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, |
38 | NCOLOURS |
39 | }; |
40 | |
41 | struct game_params { |
42 | int w, h; |
43 | }; |
44 | |
45 | typedef struct game_clues { |
46 | int w, h; |
47 | signed char *clues; |
48 | int *dsf; /* scratch space for completion check */ |
49 | int refcount; |
50 | } game_clues; |
51 | |
52 | struct game_state { |
53 | struct game_params p; |
54 | game_clues *clues; |
55 | signed char *soln; |
56 | int completed; |
57 | int used_solve; /* used to suppress completion flash */ |
58 | }; |
59 | |
60 | static game_params *default_params(void) |
61 | { |
62 | game_params *ret = snew(game_params); |
63 | |
64 | ret->w = ret->h = 8; |
65 | |
66 | return ret; |
67 | } |
68 | |
69 | static const struct game_params slant_presets[] = { |
70 | {5, 5}, |
71 | {8, 8}, |
72 | {12, 10}, |
73 | }; |
74 | |
75 | static int game_fetch_preset(int i, char **name, game_params **params) |
76 | { |
77 | game_params *ret; |
78 | char str[80]; |
79 | |
80 | if (i < 0 || i >= lenof(slant_presets)) |
81 | return FALSE; |
82 | |
83 | ret = snew(game_params); |
84 | *ret = slant_presets[i]; |
85 | |
86 | sprintf(str, "%dx%d", ret->w, ret->h); |
87 | |
88 | *name = dupstr(str); |
89 | *params = ret; |
90 | return TRUE; |
91 | } |
92 | |
93 | static void free_params(game_params *params) |
94 | { |
95 | sfree(params); |
96 | } |
97 | |
98 | static game_params *dup_params(game_params *params) |
99 | { |
100 | game_params *ret = snew(game_params); |
101 | *ret = *params; /* structure copy */ |
102 | return ret; |
103 | } |
104 | |
105 | static void decode_params(game_params *ret, char const *string) |
106 | { |
107 | ret->w = ret->h = atoi(string); |
108 | while (*string && isdigit((unsigned char)*string)) string++; |
109 | if (*string == 'x') { |
110 | string++; |
111 | ret->h = atoi(string); |
112 | } |
113 | } |
114 | |
115 | static char *encode_params(game_params *params, int full) |
116 | { |
117 | char data[256]; |
118 | |
119 | sprintf(data, "%dx%d", params->w, params->h); |
120 | |
121 | return dupstr(data); |
122 | } |
123 | |
124 | static config_item *game_configure(game_params *params) |
125 | { |
126 | config_item *ret; |
127 | char buf[80]; |
128 | |
129 | ret = snewn(3, config_item); |
130 | |
131 | ret[0].name = "Width"; |
132 | ret[0].type = C_STRING; |
133 | sprintf(buf, "%d", params->w); |
134 | ret[0].sval = dupstr(buf); |
135 | ret[0].ival = 0; |
136 | |
137 | ret[1].name = "Height"; |
138 | ret[1].type = C_STRING; |
139 | sprintf(buf, "%d", params->h); |
140 | ret[1].sval = dupstr(buf); |
141 | ret[1].ival = 0; |
142 | |
143 | ret[2].name = NULL; |
144 | ret[2].type = C_END; |
145 | ret[2].sval = NULL; |
146 | ret[2].ival = 0; |
147 | |
148 | return ret; |
149 | } |
150 | |
151 | static game_params *custom_params(config_item *cfg) |
152 | { |
153 | game_params *ret = snew(game_params); |
154 | |
155 | ret->w = atoi(cfg[0].sval); |
156 | ret->h = atoi(cfg[1].sval); |
157 | |
158 | return ret; |
159 | } |
160 | |
161 | static char *validate_params(game_params *params, int full) |
162 | { |
163 | /* |
164 | * (At least at the time of writing this comment) The grid |
165 | * generator is actually capable of handling even zero grid |
166 | * dimensions without crashing. Puzzles with a zero-area grid |
167 | * are a bit boring, though, because they're already solved :-) |
168 | */ |
169 | |
170 | if (params->w < 1 || params->h < 1) |
171 | return "Width and height must both be at least one"; |
172 | |
173 | return NULL; |
174 | } |
175 | |
176 | /* |
177 | * Utility function used by both the solver and the filled-grid |
178 | * generator. |
179 | */ |
180 | |
181 | static void fill_square(int w, int h, int y, int x, int v, |
182 | signed char *soln, int *dsf) |
183 | { |
184 | int W = w+1 /*, H = h+1 */; |
185 | |
186 | soln[y*w+x] = v; |
187 | |
188 | if (v < 0) |
189 | dsf_merge(dsf, y*W+x, (y+1)*W+(x+1)); |
190 | else |
191 | dsf_merge(dsf, y*W+(x+1), (y+1)*W+x); |
192 | } |
193 | |
194 | /* |
195 | * Scratch space for solver. |
196 | */ |
197 | struct solver_scratch { |
198 | int *dsf; |
199 | }; |
200 | |
201 | struct solver_scratch *new_scratch(int w, int h) |
202 | { |
203 | int W = w+1, H = h+1; |
204 | struct solver_scratch *ret = snew(struct solver_scratch); |
205 | ret->dsf = snewn(W*H, int); |
206 | return ret; |
207 | } |
208 | |
209 | void free_scratch(struct solver_scratch *sc) |
210 | { |
211 | sfree(sc->dsf); |
212 | sfree(sc); |
213 | } |
214 | |
215 | /* |
216 | * Solver. Returns 0 for impossibility, 1 for success, 2 for |
217 | * ambiguity or failure to converge. |
218 | */ |
219 | static int slant_solve(int w, int h, const signed char *clues, |
220 | signed char *soln, struct solver_scratch *sc) |
221 | { |
222 | int W = w+1, H = h+1; |
223 | int x, y, i; |
224 | int done_something; |
225 | |
226 | /* |
227 | * Clear the output. |
228 | */ |
229 | memset(soln, 0, w*h); |
230 | |
231 | /* |
232 | * Establish a disjoint set forest for tracking connectedness |
233 | * between grid points. |
234 | */ |
235 | for (i = 0; i < W*H; i++) |
236 | sc->dsf[i] = i; /* initially all distinct */ |
237 | |
238 | /* |
239 | * Repeatedly try to deduce something until we can't. |
240 | */ |
241 | do { |
242 | done_something = FALSE; |
243 | |
244 | /* |
245 | * Any clue point with the number of remaining lines equal |
246 | * to zero or to the number of remaining undecided |
247 | * neighbouring squares can be filled in completely. |
248 | */ |
249 | for (y = 0; y < H; y++) |
250 | for (x = 0; x < W; x++) { |
251 | int nu, nl, v, c; |
252 | |
253 | if ((c = clues[y*W+x]) < 0) |
254 | continue; |
255 | |
256 | /* |
257 | * We have a clue point. Count up the number of |
258 | * undecided neighbours, and also the number of |
259 | * lines already present. |
260 | */ |
261 | nu = 0; |
262 | nl = c; |
263 | if (x > 0 && y > 0 && (v = soln[(y-1)*w+(x-1)]) != +1) |
264 | v == 0 ? nu++ : nl--; |
265 | if (x > 0 && y < h && (v = soln[y*w+(x-1)]) != -1) |
266 | v == 0 ? nu++ : nl--; |
267 | if (x < w && y > 0 && (v = soln[(y-1)*w+x]) != -1) |
268 | v == 0 ? nu++ : nl--; |
269 | if (x < w && y < h && (v = soln[y*w+x]) != +1) |
270 | v == 0 ? nu++ : nl--; |
271 | |
272 | /* |
273 | * Check the counts. |
274 | */ |
275 | if (nl < 0 || nl > nu) { |
276 | /* |
277 | * No consistent value for this at all! |
278 | */ |
279 | return 0; /* impossible */ |
280 | } |
281 | |
282 | if (nu > 0 && (nl == 0 || nl == nu)) { |
283 | #ifdef SOLVER_DIAGNOSTICS |
284 | printf("%s around clue point at %d,%d\n", |
285 | nl ? "filling" : "emptying", x, y); |
286 | #endif |
287 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == 0) |
288 | fill_square(w, h, y-1, x-1, (nl ? -1 : +1), soln, |
289 | sc->dsf); |
290 | if (x > 0 && y < h && soln[y*w+(x-1)] == 0) |
291 | fill_square(w, h, y, x-1, (nl ? +1 : -1), soln, |
292 | sc->dsf); |
293 | if (x < w && y > 0 && soln[(y-1)*w+x] == 0) |
294 | fill_square(w, h, y-1, x, (nl ? +1 : -1), soln, |
295 | sc->dsf); |
296 | if (x < w && y < h && soln[y*w+x] == 0) |
297 | fill_square(w, h, y, x, (nl ? -1 : +1), soln, |
298 | sc->dsf); |
299 | |
300 | done_something = TRUE; |
301 | } |
302 | } |
303 | |
304 | if (done_something) |
305 | continue; |
306 | |
307 | /* |
308 | * Failing that, we now apply the second condition, which |
309 | * is that no square may be filled in such a way as to form |
310 | * a loop. |
311 | */ |
312 | for (y = 0; y < h; y++) |
313 | for (x = 0; x < w; x++) { |
314 | int fs, bs; |
315 | |
316 | if (soln[y*w+x]) |
317 | continue; /* got this one already */ |
318 | |
319 | fs = (dsf_canonify(sc->dsf, y*W+x) == |
320 | dsf_canonify(sc->dsf, (y+1)*W+(x+1))); |
321 | bs = (dsf_canonify(sc->dsf, (y+1)*W+x) == |
322 | dsf_canonify(sc->dsf, y*W+(x+1))); |
323 | |
324 | if (fs && bs) { |
325 | /* |
326 | * Loop avoidance leaves no consistent value |
327 | * for this at all! |
328 | */ |
329 | return 0; /* impossible */ |
330 | } |
331 | |
332 | if (fs) { |
333 | /* |
334 | * Top left and bottom right corners of this |
335 | * square are already connected, which means we |
336 | * aren't allowed to put a backslash in here. |
337 | */ |
338 | #ifdef SOLVER_DIAGNOSTICS |
339 | printf("placing / in %d,%d by loop avoidance\n", x, y); |
340 | #endif |
341 | fill_square(w, h, y, x, +1, soln, sc->dsf); |
342 | done_something = TRUE; |
343 | } else if (bs) { |
344 | /* |
345 | * Top right and bottom left corners of this |
346 | * square are already connected, which means we |
347 | * aren't allowed to put a forward slash in |
348 | * here. |
349 | */ |
350 | #ifdef SOLVER_DIAGNOSTICS |
351 | printf("placing \\ in %d,%d by loop avoidance\n", x, y); |
352 | #endif |
353 | fill_square(w, h, y, x, -1, soln, sc->dsf); |
354 | done_something = TRUE; |
355 | } |
356 | } |
357 | |
358 | } while (done_something); |
359 | |
360 | /* |
361 | * Solver can make no more progress. See if the grid is full. |
362 | */ |
363 | for (i = 0; i < w*h; i++) |
364 | if (!soln[i]) |
365 | return 2; /* failed to converge */ |
366 | return 1; /* success */ |
367 | } |
368 | |
369 | /* |
370 | * Filled-grid generator. |
371 | */ |
372 | static void slant_generate(int w, int h, signed char *soln, random_state *rs) |
373 | { |
374 | int W = w+1, H = h+1; |
375 | int x, y, i; |
376 | int *dsf, *indices; |
377 | |
378 | /* |
379 | * Clear the output. |
380 | */ |
381 | memset(soln, 0, w*h); |
382 | |
383 | /* |
384 | * Establish a disjoint set forest for tracking connectedness |
385 | * between grid points. |
386 | */ |
387 | dsf = snewn(W*H, int); |
388 | for (i = 0; i < W*H; i++) |
389 | dsf[i] = i; /* initially all distinct */ |
390 | |
391 | /* |
392 | * Prepare a list of the squares in the grid, and fill them in |
393 | * in a random order. |
394 | */ |
395 | indices = snewn(w*h, int); |
396 | for (i = 0; i < w*h; i++) |
397 | indices[i] = i; |
398 | shuffle(indices, w*h, sizeof(*indices), rs); |
399 | |
400 | /* |
401 | * Fill in each one in turn. |
402 | */ |
403 | for (i = 0; i < w*h; i++) { |
404 | int fs, bs, v; |
405 | |
406 | y = indices[i] / w; |
407 | x = indices[i] % w; |
408 | |
409 | fs = (dsf_canonify(dsf, y*W+x) == |
410 | dsf_canonify(dsf, (y+1)*W+(x+1))); |
411 | bs = (dsf_canonify(dsf, (y+1)*W+x) == |
412 | dsf_canonify(dsf, y*W+(x+1))); |
413 | |
414 | /* |
415 | * It isn't possible to get into a situation where we |
416 | * aren't allowed to place _either_ type of slash in a |
417 | * square. |
418 | * |
419 | * Proof (thanks to Gareth Taylor): |
420 | * |
421 | * If it were possible, it would have to be because there |
422 | * was an existing path (not using this square) between the |
423 | * top-left and bottom-right corners of this square, and |
424 | * another between the other two. These two paths would |
425 | * have to cross at some point. |
426 | * |
427 | * Obviously they can't cross in the middle of a square, so |
428 | * they must cross by sharing a point in common. But this |
429 | * isn't possible either: if you chessboard-colour all the |
430 | * points on the grid, you find that any continuous |
431 | * diagonal path is entirely composed of points of the same |
432 | * colour. And one of our two hypothetical paths is between |
433 | * two black points, and the other is between two white |
434 | * points - therefore they can have no point in common. [] |
435 | */ |
436 | assert(!(fs && bs)); |
437 | |
438 | v = fs ? +1 : bs ? -1 : 2 * random_upto(rs, 2) - 1; |
439 | fill_square(w, h, y, x, v, soln, dsf); |
440 | } |
441 | |
442 | sfree(indices); |
443 | sfree(dsf); |
444 | } |
445 | |
446 | static char *new_game_desc(game_params *params, random_state *rs, |
447 | char **aux, int interactive) |
448 | { |
449 | int w = params->w, h = params->h, W = w+1, H = h+1; |
450 | signed char *soln, *tmpsoln, *clues; |
451 | int *clueindices; |
452 | struct solver_scratch *sc; |
453 | int x, y, v, i; |
454 | char *desc; |
455 | |
456 | soln = snewn(w*h, signed char); |
457 | tmpsoln = snewn(w*h, signed char); |
458 | clues = snewn(W*H, signed char); |
459 | clueindices = snewn(W*H, int); |
460 | sc = new_scratch(w, h); |
461 | |
462 | do { |
463 | /* |
464 | * Create the filled grid. |
465 | */ |
466 | slant_generate(w, h, soln, rs); |
467 | |
468 | /* |
469 | * Fill in the complete set of clues. |
470 | */ |
471 | for (y = 0; y < H; y++) |
472 | for (x = 0; x < W; x++) { |
473 | v = 0; |
474 | |
475 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == -1) v++; |
476 | if (x > 0 && y < h && soln[y*w+(x-1)] == +1) v++; |
477 | if (x < w && y > 0 && soln[(y-1)*w+x] == +1) v++; |
478 | if (x < w && y < h && soln[y*w+x] == -1) v++; |
479 | |
480 | clues[y*W+x] = v; |
481 | } |
482 | } while (slant_solve(w, h, clues, tmpsoln, sc) != 1); |
483 | |
484 | /* |
485 | * Remove as many clues as possible while retaining solubility. |
486 | */ |
487 | for (i = 0; i < W*H; i++) |
488 | clueindices[i] = i; |
489 | shuffle(clueindices, W*H, sizeof(*clueindices), rs); |
490 | for (i = 0; i < W*H; i++) { |
491 | y = clueindices[i] / W; |
492 | x = clueindices[i] % W; |
493 | v = clues[y*W+x]; |
494 | clues[y*W+x] = -1; |
495 | if (slant_solve(w, h, clues, tmpsoln, sc) != 1) |
496 | clues[y*W+x] = v; /* put it back */ |
497 | } |
498 | |
499 | /* |
500 | * Now we have the clue set as it will be presented to the |
501 | * user. Encode it in a game desc. |
502 | */ |
503 | { |
504 | char *p; |
505 | int run, i; |
506 | |
507 | desc = snewn(W*H+1, char); |
508 | p = desc; |
509 | run = 0; |
510 | for (i = 0; i <= W*H; i++) { |
511 | int n = (i < W*H ? clues[i] : -2); |
512 | |
513 | if (n == -1) |
514 | run++; |
515 | else { |
516 | if (run) { |
517 | while (run > 0) { |
518 | int c = 'a' - 1 + run; |
519 | if (run > 26) |
520 | c = 'z'; |
521 | *p++ = c; |
522 | run -= c - ('a' - 1); |
523 | } |
524 | } |
525 | if (n >= 0) |
526 | *p++ = '0' + n; |
527 | run = 0; |
528 | } |
529 | } |
530 | assert(p - desc <= W*H); |
531 | *p++ = '\0'; |
532 | desc = sresize(desc, p - desc, char); |
533 | } |
534 | |
535 | /* |
536 | * Encode the solution as an aux_info. |
537 | */ |
538 | { |
539 | char *auxbuf; |
540 | *aux = auxbuf = snewn(w*h+1, char); |
541 | for (i = 0; i < w*h; i++) |
542 | auxbuf[i] = soln[i] < 0 ? '\\' : '/'; |
543 | auxbuf[w*h] = '\0'; |
544 | } |
545 | |
546 | free_scratch(sc); |
547 | sfree(clueindices); |
548 | sfree(clues); |
549 | sfree(tmpsoln); |
550 | sfree(soln); |
551 | |
552 | return desc; |
553 | } |
554 | |
555 | static char *validate_desc(game_params *params, char *desc) |
556 | { |
557 | int w = params->w, h = params->h, W = w+1, H = h+1; |
558 | int area = W*H; |
559 | int squares = 0; |
560 | |
561 | while (*desc) { |
562 | int n = *desc++; |
563 | if (n >= 'a' && n <= 'z') { |
564 | squares += n - 'a' + 1; |
565 | } else if (n >= '0' && n <= '4') { |
566 | squares++; |
567 | } else |
568 | return "Invalid character in game description"; |
569 | } |
570 | |
571 | if (squares < area) |
572 | return "Not enough data to fill grid"; |
573 | |
574 | if (squares > area) |
575 | return "Too much data to fit in grid"; |
576 | |
577 | return NULL; |
578 | } |
579 | |
580 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
581 | { |
582 | int w = params->w, h = params->h, W = w+1, H = h+1; |
583 | game_state *state = snew(game_state); |
584 | int area = W*H; |
585 | int squares = 0; |
586 | |
587 | state->p = *params; |
588 | state->soln = snewn(w*h, signed char); |
589 | memset(state->soln, 0, w*h); |
590 | state->completed = state->used_solve = FALSE; |
591 | |
592 | state->clues = snew(game_clues); |
593 | state->clues->w = w; |
594 | state->clues->h = h; |
595 | state->clues->clues = snewn(W*H, signed char); |
596 | state->clues->refcount = 1; |
597 | state->clues->dsf = snewn(W*H, int); |
598 | memset(state->clues->clues, -1, W*H); |
599 | while (*desc) { |
600 | int n = *desc++; |
601 | if (n >= 'a' && n <= 'z') { |
602 | squares += n - 'a' + 1; |
603 | } else if (n >= '0' && n <= '4') { |
604 | state->clues->clues[squares++] = n - '0'; |
605 | } else |
606 | assert(!"can't get here"); |
607 | } |
608 | assert(squares == area); |
609 | |
610 | return state; |
611 | } |
612 | |
613 | static game_state *dup_game(game_state *state) |
614 | { |
615 | int w = state->p.w, h = state->p.h; |
616 | game_state *ret = snew(game_state); |
617 | |
618 | ret->p = state->p; |
619 | ret->clues = state->clues; |
620 | ret->clues->refcount++; |
621 | ret->completed = state->completed; |
622 | ret->used_solve = state->used_solve; |
623 | |
624 | ret->soln = snewn(w*h, signed char); |
625 | memcpy(ret->soln, state->soln, w*h); |
626 | |
627 | return ret; |
628 | } |
629 | |
630 | static void free_game(game_state *state) |
631 | { |
632 | sfree(state); |
633 | } |
634 | |
635 | static int check_completion(game_state *state) |
636 | { |
637 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
638 | int i, x, y; |
639 | |
640 | /* |
641 | * Establish a disjoint set forest for tracking connectedness |
642 | * between grid points. Use the dsf scratch space in the shared |
643 | * clues structure, to avoid mallocing too often. |
644 | */ |
645 | for (i = 0; i < W*H; i++) |
646 | state->clues->dsf[i] = i; /* initially all distinct */ |
647 | |
648 | /* |
649 | * Now go through the grid checking connectedness. While we're |
650 | * here, also check that everything is filled in. |
651 | */ |
652 | for (y = 0; y < h; y++) |
653 | for (x = 0; x < w; x++) { |
654 | int i1, i2; |
655 | |
656 | if (state->soln[y*w+x] == 0) |
657 | return FALSE; |
658 | if (state->soln[y*w+x] < 0) { |
659 | i1 = y*W+x; |
660 | i2 = (y+1)*W+(x+1); |
661 | } else { |
662 | i1 = (y+1)*W+x; |
663 | i2 = y*W+(x+1); |
664 | } |
665 | |
666 | /* |
667 | * Our edge connects i1 with i2. If they're already |
668 | * connected, return failure. Otherwise, link them. |
669 | */ |
670 | if (dsf_canonify(state->clues->dsf, i1) == |
671 | dsf_canonify(state->clues->dsf, i2)) |
672 | return FALSE; |
673 | else |
674 | dsf_merge(state->clues->dsf, i1, i2); |
675 | } |
676 | |
677 | /* |
678 | * The grid is _a_ valid grid; let's see if it matches the |
679 | * clues. |
680 | */ |
681 | for (y = 0; y < H; y++) |
682 | for (x = 0; x < W; x++) { |
683 | int v, c; |
684 | |
685 | if ((c = state->clues->clues[y*W+x]) < 0) |
686 | continue; |
687 | |
688 | v = 0; |
689 | |
690 | if (x > 0 && y > 0 && state->soln[(y-1)*w+(x-1)] == -1) v++; |
691 | if (x > 0 && y < h && state->soln[y*w+(x-1)] == +1) v++; |
692 | if (x < w && y > 0 && state->soln[(y-1)*w+x] == +1) v++; |
693 | if (x < w && y < h && state->soln[y*w+x] == -1) v++; |
694 | |
695 | if (c != v) |
696 | return FALSE; |
697 | } |
698 | |
699 | return TRUE; |
700 | } |
701 | |
702 | static char *solve_game(game_state *state, game_state *currstate, |
703 | char *aux, char **error) |
704 | { |
705 | int w = state->p.w, h = state->p.h; |
706 | signed char *soln; |
707 | int bs, ret; |
708 | int free_soln = FALSE; |
709 | char *move, buf[80]; |
710 | int movelen, movesize; |
711 | int x, y; |
712 | |
713 | if (aux) { |
714 | /* |
715 | * If we already have the solution, save ourselves some |
716 | * time. |
717 | */ |
718 | soln = (signed char *)aux; |
719 | bs = (signed char)'\\'; |
720 | free_soln = FALSE; |
721 | } else { |
722 | struct solver_scratch *sc = new_scratch(w, h); |
723 | soln = snewn(w*h, signed char); |
724 | bs = -1; |
725 | ret = slant_solve(w, h, state->clues->clues, soln, sc); |
726 | free_scratch(sc); |
727 | if (ret != 1) { |
728 | sfree(soln); |
729 | if (ret == 0) |
730 | return "This puzzle is not self-consistent"; |
731 | else |
732 | return "Unable to find a unique solution for this puzzle"; |
733 | } |
734 | free_soln = TRUE; |
735 | } |
736 | |
737 | /* |
738 | * Construct a move string which turns the current state into |
739 | * the solved state. |
740 | */ |
741 | movesize = 256; |
742 | move = snewn(movesize, char); |
743 | movelen = 0; |
744 | move[movelen++] = 'S'; |
745 | move[movelen] = '\0'; |
746 | for (y = 0; y < h; y++) |
747 | for (x = 0; x < w; x++) { |
748 | int v = (soln[y*w+x] == bs ? -1 : +1); |
749 | if (state->soln[y*w+x] != v) { |
750 | int len = sprintf(buf, ";%c%d,%d", v < 0 ? '\\' : '/', x, y); |
751 | if (movelen + len >= movesize) { |
752 | movesize = movelen + len + 256; |
753 | move = sresize(move, movesize, char); |
754 | } |
755 | strcpy(move + movelen, buf); |
756 | movelen += len; |
757 | } |
758 | } |
759 | |
760 | if (free_soln) |
761 | sfree(soln); |
762 | |
763 | return move; |
764 | } |
765 | |
766 | static char *game_text_format(game_state *state) |
767 | { |
768 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
769 | int x, y, len; |
770 | char *ret, *p; |
771 | |
772 | /* |
773 | * There are h+H rows of w+W columns. |
774 | */ |
775 | len = (h+H) * (w+W+1) + 1; |
776 | ret = snewn(len, char); |
777 | p = ret; |
778 | |
779 | for (y = 0; y < H; y++) { |
780 | for (x = 0; x < W; x++) { |
781 | if (state->clues->clues[y*W+x] >= 0) |
782 | *p++ = state->clues->clues[y*W+x] + '0'; |
783 | else |
784 | *p++ = '+'; |
785 | if (x < w) |
786 | *p++ = '-'; |
787 | } |
788 | *p++ = '\n'; |
789 | if (y < h) { |
790 | for (x = 0; x < W; x++) { |
791 | *p++ = '|'; |
792 | if (x < w) { |
793 | if (state->soln[y*w+x] != 0) |
794 | *p++ = (state->soln[y*w+x] < 0 ? '\\' : '/'); |
795 | else |
796 | *p++ = ' '; |
797 | } |
798 | } |
799 | *p++ = '\n'; |
800 | } |
801 | } |
802 | *p++ = '\0'; |
803 | |
804 | assert(p - ret == len); |
805 | return ret; |
806 | } |
807 | |
808 | static game_ui *new_ui(game_state *state) |
809 | { |
810 | return NULL; |
811 | } |
812 | |
813 | static void free_ui(game_ui *ui) |
814 | { |
815 | } |
816 | |
817 | static char *encode_ui(game_ui *ui) |
818 | { |
819 | return NULL; |
820 | } |
821 | |
822 | static void decode_ui(game_ui *ui, char *encoding) |
823 | { |
824 | } |
825 | |
826 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
827 | game_state *newstate) |
828 | { |
829 | } |
830 | |
831 | #define PREFERRED_TILESIZE 32 |
832 | #define TILESIZE (ds->tilesize) |
833 | #define BORDER TILESIZE |
834 | #define CLUE_RADIUS (TILESIZE / 3) |
835 | #define CLUE_TEXTSIZE (TILESIZE / 2) |
836 | #define COORD(x) ( (x) * TILESIZE + BORDER ) |
837 | #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 ) |
838 | |
839 | #define FLASH_TIME 0.30F |
840 | |
841 | /* |
842 | * Bit fields in the `grid' and `todraw' elements of the drawstate. |
843 | */ |
844 | #define BACKSLASH 0x0001 |
845 | #define FORWSLASH 0x0002 |
846 | #define L_T 0x0004 |
847 | #define L_B 0x0008 |
848 | #define T_L 0x0010 |
849 | #define T_R 0x0020 |
850 | #define R_T 0x0040 |
851 | #define R_B 0x0080 |
852 | #define B_L 0x0100 |
853 | #define B_R 0x0200 |
854 | #define C_TL 0x0400 |
855 | #define C_TR 0x0800 |
856 | #define C_BL 0x1000 |
857 | #define C_BR 0x2000 |
858 | #define FLASH 0x4000 |
859 | |
860 | struct game_drawstate { |
861 | int tilesize; |
862 | int started; |
863 | int *grid; |
864 | int *todraw; |
865 | }; |
866 | |
867 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
868 | int x, int y, int button) |
869 | { |
870 | int w = state->p.w, h = state->p.h; |
871 | |
872 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
873 | int v; |
874 | char buf[80]; |
875 | |
876 | x = FROMCOORD(x); |
877 | y = FROMCOORD(y); |
878 | if (x < 0 || y < 0 || x >= w || y >= h) |
879 | return NULL; |
880 | |
881 | if (button == LEFT_BUTTON) { |
882 | /* |
883 | * Left-clicking cycles blank -> \ -> / -> blank. |
884 | */ |
885 | v = state->soln[y*w+x] - 1; |
886 | if (v == -2) |
887 | v = +1; |
888 | } else { |
889 | /* |
890 | * Right-clicking cycles blank -> / -> \ -> blank. |
891 | */ |
892 | v = state->soln[y*w+x] + 1; |
893 | if (v == +2) |
894 | v = -1; |
895 | } |
896 | |
897 | sprintf(buf, "%c%d,%d", v==-1 ? '\\' : v==+1 ? '/' : 'C', x, y); |
898 | return dupstr(buf); |
899 | } |
900 | |
901 | return NULL; |
902 | } |
903 | |
904 | static game_state *execute_move(game_state *state, char *move) |
905 | { |
906 | int w = state->p.w, h = state->p.h; |
907 | char c; |
908 | int x, y, n; |
909 | game_state *ret = dup_game(state); |
910 | |
911 | while (*move) { |
912 | c = *move; |
913 | if (c == 'S') { |
914 | ret->used_solve = TRUE; |
915 | move++; |
916 | } else if (c == '\\' || c == '/' || c == 'C') { |
917 | move++; |
918 | if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || |
919 | x < 0 || y < 0 || x >= w || y >= h) { |
920 | free_game(ret); |
921 | return NULL; |
922 | } |
923 | ret->soln[y*w+x] = (c == '\\' ? -1 : c == '/' ? +1 : 0); |
924 | move += n; |
925 | } else { |
926 | free_game(ret); |
927 | return NULL; |
928 | } |
929 | if (*move == ';') |
930 | move++; |
931 | else if (*move) { |
932 | free_game(ret); |
933 | return NULL; |
934 | } |
935 | } |
936 | |
937 | if (!ret->completed) |
938 | ret->completed = check_completion(ret); |
939 | |
940 | return ret; |
941 | } |
942 | |
943 | /* ---------------------------------------------------------------------- |
944 | * Drawing routines. |
945 | */ |
946 | |
947 | static void game_compute_size(game_params *params, int tilesize, |
948 | int *x, int *y) |
949 | { |
950 | /* fool the macros */ |
951 | struct dummy { int tilesize; } dummy = { tilesize }, *ds = &dummy; |
952 | |
953 | *x = 2 * BORDER + params->w * TILESIZE + 1; |
954 | *y = 2 * BORDER + params->h * TILESIZE + 1; |
955 | } |
956 | |
957 | static void game_set_size(game_drawstate *ds, game_params *params, |
958 | int tilesize) |
959 | { |
960 | ds->tilesize = tilesize; |
961 | } |
962 | |
963 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
964 | { |
965 | float *ret = snewn(3 * NCOLOURS, float); |
966 | |
967 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
968 | |
969 | ret[COL_GRID * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.7F; |
970 | ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.7F; |
971 | ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.7F; |
972 | |
973 | ret[COL_INK * 3 + 0] = 0.0F; |
974 | ret[COL_INK * 3 + 1] = 0.0F; |
975 | ret[COL_INK * 3 + 2] = 0.0F; |
976 | |
977 | *ncolours = NCOLOURS; |
978 | return ret; |
979 | } |
980 | |
981 | static game_drawstate *game_new_drawstate(game_state *state) |
982 | { |
983 | int w = state->p.w, h = state->p.h; |
984 | int i; |
985 | struct game_drawstate *ds = snew(struct game_drawstate); |
986 | |
987 | ds->tilesize = 0; |
988 | ds->started = FALSE; |
989 | ds->grid = snewn(w*h, int); |
990 | ds->todraw = snewn(w*h, int); |
991 | for (i = 0; i < w*h; i++) |
992 | ds->grid[i] = ds->todraw[i] = -1; |
993 | |
994 | return ds; |
995 | } |
996 | |
997 | static void game_free_drawstate(game_drawstate *ds) |
998 | { |
999 | sfree(ds->grid); |
1000 | sfree(ds); |
1001 | } |
1002 | |
1003 | static void draw_clue(frontend *fe, game_drawstate *ds, |
1004 | int x, int y, int v) |
1005 | { |
1006 | char p[2]; |
1007 | |
1008 | if (v < 0) |
1009 | return; |
1010 | |
1011 | p[0] = v + '0'; |
1012 | p[1] = '\0'; |
1013 | draw_circle(fe, COORD(x), COORD(y), CLUE_RADIUS, |
1014 | COL_BACKGROUND, COL_INK); |
1015 | draw_text(fe, COORD(x), COORD(y), FONT_VARIABLE, |
1016 | CLUE_TEXTSIZE, ALIGN_VCENTRE|ALIGN_HCENTRE, |
1017 | COL_INK, p); |
1018 | } |
1019 | |
1020 | static void draw_tile(frontend *fe, game_drawstate *ds, game_clues *clues, |
1021 | int x, int y, int v) |
1022 | { |
1023 | int w = clues->w /*, h = clues->h*/, W = w+1 /*, H = h+1 */; |
1024 | int xx, yy; |
1025 | |
1026 | clip(fe, COORD(x), COORD(y), TILESIZE+1, TILESIZE+1); |
1027 | |
1028 | draw_rect(fe, COORD(x), COORD(y), TILESIZE, TILESIZE, |
1029 | (v & FLASH) ? COL_GRID : COL_BACKGROUND); |
1030 | |
1031 | /* |
1032 | * Draw the grid lines. |
1033 | */ |
1034 | draw_line(fe, COORD(x), COORD(y), COORD(x+1), COORD(y), COL_GRID); |
1035 | draw_line(fe, COORD(x), COORD(y+1), COORD(x+1), COORD(y+1), COL_GRID); |
1036 | draw_line(fe, COORD(x), COORD(y), COORD(x), COORD(y+1), COL_GRID); |
1037 | draw_line(fe, COORD(x+1), COORD(y), COORD(x+1), COORD(y+1), COL_GRID); |
1038 | |
1039 | /* |
1040 | * Draw the slash. |
1041 | */ |
1042 | if (v & BACKSLASH) { |
1043 | draw_line(fe, COORD(x), COORD(y), COORD(x+1), COORD(y+1), COL_INK); |
1044 | draw_line(fe, COORD(x)+1, COORD(y), COORD(x+1), COORD(y+1)-1, |
1045 | COL_INK); |
1046 | draw_line(fe, COORD(x), COORD(y)+1, COORD(x+1)-1, COORD(y+1), |
1047 | COL_INK); |
1048 | } else if (v & FORWSLASH) { |
1049 | draw_line(fe, COORD(x+1), COORD(y), COORD(x), COORD(y+1), COL_INK); |
1050 | draw_line(fe, COORD(x+1)-1, COORD(y), COORD(x), COORD(y+1)-1, |
1051 | COL_INK); |
1052 | draw_line(fe, COORD(x+1), COORD(y)+1, COORD(x)+1, COORD(y+1), |
1053 | COL_INK); |
1054 | } |
1055 | |
1056 | /* |
1057 | * Draw dots on the grid corners that appear if a slash is in a |
1058 | * neighbouring cell. |
1059 | */ |
1060 | if (v & L_T) |
1061 | draw_rect(fe, COORD(x), COORD(y)+1, 1, 1, COL_INK); |
1062 | if (v & L_B) |
1063 | draw_rect(fe, COORD(x), COORD(y+1)-1, 1, 1, COL_INK); |
1064 | if (v & R_T) |
1065 | draw_rect(fe, COORD(x+1), COORD(y)+1, 1, 1, COL_INK); |
1066 | if (v & R_B) |
1067 | draw_rect(fe, COORD(x+1), COORD(y+1)-1, 1, 1, COL_INK); |
1068 | if (v & T_L) |
1069 | draw_rect(fe, COORD(x)+1, COORD(y), 1, 1, COL_INK); |
1070 | if (v & T_R) |
1071 | draw_rect(fe, COORD(x+1)-1, COORD(y), 1, 1, COL_INK); |
1072 | if (v & B_L) |
1073 | draw_rect(fe, COORD(x)+1, COORD(y+1), 1, 1, COL_INK); |
1074 | if (v & B_R) |
1075 | draw_rect(fe, COORD(x+1)-1, COORD(y+1), 1, 1, COL_INK); |
1076 | if (v & C_TL) |
1077 | draw_rect(fe, COORD(x), COORD(y), 1, 1, COL_INK); |
1078 | if (v & C_TR) |
1079 | draw_rect(fe, COORD(x+1), COORD(y), 1, 1, COL_INK); |
1080 | if (v & C_BL) |
1081 | draw_rect(fe, COORD(x), COORD(y+1), 1, 1, COL_INK); |
1082 | if (v & C_BR) |
1083 | draw_rect(fe, COORD(x+1), COORD(y+1), 1, 1, COL_INK); |
1084 | |
1085 | /* |
1086 | * And finally the clues at the corners. |
1087 | */ |
1088 | for (xx = x; xx <= x+1; xx++) |
1089 | for (yy = y; yy <= y+1; yy++) |
1090 | draw_clue(fe, ds, xx, yy, clues->clues[yy*W+xx]); |
1091 | |
1092 | unclip(fe); |
1093 | draw_update(fe, COORD(x), COORD(y), TILESIZE+1, TILESIZE+1); |
1094 | } |
1095 | |
1096 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
1097 | game_state *state, int dir, game_ui *ui, |
1098 | float animtime, float flashtime) |
1099 | { |
6c48bdb7 |
1100 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1101 | int x, y; |
1102 | int flashing; |
1103 | |
1104 | if (flashtime > 0) |
1105 | flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; |
1106 | else |
1107 | flashing = FALSE; |
1108 | |
1109 | if (!ds->started) { |
1110 | int ww, wh; |
1111 | game_compute_size(&state->p, TILESIZE, &ww, &wh); |
1112 | draw_rect(fe, 0, 0, ww, wh, COL_BACKGROUND); |
1113 | draw_update(fe, 0, 0, ww, wh); |
1114 | |
1115 | /* |
1116 | * Draw any clues on the very edges (since normal tile |
1117 | * redraw won't draw the bits outside the grid boundary). |
1118 | */ |
6c48bdb7 |
1119 | for (y = 0; y < H; y++) { |
f1010613 |
1120 | draw_clue(fe, ds, 0, y, state->clues->clues[y*W+0]); |
1121 | draw_clue(fe, ds, w, y, state->clues->clues[y*W+w]); |
1122 | } |
6c48bdb7 |
1123 | for (x = 0; x < W; x++) { |
f1010613 |
1124 | draw_clue(fe, ds, x, 0, state->clues->clues[0*W+x]); |
1125 | draw_clue(fe, ds, x, h, state->clues->clues[h*W+x]); |
1126 | } |
1127 | |
1128 | ds->started = TRUE; |
1129 | } |
1130 | |
1131 | /* |
1132 | * Loop over the grid and work out where all the slashes are. |
1133 | * We need to do this because a slash in one square affects the |
1134 | * drawing of the next one along. |
1135 | */ |
1136 | for (y = 0; y < h; y++) |
1137 | for (x = 0; x < w; x++) |
1138 | ds->todraw[y*w+x] = flashing ? FLASH : 0; |
1139 | |
1140 | for (y = 0; y < h; y++) { |
1141 | for (x = 0; x < w; x++) { |
1142 | if (state->soln[y*w+x] < 0) { |
1143 | ds->todraw[y*w+x] |= BACKSLASH; |
1144 | if (x > 0) |
1145 | ds->todraw[y*w+(x-1)] |= R_T | C_TR; |
1146 | if (x+1 < w) |
1147 | ds->todraw[y*w+(x+1)] |= L_B | C_BL; |
1148 | if (y > 0) |
1149 | ds->todraw[(y-1)*w+x] |= B_L | C_BL; |
1150 | if (y+1 < h) |
1151 | ds->todraw[(y+1)*w+x] |= T_R | C_TR; |
1152 | if (x > 0 && y > 0) |
1153 | ds->todraw[(y-1)*w+(x-1)] |= C_BR; |
1154 | if (x+1 < w && y+1 < h) |
1155 | ds->todraw[(y+1)*w+(x+1)] |= C_TL; |
1156 | } else if (state->soln[y*w+x] > 0) { |
1157 | ds->todraw[y*w+x] |= FORWSLASH; |
1158 | if (x > 0) |
1159 | ds->todraw[y*w+(x-1)] |= R_B | C_BR; |
1160 | if (x+1 < w) |
1161 | ds->todraw[y*w+(x+1)] |= L_T | C_TL; |
1162 | if (y > 0) |
1163 | ds->todraw[(y-1)*w+x] |= B_R | C_BR; |
1164 | if (y+1 < h) |
1165 | ds->todraw[(y+1)*w+x] |= T_L | C_TL; |
1166 | if (x > 0 && y+1 < h) |
1167 | ds->todraw[(y+1)*w+(x-1)] |= C_TR; |
1168 | if (x+1 < w && y > 0) |
1169 | ds->todraw[(y-1)*w+(x+1)] |= C_BL; |
1170 | } |
1171 | } |
1172 | } |
1173 | |
1174 | /* |
1175 | * Now go through and draw the grid squares. |
1176 | */ |
1177 | for (y = 0; y < h; y++) { |
1178 | for (x = 0; x < w; x++) { |
1179 | if (ds->todraw[y*w+x] != ds->grid[y*w+x]) { |
1180 | draw_tile(fe, ds, state->clues, x, y, ds->todraw[y*w+x]); |
1181 | ds->grid[y*w+x] = ds->todraw[y*w+x]; |
1182 | } |
1183 | } |
1184 | } |
1185 | } |
1186 | |
1187 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1188 | int dir, game_ui *ui) |
1189 | { |
1190 | return 0.0F; |
1191 | } |
1192 | |
1193 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
1194 | int dir, game_ui *ui) |
1195 | { |
1196 | if (!oldstate->completed && newstate->completed && |
1197 | !oldstate->used_solve && !newstate->used_solve) |
1198 | return FLASH_TIME; |
1199 | |
1200 | return 0.0F; |
1201 | } |
1202 | |
1203 | static int game_wants_statusbar(void) |
1204 | { |
1205 | return FALSE; |
1206 | } |
1207 | |
1208 | static int game_timing_state(game_state *state, game_ui *ui) |
1209 | { |
1210 | return TRUE; |
1211 | } |
1212 | |
1213 | #ifdef COMBINED |
1214 | #define thegame slant |
1215 | #endif |
1216 | |
1217 | const struct game thegame = { |
1218 | "Slant", "games.slant", |
1219 | default_params, |
1220 | game_fetch_preset, |
1221 | decode_params, |
1222 | encode_params, |
1223 | free_params, |
1224 | dup_params, |
1225 | TRUE, game_configure, custom_params, |
1226 | validate_params, |
1227 | new_game_desc, |
1228 | validate_desc, |
1229 | new_game, |
1230 | dup_game, |
1231 | free_game, |
1232 | TRUE, solve_game, |
1233 | TRUE, game_text_format, |
1234 | new_ui, |
1235 | free_ui, |
1236 | encode_ui, |
1237 | decode_ui, |
1238 | game_changed_state, |
1239 | interpret_move, |
1240 | execute_move, |
1241 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
1242 | game_colours, |
1243 | game_new_drawstate, |
1244 | game_free_drawstate, |
1245 | game_redraw, |
1246 | game_anim_length, |
1247 | game_flash_length, |
1248 | game_wants_statusbar, |
1249 | FALSE, game_timing_state, |
1250 | 0, /* mouse_priorities */ |
1251 | }; |