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, |
f1010613 |
40 | NCOLOURS |
41 | }; |
42 | |
43 | struct game_params { |
44 | int w, h; |
45 | }; |
46 | |
47 | typedef struct game_clues { |
48 | int w, h; |
49 | signed char *clues; |
50 | int *dsf; /* scratch space for completion check */ |
51 | int refcount; |
52 | } game_clues; |
53 | |
54 | struct game_state { |
55 | struct game_params p; |
56 | game_clues *clues; |
57 | signed char *soln; |
58 | int completed; |
59 | int used_solve; /* used to suppress completion flash */ |
60 | }; |
61 | |
62 | static game_params *default_params(void) |
63 | { |
64 | game_params *ret = snew(game_params); |
65 | |
66 | ret->w = ret->h = 8; |
67 | |
68 | return ret; |
69 | } |
70 | |
71 | static const struct game_params slant_presets[] = { |
72 | {5, 5}, |
73 | {8, 8}, |
74 | {12, 10}, |
75 | }; |
76 | |
77 | static int game_fetch_preset(int i, char **name, game_params **params) |
78 | { |
79 | game_params *ret; |
80 | char str[80]; |
81 | |
82 | if (i < 0 || i >= lenof(slant_presets)) |
83 | return FALSE; |
84 | |
85 | ret = snew(game_params); |
86 | *ret = slant_presets[i]; |
87 | |
88 | sprintf(str, "%dx%d", ret->w, ret->h); |
89 | |
90 | *name = dupstr(str); |
91 | *params = ret; |
92 | return TRUE; |
93 | } |
94 | |
95 | static void free_params(game_params *params) |
96 | { |
97 | sfree(params); |
98 | } |
99 | |
100 | static game_params *dup_params(game_params *params) |
101 | { |
102 | game_params *ret = snew(game_params); |
103 | *ret = *params; /* structure copy */ |
104 | return ret; |
105 | } |
106 | |
107 | static void decode_params(game_params *ret, char const *string) |
108 | { |
109 | ret->w = ret->h = atoi(string); |
110 | while (*string && isdigit((unsigned char)*string)) string++; |
111 | if (*string == 'x') { |
112 | string++; |
113 | ret->h = atoi(string); |
114 | } |
115 | } |
116 | |
117 | static char *encode_params(game_params *params, int full) |
118 | { |
119 | char data[256]; |
120 | |
121 | sprintf(data, "%dx%d", params->w, params->h); |
122 | |
123 | return dupstr(data); |
124 | } |
125 | |
126 | static config_item *game_configure(game_params *params) |
127 | { |
128 | config_item *ret; |
129 | char buf[80]; |
130 | |
131 | ret = snewn(3, config_item); |
132 | |
133 | ret[0].name = "Width"; |
134 | ret[0].type = C_STRING; |
135 | sprintf(buf, "%d", params->w); |
136 | ret[0].sval = dupstr(buf); |
137 | ret[0].ival = 0; |
138 | |
139 | ret[1].name = "Height"; |
140 | ret[1].type = C_STRING; |
141 | sprintf(buf, "%d", params->h); |
142 | ret[1].sval = dupstr(buf); |
143 | ret[1].ival = 0; |
144 | |
145 | ret[2].name = NULL; |
146 | ret[2].type = C_END; |
147 | ret[2].sval = NULL; |
148 | ret[2].ival = 0; |
149 | |
150 | return ret; |
151 | } |
152 | |
153 | static game_params *custom_params(config_item *cfg) |
154 | { |
155 | game_params *ret = snew(game_params); |
156 | |
157 | ret->w = atoi(cfg[0].sval); |
158 | ret->h = atoi(cfg[1].sval); |
159 | |
160 | return ret; |
161 | } |
162 | |
163 | static char *validate_params(game_params *params, int full) |
164 | { |
165 | /* |
166 | * (At least at the time of writing this comment) The grid |
167 | * generator is actually capable of handling even zero grid |
168 | * dimensions without crashing. Puzzles with a zero-area grid |
169 | * are a bit boring, though, because they're already solved :-) |
170 | */ |
171 | |
172 | if (params->w < 1 || params->h < 1) |
173 | return "Width and height must both be at least one"; |
174 | |
175 | return NULL; |
176 | } |
177 | |
178 | /* |
179 | * Utility function used by both the solver and the filled-grid |
180 | * generator. |
181 | */ |
182 | |
183 | static void fill_square(int w, int h, int y, int x, int v, |
184 | signed char *soln, int *dsf) |
185 | { |
186 | int W = w+1 /*, H = h+1 */; |
187 | |
188 | soln[y*w+x] = v; |
189 | |
190 | if (v < 0) |
191 | dsf_merge(dsf, y*W+x, (y+1)*W+(x+1)); |
192 | else |
193 | dsf_merge(dsf, y*W+(x+1), (y+1)*W+x); |
194 | } |
195 | |
196 | /* |
197 | * Scratch space for solver. |
198 | */ |
199 | struct solver_scratch { |
200 | int *dsf; |
201 | }; |
202 | |
986cc2de |
203 | static struct solver_scratch *new_scratch(int w, int h) |
f1010613 |
204 | { |
205 | int W = w+1, H = h+1; |
206 | struct solver_scratch *ret = snew(struct solver_scratch); |
207 | ret->dsf = snewn(W*H, int); |
208 | return ret; |
209 | } |
210 | |
986cc2de |
211 | static void free_scratch(struct solver_scratch *sc) |
f1010613 |
212 | { |
213 | sfree(sc->dsf); |
214 | sfree(sc); |
215 | } |
216 | |
217 | /* |
218 | * Solver. Returns 0 for impossibility, 1 for success, 2 for |
219 | * ambiguity or failure to converge. |
220 | */ |
221 | static int slant_solve(int w, int h, const signed char *clues, |
222 | signed char *soln, struct solver_scratch *sc) |
223 | { |
224 | int W = w+1, H = h+1; |
225 | int x, y, i; |
226 | int done_something; |
227 | |
228 | /* |
229 | * Clear the output. |
230 | */ |
231 | memset(soln, 0, w*h); |
232 | |
233 | /* |
234 | * Establish a disjoint set forest for tracking connectedness |
235 | * between grid points. |
236 | */ |
237 | for (i = 0; i < W*H; i++) |
238 | sc->dsf[i] = i; /* initially all distinct */ |
239 | |
240 | /* |
241 | * Repeatedly try to deduce something until we can't. |
242 | */ |
243 | do { |
244 | done_something = FALSE; |
245 | |
246 | /* |
247 | * Any clue point with the number of remaining lines equal |
248 | * to zero or to the number of remaining undecided |
249 | * neighbouring squares can be filled in completely. |
250 | */ |
251 | for (y = 0; y < H; y++) |
252 | for (x = 0; x < W; x++) { |
253 | int nu, nl, v, c; |
254 | |
255 | if ((c = clues[y*W+x]) < 0) |
256 | continue; |
257 | |
258 | /* |
259 | * We have a clue point. Count up the number of |
260 | * undecided neighbours, and also the number of |
261 | * lines already present. |
262 | */ |
263 | nu = 0; |
264 | nl = c; |
265 | if (x > 0 && y > 0 && (v = soln[(y-1)*w+(x-1)]) != +1) |
266 | v == 0 ? nu++ : nl--; |
267 | if (x > 0 && y < h && (v = soln[y*w+(x-1)]) != -1) |
268 | v == 0 ? nu++ : nl--; |
269 | if (x < w && y > 0 && (v = soln[(y-1)*w+x]) != -1) |
270 | v == 0 ? nu++ : nl--; |
271 | if (x < w && y < h && (v = soln[y*w+x]) != +1) |
272 | v == 0 ? nu++ : nl--; |
273 | |
274 | /* |
275 | * Check the counts. |
276 | */ |
277 | if (nl < 0 || nl > nu) { |
278 | /* |
279 | * No consistent value for this at all! |
280 | */ |
281 | return 0; /* impossible */ |
282 | } |
283 | |
284 | if (nu > 0 && (nl == 0 || nl == nu)) { |
285 | #ifdef SOLVER_DIAGNOSTICS |
286 | printf("%s around clue point at %d,%d\n", |
287 | nl ? "filling" : "emptying", x, y); |
288 | #endif |
289 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == 0) |
290 | fill_square(w, h, y-1, x-1, (nl ? -1 : +1), soln, |
291 | sc->dsf); |
292 | if (x > 0 && y < h && soln[y*w+(x-1)] == 0) |
293 | fill_square(w, h, y, x-1, (nl ? +1 : -1), soln, |
294 | sc->dsf); |
295 | if (x < w && y > 0 && soln[(y-1)*w+x] == 0) |
296 | fill_square(w, h, y-1, x, (nl ? +1 : -1), soln, |
297 | sc->dsf); |
298 | if (x < w && y < h && soln[y*w+x] == 0) |
299 | fill_square(w, h, y, x, (nl ? -1 : +1), soln, |
300 | sc->dsf); |
301 | |
302 | done_something = TRUE; |
303 | } |
304 | } |
305 | |
306 | if (done_something) |
307 | continue; |
308 | |
309 | /* |
310 | * Failing that, we now apply the second condition, which |
311 | * is that no square may be filled in such a way as to form |
312 | * a loop. |
313 | */ |
314 | for (y = 0; y < h; y++) |
315 | for (x = 0; x < w; x++) { |
316 | int fs, bs; |
317 | |
318 | if (soln[y*w+x]) |
319 | continue; /* got this one already */ |
320 | |
321 | fs = (dsf_canonify(sc->dsf, y*W+x) == |
322 | dsf_canonify(sc->dsf, (y+1)*W+(x+1))); |
323 | bs = (dsf_canonify(sc->dsf, (y+1)*W+x) == |
324 | dsf_canonify(sc->dsf, y*W+(x+1))); |
325 | |
326 | if (fs && bs) { |
327 | /* |
328 | * Loop avoidance leaves no consistent value |
329 | * for this at all! |
330 | */ |
331 | return 0; /* impossible */ |
332 | } |
333 | |
334 | if (fs) { |
335 | /* |
336 | * Top left and bottom right corners of this |
337 | * square are already connected, which means we |
338 | * aren't allowed to put a backslash in here. |
339 | */ |
340 | #ifdef SOLVER_DIAGNOSTICS |
341 | printf("placing / in %d,%d by loop avoidance\n", x, y); |
342 | #endif |
343 | fill_square(w, h, y, x, +1, soln, sc->dsf); |
344 | done_something = TRUE; |
345 | } else if (bs) { |
346 | /* |
347 | * Top right and bottom left corners of this |
348 | * square are already connected, which means we |
349 | * aren't allowed to put a forward slash in |
350 | * here. |
351 | */ |
352 | #ifdef SOLVER_DIAGNOSTICS |
353 | printf("placing \\ in %d,%d by loop avoidance\n", x, y); |
354 | #endif |
355 | fill_square(w, h, y, x, -1, soln, sc->dsf); |
356 | done_something = TRUE; |
357 | } |
358 | } |
359 | |
360 | } while (done_something); |
361 | |
362 | /* |
363 | * Solver can make no more progress. See if the grid is full. |
364 | */ |
365 | for (i = 0; i < w*h; i++) |
366 | if (!soln[i]) |
367 | return 2; /* failed to converge */ |
368 | return 1; /* success */ |
369 | } |
370 | |
371 | /* |
372 | * Filled-grid generator. |
373 | */ |
374 | static void slant_generate(int w, int h, signed char *soln, random_state *rs) |
375 | { |
376 | int W = w+1, H = h+1; |
377 | int x, y, i; |
378 | int *dsf, *indices; |
379 | |
380 | /* |
381 | * Clear the output. |
382 | */ |
383 | memset(soln, 0, w*h); |
384 | |
385 | /* |
386 | * Establish a disjoint set forest for tracking connectedness |
387 | * between grid points. |
388 | */ |
389 | dsf = snewn(W*H, int); |
390 | for (i = 0; i < W*H; i++) |
391 | dsf[i] = i; /* initially all distinct */ |
392 | |
393 | /* |
394 | * Prepare a list of the squares in the grid, and fill them in |
395 | * in a random order. |
396 | */ |
397 | indices = snewn(w*h, int); |
398 | for (i = 0; i < w*h; i++) |
399 | indices[i] = i; |
400 | shuffle(indices, w*h, sizeof(*indices), rs); |
401 | |
402 | /* |
403 | * Fill in each one in turn. |
404 | */ |
405 | for (i = 0; i < w*h; i++) { |
406 | int fs, bs, v; |
407 | |
408 | y = indices[i] / w; |
409 | x = indices[i] % w; |
410 | |
411 | fs = (dsf_canonify(dsf, y*W+x) == |
412 | dsf_canonify(dsf, (y+1)*W+(x+1))); |
413 | bs = (dsf_canonify(dsf, (y+1)*W+x) == |
414 | dsf_canonify(dsf, y*W+(x+1))); |
415 | |
416 | /* |
417 | * It isn't possible to get into a situation where we |
418 | * aren't allowed to place _either_ type of slash in a |
419 | * square. |
420 | * |
421 | * Proof (thanks to Gareth Taylor): |
422 | * |
423 | * If it were possible, it would have to be because there |
424 | * was an existing path (not using this square) between the |
425 | * top-left and bottom-right corners of this square, and |
426 | * another between the other two. These two paths would |
427 | * have to cross at some point. |
428 | * |
429 | * Obviously they can't cross in the middle of a square, so |
430 | * they must cross by sharing a point in common. But this |
431 | * isn't possible either: if you chessboard-colour all the |
432 | * points on the grid, you find that any continuous |
433 | * diagonal path is entirely composed of points of the same |
434 | * colour. And one of our two hypothetical paths is between |
435 | * two black points, and the other is between two white |
436 | * points - therefore they can have no point in common. [] |
437 | */ |
438 | assert(!(fs && bs)); |
439 | |
440 | v = fs ? +1 : bs ? -1 : 2 * random_upto(rs, 2) - 1; |
441 | fill_square(w, h, y, x, v, soln, dsf); |
442 | } |
443 | |
444 | sfree(indices); |
445 | sfree(dsf); |
446 | } |
447 | |
448 | static char *new_game_desc(game_params *params, random_state *rs, |
449 | char **aux, int interactive) |
450 | { |
451 | int w = params->w, h = params->h, W = w+1, H = h+1; |
452 | signed char *soln, *tmpsoln, *clues; |
453 | int *clueindices; |
454 | struct solver_scratch *sc; |
455 | int x, y, v, i; |
456 | char *desc; |
457 | |
458 | soln = snewn(w*h, signed char); |
459 | tmpsoln = snewn(w*h, signed char); |
460 | clues = snewn(W*H, signed char); |
461 | clueindices = snewn(W*H, int); |
462 | sc = new_scratch(w, h); |
463 | |
464 | do { |
465 | /* |
466 | * Create the filled grid. |
467 | */ |
468 | slant_generate(w, h, soln, rs); |
469 | |
470 | /* |
471 | * Fill in the complete set of clues. |
472 | */ |
473 | for (y = 0; y < H; y++) |
474 | for (x = 0; x < W; x++) { |
475 | v = 0; |
476 | |
477 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == -1) v++; |
478 | if (x > 0 && y < h && soln[y*w+(x-1)] == +1) v++; |
479 | if (x < w && y > 0 && soln[(y-1)*w+x] == +1) v++; |
480 | if (x < w && y < h && soln[y*w+x] == -1) v++; |
481 | |
482 | clues[y*W+x] = v; |
483 | } |
484 | } while (slant_solve(w, h, clues, tmpsoln, sc) != 1); |
485 | |
486 | /* |
487 | * Remove as many clues as possible while retaining solubility. |
488 | */ |
489 | for (i = 0; i < W*H; i++) |
490 | clueindices[i] = i; |
491 | shuffle(clueindices, W*H, sizeof(*clueindices), rs); |
492 | for (i = 0; i < W*H; i++) { |
493 | y = clueindices[i] / W; |
494 | x = clueindices[i] % W; |
495 | v = clues[y*W+x]; |
496 | clues[y*W+x] = -1; |
497 | if (slant_solve(w, h, clues, tmpsoln, sc) != 1) |
498 | clues[y*W+x] = v; /* put it back */ |
499 | } |
500 | |
501 | /* |
502 | * Now we have the clue set as it will be presented to the |
503 | * user. Encode it in a game desc. |
504 | */ |
505 | { |
506 | char *p; |
507 | int run, i; |
508 | |
509 | desc = snewn(W*H+1, char); |
510 | p = desc; |
511 | run = 0; |
512 | for (i = 0; i <= W*H; i++) { |
513 | int n = (i < W*H ? clues[i] : -2); |
514 | |
515 | if (n == -1) |
516 | run++; |
517 | else { |
518 | if (run) { |
519 | while (run > 0) { |
520 | int c = 'a' - 1 + run; |
521 | if (run > 26) |
522 | c = 'z'; |
523 | *p++ = c; |
524 | run -= c - ('a' - 1); |
525 | } |
526 | } |
527 | if (n >= 0) |
528 | *p++ = '0' + n; |
529 | run = 0; |
530 | } |
531 | } |
532 | assert(p - desc <= W*H); |
533 | *p++ = '\0'; |
534 | desc = sresize(desc, p - desc, char); |
535 | } |
536 | |
537 | /* |
538 | * Encode the solution as an aux_info. |
539 | */ |
540 | { |
541 | char *auxbuf; |
542 | *aux = auxbuf = snewn(w*h+1, char); |
543 | for (i = 0; i < w*h; i++) |
544 | auxbuf[i] = soln[i] < 0 ? '\\' : '/'; |
545 | auxbuf[w*h] = '\0'; |
546 | } |
547 | |
548 | free_scratch(sc); |
549 | sfree(clueindices); |
550 | sfree(clues); |
551 | sfree(tmpsoln); |
552 | sfree(soln); |
553 | |
554 | return desc; |
555 | } |
556 | |
557 | static char *validate_desc(game_params *params, char *desc) |
558 | { |
559 | int w = params->w, h = params->h, W = w+1, H = h+1; |
560 | int area = W*H; |
561 | int squares = 0; |
562 | |
563 | while (*desc) { |
564 | int n = *desc++; |
565 | if (n >= 'a' && n <= 'z') { |
566 | squares += n - 'a' + 1; |
567 | } else if (n >= '0' && n <= '4') { |
568 | squares++; |
569 | } else |
570 | return "Invalid character in game description"; |
571 | } |
572 | |
573 | if (squares < area) |
574 | return "Not enough data to fill grid"; |
575 | |
576 | if (squares > area) |
577 | return "Too much data to fit in grid"; |
578 | |
579 | return NULL; |
580 | } |
581 | |
582 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
583 | { |
584 | int w = params->w, h = params->h, W = w+1, H = h+1; |
585 | game_state *state = snew(game_state); |
586 | int area = W*H; |
587 | int squares = 0; |
588 | |
589 | state->p = *params; |
590 | state->soln = snewn(w*h, signed char); |
591 | memset(state->soln, 0, w*h); |
592 | state->completed = state->used_solve = FALSE; |
593 | |
594 | state->clues = snew(game_clues); |
595 | state->clues->w = w; |
596 | state->clues->h = h; |
597 | state->clues->clues = snewn(W*H, signed char); |
598 | state->clues->refcount = 1; |
599 | state->clues->dsf = snewn(W*H, int); |
600 | memset(state->clues->clues, -1, W*H); |
601 | while (*desc) { |
602 | int n = *desc++; |
603 | if (n >= 'a' && n <= 'z') { |
604 | squares += n - 'a' + 1; |
605 | } else if (n >= '0' && n <= '4') { |
606 | state->clues->clues[squares++] = n - '0'; |
607 | } else |
608 | assert(!"can't get here"); |
609 | } |
610 | assert(squares == area); |
611 | |
612 | return state; |
613 | } |
614 | |
615 | static game_state *dup_game(game_state *state) |
616 | { |
617 | int w = state->p.w, h = state->p.h; |
618 | game_state *ret = snew(game_state); |
619 | |
620 | ret->p = state->p; |
621 | ret->clues = state->clues; |
622 | ret->clues->refcount++; |
623 | ret->completed = state->completed; |
624 | ret->used_solve = state->used_solve; |
625 | |
626 | ret->soln = snewn(w*h, signed char); |
627 | memcpy(ret->soln, state->soln, w*h); |
628 | |
629 | return ret; |
630 | } |
631 | |
632 | static void free_game(game_state *state) |
633 | { |
986cc2de |
634 | sfree(state->soln); |
635 | assert(state->clues); |
636 | if (--state->clues->refcount <= 0) { |
637 | sfree(state->clues->clues); |
638 | sfree(state->clues->dsf); |
639 | sfree(state->clues); |
640 | } |
f1010613 |
641 | sfree(state); |
642 | } |
643 | |
644 | static int check_completion(game_state *state) |
645 | { |
646 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
647 | int i, x, y; |
648 | |
649 | /* |
650 | * Establish a disjoint set forest for tracking connectedness |
651 | * between grid points. Use the dsf scratch space in the shared |
652 | * clues structure, to avoid mallocing too often. |
653 | */ |
654 | for (i = 0; i < W*H; i++) |
655 | state->clues->dsf[i] = i; /* initially all distinct */ |
656 | |
657 | /* |
658 | * Now go through the grid checking connectedness. While we're |
659 | * here, also check that everything is filled in. |
660 | */ |
661 | for (y = 0; y < h; y++) |
662 | for (x = 0; x < w; x++) { |
663 | int i1, i2; |
664 | |
665 | if (state->soln[y*w+x] == 0) |
666 | return FALSE; |
667 | if (state->soln[y*w+x] < 0) { |
668 | i1 = y*W+x; |
669 | i2 = (y+1)*W+(x+1); |
670 | } else { |
671 | i1 = (y+1)*W+x; |
672 | i2 = y*W+(x+1); |
673 | } |
674 | |
675 | /* |
676 | * Our edge connects i1 with i2. If they're already |
677 | * connected, return failure. Otherwise, link them. |
678 | */ |
679 | if (dsf_canonify(state->clues->dsf, i1) == |
680 | dsf_canonify(state->clues->dsf, i2)) |
681 | return FALSE; |
682 | else |
683 | dsf_merge(state->clues->dsf, i1, i2); |
684 | } |
685 | |
686 | /* |
687 | * The grid is _a_ valid grid; let's see if it matches the |
688 | * clues. |
689 | */ |
690 | for (y = 0; y < H; y++) |
691 | for (x = 0; x < W; x++) { |
692 | int v, c; |
693 | |
694 | if ((c = state->clues->clues[y*W+x]) < 0) |
695 | continue; |
696 | |
697 | v = 0; |
698 | |
699 | if (x > 0 && y > 0 && state->soln[(y-1)*w+(x-1)] == -1) v++; |
700 | if (x > 0 && y < h && state->soln[y*w+(x-1)] == +1) v++; |
701 | if (x < w && y > 0 && state->soln[(y-1)*w+x] == +1) v++; |
702 | if (x < w && y < h && state->soln[y*w+x] == -1) v++; |
703 | |
704 | if (c != v) |
705 | return FALSE; |
706 | } |
707 | |
708 | return TRUE; |
709 | } |
710 | |
711 | static char *solve_game(game_state *state, game_state *currstate, |
712 | char *aux, char **error) |
713 | { |
714 | int w = state->p.w, h = state->p.h; |
715 | signed char *soln; |
716 | int bs, ret; |
717 | int free_soln = FALSE; |
718 | char *move, buf[80]; |
719 | int movelen, movesize; |
720 | int x, y; |
721 | |
722 | if (aux) { |
723 | /* |
724 | * If we already have the solution, save ourselves some |
725 | * time. |
726 | */ |
727 | soln = (signed char *)aux; |
728 | bs = (signed char)'\\'; |
729 | free_soln = FALSE; |
730 | } else { |
731 | struct solver_scratch *sc = new_scratch(w, h); |
732 | soln = snewn(w*h, signed char); |
733 | bs = -1; |
734 | ret = slant_solve(w, h, state->clues->clues, soln, sc); |
735 | free_scratch(sc); |
736 | if (ret != 1) { |
737 | sfree(soln); |
738 | if (ret == 0) |
8349ac38 |
739 | *error = "This puzzle is not self-consistent"; |
f1010613 |
740 | else |
8349ac38 |
741 | *error = "Unable to find a unique solution for this puzzle"; |
742 | return NULL; |
f1010613 |
743 | } |
744 | free_soln = TRUE; |
745 | } |
746 | |
747 | /* |
748 | * Construct a move string which turns the current state into |
749 | * the solved state. |
750 | */ |
751 | movesize = 256; |
752 | move = snewn(movesize, char); |
753 | movelen = 0; |
754 | move[movelen++] = 'S'; |
755 | move[movelen] = '\0'; |
756 | for (y = 0; y < h; y++) |
757 | for (x = 0; x < w; x++) { |
758 | int v = (soln[y*w+x] == bs ? -1 : +1); |
759 | if (state->soln[y*w+x] != v) { |
986cc2de |
760 | int len = sprintf(buf, ";%c%d,%d", (int)(v < 0 ? '\\' : '/'), x, y); |
f1010613 |
761 | if (movelen + len >= movesize) { |
762 | movesize = movelen + len + 256; |
763 | move = sresize(move, movesize, char); |
764 | } |
765 | strcpy(move + movelen, buf); |
766 | movelen += len; |
767 | } |
768 | } |
769 | |
770 | if (free_soln) |
771 | sfree(soln); |
772 | |
773 | return move; |
774 | } |
775 | |
776 | static char *game_text_format(game_state *state) |
777 | { |
778 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
779 | int x, y, len; |
780 | char *ret, *p; |
781 | |
782 | /* |
783 | * There are h+H rows of w+W columns. |
784 | */ |
785 | len = (h+H) * (w+W+1) + 1; |
786 | ret = snewn(len, char); |
787 | p = ret; |
788 | |
789 | for (y = 0; y < H; y++) { |
790 | for (x = 0; x < W; x++) { |
791 | if (state->clues->clues[y*W+x] >= 0) |
792 | *p++ = state->clues->clues[y*W+x] + '0'; |
793 | else |
794 | *p++ = '+'; |
795 | if (x < w) |
796 | *p++ = '-'; |
797 | } |
798 | *p++ = '\n'; |
799 | if (y < h) { |
800 | for (x = 0; x < W; x++) { |
801 | *p++ = '|'; |
802 | if (x < w) { |
803 | if (state->soln[y*w+x] != 0) |
804 | *p++ = (state->soln[y*w+x] < 0 ? '\\' : '/'); |
805 | else |
806 | *p++ = ' '; |
807 | } |
808 | } |
809 | *p++ = '\n'; |
810 | } |
811 | } |
812 | *p++ = '\0'; |
813 | |
814 | assert(p - ret == len); |
815 | return ret; |
816 | } |
817 | |
818 | static game_ui *new_ui(game_state *state) |
819 | { |
820 | return NULL; |
821 | } |
822 | |
823 | static void free_ui(game_ui *ui) |
824 | { |
825 | } |
826 | |
827 | static char *encode_ui(game_ui *ui) |
828 | { |
829 | return NULL; |
830 | } |
831 | |
832 | static void decode_ui(game_ui *ui, char *encoding) |
833 | { |
834 | } |
835 | |
836 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
837 | game_state *newstate) |
838 | { |
839 | } |
840 | |
841 | #define PREFERRED_TILESIZE 32 |
842 | #define TILESIZE (ds->tilesize) |
843 | #define BORDER TILESIZE |
844 | #define CLUE_RADIUS (TILESIZE / 3) |
845 | #define CLUE_TEXTSIZE (TILESIZE / 2) |
846 | #define COORD(x) ( (x) * TILESIZE + BORDER ) |
847 | #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 ) |
848 | |
849 | #define FLASH_TIME 0.30F |
850 | |
851 | /* |
852 | * Bit fields in the `grid' and `todraw' elements of the drawstate. |
853 | */ |
854 | #define BACKSLASH 0x0001 |
855 | #define FORWSLASH 0x0002 |
856 | #define L_T 0x0004 |
857 | #define L_B 0x0008 |
858 | #define T_L 0x0010 |
859 | #define T_R 0x0020 |
860 | #define R_T 0x0040 |
861 | #define R_B 0x0080 |
862 | #define B_L 0x0100 |
863 | #define B_R 0x0200 |
864 | #define C_TL 0x0400 |
865 | #define C_TR 0x0800 |
866 | #define C_BL 0x1000 |
867 | #define C_BR 0x2000 |
868 | #define FLASH 0x4000 |
869 | |
870 | struct game_drawstate { |
871 | int tilesize; |
872 | int started; |
873 | int *grid; |
874 | int *todraw; |
875 | }; |
876 | |
877 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
878 | int x, int y, int button) |
879 | { |
880 | int w = state->p.w, h = state->p.h; |
881 | |
882 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
883 | int v; |
884 | char buf[80]; |
885 | |
886 | x = FROMCOORD(x); |
887 | y = FROMCOORD(y); |
888 | if (x < 0 || y < 0 || x >= w || y >= h) |
889 | return NULL; |
890 | |
891 | if (button == LEFT_BUTTON) { |
892 | /* |
893 | * Left-clicking cycles blank -> \ -> / -> blank. |
894 | */ |
895 | v = state->soln[y*w+x] - 1; |
896 | if (v == -2) |
897 | v = +1; |
898 | } else { |
899 | /* |
900 | * Right-clicking cycles blank -> / -> \ -> blank. |
901 | */ |
902 | v = state->soln[y*w+x] + 1; |
903 | if (v == +2) |
904 | v = -1; |
905 | } |
906 | |
986cc2de |
907 | sprintf(buf, "%c%d,%d", (int)(v==-1 ? '\\' : v==+1 ? '/' : 'C'), x, y); |
f1010613 |
908 | return dupstr(buf); |
909 | } |
910 | |
911 | return NULL; |
912 | } |
913 | |
914 | static game_state *execute_move(game_state *state, char *move) |
915 | { |
916 | int w = state->p.w, h = state->p.h; |
917 | char c; |
918 | int x, y, n; |
919 | game_state *ret = dup_game(state); |
920 | |
921 | while (*move) { |
922 | c = *move; |
923 | if (c == 'S') { |
924 | ret->used_solve = TRUE; |
925 | move++; |
926 | } else if (c == '\\' || c == '/' || c == 'C') { |
927 | move++; |
928 | if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || |
929 | x < 0 || y < 0 || x >= w || y >= h) { |
930 | free_game(ret); |
931 | return NULL; |
932 | } |
933 | ret->soln[y*w+x] = (c == '\\' ? -1 : c == '/' ? +1 : 0); |
934 | move += n; |
935 | } else { |
936 | free_game(ret); |
937 | return NULL; |
938 | } |
939 | if (*move == ';') |
940 | move++; |
941 | else if (*move) { |
942 | free_game(ret); |
943 | return NULL; |
944 | } |
945 | } |
946 | |
947 | if (!ret->completed) |
948 | ret->completed = check_completion(ret); |
949 | |
950 | return ret; |
951 | } |
952 | |
953 | /* ---------------------------------------------------------------------- |
954 | * Drawing routines. |
955 | */ |
956 | |
957 | static void game_compute_size(game_params *params, int tilesize, |
958 | int *x, int *y) |
959 | { |
960 | /* fool the macros */ |
961 | struct dummy { int tilesize; } dummy = { tilesize }, *ds = &dummy; |
962 | |
963 | *x = 2 * BORDER + params->w * TILESIZE + 1; |
964 | *y = 2 * BORDER + params->h * TILESIZE + 1; |
965 | } |
966 | |
967 | static void game_set_size(game_drawstate *ds, game_params *params, |
968 | int tilesize) |
969 | { |
970 | ds->tilesize = tilesize; |
971 | } |
972 | |
973 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
974 | { |
975 | float *ret = snewn(3 * NCOLOURS, float); |
976 | |
977 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
978 | |
979 | ret[COL_GRID * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.7F; |
980 | ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.7F; |
981 | ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.7F; |
982 | |
983 | ret[COL_INK * 3 + 0] = 0.0F; |
984 | ret[COL_INK * 3 + 1] = 0.0F; |
985 | ret[COL_INK * 3 + 2] = 0.0F; |
986 | |
e3478a4b |
987 | ret[COL_SLANT1 * 3 + 0] = 0.0F; |
988 | ret[COL_SLANT1 * 3 + 1] = 0.0F; |
989 | ret[COL_SLANT1 * 3 + 2] = 0.0F; |
990 | |
991 | ret[COL_SLANT2 * 3 + 0] = 0.0F; |
992 | ret[COL_SLANT2 * 3 + 1] = 0.0F; |
993 | ret[COL_SLANT2 * 3 + 2] = 0.0F; |
994 | |
f1010613 |
995 | *ncolours = NCOLOURS; |
996 | return ret; |
997 | } |
998 | |
999 | static game_drawstate *game_new_drawstate(game_state *state) |
1000 | { |
1001 | int w = state->p.w, h = state->p.h; |
1002 | int i; |
1003 | struct game_drawstate *ds = snew(struct game_drawstate); |
1004 | |
1005 | ds->tilesize = 0; |
1006 | ds->started = FALSE; |
1007 | ds->grid = snewn(w*h, int); |
1008 | ds->todraw = snewn(w*h, int); |
1009 | for (i = 0; i < w*h; i++) |
1010 | ds->grid[i] = ds->todraw[i] = -1; |
1011 | |
1012 | return ds; |
1013 | } |
1014 | |
1015 | static void game_free_drawstate(game_drawstate *ds) |
1016 | { |
986cc2de |
1017 | sfree(ds->todraw); |
f1010613 |
1018 | sfree(ds->grid); |
1019 | sfree(ds); |
1020 | } |
1021 | |
1022 | static void draw_clue(frontend *fe, game_drawstate *ds, |
1023 | int x, int y, int v) |
1024 | { |
1025 | char p[2]; |
e3478a4b |
1026 | int col = ((x ^ y) & 1) ? COL_SLANT1 : COL_SLANT2; |
f1010613 |
1027 | |
1028 | if (v < 0) |
1029 | return; |
1030 | |
1031 | p[0] = v + '0'; |
1032 | p[1] = '\0'; |
e3478a4b |
1033 | draw_circle(fe, COORD(x), COORD(y), CLUE_RADIUS, COL_BACKGROUND, col); |
f1010613 |
1034 | draw_text(fe, COORD(x), COORD(y), FONT_VARIABLE, |
1035 | CLUE_TEXTSIZE, ALIGN_VCENTRE|ALIGN_HCENTRE, |
1036 | COL_INK, p); |
1037 | } |
1038 | |
1039 | static void draw_tile(frontend *fe, game_drawstate *ds, game_clues *clues, |
1040 | int x, int y, int v) |
1041 | { |
1042 | int w = clues->w /*, h = clues->h*/, W = w+1 /*, H = h+1 */; |
1043 | int xx, yy; |
e3478a4b |
1044 | int chesscolour = (x ^ y) & 1; |
1045 | int fscol = chesscolour ? COL_SLANT2 : COL_SLANT1; |
1046 | int bscol = chesscolour ? COL_SLANT1 : COL_SLANT2; |
f1010613 |
1047 | |
1048 | clip(fe, COORD(x), COORD(y), TILESIZE+1, TILESIZE+1); |
1049 | |
1050 | draw_rect(fe, COORD(x), COORD(y), TILESIZE, TILESIZE, |
1051 | (v & FLASH) ? COL_GRID : COL_BACKGROUND); |
1052 | |
1053 | /* |
1054 | * Draw the grid lines. |
1055 | */ |
1056 | draw_line(fe, COORD(x), COORD(y), COORD(x+1), COORD(y), COL_GRID); |
1057 | draw_line(fe, COORD(x), COORD(y+1), COORD(x+1), COORD(y+1), COL_GRID); |
1058 | draw_line(fe, COORD(x), COORD(y), COORD(x), COORD(y+1), COL_GRID); |
1059 | draw_line(fe, COORD(x+1), COORD(y), COORD(x+1), COORD(y+1), COL_GRID); |
1060 | |
1061 | /* |
1062 | * Draw the slash. |
1063 | */ |
1064 | if (v & BACKSLASH) { |
e3478a4b |
1065 | draw_line(fe, COORD(x), COORD(y), COORD(x+1), COORD(y+1), bscol); |
f1010613 |
1066 | draw_line(fe, COORD(x)+1, COORD(y), COORD(x+1), COORD(y+1)-1, |
e3478a4b |
1067 | bscol); |
f1010613 |
1068 | draw_line(fe, COORD(x), COORD(y)+1, COORD(x+1)-1, COORD(y+1), |
e3478a4b |
1069 | bscol); |
f1010613 |
1070 | } else if (v & FORWSLASH) { |
e3478a4b |
1071 | draw_line(fe, COORD(x+1), COORD(y), COORD(x), COORD(y+1), fscol); |
f1010613 |
1072 | draw_line(fe, COORD(x+1)-1, COORD(y), COORD(x), COORD(y+1)-1, |
e3478a4b |
1073 | fscol); |
f1010613 |
1074 | draw_line(fe, COORD(x+1), COORD(y)+1, COORD(x)+1, COORD(y+1), |
e3478a4b |
1075 | fscol); |
f1010613 |
1076 | } |
1077 | |
1078 | /* |
1079 | * Draw dots on the grid corners that appear if a slash is in a |
1080 | * neighbouring cell. |
1081 | */ |
1082 | if (v & L_T) |
e3478a4b |
1083 | draw_rect(fe, COORD(x), COORD(y)+1, 1, 1, bscol); |
f1010613 |
1084 | if (v & L_B) |
e3478a4b |
1085 | draw_rect(fe, COORD(x), COORD(y+1)-1, 1, 1, fscol); |
f1010613 |
1086 | if (v & R_T) |
e3478a4b |
1087 | draw_rect(fe, COORD(x+1), COORD(y)+1, 1, 1, fscol); |
f1010613 |
1088 | if (v & R_B) |
e3478a4b |
1089 | draw_rect(fe, COORD(x+1), COORD(y+1)-1, 1, 1, bscol); |
f1010613 |
1090 | if (v & T_L) |
e3478a4b |
1091 | draw_rect(fe, COORD(x)+1, COORD(y), 1, 1, bscol); |
f1010613 |
1092 | if (v & T_R) |
e3478a4b |
1093 | draw_rect(fe, COORD(x+1)-1, COORD(y), 1, 1, fscol); |
f1010613 |
1094 | if (v & B_L) |
e3478a4b |
1095 | draw_rect(fe, COORD(x)+1, COORD(y+1), 1, 1, fscol); |
f1010613 |
1096 | if (v & B_R) |
e3478a4b |
1097 | draw_rect(fe, COORD(x+1)-1, COORD(y+1), 1, 1, bscol); |
f1010613 |
1098 | if (v & C_TL) |
e3478a4b |
1099 | draw_rect(fe, COORD(x), COORD(y), 1, 1, bscol); |
f1010613 |
1100 | if (v & C_TR) |
e3478a4b |
1101 | draw_rect(fe, COORD(x+1), COORD(y), 1, 1, fscol); |
f1010613 |
1102 | if (v & C_BL) |
e3478a4b |
1103 | draw_rect(fe, COORD(x), COORD(y+1), 1, 1, fscol); |
f1010613 |
1104 | if (v & C_BR) |
e3478a4b |
1105 | draw_rect(fe, COORD(x+1), COORD(y+1), 1, 1, bscol); |
f1010613 |
1106 | |
1107 | /* |
1108 | * And finally the clues at the corners. |
1109 | */ |
1110 | for (xx = x; xx <= x+1; xx++) |
1111 | for (yy = y; yy <= y+1; yy++) |
1112 | draw_clue(fe, ds, xx, yy, clues->clues[yy*W+xx]); |
1113 | |
1114 | unclip(fe); |
1115 | draw_update(fe, COORD(x), COORD(y), TILESIZE+1, TILESIZE+1); |
1116 | } |
1117 | |
1118 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
1119 | game_state *state, int dir, game_ui *ui, |
1120 | float animtime, float flashtime) |
1121 | { |
6c48bdb7 |
1122 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1123 | int x, y; |
1124 | int flashing; |
1125 | |
1126 | if (flashtime > 0) |
1127 | flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; |
1128 | else |
1129 | flashing = FALSE; |
1130 | |
1131 | if (!ds->started) { |
1132 | int ww, wh; |
1133 | game_compute_size(&state->p, TILESIZE, &ww, &wh); |
1134 | draw_rect(fe, 0, 0, ww, wh, COL_BACKGROUND); |
1135 | draw_update(fe, 0, 0, ww, wh); |
1136 | |
1137 | /* |
1138 | * Draw any clues on the very edges (since normal tile |
1139 | * redraw won't draw the bits outside the grid boundary). |
1140 | */ |
6c48bdb7 |
1141 | for (y = 0; y < H; y++) { |
f1010613 |
1142 | draw_clue(fe, ds, 0, y, state->clues->clues[y*W+0]); |
1143 | draw_clue(fe, ds, w, y, state->clues->clues[y*W+w]); |
1144 | } |
6c48bdb7 |
1145 | for (x = 0; x < W; x++) { |
f1010613 |
1146 | draw_clue(fe, ds, x, 0, state->clues->clues[0*W+x]); |
1147 | draw_clue(fe, ds, x, h, state->clues->clues[h*W+x]); |
1148 | } |
1149 | |
1150 | ds->started = TRUE; |
1151 | } |
1152 | |
1153 | /* |
1154 | * Loop over the grid and work out where all the slashes are. |
1155 | * We need to do this because a slash in one square affects the |
1156 | * drawing of the next one along. |
1157 | */ |
1158 | for (y = 0; y < h; y++) |
1159 | for (x = 0; x < w; x++) |
1160 | ds->todraw[y*w+x] = flashing ? FLASH : 0; |
1161 | |
1162 | for (y = 0; y < h; y++) { |
1163 | for (x = 0; x < w; x++) { |
1164 | if (state->soln[y*w+x] < 0) { |
1165 | ds->todraw[y*w+x] |= BACKSLASH; |
1166 | if (x > 0) |
1167 | ds->todraw[y*w+(x-1)] |= R_T | C_TR; |
1168 | if (x+1 < w) |
1169 | ds->todraw[y*w+(x+1)] |= L_B | C_BL; |
1170 | if (y > 0) |
1171 | ds->todraw[(y-1)*w+x] |= B_L | C_BL; |
1172 | if (y+1 < h) |
1173 | ds->todraw[(y+1)*w+x] |= T_R | C_TR; |
1174 | if (x > 0 && y > 0) |
1175 | ds->todraw[(y-1)*w+(x-1)] |= C_BR; |
1176 | if (x+1 < w && y+1 < h) |
1177 | ds->todraw[(y+1)*w+(x+1)] |= C_TL; |
1178 | } else if (state->soln[y*w+x] > 0) { |
1179 | ds->todraw[y*w+x] |= FORWSLASH; |
1180 | if (x > 0) |
1181 | ds->todraw[y*w+(x-1)] |= R_B | C_BR; |
1182 | if (x+1 < w) |
1183 | ds->todraw[y*w+(x+1)] |= L_T | C_TL; |
1184 | if (y > 0) |
1185 | ds->todraw[(y-1)*w+x] |= B_R | C_BR; |
1186 | if (y+1 < h) |
1187 | ds->todraw[(y+1)*w+x] |= T_L | C_TL; |
1188 | if (x > 0 && y+1 < h) |
1189 | ds->todraw[(y+1)*w+(x-1)] |= C_TR; |
1190 | if (x+1 < w && y > 0) |
1191 | ds->todraw[(y-1)*w+(x+1)] |= C_BL; |
1192 | } |
1193 | } |
1194 | } |
1195 | |
1196 | /* |
1197 | * Now go through and draw the grid squares. |
1198 | */ |
1199 | for (y = 0; y < h; y++) { |
1200 | for (x = 0; x < w; x++) { |
1201 | if (ds->todraw[y*w+x] != ds->grid[y*w+x]) { |
1202 | draw_tile(fe, ds, state->clues, x, y, ds->todraw[y*w+x]); |
1203 | ds->grid[y*w+x] = ds->todraw[y*w+x]; |
1204 | } |
1205 | } |
1206 | } |
1207 | } |
1208 | |
1209 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1210 | int dir, game_ui *ui) |
1211 | { |
1212 | return 0.0F; |
1213 | } |
1214 | |
1215 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
1216 | int dir, game_ui *ui) |
1217 | { |
1218 | if (!oldstate->completed && newstate->completed && |
1219 | !oldstate->used_solve && !newstate->used_solve) |
1220 | return FLASH_TIME; |
1221 | |
1222 | return 0.0F; |
1223 | } |
1224 | |
1225 | static int game_wants_statusbar(void) |
1226 | { |
1227 | return FALSE; |
1228 | } |
1229 | |
1230 | static int game_timing_state(game_state *state, game_ui *ui) |
1231 | { |
1232 | return TRUE; |
1233 | } |
1234 | |
1235 | #ifdef COMBINED |
1236 | #define thegame slant |
1237 | #endif |
1238 | |
1239 | const struct game thegame = { |
1240 | "Slant", "games.slant", |
1241 | default_params, |
1242 | game_fetch_preset, |
1243 | decode_params, |
1244 | encode_params, |
1245 | free_params, |
1246 | dup_params, |
1247 | TRUE, game_configure, custom_params, |
1248 | validate_params, |
1249 | new_game_desc, |
1250 | validate_desc, |
1251 | new_game, |
1252 | dup_game, |
1253 | free_game, |
1254 | TRUE, solve_game, |
1255 | TRUE, game_text_format, |
1256 | new_ui, |
1257 | free_ui, |
1258 | encode_ui, |
1259 | decode_ui, |
1260 | game_changed_state, |
1261 | interpret_move, |
1262 | execute_move, |
1263 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
1264 | game_colours, |
1265 | game_new_drawstate, |
1266 | game_free_drawstate, |
1267 | game_redraw, |
1268 | game_anim_length, |
1269 | game_flash_length, |
1270 | game_wants_statusbar, |
1271 | FALSE, game_timing_state, |
1272 | 0, /* mouse_priorities */ |
1273 | }; |