an existing |
1243 | * loop appears on the boundary of a new one, so that there are |
1244 | * multiple possible paths that would come back to the starting |
1245 | * point, it will pick the one that allows it to turn right |
1246 | * most sharply and hence the one that does not re-surround the |
1247 | * area of the previous one). Thus, the total time taken in |
1248 | * searching round loops is linear in the grid area since every |
1249 | * edge is visited at most twice. |
f1010613 |
1250 | */ |
8aa366aa |
1251 | dsf = state->clues->tmpdsf; |
1252 | for (i = 0; i < W*H; i++) |
1253 | dsf[i] = i; /* initially all distinct */ |
1254 | for (y = 0; y < h; y++) |
1255 | for (x = 0; x < w; x++) { |
1256 | int i1, i2; |
1257 | |
1258 | if (state->soln[y*w+x] == 0) |
1259 | continue; |
1260 | if (state->soln[y*w+x] < 0) { |
1261 | i1 = y*W+x; |
1262 | i2 = (y+1)*W+(x+1); |
1263 | } else { |
1264 | i1 = y*W+(x+1); |
1265 | i2 = (y+1)*W+x; |
1266 | } |
1267 | |
9dc3c55b |
1268 | /* |
8aa366aa |
1269 | * Our edge connects i1 with i2. If they're already |
1270 | * connected, flag an error. Otherwise, link them. |
9dc3c55b |
1271 | */ |
8aa366aa |
1272 | if (dsf_canonify(dsf, i1) == dsf_canonify(dsf, i2)) { |
1273 | int x1, y1, x2, y2, dx, dy, dt, pass; |
f1010613 |
1274 | |
8aa366aa |
1275 | err = TRUE; |
1276 | |
1277 | /* |
1278 | * Now search around the boundary of the loop to |
1279 | * highlight it. |
1280 | * |
1281 | * We have to do this in two passes. The first |
1282 | * time, we toggle ERR_SQUARE_TMP on each edge; |
1283 | * this pass terminates with ERR_SQUARE_TMP set on |
1284 | * exactly the loop edges. In the second pass, we |
1285 | * trace round that loop again and turn |
1286 | * ERR_SQUARE_TMP into ERR_SQUARE. We have to do |
1287 | * this because otherwise we might cancel part of a |
1288 | * loop highlighted in a previous iteration of the |
1289 | * outer loop. |
1290 | */ |
1291 | |
1292 | for (pass = 0; pass < 2; pass++) { |
1293 | |
1294 | x1 = i1 % W; |
1295 | y1 = i1 / W; |
1296 | x2 = i2 % W; |
1297 | y2 = i2 / W; |
1298 | |
1299 | do { |
1300 | /* Mark this edge. */ |
1301 | if (pass == 0) { |
1302 | state->errors[min(y1,y2)*W+min(x1,x2)] ^= |
1303 | ERR_SQUARE_TMP; |
1304 | } else { |
1305 | state->errors[min(y1,y2)*W+min(x1,x2)] |= |
1306 | ERR_SQUARE; |
1307 | state->errors[min(y1,y2)*W+min(x1,x2)] &= |
1308 | ~ERR_SQUARE_TMP; |
1309 | } |
1310 | |
1311 | /* |
1312 | * Progress to the next edge by turning as |
1313 | * sharply right as possible. In fact we do |
1314 | * this by facing back along the edge and |
1315 | * turning _left_ until we see an edge we |
1316 | * can follow. |
1317 | */ |
1318 | dx = x1 - x2; |
1319 | dy = y1 - y2; |
1320 | |
1321 | for (i = 0; i < 4; i++) { |
1322 | /* |
1323 | * Rotate (dx,dy) to the left. |
1324 | */ |
1325 | dt = dx; dx = dy; dy = -dt; |
1326 | |
1327 | /* |
1328 | * See if (x2,y2) has an edge in direction |
1329 | * (dx,dy). |
1330 | */ |
1331 | if (x2+dx < 0 || x2+dx >= W || |
1332 | y2+dy < 0 || y2+dy >= H) |
1333 | continue; /* off the side of the grid */ |
1334 | /* In the second pass, ignore unmarked edges. */ |
1335 | if (pass == 1 && |
1336 | !(state->errors[(y2-(dy<0))*W+x2-(dx<0)] & |
1337 | ERR_SQUARE_TMP)) |
1338 | continue; |
1339 | if (state->soln[(y2-(dy<0))*w+x2-(dx<0)] == |
1340 | (dx==dy ? -1 : +1)) |
1341 | break; |
1342 | } |
1343 | |
1344 | /* |
1345 | * In pass 0, we expect to have found |
1346 | * _some_ edge we can follow, even if it |
1347 | * was found by rotating all the way round |
1348 | * and going back the way we came. |
1349 | * |
1350 | * In pass 1, because we're removing the |
1351 | * mark on each edge that allows us to |
1352 | * follow it, we expect to find _no_ edge |
1353 | * we can follow when we've come all the |
1354 | * way round the loop. |
1355 | */ |
1356 | if (pass == 1 && i == 4) |
1357 | break; |
1358 | assert(i < 4); |
1359 | |
1360 | /* |
1361 | * Set x1,y1 to x2,y2, and x2,y2 to be the |
1362 | * other end of the new edge. |
1363 | */ |
1364 | x1 = x2; |
1365 | y1 = y2; |
1366 | x2 += dx; |
1367 | y2 += dy; |
1368 | } while (y2*W+x2 != i2); |
1369 | |
1370 | } |
1371 | |
1372 | } else |
1373 | dsf_merge(dsf, i1, i2); |
1374 | } |
f1010613 |
1375 | |
1376 | /* |
9dc3c55b |
1377 | * Now go through and check the degree of each clue vertex, and |
1378 | * mark it with ERR_VERTEX if it cannot be fulfilled. |
f1010613 |
1379 | */ |
1380 | for (y = 0; y < H; y++) |
9dc3c55b |
1381 | for (x = 0; x < W; x++) { |
1382 | int c; |
f1010613 |
1383 | |
1384 | if ((c = state->clues->clues[y*W+x]) < 0) |
1385 | continue; |
1386 | |
9dc3c55b |
1387 | /* |
1388 | * Check to see if there are too many connections to |
1389 | * this vertex _or_ too many non-connections. Either is |
1390 | * grounds for marking the vertex as erroneous. |
1391 | */ |
1392 | if (vertex_degree(w, h, state->soln, x, y, |
1393 | FALSE, NULL, NULL) > c || |
1394 | vertex_degree(w, h, state->soln, x, y, |
1395 | TRUE, NULL, NULL) > 4-c) { |
1396 | state->errors[y*W+x] |= ERR_VERTEX; |
1397 | err = TRUE; |
1398 | } |
1399 | } |
1400 | |
1401 | /* |
1402 | * Now our actual victory condition is that (a) none of the |
1403 | * above code marked anything as erroneous, and (b) every |
1404 | * square has an edge in it. |
1405 | */ |
f1010613 |
1406 | |
9dc3c55b |
1407 | if (err) |
1408 | return FALSE; |
f1010613 |
1409 | |
9dc3c55b |
1410 | for (y = 0; y < h; y++) |
1411 | for (x = 0; x < w; x++) |
1412 | if (state->soln[y*w+x] == 0) |
f1010613 |
1413 | return FALSE; |
f1010613 |
1414 | |
1415 | return TRUE; |
1416 | } |
1417 | |
1418 | static char *solve_game(game_state *state, game_state *currstate, |
1419 | char *aux, char **error) |
1420 | { |
1421 | int w = state->p.w, h = state->p.h; |
1422 | signed char *soln; |
1423 | int bs, ret; |
1424 | int free_soln = FALSE; |
1425 | char *move, buf[80]; |
1426 | int movelen, movesize; |
1427 | int x, y; |
1428 | |
1429 | if (aux) { |
1430 | /* |
1431 | * If we already have the solution, save ourselves some |
1432 | * time. |
1433 | */ |
1434 | soln = (signed char *)aux; |
1435 | bs = (signed char)'\\'; |
1436 | free_soln = FALSE; |
1437 | } else { |
1438 | struct solver_scratch *sc = new_scratch(w, h); |
1439 | soln = snewn(w*h, signed char); |
1440 | bs = -1; |
b926ba00 |
1441 | ret = slant_solve(w, h, state->clues->clues, soln, sc, DIFF_HARD); |
f1010613 |
1442 | free_scratch(sc); |
1443 | if (ret != 1) { |
1444 | sfree(soln); |
1445 | if (ret == 0) |
8349ac38 |
1446 | *error = "This puzzle is not self-consistent"; |
f1010613 |
1447 | else |
8349ac38 |
1448 | *error = "Unable to find a unique solution for this puzzle"; |
1449 | return NULL; |
f1010613 |
1450 | } |
1451 | free_soln = TRUE; |
1452 | } |
1453 | |
1454 | /* |
1455 | * Construct a move string which turns the current state into |
1456 | * the solved state. |
1457 | */ |
1458 | movesize = 256; |
1459 | move = snewn(movesize, char); |
1460 | movelen = 0; |
1461 | move[movelen++] = 'S'; |
1462 | move[movelen] = '\0'; |
1463 | for (y = 0; y < h; y++) |
1464 | for (x = 0; x < w; x++) { |
1465 | int v = (soln[y*w+x] == bs ? -1 : +1); |
1466 | if (state->soln[y*w+x] != v) { |
986cc2de |
1467 | int len = sprintf(buf, ";%c%d,%d", (int)(v < 0 ? '\\' : '/'), x, y); |
f1010613 |
1468 | if (movelen + len >= movesize) { |
1469 | movesize = movelen + len + 256; |
1470 | move = sresize(move, movesize, char); |
1471 | } |
1472 | strcpy(move + movelen, buf); |
1473 | movelen += len; |
1474 | } |
1475 | } |
1476 | |
1477 | if (free_soln) |
1478 | sfree(soln); |
1479 | |
1480 | return move; |
1481 | } |
1482 | |
1483 | static char *game_text_format(game_state *state) |
1484 | { |
1485 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
1486 | int x, y, len; |
1487 | char *ret, *p; |
1488 | |
1489 | /* |
1490 | * There are h+H rows of w+W columns. |
1491 | */ |
1492 | len = (h+H) * (w+W+1) + 1; |
1493 | ret = snewn(len, char); |
1494 | p = ret; |
1495 | |
1496 | for (y = 0; y < H; y++) { |
1497 | for (x = 0; x < W; x++) { |
1498 | if (state->clues->clues[y*W+x] >= 0) |
1499 | *p++ = state->clues->clues[y*W+x] + '0'; |
1500 | else |
1501 | *p++ = '+'; |
1502 | if (x < w) |
1503 | *p++ = '-'; |
1504 | } |
1505 | *p++ = '\n'; |
1506 | if (y < h) { |
1507 | for (x = 0; x < W; x++) { |
1508 | *p++ = '|'; |
1509 | if (x < w) { |
1510 | if (state->soln[y*w+x] != 0) |
1511 | *p++ = (state->soln[y*w+x] < 0 ? '\\' : '/'); |
1512 | else |
1513 | *p++ = ' '; |
1514 | } |
1515 | } |
1516 | *p++ = '\n'; |
1517 | } |
1518 | } |
1519 | *p++ = '\0'; |
1520 | |
1521 | assert(p - ret == len); |
1522 | return ret; |
1523 | } |
1524 | |
1525 | static game_ui *new_ui(game_state *state) |
1526 | { |
1527 | return NULL; |
1528 | } |
1529 | |
1530 | static void free_ui(game_ui *ui) |
1531 | { |
1532 | } |
1533 | |
1534 | static char *encode_ui(game_ui *ui) |
1535 | { |
1536 | return NULL; |
1537 | } |
1538 | |
1539 | static void decode_ui(game_ui *ui, char *encoding) |
1540 | { |
1541 | } |
1542 | |
1543 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
1544 | game_state *newstate) |
1545 | { |
1546 | } |
1547 | |
1548 | #define PREFERRED_TILESIZE 32 |
1549 | #define TILESIZE (ds->tilesize) |
1550 | #define BORDER TILESIZE |
1551 | #define CLUE_RADIUS (TILESIZE / 3) |
1552 | #define CLUE_TEXTSIZE (TILESIZE / 2) |
1553 | #define COORD(x) ( (x) * TILESIZE + BORDER ) |
1554 | #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 ) |
1555 | |
1556 | #define FLASH_TIME 0.30F |
1557 | |
1558 | /* |
1559 | * Bit fields in the `grid' and `todraw' elements of the drawstate. |
1560 | */ |
9dc3c55b |
1561 | #define BACKSLASH 0x00000001L |
1562 | #define FORWSLASH 0x00000002L |
1563 | #define L_T 0x00000004L |
1564 | #define ERR_L_T 0x00000008L |
1565 | #define L_B 0x00000010L |
1566 | #define ERR_L_B 0x00000020L |
1567 | #define T_L 0x00000040L |
1568 | #define ERR_T_L 0x00000080L |
1569 | #define T_R 0x00000100L |
1570 | #define ERR_T_R 0x00000200L |
1571 | #define C_TL 0x00000400L |
1572 | #define ERR_C_TL 0x00000800L |
1573 | #define FLASH 0x00001000L |
1574 | #define ERRSLASH 0x00002000L |
1575 | #define ERR_TL 0x00004000L |
1576 | #define ERR_TR 0x00008000L |
1577 | #define ERR_BL 0x00010000L |
1578 | #define ERR_BR 0x00020000L |
f1010613 |
1579 | |
1580 | struct game_drawstate { |
1581 | int tilesize; |
1582 | int started; |
9dc3c55b |
1583 | long *grid; |
1584 | long *todraw; |
f1010613 |
1585 | }; |
1586 | |
1587 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
1588 | int x, int y, int button) |
1589 | { |
1590 | int w = state->p.w, h = state->p.h; |
1591 | |
1592 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
1593 | int v; |
1594 | char buf[80]; |
1595 | |
68bf6206 |
1596 | /* |
1597 | * This is an utterly awful hack which I should really sort out |
1598 | * by means of a proper configuration mechanism. One Slant |
1599 | * player has observed that they prefer the mouse buttons to |
1600 | * function exactly the opposite way round, so here's a |
1601 | * mechanism for environment-based configuration. I cache the |
1602 | * result in a global variable - yuck! - to avoid repeated |
1603 | * lookups. |
1604 | */ |
1605 | { |
1606 | static int swap_buttons = -1; |
1607 | if (swap_buttons < 0) { |
1608 | char *env = getenv("SLANT_SWAP_BUTTONS"); |
1609 | swap_buttons = (env && (env[0] == 'y' || env[0] == 'Y')); |
1610 | } |
1611 | if (swap_buttons) { |
1612 | if (button == LEFT_BUTTON) |
1613 | button = RIGHT_BUTTON; |
1614 | else |
1615 | button = LEFT_BUTTON; |
1616 | } |
1617 | } |
1618 | |
f1010613 |
1619 | x = FROMCOORD(x); |
1620 | y = FROMCOORD(y); |
1621 | if (x < 0 || y < 0 || x >= w || y >= h) |
1622 | return NULL; |
1623 | |
1624 | if (button == LEFT_BUTTON) { |
1625 | /* |
1626 | * Left-clicking cycles blank -> \ -> / -> blank. |
1627 | */ |
1628 | v = state->soln[y*w+x] - 1; |
1629 | if (v == -2) |
1630 | v = +1; |
1631 | } else { |
1632 | /* |
1633 | * Right-clicking cycles blank -> / -> \ -> blank. |
1634 | */ |
1635 | v = state->soln[y*w+x] + 1; |
1636 | if (v == +2) |
1637 | v = -1; |
1638 | } |
1639 | |
986cc2de |
1640 | sprintf(buf, "%c%d,%d", (int)(v==-1 ? '\\' : v==+1 ? '/' : 'C'), x, y); |
f1010613 |
1641 | return dupstr(buf); |
1642 | } |
1643 | |
1644 | return NULL; |
1645 | } |
1646 | |
1647 | static game_state *execute_move(game_state *state, char *move) |
1648 | { |
1649 | int w = state->p.w, h = state->p.h; |
1650 | char c; |
1651 | int x, y, n; |
1652 | game_state *ret = dup_game(state); |
1653 | |
1654 | while (*move) { |
1655 | c = *move; |
1656 | if (c == 'S') { |
1657 | ret->used_solve = TRUE; |
1658 | move++; |
1659 | } else if (c == '\\' || c == '/' || c == 'C') { |
1660 | move++; |
1661 | if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || |
1662 | x < 0 || y < 0 || x >= w || y >= h) { |
1663 | free_game(ret); |
1664 | return NULL; |
1665 | } |
1666 | ret->soln[y*w+x] = (c == '\\' ? -1 : c == '/' ? +1 : 0); |
1667 | move += n; |
1668 | } else { |
1669 | free_game(ret); |
1670 | return NULL; |
1671 | } |
1672 | if (*move == ';') |
1673 | move++; |
1674 | else if (*move) { |
1675 | free_game(ret); |
1676 | return NULL; |
1677 | } |
1678 | } |
1679 | |
9dc3c55b |
1680 | /* |
1681 | * We never clear the `completed' flag, but we must always |
1682 | * re-run the completion check because it also highlights |
1683 | * errors in the grid. |
1684 | */ |
1685 | ret->completed = check_completion(ret) || ret->completed; |
f1010613 |
1686 | |
1687 | return ret; |
1688 | } |
1689 | |
1690 | /* ---------------------------------------------------------------------- |
1691 | * Drawing routines. |
1692 | */ |
1693 | |
1694 | static void game_compute_size(game_params *params, int tilesize, |
1695 | int *x, int *y) |
1696 | { |
1697 | /* fool the macros */ |
1698 | struct dummy { int tilesize; } dummy = { tilesize }, *ds = &dummy; |
1699 | |
1700 | *x = 2 * BORDER + params->w * TILESIZE + 1; |
1701 | *y = 2 * BORDER + params->h * TILESIZE + 1; |
1702 | } |
1703 | |
dafd6cf6 |
1704 | static void game_set_size(drawing *dr, game_drawstate *ds, |
1705 | game_params *params, int tilesize) |
f1010613 |
1706 | { |
1707 | ds->tilesize = tilesize; |
1708 | } |
1709 | |
8266f3fc |
1710 | static float *game_colours(frontend *fe, int *ncolours) |
f1010613 |
1711 | { |
1712 | float *ret = snewn(3 * NCOLOURS, float); |
1713 | |
1714 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
1715 | |
1716 | ret[COL_GRID * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.7F; |
1717 | ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.7F; |
1718 | ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.7F; |
1719 | |
1720 | ret[COL_INK * 3 + 0] = 0.0F; |
1721 | ret[COL_INK * 3 + 1] = 0.0F; |
1722 | ret[COL_INK * 3 + 2] = 0.0F; |
1723 | |
e3478a4b |
1724 | ret[COL_SLANT1 * 3 + 0] = 0.0F; |
1725 | ret[COL_SLANT1 * 3 + 1] = 0.0F; |
1726 | ret[COL_SLANT1 * 3 + 2] = 0.0F; |
1727 | |
1728 | ret[COL_SLANT2 * 3 + 0] = 0.0F; |
1729 | ret[COL_SLANT2 * 3 + 1] = 0.0F; |
1730 | ret[COL_SLANT2 * 3 + 2] = 0.0F; |
1731 | |
9dc3c55b |
1732 | ret[COL_ERROR * 3 + 0] = 1.0F; |
1733 | ret[COL_ERROR * 3 + 1] = 0.0F; |
1734 | ret[COL_ERROR * 3 + 2] = 0.0F; |
1735 | |
f1010613 |
1736 | *ncolours = NCOLOURS; |
1737 | return ret; |
1738 | } |
1739 | |
dafd6cf6 |
1740 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
f1010613 |
1741 | { |
1742 | int w = state->p.w, h = state->p.h; |
1743 | int i; |
1744 | struct game_drawstate *ds = snew(struct game_drawstate); |
1745 | |
1746 | ds->tilesize = 0; |
1747 | ds->started = FALSE; |
9dc3c55b |
1748 | ds->grid = snewn((w+2)*(h+2), long); |
1749 | ds->todraw = snewn((w+2)*(h+2), long); |
1750 | for (i = 0; i < (w+2)*(h+2); i++) |
f1010613 |
1751 | ds->grid[i] = ds->todraw[i] = -1; |
1752 | |
1753 | return ds; |
1754 | } |
1755 | |
dafd6cf6 |
1756 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
f1010613 |
1757 | { |
986cc2de |
1758 | sfree(ds->todraw); |
f1010613 |
1759 | sfree(ds->grid); |
1760 | sfree(ds); |
1761 | } |
1762 | |
dafd6cf6 |
1763 | static void draw_clue(drawing *dr, game_drawstate *ds, |
1764 | int x, int y, long v, long err, int bg, int colour) |
f1010613 |
1765 | { |
1766 | char p[2]; |
dafd6cf6 |
1767 | int ccol = colour >= 0 ? colour : ((x ^ y) & 1) ? COL_SLANT1 : COL_SLANT2; |
1768 | int tcol = colour >= 0 ? colour : err ? COL_ERROR : COL_INK; |
f1010613 |
1769 | |
1770 | if (v < 0) |
1771 | return; |
1772 | |
1773 | p[0] = v + '0'; |
1774 | p[1] = '\0'; |
dafd6cf6 |
1775 | draw_circle(dr, COORD(x), COORD(y), CLUE_RADIUS, |
1776 | bg >= 0 ? bg : COL_BACKGROUND, ccol); |
1777 | draw_text(dr, COORD(x), COORD(y), FONT_VARIABLE, |
9dc3c55b |
1778 | CLUE_TEXTSIZE, ALIGN_VCENTRE|ALIGN_HCENTRE, tcol, p); |
f1010613 |
1779 | } |
1780 | |
dafd6cf6 |
1781 | static void draw_tile(drawing *dr, game_drawstate *ds, game_clues *clues, |
5788a57e |
1782 | int x, int y, long v) |
f1010613 |
1783 | { |
9dc3c55b |
1784 | int w = clues->w, h = clues->h, W = w+1 /*, H = h+1 */; |
e3478a4b |
1785 | int chesscolour = (x ^ y) & 1; |
1786 | int fscol = chesscolour ? COL_SLANT2 : COL_SLANT1; |
1787 | int bscol = chesscolour ? COL_SLANT1 : COL_SLANT2; |
f1010613 |
1788 | |
dafd6cf6 |
1789 | clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
f1010613 |
1790 | |
dafd6cf6 |
1791 | draw_rect(dr, COORD(x), COORD(y), TILESIZE, TILESIZE, |
f1010613 |
1792 | (v & FLASH) ? COL_GRID : COL_BACKGROUND); |
1793 | |
1794 | /* |
1795 | * Draw the grid lines. |
1796 | */ |
9dc3c55b |
1797 | if (x >= 0 && x < w && y >= 0) |
dafd6cf6 |
1798 | draw_rect(dr, COORD(x), COORD(y), TILESIZE+1, 1, COL_GRID); |
9dc3c55b |
1799 | if (x >= 0 && x < w && y < h) |
dafd6cf6 |
1800 | draw_rect(dr, COORD(x), COORD(y+1), TILESIZE+1, 1, COL_GRID); |
9dc3c55b |
1801 | if (y >= 0 && y < h && x >= 0) |
dafd6cf6 |
1802 | draw_rect(dr, COORD(x), COORD(y), 1, TILESIZE+1, COL_GRID); |
9dc3c55b |
1803 | if (y >= 0 && y < h && x < w) |
dafd6cf6 |
1804 | draw_rect(dr, COORD(x+1), COORD(y), 1, TILESIZE+1, COL_GRID); |
9dc3c55b |
1805 | if (x == -1 && y == -1) |
dafd6cf6 |
1806 | draw_rect(dr, COORD(x+1), COORD(y+1), 1, 1, COL_GRID); |
9dc3c55b |
1807 | if (x == -1 && y == h) |
dafd6cf6 |
1808 | draw_rect(dr, COORD(x+1), COORD(y), 1, 1, COL_GRID); |
9dc3c55b |
1809 | if (x == w && y == -1) |
dafd6cf6 |
1810 | draw_rect(dr, COORD(x), COORD(y+1), 1, 1, COL_GRID); |
9dc3c55b |
1811 | if (x == w && y == h) |
dafd6cf6 |
1812 | draw_rect(dr, COORD(x), COORD(y), 1, 1, COL_GRID); |
f1010613 |
1813 | |
1814 | /* |
1815 | * Draw the slash. |
1816 | */ |
1817 | if (v & BACKSLASH) { |
9dc3c55b |
1818 | int scol = (v & ERRSLASH) ? COL_ERROR : bscol; |
dafd6cf6 |
1819 | draw_line(dr, COORD(x), COORD(y), COORD(x+1), COORD(y+1), scol); |
1820 | draw_line(dr, COORD(x)+1, COORD(y), COORD(x+1), COORD(y+1)-1, |
9dc3c55b |
1821 | scol); |
dafd6cf6 |
1822 | draw_line(dr, COORD(x), COORD(y)+1, COORD(x+1)-1, COORD(y+1), |
9dc3c55b |
1823 | scol); |
f1010613 |
1824 | } else if (v & FORWSLASH) { |
9dc3c55b |
1825 | int scol = (v & ERRSLASH) ? COL_ERROR : fscol; |
dafd6cf6 |
1826 | draw_line(dr, COORD(x+1), COORD(y), COORD(x), COORD(y+1), scol); |
1827 | draw_line(dr, COORD(x+1)-1, COORD(y), COORD(x), COORD(y+1)-1, |
9dc3c55b |
1828 | scol); |
dafd6cf6 |
1829 | draw_line(dr, COORD(x+1), COORD(y)+1, COORD(x)+1, COORD(y+1), |
9dc3c55b |
1830 | scol); |
f1010613 |
1831 | } |
1832 | |
1833 | /* |
1834 | * Draw dots on the grid corners that appear if a slash is in a |
1835 | * neighbouring cell. |
1836 | */ |
9dc3c55b |
1837 | if (v & (L_T | BACKSLASH)) |
dafd6cf6 |
1838 | draw_rect(dr, COORD(x), COORD(y)+1, 1, 1, |
ae4bc2cf |
1839 | (v & ERR_L_T ? COL_ERROR : bscol)); |
9dc3c55b |
1840 | if (v & (L_B | FORWSLASH)) |
dafd6cf6 |
1841 | draw_rect(dr, COORD(x), COORD(y+1)-1, 1, 1, |
ae4bc2cf |
1842 | (v & ERR_L_B ? COL_ERROR : fscol)); |
9dc3c55b |
1843 | if (v & (T_L | BACKSLASH)) |
dafd6cf6 |
1844 | draw_rect(dr, COORD(x)+1, COORD(y), 1, 1, |
ae4bc2cf |
1845 | (v & ERR_T_L ? COL_ERROR : bscol)); |
9dc3c55b |
1846 | if (v & (T_R | FORWSLASH)) |
dafd6cf6 |
1847 | draw_rect(dr, COORD(x+1)-1, COORD(y), 1, 1, |
ae4bc2cf |
1848 | (v & ERR_T_R ? COL_ERROR : fscol)); |
9dc3c55b |
1849 | if (v & (C_TL | BACKSLASH)) |
dafd6cf6 |
1850 | draw_rect(dr, COORD(x), COORD(y), 1, 1, |
ae4bc2cf |
1851 | (v & ERR_C_TL ? COL_ERROR : bscol)); |
f1010613 |
1852 | |
1853 | /* |
1854 | * And finally the clues at the corners. |
1855 | */ |
9dc3c55b |
1856 | if (x >= 0 && y >= 0) |
dafd6cf6 |
1857 | draw_clue(dr, ds, x, y, clues->clues[y*W+x], v & ERR_TL, -1, -1); |
9dc3c55b |
1858 | if (x < w && y >= 0) |
dafd6cf6 |
1859 | draw_clue(dr, ds, x+1, y, clues->clues[y*W+(x+1)], v & ERR_TR, -1, -1); |
9dc3c55b |
1860 | if (x >= 0 && y < h) |
dafd6cf6 |
1861 | draw_clue(dr, ds, x, y+1, clues->clues[(y+1)*W+x], v & ERR_BL, -1, -1); |
9dc3c55b |
1862 | if (x < w && y < h) |
dafd6cf6 |
1863 | draw_clue(dr, ds, x+1, y+1, clues->clues[(y+1)*W+(x+1)], v & ERR_BR, |
1864 | -1, -1); |
f1010613 |
1865 | |
dafd6cf6 |
1866 | unclip(dr); |
1867 | draw_update(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
f1010613 |
1868 | } |
1869 | |
dafd6cf6 |
1870 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
f1010613 |
1871 | game_state *state, int dir, game_ui *ui, |
1872 | float animtime, float flashtime) |
1873 | { |
6c48bdb7 |
1874 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1875 | int x, y; |
1876 | int flashing; |
1877 | |
1878 | if (flashtime > 0) |
1879 | flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; |
1880 | else |
1881 | flashing = FALSE; |
1882 | |
1883 | if (!ds->started) { |
1884 | int ww, wh; |
1885 | game_compute_size(&state->p, TILESIZE, &ww, &wh); |
dafd6cf6 |
1886 | draw_rect(dr, 0, 0, ww, wh, COL_BACKGROUND); |
1887 | draw_update(dr, 0, 0, ww, wh); |
f1010613 |
1888 | ds->started = TRUE; |
1889 | } |
1890 | |
1891 | /* |
1892 | * Loop over the grid and work out where all the slashes are. |
1893 | * We need to do this because a slash in one square affects the |
1894 | * drawing of the next one along. |
1895 | */ |
9dc3c55b |
1896 | for (y = -1; y <= h; y++) |
1897 | for (x = -1; x <= w; x++) { |
1898 | if (x >= 0 && x < w && y >= 0 && y < h) |
1899 | ds->todraw[(y+1)*(w+2)+(x+1)] = flashing ? FLASH : 0; |
1900 | else |
1901 | ds->todraw[(y+1)*(w+2)+(x+1)] = 0; |
1902 | } |
f1010613 |
1903 | |
1904 | for (y = 0; y < h; y++) { |
1905 | for (x = 0; x < w; x++) { |
9dc3c55b |
1906 | int err = state->errors[y*W+x] & ERR_SQUARE; |
1907 | |
f1010613 |
1908 | if (state->soln[y*w+x] < 0) { |
9dc3c55b |
1909 | ds->todraw[(y+1)*(w+2)+(x+1)] |= BACKSLASH; |
1910 | ds->todraw[(y+2)*(w+2)+(x+1)] |= T_R; |
1911 | ds->todraw[(y+1)*(w+2)+(x+2)] |= L_B; |
1912 | ds->todraw[(y+2)*(w+2)+(x+2)] |= C_TL; |
1913 | if (err) { |
ae4bc2cf |
1914 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERRSLASH | |
1915 | ERR_T_L | ERR_L_T | ERR_C_TL; |
9dc3c55b |
1916 | ds->todraw[(y+2)*(w+2)+(x+1)] |= ERR_T_R; |
1917 | ds->todraw[(y+1)*(w+2)+(x+2)] |= ERR_L_B; |
1918 | ds->todraw[(y+2)*(w+2)+(x+2)] |= ERR_C_TL; |
1919 | } |
f1010613 |
1920 | } else if (state->soln[y*w+x] > 0) { |
9dc3c55b |
1921 | ds->todraw[(y+1)*(w+2)+(x+1)] |= FORWSLASH; |
1922 | ds->todraw[(y+1)*(w+2)+(x+2)] |= L_T | C_TL; |
1923 | ds->todraw[(y+2)*(w+2)+(x+1)] |= T_L | C_TL; |
1924 | if (err) { |
ae4bc2cf |
1925 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERRSLASH | |
1926 | ERR_L_B | ERR_T_R; |
9dc3c55b |
1927 | ds->todraw[(y+1)*(w+2)+(x+2)] |= ERR_L_T | ERR_C_TL; |
1928 | ds->todraw[(y+2)*(w+2)+(x+1)] |= ERR_T_L | ERR_C_TL; |
1929 | } |
f1010613 |
1930 | } |
1931 | } |
1932 | } |
1933 | |
9dc3c55b |
1934 | for (y = 0; y < H; y++) |
1935 | for (x = 0; x < W; x++) |
1936 | if (state->errors[y*W+x] & ERR_VERTEX) { |
1937 | ds->todraw[y*(w+2)+x] |= ERR_BR; |
1938 | ds->todraw[y*(w+2)+(x+1)] |= ERR_BL; |
1939 | ds->todraw[(y+1)*(w+2)+x] |= ERR_TR; |
1940 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERR_TL; |
1941 | } |
1942 | |
f1010613 |
1943 | /* |
1944 | * Now go through and draw the grid squares. |
1945 | */ |
9dc3c55b |
1946 | for (y = -1; y <= h; y++) { |
1947 | for (x = -1; x <= w; x++) { |
1948 | if (ds->todraw[(y+1)*(w+2)+(x+1)] != ds->grid[(y+1)*(w+2)+(x+1)]) { |
dafd6cf6 |
1949 | draw_tile(dr, ds, state->clues, x, y, |
9dc3c55b |
1950 | ds->todraw[(y+1)*(w+2)+(x+1)]); |
1951 | ds->grid[(y+1)*(w+2)+(x+1)] = ds->todraw[(y+1)*(w+2)+(x+1)]; |
f1010613 |
1952 | } |
1953 | } |
1954 | } |
1955 | } |
1956 | |
1957 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1958 | int dir, game_ui *ui) |
1959 | { |
1960 | return 0.0F; |
1961 | } |
1962 | |
1963 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
1964 | int dir, game_ui *ui) |
1965 | { |
1966 | if (!oldstate->completed && newstate->completed && |
1967 | !oldstate->used_solve && !newstate->used_solve) |
1968 | return FLASH_TIME; |
1969 | |
1970 | return 0.0F; |
1971 | } |
1972 | |
f1010613 |
1973 | static int game_timing_state(game_state *state, game_ui *ui) |
1974 | { |
1975 | return TRUE; |
1976 | } |
1977 | |
dafd6cf6 |
1978 | static void game_print_size(game_params *params, float *x, float *y) |
1979 | { |
1980 | int pw, ph; |
1981 | |
1982 | /* |
1983 | * I'll use 6mm squares by default. |
1984 | */ |
1985 | game_compute_size(params, 600, &pw, &ph); |
1986 | *x = pw / 100.0; |
1987 | *y = ph / 100.0; |
1988 | } |
1989 | |
1990 | static void game_print(drawing *dr, game_state *state, int tilesize) |
1991 | { |
1992 | int w = state->p.w, h = state->p.h, W = w+1; |
1993 | int ink = print_mono_colour(dr, 0); |
1994 | int paper = print_mono_colour(dr, 1); |
1995 | int x, y; |
1996 | |
1997 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
1998 | game_drawstate ads, *ds = &ads; |
4413ef0f |
1999 | game_set_size(dr, ds, NULL, tilesize); |
dafd6cf6 |
2000 | |
2001 | /* |
2002 | * Border. |
2003 | */ |
2004 | print_line_width(dr, TILESIZE / 16); |
2005 | draw_rect_outline(dr, COORD(0), COORD(0), w*TILESIZE, h*TILESIZE, ink); |
2006 | |
2007 | /* |
2008 | * Grid. |
2009 | */ |
2010 | print_line_width(dr, TILESIZE / 24); |
2011 | for (x = 1; x < w; x++) |
2012 | draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), ink); |
2013 | for (y = 1; y < h; y++) |
2014 | draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), ink); |
2015 | |
2016 | /* |
2017 | * Solution. |
2018 | */ |
2019 | print_line_width(dr, TILESIZE / 12); |
2020 | for (y = 0; y < h; y++) |
2021 | for (x = 0; x < w; x++) |
2022 | if (state->soln[y*w+x]) { |
2023 | int ly, ry; |
2024 | /* |
2025 | * To prevent nasty line-ending artefacts at |
2026 | * corners, I'll do something slightly cunning |
2027 | * here. |
2028 | */ |
2029 | clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
2030 | if (state->soln[y*w+x] < 0) |
2031 | ly = y-1, ry = y+2; |
2032 | else |
2033 | ry = y-1, ly = y+2; |
2034 | draw_line(dr, COORD(x-1), COORD(ly), COORD(x+2), COORD(ry), |
2035 | ink); |
2036 | unclip(dr); |
2037 | } |
2038 | |
2039 | /* |
2040 | * Clues. |
2041 | */ |
2042 | print_line_width(dr, TILESIZE / 24); |
2043 | for (y = 0; y <= h; y++) |
2044 | for (x = 0; x <= w; x++) |
2045 | draw_clue(dr, ds, x, y, state->clues->clues[y*W+x], |
2046 | FALSE, paper, ink); |
2047 | } |
2048 | |
f1010613 |
2049 | #ifdef COMBINED |
2050 | #define thegame slant |
2051 | #endif |
2052 | |
2053 | const struct game thegame = { |
2054 | "Slant", "games.slant", |
2055 | default_params, |
2056 | game_fetch_preset, |
2057 | decode_params, |
2058 | encode_params, |
2059 | free_params, |
2060 | dup_params, |
2061 | TRUE, game_configure, custom_params, |
2062 | validate_params, |
2063 | new_game_desc, |
2064 | validate_desc, |
2065 | new_game, |
2066 | dup_game, |
2067 | free_game, |
2068 | TRUE, solve_game, |
2069 | TRUE, game_text_format, |
2070 | new_ui, |
2071 | free_ui, |
2072 | encode_ui, |
2073 | decode_ui, |
2074 | game_changed_state, |
2075 | interpret_move, |
2076 | execute_move, |
2077 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
2078 | game_colours, |
2079 | game_new_drawstate, |
2080 | game_free_drawstate, |
2081 | game_redraw, |
2082 | game_anim_length, |
2083 | game_flash_length, |
dafd6cf6 |
2084 | TRUE, FALSE, game_print_size, game_print, |
ac9f41c4 |
2085 | FALSE, /* wants_statusbar */ |
f1010613 |
2086 | FALSE, game_timing_state, |
2705d374 |
2087 | 0, /* flags */ |
f1010613 |
2088 | }; |
b926ba00 |
2089 | |
2090 | #ifdef STANDALONE_SOLVER |
2091 | |
2092 | #include <stdarg.h> |
2093 | |
b926ba00 |
2094 | int main(int argc, char **argv) |
2095 | { |
2096 | game_params *p; |
2097 | game_state *s; |
2098 | char *id = NULL, *desc, *err; |
2099 | int grade = FALSE; |
ccda7394 |
2100 | int ret, diff, really_verbose = FALSE; |
b926ba00 |
2101 | struct solver_scratch *sc; |
2102 | |
2103 | while (--argc > 0) { |
2104 | char *p = *++argv; |
2105 | if (!strcmp(p, "-v")) { |
ccda7394 |
2106 | really_verbose = TRUE; |
b926ba00 |
2107 | } else if (!strcmp(p, "-g")) { |
2108 | grade = TRUE; |
2109 | } else if (*p == '-') { |
2110 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
2111 | return 1; |
2112 | } else { |
2113 | id = p; |
2114 | } |
2115 | } |
2116 | |
2117 | if (!id) { |
2118 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
2119 | return 1; |
2120 | } |
2121 | |
2122 | desc = strchr(id, ':'); |
2123 | if (!desc) { |
2124 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
2125 | return 1; |
2126 | } |
2127 | *desc++ = '\0'; |
2128 | |
2129 | p = default_params(); |
2130 | decode_params(p, id); |
2131 | err = validate_desc(p, desc); |
2132 | if (err) { |
2133 | fprintf(stderr, "%s: %s\n", argv[0], err); |
2134 | return 1; |
2135 | } |
2136 | s = new_game(NULL, p, desc); |
2137 | |
2138 | sc = new_scratch(p->w, p->h); |
2139 | |
ccda7394 |
2140 | /* |
2141 | * When solving an Easy puzzle, we don't want to bother the |
2142 | * user with Hard-level deductions. For this reason, we grade |
2143 | * the puzzle internally before doing anything else. |
2144 | */ |
8067a45b |
2145 | ret = -1; /* placate optimiser */ |
ccda7394 |
2146 | for (diff = 0; diff < DIFFCOUNT; diff++) { |
b926ba00 |
2147 | ret = slant_solve(p->w, p->h, s->clues->clues, |
ccda7394 |
2148 | s->soln, sc, diff); |
2149 | if (ret < 2) |
2150 | break; |
2151 | } |
2152 | |
2153 | if (diff == DIFFCOUNT) { |
2154 | if (grade) |
2155 | printf("Difficulty rating: harder than Hard, or ambiguous\n"); |
2156 | else |
2157 | printf("Unable to find a unique solution\n"); |
2158 | } else { |
2159 | if (grade) { |
b926ba00 |
2160 | if (ret == 0) |
2161 | printf("Difficulty rating: impossible (no solution exists)\n"); |
2162 | else if (ret == 1) |
ccda7394 |
2163 | printf("Difficulty rating: %s\n", slant_diffnames[diff]); |
2164 | } else { |
2165 | verbose = really_verbose; |
2166 | ret = slant_solve(p->w, p->h, s->clues->clues, |
2167 | s->soln, sc, diff); |
2168 | if (ret == 0) |
2169 | printf("Puzzle is inconsistent\n"); |
b926ba00 |
2170 | else |
ccda7394 |
2171 | fputs(game_text_format(s), stdout); |
b926ba00 |
2172 | } |
b926ba00 |
2173 | } |
2174 | |
2175 | return 0; |
2176 | } |
2177 | |
2178 | #endif |