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> |
b3d64b2b |
27 | #include <stdarg.h> |
f1010613 |
28 | #include <string.h> |
29 | #include <assert.h> |
30 | #include <ctype.h> |
31 | #include <math.h> |
32 | |
33 | #include "puzzles.h" |
34 | |
35 | enum { |
36 | COL_BACKGROUND, |
37 | COL_GRID, |
38 | COL_INK, |
e3478a4b |
39 | COL_SLANT1, |
40 | COL_SLANT2, |
9dc3c55b |
41 | COL_ERROR, |
f1010613 |
42 | NCOLOURS |
43 | }; |
44 | |
b926ba00 |
45 | /* |
46 | * In standalone solver mode, `verbose' is a variable which can be |
47 | * set by command-line option; in debugging mode it's simply always |
48 | * true. |
49 | */ |
50 | #if defined STANDALONE_SOLVER |
51 | #define SOLVER_DIAGNOSTICS |
52 | int verbose = FALSE; |
53 | #elif defined SOLVER_DIAGNOSTICS |
54 | #define verbose TRUE |
55 | #endif |
56 | |
57 | /* |
58 | * Difficulty levels. I do some macro ickery here to ensure that my |
59 | * enum and the various forms of my name list always match up. |
60 | */ |
61 | #define DIFFLIST(A) \ |
62 | A(EASY,Easy,e) \ |
63 | A(HARD,Hard,h) |
64 | #define ENUM(upper,title,lower) DIFF_ ## upper, |
65 | #define TITLE(upper,title,lower) #title, |
66 | #define ENCODE(upper,title,lower) #lower |
67 | #define CONFIG(upper,title,lower) ":" #title |
68 | enum { DIFFLIST(ENUM) DIFFCOUNT }; |
69 | static char const *const slant_diffnames[] = { DIFFLIST(TITLE) }; |
70 | static char const slant_diffchars[] = DIFFLIST(ENCODE); |
71 | #define DIFFCONFIG DIFFLIST(CONFIG) |
72 | |
f1010613 |
73 | struct game_params { |
b926ba00 |
74 | int w, h, diff; |
f1010613 |
75 | }; |
76 | |
77 | typedef struct game_clues { |
78 | int w, h; |
79 | signed char *clues; |
8aa366aa |
80 | int *tmpdsf; |
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81 | int refcount; |
82 | } game_clues; |
83 | |
9dc3c55b |
84 | #define ERR_VERTEX 1 |
85 | #define ERR_SQUARE 2 |
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]); |
f1010613 |
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; |
f1010613 |
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 | /* |
b3d64b2b |
276 | * Stores possible v-shapes. This array is w by h in size, but |
277 | * not every bit of every entry is meaningful. The bits mean: |
278 | * |
279 | * - bit 0 for a square means that that square and the one to |
280 | * its right might form a v-shape between them |
281 | * - bit 1 for a square means that that square and the one to |
282 | * its right might form a ^-shape between them |
283 | * - bit 2 for a square means that that square and the one |
284 | * below it might form a >-shape between them |
285 | * - bit 3 for a square means that that square and the one |
286 | * below it might form a <-shape between them |
287 | * |
288 | * Any starting 1 or 3 clue rules out four bits in this array |
a5712538 |
289 | * immediately; a 2 clue propagates any ruled-out bit past it |
290 | * (if the two squares on one side of a 2 cannot be a v-shape, |
291 | * then neither can the two on the other side be the same |
292 | * v-shape); we can rule out further bits during play using |
b3d64b2b |
293 | * partially filled 2 clues; whenever a pair of squares is |
294 | * known not to be _either_ kind of v-shape, we can mark them |
295 | * as equivalent. |
296 | */ |
297 | unsigned char *vbitmap; |
298 | |
299 | /* |
b926ba00 |
300 | * Useful to have this information automatically passed to |
301 | * solver subroutines. (This pointer is not dynamically |
302 | * allocated by new_scratch and free_scratch.) |
303 | */ |
304 | const signed char *clues; |
f1010613 |
305 | }; |
306 | |
986cc2de |
307 | static struct solver_scratch *new_scratch(int w, int h) |
f1010613 |
308 | { |
309 | int W = w+1, H = h+1; |
310 | struct solver_scratch *ret = snew(struct solver_scratch); |
b926ba00 |
311 | ret->connected = snewn(W*H, int); |
312 | ret->exits = snewn(W*H, int); |
313 | ret->border = snewn(W*H, unsigned char); |
314 | ret->equiv = snewn(w*h, int); |
315 | ret->slashval = snewn(w*h, signed char); |
b3d64b2b |
316 | ret->vbitmap = snewn(w*h, unsigned char); |
f1010613 |
317 | return ret; |
318 | } |
319 | |
986cc2de |
320 | static void free_scratch(struct solver_scratch *sc) |
f1010613 |
321 | { |
b3d64b2b |
322 | sfree(sc->vbitmap); |
b926ba00 |
323 | sfree(sc->slashval); |
324 | sfree(sc->equiv); |
325 | sfree(sc->border); |
326 | sfree(sc->exits); |
327 | sfree(sc->connected); |
f1010613 |
328 | sfree(sc); |
329 | } |
330 | |
331 | /* |
b926ba00 |
332 | * Wrapper on dsf_merge() which updates the `exits' and `border' |
333 | * arrays. |
334 | */ |
335 | static void merge_vertices(int *connected, |
336 | struct solver_scratch *sc, int i, int j) |
337 | { |
338 | int exits = -1, border = FALSE; /* initialise to placate optimiser */ |
339 | |
340 | if (sc) { |
341 | i = dsf_canonify(connected, i); |
342 | j = dsf_canonify(connected, j); |
343 | |
344 | /* |
345 | * We have used one possible exit from each of the two |
346 | * classes. Thus, the viable exit count of the new class is |
347 | * the sum of the old exit counts minus two. |
348 | */ |
349 | exits = sc->exits[i] + sc->exits[j] - 2; |
350 | |
351 | border = sc->border[i] || sc->border[j]; |
352 | } |
353 | |
354 | dsf_merge(connected, i, j); |
355 | |
356 | if (sc) { |
357 | i = dsf_canonify(connected, i); |
358 | sc->exits[i] = exits; |
359 | sc->border[i] = border; |
360 | } |
361 | } |
362 | |
363 | /* |
364 | * Called when we have just blocked one way out of a particular |
365 | * point. If that point is a non-clue point (thus has a variable |
366 | * number of exits), we have therefore decreased its potential exit |
367 | * count, so we must decrement the exit count for the group as a |
368 | * whole. |
369 | */ |
370 | static void decr_exits(struct solver_scratch *sc, int i) |
371 | { |
372 | if (sc->clues[i] < 0) { |
373 | i = dsf_canonify(sc->connected, i); |
374 | sc->exits[i]--; |
375 | } |
376 | } |
377 | |
378 | static void fill_square(int w, int h, int x, int y, int v, |
379 | signed char *soln, |
380 | int *connected, struct solver_scratch *sc) |
381 | { |
382 | int W = w+1 /*, H = h+1 */; |
383 | |
384 | assert(x >= 0 && x < w && y >= 0 && y < h); |
385 | |
386 | if (soln[y*w+x] != 0) { |
387 | return; /* do nothing */ |
388 | } |
389 | |
390 | #ifdef SOLVER_DIAGNOSTICS |
391 | if (verbose) |
392 | printf(" placing %c in %d,%d\n", v == -1 ? '\\' : '/', x, y); |
393 | #endif |
394 | |
395 | soln[y*w+x] = v; |
396 | |
397 | if (sc) { |
398 | int c = dsf_canonify(sc->equiv, y*w+x); |
399 | sc->slashval[c] = v; |
400 | } |
401 | |
402 | if (v < 0) { |
403 | merge_vertices(connected, sc, y*W+x, (y+1)*W+(x+1)); |
404 | if (sc) { |
405 | decr_exits(sc, y*W+(x+1)); |
406 | decr_exits(sc, (y+1)*W+x); |
407 | } |
408 | } else { |
409 | merge_vertices(connected, sc, y*W+(x+1), (y+1)*W+x); |
410 | if (sc) { |
411 | decr_exits(sc, y*W+x); |
412 | decr_exits(sc, (y+1)*W+(x+1)); |
413 | } |
414 | } |
415 | } |
416 | |
b3d64b2b |
417 | static int vbitmap_clear(int w, int h, struct solver_scratch *sc, |
418 | int x, int y, int vbits, char *reason, ...) |
419 | { |
420 | int done_something = FALSE; |
421 | int vbit; |
422 | |
423 | for (vbit = 1; vbit <= 8; vbit <<= 1) |
424 | if (vbits & sc->vbitmap[y*w+x] & vbit) { |
425 | done_something = TRUE; |
426 | #ifdef SOLVER_DIAGNOSTICS |
427 | if (verbose) { |
428 | va_list ap; |
429 | |
430 | printf("ruling out %c shape at (%d,%d)-(%d,%d) (", |
431 | "!v^!>!!!<"[vbit], x, y, |
432 | x+((vbit&0x3)!=0), y+((vbit&0xC)!=0)); |
433 | |
434 | va_start(ap, reason); |
435 | vprintf(reason, ap); |
436 | va_end(ap); |
437 | |
438 | printf(")\n"); |
439 | } |
440 | #endif |
441 | sc->vbitmap[y*w+x] &= ~vbit; |
442 | } |
443 | |
444 | return done_something; |
445 | } |
446 | |
b926ba00 |
447 | /* |
f1010613 |
448 | * Solver. Returns 0 for impossibility, 1 for success, 2 for |
449 | * ambiguity or failure to converge. |
450 | */ |
451 | static int slant_solve(int w, int h, const signed char *clues, |
b926ba00 |
452 | signed char *soln, struct solver_scratch *sc, |
453 | int difficulty) |
f1010613 |
454 | { |
455 | int W = w+1, H = h+1; |
b926ba00 |
456 | int x, y, i, j; |
f1010613 |
457 | int done_something; |
458 | |
459 | /* |
460 | * Clear the output. |
461 | */ |
462 | memset(soln, 0, w*h); |
463 | |
b926ba00 |
464 | sc->clues = clues; |
465 | |
f1010613 |
466 | /* |
467 | * Establish a disjoint set forest for tracking connectedness |
468 | * between grid points. |
469 | */ |
cd28b679 |
470 | dsf_init(sc->connected, W*H); |
b926ba00 |
471 | |
472 | /* |
473 | * Establish a disjoint set forest for tracking which squares |
474 | * are known to slant in the same direction. |
475 | */ |
cd28b679 |
476 | dsf_init(sc->equiv, w*h); |
b926ba00 |
477 | |
478 | /* |
479 | * Clear the slashval array. |
480 | */ |
481 | memset(sc->slashval, 0, w*h); |
482 | |
483 | /* |
b3d64b2b |
484 | * Set up the vbitmap array. Initially all types of v are possible. |
485 | */ |
486 | memset(sc->vbitmap, 0xF, w*h); |
487 | |
488 | /* |
a5712538 |
489 | * Initialise the `exits' and `border' arrays. These are used |
b926ba00 |
490 | * to do second-order loop avoidance: the dual of the no loops |
491 | * constraint is that every point must be somehow connected to |
492 | * the border of the grid (otherwise there would be a solid |
493 | * loop around it which prevented this). |
494 | * |
495 | * I define a `dead end' to be a connected group of points |
496 | * which contains no border point, and which can form at most |
497 | * one new connection outside itself. Then I forbid placing an |
498 | * edge so that it connects together two dead-end groups, since |
499 | * this would yield a non-border-connected isolated subgraph |
500 | * with no further scope to extend it. |
501 | */ |
502 | for (y = 0; y < H; y++) |
503 | for (x = 0; x < W; x++) { |
504 | if (y == 0 || y == H-1 || x == 0 || x == W-1) |
505 | sc->border[y*W+x] = TRUE; |
506 | else |
507 | sc->border[y*W+x] = FALSE; |
508 | |
509 | if (clues[y*W+x] < 0) |
510 | sc->exits[y*W+x] = 4; |
511 | else |
512 | sc->exits[y*W+x] = clues[y*W+x]; |
513 | } |
514 | |
515 | /* |
f1010613 |
516 | * Repeatedly try to deduce something until we can't. |
517 | */ |
518 | do { |
519 | done_something = FALSE; |
520 | |
521 | /* |
522 | * Any clue point with the number of remaining lines equal |
523 | * to zero or to the number of remaining undecided |
524 | * neighbouring squares can be filled in completely. |
525 | */ |
526 | for (y = 0; y < H; y++) |
527 | for (x = 0; x < W; x++) { |
b926ba00 |
528 | struct { |
529 | int pos, slash; |
530 | } neighbours[4]; |
531 | int nneighbours; |
532 | int nu, nl, c, s, eq, eq2, last, meq, mj1, mj2; |
f1010613 |
533 | |
534 | if ((c = clues[y*W+x]) < 0) |
535 | continue; |
536 | |
537 | /* |
b926ba00 |
538 | * We have a clue point. Start by listing its |
539 | * neighbouring squares, in order around the point, |
540 | * together with the type of slash that would be |
541 | * required in that square to connect to the point. |
542 | */ |
543 | nneighbours = 0; |
544 | if (x > 0 && y > 0) { |
545 | neighbours[nneighbours].pos = (y-1)*w+(x-1); |
546 | neighbours[nneighbours].slash = -1; |
547 | nneighbours++; |
548 | } |
549 | if (x > 0 && y < h) { |
550 | neighbours[nneighbours].pos = y*w+(x-1); |
551 | neighbours[nneighbours].slash = +1; |
552 | nneighbours++; |
553 | } |
554 | if (x < w && y < h) { |
555 | neighbours[nneighbours].pos = y*w+x; |
556 | neighbours[nneighbours].slash = -1; |
557 | nneighbours++; |
558 | } |
559 | if (x < w && y > 0) { |
560 | neighbours[nneighbours].pos = (y-1)*w+x; |
561 | neighbours[nneighbours].slash = +1; |
562 | nneighbours++; |
563 | } |
564 | |
565 | /* |
566 | * Count up the number of undecided neighbours, and |
567 | * also the number of lines already present. |
568 | * |
569 | * If we're not on DIFF_EASY, then in this loop we |
570 | * also track whether we've seen two adjacent empty |
571 | * squares belonging to the same equivalence class |
572 | * (meaning they have the same type of slash). If |
573 | * so, we count them jointly as one line. |
f1010613 |
574 | */ |
575 | nu = 0; |
576 | nl = c; |
b926ba00 |
577 | last = neighbours[nneighbours-1].pos; |
578 | if (soln[last] == 0) |
579 | eq = dsf_canonify(sc->equiv, last); |
580 | else |
581 | eq = -1; |
582 | meq = mj1 = mj2 = -1; |
583 | for (i = 0; i < nneighbours; i++) { |
584 | j = neighbours[i].pos; |
585 | s = neighbours[i].slash; |
586 | if (soln[j] == 0) { |
587 | nu++; /* undecided */ |
588 | if (meq < 0 && difficulty > DIFF_EASY) { |
589 | eq2 = dsf_canonify(sc->equiv, j); |
590 | if (eq == eq2 && last != j) { |
591 | /* |
592 | * We've found an equivalent pair. |
593 | * Mark it. This also inhibits any |
594 | * further equivalence tracking |
595 | * around this square, since we can |
596 | * only handle one pair (and in |
597 | * particular we want to avoid |
598 | * being misled by two overlapping |
599 | * equivalence pairs). |
600 | */ |
601 | meq = eq; |
602 | mj1 = last; |
603 | mj2 = j; |
604 | nl--; /* count one line */ |
605 | nu -= 2; /* and lose two undecideds */ |
606 | } else |
607 | eq = eq2; |
608 | } |
609 | } else { |
610 | eq = -1; |
611 | if (soln[j] == s) |
612 | nl--; /* here's a line */ |
613 | } |
614 | last = j; |
615 | } |
f1010613 |
616 | |
617 | /* |
618 | * Check the counts. |
619 | */ |
620 | if (nl < 0 || nl > nu) { |
621 | /* |
622 | * No consistent value for this at all! |
623 | */ |
b926ba00 |
624 | #ifdef SOLVER_DIAGNOSTICS |
625 | if (verbose) |
626 | printf("need %d / %d lines around clue point at %d,%d!\n", |
627 | nl, nu, x, y); |
628 | #endif |
f1010613 |
629 | return 0; /* impossible */ |
630 | } |
631 | |
632 | if (nu > 0 && (nl == 0 || nl == nu)) { |
633 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
634 | if (verbose) { |
635 | if (meq >= 0) |
636 | printf("partially (since %d,%d == %d,%d) ", |
637 | mj1%w, mj1/w, mj2%w, mj2/w); |
638 | printf("%s around clue point at %d,%d\n", |
639 | nl ? "filling" : "emptying", x, y); |
640 | } |
f1010613 |
641 | #endif |
b926ba00 |
642 | for (i = 0; i < nneighbours; i++) { |
643 | j = neighbours[i].pos; |
644 | s = neighbours[i].slash; |
645 | if (soln[j] == 0 && j != mj1 && j != mj2) |
646 | fill_square(w, h, j%w, j/w, (nl ? s : -s), soln, |
647 | sc->connected, sc); |
648 | } |
f1010613 |
649 | |
650 | done_something = TRUE; |
b926ba00 |
651 | } else if (nu == 2 && nl == 1 && difficulty > DIFF_EASY) { |
652 | /* |
653 | * If we have precisely two undecided squares |
654 | * and precisely one line to place between |
655 | * them, _and_ those squares are adjacent, then |
656 | * we can mark them as equivalent to one |
657 | * another. |
658 | * |
659 | * This even applies if meq >= 0: if we have a |
660 | * 2 clue point and two of its neighbours are |
661 | * already marked equivalent, we can indeed |
662 | * mark the other two as equivalent. |
663 | * |
664 | * We don't bother with this on DIFF_EASY, |
665 | * since we wouldn't have used the results |
666 | * anyway. |
667 | */ |
668 | last = -1; |
669 | for (i = 0; i < nneighbours; i++) { |
670 | j = neighbours[i].pos; |
671 | if (soln[j] == 0 && j != mj1 && j != mj2) { |
672 | if (last < 0) |
673 | last = i; |
674 | else if (last == i-1 || (last == 0 && i == 3)) |
675 | break; /* found a pair */ |
676 | } |
677 | } |
678 | if (i < nneighbours) { |
679 | int sv1, sv2; |
680 | |
681 | assert(last >= 0); |
682 | /* |
683 | * neighbours[last] and neighbours[i] are |
684 | * the pair. Mark them equivalent. |
685 | */ |
686 | #ifdef SOLVER_DIAGNOSTICS |
687 | if (verbose) { |
688 | if (meq >= 0) |
689 | printf("since %d,%d == %d,%d, ", |
690 | mj1%w, mj1/w, mj2%w, mj2/w); |
691 | } |
692 | #endif |
693 | mj1 = neighbours[last].pos; |
694 | mj2 = neighbours[i].pos; |
695 | #ifdef SOLVER_DIAGNOSTICS |
696 | if (verbose) |
697 | printf("clue point at %d,%d implies %d,%d == %d," |
698 | "%d\n", x, y, mj1%w, mj1/w, mj2%w, mj2/w); |
699 | #endif |
700 | mj1 = dsf_canonify(sc->equiv, mj1); |
701 | sv1 = sc->slashval[mj1]; |
702 | mj2 = dsf_canonify(sc->equiv, mj2); |
703 | sv2 = sc->slashval[mj2]; |
704 | if (sv1 != 0 && sv2 != 0 && sv1 != sv2) { |
705 | #ifdef SOLVER_DIAGNOSTICS |
706 | if (verbose) |
707 | printf("merged two equivalence classes with" |
708 | " different slash values!\n"); |
709 | #endif |
710 | return 0; |
711 | } |
712 | sv1 = sv1 ? sv1 : sv2; |
713 | dsf_merge(sc->equiv, mj1, mj2); |
714 | mj1 = dsf_canonify(sc->equiv, mj1); |
715 | sc->slashval[mj1] = sv1; |
716 | } |
f1010613 |
717 | } |
718 | } |
719 | |
720 | if (done_something) |
721 | continue; |
722 | |
723 | /* |
724 | * Failing that, we now apply the second condition, which |
725 | * is that no square may be filled in such a way as to form |
b926ba00 |
726 | * a loop. Also in this loop (since it's over squares |
727 | * rather than points), we check slashval to see if we've |
728 | * already filled in another square in the same equivalence |
729 | * class. |
730 | * |
731 | * The slashval check is disabled on DIFF_EASY, as is dead |
732 | * end avoidance. Only _immediate_ loop avoidance remains. |
f1010613 |
733 | */ |
734 | for (y = 0; y < h; y++) |
735 | for (x = 0; x < w; x++) { |
b926ba00 |
736 | int fs, bs, v; |
737 | int c1, c2; |
738 | #ifdef SOLVER_DIAGNOSTICS |
739 | char *reason = "<internal error>"; |
740 | #endif |
f1010613 |
741 | |
742 | if (soln[y*w+x]) |
743 | continue; /* got this one already */ |
744 | |
b926ba00 |
745 | fs = FALSE; |
746 | bs = FALSE; |
747 | |
748 | if (difficulty > DIFF_EASY) |
749 | v = sc->slashval[dsf_canonify(sc->equiv, y*w+x)]; |
750 | else |
751 | v = 0; |
752 | |
753 | /* |
754 | * Try to rule out connectivity between (x,y) and |
755 | * (x+1,y+1); if successful, we will deduce that we |
756 | * must have a forward slash. |
757 | */ |
758 | c1 = dsf_canonify(sc->connected, y*W+x); |
759 | c2 = dsf_canonify(sc->connected, (y+1)*W+(x+1)); |
760 | if (c1 == c2) { |
761 | fs = TRUE; |
762 | #ifdef SOLVER_DIAGNOSTICS |
763 | reason = "simple loop avoidance"; |
764 | #endif |
765 | } |
766 | if (difficulty > DIFF_EASY && |
767 | !sc->border[c1] && !sc->border[c2] && |
768 | sc->exits[c1] <= 1 && sc->exits[c2] <= 1) { |
769 | fs = TRUE; |
770 | #ifdef SOLVER_DIAGNOSTICS |
771 | reason = "dead end avoidance"; |
772 | #endif |
773 | } |
774 | if (v == +1) { |
775 | fs = TRUE; |
776 | #ifdef SOLVER_DIAGNOSTICS |
777 | reason = "equivalence to an already filled square"; |
778 | #endif |
779 | } |
780 | |
781 | /* |
782 | * Now do the same between (x+1,y) and (x,y+1), to |
783 | * see if we are required to have a backslash. |
784 | */ |
785 | c1 = dsf_canonify(sc->connected, y*W+(x+1)); |
786 | c2 = dsf_canonify(sc->connected, (y+1)*W+x); |
787 | if (c1 == c2) { |
788 | bs = TRUE; |
789 | #ifdef SOLVER_DIAGNOSTICS |
790 | reason = "simple loop avoidance"; |
791 | #endif |
792 | } |
793 | if (difficulty > DIFF_EASY && |
794 | !sc->border[c1] && !sc->border[c2] && |
795 | sc->exits[c1] <= 1 && sc->exits[c2] <= 1) { |
796 | bs = TRUE; |
797 | #ifdef SOLVER_DIAGNOSTICS |
798 | reason = "dead end avoidance"; |
799 | #endif |
800 | } |
801 | if (v == -1) { |
802 | bs = TRUE; |
803 | #ifdef SOLVER_DIAGNOSTICS |
804 | reason = "equivalence to an already filled square"; |
805 | #endif |
806 | } |
f1010613 |
807 | |
808 | if (fs && bs) { |
809 | /* |
b926ba00 |
810 | * No consistent value for this at all! |
f1010613 |
811 | */ |
b926ba00 |
812 | #ifdef SOLVER_DIAGNOSTICS |
813 | if (verbose) |
814 | printf("%d,%d has no consistent slash!\n", x, y); |
815 | #endif |
f1010613 |
816 | return 0; /* impossible */ |
817 | } |
818 | |
819 | if (fs) { |
f1010613 |
820 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
821 | if (verbose) |
822 | printf("employing %s\n", reason); |
f1010613 |
823 | #endif |
b926ba00 |
824 | fill_square(w, h, x, y, +1, soln, sc->connected, sc); |
f1010613 |
825 | done_something = TRUE; |
826 | } else if (bs) { |
f1010613 |
827 | #ifdef SOLVER_DIAGNOSTICS |
b926ba00 |
828 | if (verbose) |
829 | printf("employing %s\n", reason); |
f1010613 |
830 | #endif |
b926ba00 |
831 | fill_square(w, h, x, y, -1, soln, sc->connected, sc); |
f1010613 |
832 | done_something = TRUE; |
833 | } |
834 | } |
835 | |
b3d64b2b |
836 | if (done_something) |
837 | continue; |
838 | |
839 | /* |
840 | * Now see what we can do with the vbitmap array. All |
841 | * vbitmap deductions are disabled at Easy level. |
842 | */ |
843 | if (difficulty <= DIFF_EASY) |
844 | continue; |
845 | |
846 | for (y = 0; y < h; y++) |
847 | for (x = 0; x < w; x++) { |
848 | int s, c; |
849 | |
850 | /* |
851 | * Any line already placed in a square must rule |
852 | * out any type of v which contradicts it. |
853 | */ |
854 | if ((s = soln[y*w+x]) != 0) { |
855 | if (x > 0) |
856 | done_something |= |
857 | vbitmap_clear(w, h, sc, x-1, y, (s < 0 ? 0x1 : 0x2), |
858 | "contradicts known edge at (%d,%d)",x,y); |
859 | if (x+1 < w) |
860 | done_something |= |
861 | vbitmap_clear(w, h, sc, x, y, (s < 0 ? 0x2 : 0x1), |
862 | "contradicts known edge at (%d,%d)",x,y); |
863 | if (y > 0) |
864 | done_something |= |
865 | vbitmap_clear(w, h, sc, x, y-1, (s < 0 ? 0x4 : 0x8), |
866 | "contradicts known edge at (%d,%d)",x,y); |
867 | if (y+1 < h) |
868 | done_something |= |
869 | vbitmap_clear(w, h, sc, x, y, (s < 0 ? 0x8 : 0x4), |
870 | "contradicts known edge at (%d,%d)",x,y); |
871 | } |
872 | |
873 | /* |
874 | * If both types of v are ruled out for a pair of |
875 | * adjacent squares, mark them as equivalent. |
876 | */ |
877 | if (x+1 < w && !(sc->vbitmap[y*w+x] & 0x3)) { |
878 | int n1 = y*w+x, n2 = y*w+(x+1); |
879 | if (dsf_canonify(sc->equiv, n1) != |
880 | dsf_canonify(sc->equiv, n2)) { |
881 | dsf_merge(sc->equiv, n1, n2); |
882 | done_something = TRUE; |
883 | #ifdef SOLVER_DIAGNOSTICS |
884 | if (verbose) |
885 | printf("(%d,%d) and (%d,%d) must be equivalent" |
886 | " because both v-shapes are ruled out\n", |
887 | x, y, x+1, y); |
888 | #endif |
889 | } |
890 | } |
891 | if (y+1 < h && !(sc->vbitmap[y*w+x] & 0xC)) { |
892 | int n1 = y*w+x, n2 = (y+1)*w+x; |
893 | if (dsf_canonify(sc->equiv, n1) != |
894 | dsf_canonify(sc->equiv, n2)) { |
895 | dsf_merge(sc->equiv, n1, n2); |
896 | done_something = TRUE; |
897 | #ifdef SOLVER_DIAGNOSTICS |
898 | if (verbose) |
899 | printf("(%d,%d) and (%d,%d) must be equivalent" |
900 | " because both v-shapes are ruled out\n", |
901 | x, y, x, y+1); |
902 | #endif |
903 | } |
904 | } |
905 | |
906 | /* |
907 | * The remaining work in this loop only works |
908 | * around non-edge clue points. |
909 | */ |
910 | if (y == 0 || x == 0) |
911 | continue; |
912 | if ((c = clues[y*W+x]) < 0) |
913 | continue; |
914 | |
915 | /* |
916 | * x,y marks a clue point not on the grid edge. See |
917 | * if this clue point allows us to rule out any v |
918 | * shapes. |
919 | */ |
920 | |
921 | if (c == 1) { |
922 | /* |
923 | * A 1 clue can never have any v shape pointing |
924 | * at it. |
925 | */ |
926 | done_something |= |
927 | vbitmap_clear(w, h, sc, x-1, y-1, 0x5, |
928 | "points at 1 clue at (%d,%d)", x, y); |
929 | done_something |= |
930 | vbitmap_clear(w, h, sc, x-1, y, 0x2, |
931 | "points at 1 clue at (%d,%d)", x, y); |
932 | done_something |= |
933 | vbitmap_clear(w, h, sc, x, y-1, 0x8, |
934 | "points at 1 clue at (%d,%d)", x, y); |
935 | } else if (c == 3) { |
936 | /* |
937 | * A 3 clue can never have any v shape pointing |
938 | * away from it. |
939 | */ |
940 | done_something |= |
941 | vbitmap_clear(w, h, sc, x-1, y-1, 0xA, |
942 | "points away from 3 clue at (%d,%d)", x, y); |
943 | done_something |= |
944 | vbitmap_clear(w, h, sc, x-1, y, 0x1, |
945 | "points away from 3 clue at (%d,%d)", x, y); |
946 | done_something |= |
947 | vbitmap_clear(w, h, sc, x, y-1, 0x4, |
948 | "points away from 3 clue at (%d,%d)", x, y); |
949 | } else if (c == 2) { |
950 | /* |
951 | * If a 2 clue has any kind of v ruled out on |
952 | * one side of it, the same v is ruled out on |
953 | * the other side. |
954 | */ |
955 | done_something |= |
956 | vbitmap_clear(w, h, sc, x-1, y-1, |
957 | (sc->vbitmap[(y )*w+(x-1)] & 0x3) ^ 0x3, |
958 | "propagated by 2 clue at (%d,%d)", x, y); |
959 | done_something |= |
960 | vbitmap_clear(w, h, sc, x-1, y-1, |
961 | (sc->vbitmap[(y-1)*w+(x )] & 0xC) ^ 0xC, |
962 | "propagated by 2 clue at (%d,%d)", x, y); |
963 | done_something |= |
964 | vbitmap_clear(w, h, sc, x-1, y, |
965 | (sc->vbitmap[(y-1)*w+(x-1)] & 0x3) ^ 0x3, |
966 | "propagated by 2 clue at (%d,%d)", x, y); |
967 | done_something |= |
968 | vbitmap_clear(w, h, sc, x, y-1, |
969 | (sc->vbitmap[(y-1)*w+(x-1)] & 0xC) ^ 0xC, |
970 | "propagated by 2 clue at (%d,%d)", x, y); |
971 | } |
972 | |
973 | #undef CLEARBITS |
974 | |
975 | } |
976 | |
f1010613 |
977 | } while (done_something); |
978 | |
979 | /* |
980 | * Solver can make no more progress. See if the grid is full. |
981 | */ |
982 | for (i = 0; i < w*h; i++) |
983 | if (!soln[i]) |
984 | return 2; /* failed to converge */ |
985 | return 1; /* success */ |
986 | } |
987 | |
988 | /* |
989 | * Filled-grid generator. |
990 | */ |
991 | static void slant_generate(int w, int h, signed char *soln, random_state *rs) |
992 | { |
993 | int W = w+1, H = h+1; |
994 | int x, y, i; |
b926ba00 |
995 | int *connected, *indices; |
f1010613 |
996 | |
997 | /* |
998 | * Clear the output. |
999 | */ |
1000 | memset(soln, 0, w*h); |
1001 | |
1002 | /* |
1003 | * Establish a disjoint set forest for tracking connectedness |
1004 | * between grid points. |
1005 | */ |
cd28b679 |
1006 | connected = snew_dsf(W*H); |
f1010613 |
1007 | |
1008 | /* |
1009 | * Prepare a list of the squares in the grid, and fill them in |
1010 | * in a random order. |
1011 | */ |
1012 | indices = snewn(w*h, int); |
1013 | for (i = 0; i < w*h; i++) |
1014 | indices[i] = i; |
1015 | shuffle(indices, w*h, sizeof(*indices), rs); |
1016 | |
1017 | /* |
1018 | * Fill in each one in turn. |
1019 | */ |
1020 | for (i = 0; i < w*h; i++) { |
1021 | int fs, bs, v; |
1022 | |
1023 | y = indices[i] / w; |
1024 | x = indices[i] % w; |
1025 | |
b926ba00 |
1026 | fs = (dsf_canonify(connected, y*W+x) == |
1027 | dsf_canonify(connected, (y+1)*W+(x+1))); |
1028 | bs = (dsf_canonify(connected, (y+1)*W+x) == |
1029 | dsf_canonify(connected, y*W+(x+1))); |
f1010613 |
1030 | |
1031 | /* |
1032 | * It isn't possible to get into a situation where we |
1033 | * aren't allowed to place _either_ type of slash in a |
b926ba00 |
1034 | * square. Thus, filled-grid generation never has to |
1035 | * backtrack. |
f1010613 |
1036 | * |
1037 | * Proof (thanks to Gareth Taylor): |
1038 | * |
1039 | * If it were possible, it would have to be because there |
1040 | * was an existing path (not using this square) between the |
1041 | * top-left and bottom-right corners of this square, and |
1042 | * another between the other two. These two paths would |
1043 | * have to cross at some point. |
1044 | * |
1045 | * Obviously they can't cross in the middle of a square, so |
1046 | * they must cross by sharing a point in common. But this |
1047 | * isn't possible either: if you chessboard-colour all the |
1048 | * points on the grid, you find that any continuous |
1049 | * diagonal path is entirely composed of points of the same |
1050 | * colour. And one of our two hypothetical paths is between |
1051 | * two black points, and the other is between two white |
1052 | * points - therefore they can have no point in common. [] |
1053 | */ |
1054 | assert(!(fs && bs)); |
1055 | |
1056 | v = fs ? +1 : bs ? -1 : 2 * random_upto(rs, 2) - 1; |
b926ba00 |
1057 | fill_square(w, h, x, y, v, soln, connected, NULL); |
f1010613 |
1058 | } |
1059 | |
1060 | sfree(indices); |
b926ba00 |
1061 | sfree(connected); |
f1010613 |
1062 | } |
1063 | |
1064 | static char *new_game_desc(game_params *params, random_state *rs, |
1065 | char **aux, int interactive) |
1066 | { |
1067 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1068 | signed char *soln, *tmpsoln, *clues; |
1069 | int *clueindices; |
1070 | struct solver_scratch *sc; |
b926ba00 |
1071 | int x, y, v, i, j; |
f1010613 |
1072 | char *desc; |
1073 | |
1074 | soln = snewn(w*h, signed char); |
1075 | tmpsoln = snewn(w*h, signed char); |
1076 | clues = snewn(W*H, signed char); |
1077 | clueindices = snewn(W*H, int); |
1078 | sc = new_scratch(w, h); |
1079 | |
1080 | do { |
1081 | /* |
1082 | * Create the filled grid. |
1083 | */ |
1084 | slant_generate(w, h, soln, rs); |
1085 | |
1086 | /* |
1087 | * Fill in the complete set of clues. |
1088 | */ |
1089 | for (y = 0; y < H; y++) |
1090 | for (x = 0; x < W; x++) { |
1091 | v = 0; |
1092 | |
1093 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == -1) v++; |
1094 | if (x > 0 && y < h && soln[y*w+(x-1)] == +1) v++; |
1095 | if (x < w && y > 0 && soln[(y-1)*w+x] == +1) v++; |
1096 | if (x < w && y < h && soln[y*w+x] == -1) v++; |
1097 | |
1098 | clues[y*W+x] = v; |
1099 | } |
f1010613 |
1100 | |
b926ba00 |
1101 | /* |
1102 | * With all clue points filled in, all puzzles are easy: we can |
1103 | * simply process the clue points in lexicographic order, and |
1104 | * at each clue point we will always have at most one square |
1105 | * undecided, which we can then fill in uniquely. |
1106 | */ |
1107 | assert(slant_solve(w, h, clues, tmpsoln, sc, DIFF_EASY) == 1); |
1108 | |
1109 | /* |
1110 | * Remove as many clues as possible while retaining solubility. |
1111 | * |
1112 | * In DIFF_HARD mode, we prioritise the removal of obvious |
1113 | * starting points (4s, 0s, border 2s and corner 1s), on |
1114 | * the grounds that having as few of these as possible |
1115 | * seems like a good thing. In particular, we can often get |
1116 | * away without _any_ completely obvious starting points, |
1117 | * which is even better. |
1118 | */ |
1119 | for (i = 0; i < W*H; i++) |
1120 | clueindices[i] = i; |
1121 | shuffle(clueindices, W*H, sizeof(*clueindices), rs); |
1122 | for (j = 0; j < 2; j++) { |
1123 | for (i = 0; i < W*H; i++) { |
1124 | int pass, yb, xb; |
1125 | |
1126 | y = clueindices[i] / W; |
1127 | x = clueindices[i] % W; |
1128 | v = clues[y*W+x]; |
1129 | |
1130 | /* |
1131 | * Identify which pass we should process this point |
1132 | * in. If it's an obvious start point, _or_ we're |
1133 | * in DIFF_EASY, then it goes in pass 0; otherwise |
1134 | * pass 1. |
1135 | */ |
1136 | xb = (x == 0 || x == W-1); |
1137 | yb = (y == 0 || y == H-1); |
1138 | if (params->diff == DIFF_EASY || v == 4 || v == 0 || |
1139 | (v == 2 && (xb||yb)) || (v == 1 && xb && yb)) |
1140 | pass = 0; |
1141 | else |
1142 | pass = 1; |
1143 | |
1144 | if (pass == j) { |
1145 | clues[y*W+x] = -1; |
1146 | if (slant_solve(w, h, clues, tmpsoln, sc, |
1147 | params->diff) != 1) |
1148 | clues[y*W+x] = v; /* put it back */ |
1149 | } |
1150 | } |
1151 | } |
1152 | |
1153 | /* |
1154 | * And finally, verify that the grid is of _at least_ the |
1155 | * requested difficulty, by running the solver one level |
1156 | * down and verifying that it can't manage it. |
1157 | */ |
1158 | } while (params->diff > 0 && |
1159 | slant_solve(w, h, clues, tmpsoln, sc, params->diff - 1) <= 1); |
f1010613 |
1160 | |
1161 | /* |
1162 | * Now we have the clue set as it will be presented to the |
1163 | * user. Encode it in a game desc. |
1164 | */ |
1165 | { |
1166 | char *p; |
1167 | int run, i; |
1168 | |
1169 | desc = snewn(W*H+1, char); |
1170 | p = desc; |
1171 | run = 0; |
1172 | for (i = 0; i <= W*H; i++) { |
1173 | int n = (i < W*H ? clues[i] : -2); |
1174 | |
1175 | if (n == -1) |
1176 | run++; |
1177 | else { |
1178 | if (run) { |
1179 | while (run > 0) { |
1180 | int c = 'a' - 1 + run; |
1181 | if (run > 26) |
1182 | c = 'z'; |
1183 | *p++ = c; |
1184 | run -= c - ('a' - 1); |
1185 | } |
1186 | } |
1187 | if (n >= 0) |
1188 | *p++ = '0' + n; |
1189 | run = 0; |
1190 | } |
1191 | } |
1192 | assert(p - desc <= W*H); |
1193 | *p++ = '\0'; |
1194 | desc = sresize(desc, p - desc, char); |
1195 | } |
1196 | |
1197 | /* |
1198 | * Encode the solution as an aux_info. |
1199 | */ |
1200 | { |
1201 | char *auxbuf; |
1202 | *aux = auxbuf = snewn(w*h+1, char); |
1203 | for (i = 0; i < w*h; i++) |
1204 | auxbuf[i] = soln[i] < 0 ? '\\' : '/'; |
1205 | auxbuf[w*h] = '\0'; |
1206 | } |
1207 | |
1208 | free_scratch(sc); |
1209 | sfree(clueindices); |
1210 | sfree(clues); |
1211 | sfree(tmpsoln); |
1212 | sfree(soln); |
1213 | |
1214 | return desc; |
1215 | } |
1216 | |
1217 | static char *validate_desc(game_params *params, char *desc) |
1218 | { |
1219 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1220 | int area = W*H; |
1221 | int squares = 0; |
1222 | |
1223 | while (*desc) { |
1224 | int n = *desc++; |
1225 | if (n >= 'a' && n <= 'z') { |
1226 | squares += n - 'a' + 1; |
1227 | } else if (n >= '0' && n <= '4') { |
1228 | squares++; |
1229 | } else |
1230 | return "Invalid character in game description"; |
1231 | } |
1232 | |
1233 | if (squares < area) |
1234 | return "Not enough data to fill grid"; |
1235 | |
1236 | if (squares > area) |
1237 | return "Too much data to fit in grid"; |
1238 | |
1239 | return NULL; |
1240 | } |
1241 | |
dafd6cf6 |
1242 | static game_state *new_game(midend *me, game_params *params, char *desc) |
f1010613 |
1243 | { |
1244 | int w = params->w, h = params->h, W = w+1, H = h+1; |
1245 | game_state *state = snew(game_state); |
1246 | int area = W*H; |
1247 | int squares = 0; |
1248 | |
1249 | state->p = *params; |
1250 | state->soln = snewn(w*h, signed char); |
1251 | memset(state->soln, 0, w*h); |
1252 | state->completed = state->used_solve = FALSE; |
9dc3c55b |
1253 | state->errors = snewn(W*H, unsigned char); |
1254 | memset(state->errors, 0, W*H); |
f1010613 |
1255 | |
1256 | state->clues = snew(game_clues); |
1257 | state->clues->w = w; |
1258 | state->clues->h = h; |
1259 | state->clues->clues = snewn(W*H, signed char); |
1260 | state->clues->refcount = 1; |
f5512c77 |
1261 | state->clues->tmpdsf = snewn(W*H*2+W+H, int); |
f1010613 |
1262 | memset(state->clues->clues, -1, W*H); |
1263 | while (*desc) { |
1264 | int n = *desc++; |
1265 | if (n >= 'a' && n <= 'z') { |
1266 | squares += n - 'a' + 1; |
1267 | } else if (n >= '0' && n <= '4') { |
1268 | state->clues->clues[squares++] = n - '0'; |
1269 | } else |
1270 | assert(!"can't get here"); |
1271 | } |
1272 | assert(squares == area); |
1273 | |
1274 | return state; |
1275 | } |
1276 | |
1277 | static game_state *dup_game(game_state *state) |
1278 | { |
9dc3c55b |
1279 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1280 | game_state *ret = snew(game_state); |
1281 | |
1282 | ret->p = state->p; |
1283 | ret->clues = state->clues; |
1284 | ret->clues->refcount++; |
1285 | ret->completed = state->completed; |
1286 | ret->used_solve = state->used_solve; |
1287 | |
1288 | ret->soln = snewn(w*h, signed char); |
1289 | memcpy(ret->soln, state->soln, w*h); |
1290 | |
9dc3c55b |
1291 | ret->errors = snewn(W*H, unsigned char); |
1292 | memcpy(ret->errors, state->errors, W*H); |
1293 | |
f1010613 |
1294 | return ret; |
1295 | } |
1296 | |
1297 | static void free_game(game_state *state) |
1298 | { |
9dc3c55b |
1299 | sfree(state->errors); |
986cc2de |
1300 | sfree(state->soln); |
1301 | assert(state->clues); |
1302 | if (--state->clues->refcount <= 0) { |
1303 | sfree(state->clues->clues); |
8aa366aa |
1304 | sfree(state->clues->tmpdsf); |
986cc2de |
1305 | sfree(state->clues); |
1306 | } |
f1010613 |
1307 | sfree(state); |
1308 | } |
1309 | |
9dc3c55b |
1310 | /* |
1311 | * Utility function to return the current degree of a vertex. If |
1312 | * `anti' is set, it returns the number of filled-in edges |
1313 | * surrounding the point which _don't_ connect to it; thus 4 minus |
1314 | * its anti-degree is the maximum degree it could have if all the |
1315 | * empty spaces around it were filled in. |
1316 | * |
1317 | * (Yes, _4_ minus its anti-degree even if it's a border vertex.) |
1318 | * |
1319 | * If ret > 0, *sx and *sy are set to the coordinates of one of the |
1320 | * squares that contributed to it. |
1321 | */ |
1322 | static int vertex_degree(int w, int h, signed char *soln, int x, int y, |
1323 | int anti, int *sx, int *sy) |
1324 | { |
1325 | int ret = 0; |
1326 | |
1327 | assert(x >= 0 && x <= w && y >= 0 && y <= h); |
1328 | if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] - anti < 0) { |
1329 | if (sx) *sx = x-1; |
1330 | if (sy) *sy = y-1; |
1331 | ret++; |
1332 | } |
1333 | if (x > 0 && y < h && soln[y*w+(x-1)] + anti > 0) { |
1334 | if (sx) *sx = x-1; |
1335 | if (sy) *sy = y; |
1336 | ret++; |
1337 | } |
1338 | if (x < w && y > 0 && soln[(y-1)*w+x] + anti > 0) { |
1339 | if (sx) *sx = x; |
1340 | if (sy) *sy = y-1; |
1341 | ret++; |
1342 | } |
1343 | if (x < w && y < h && soln[y*w+x] - anti < 0) { |
1344 | if (sx) *sx = x; |
1345 | if (sy) *sy = y; |
1346 | ret++; |
1347 | } |
1348 | |
1349 | return anti ? 4 - ret : ret; |
1350 | } |
1351 | |
f1010613 |
1352 | static int check_completion(game_state *state) |
1353 | { |
1354 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f5512c77 |
1355 | int x, y, err = FALSE; |
8aa366aa |
1356 | int *dsf; |
9dc3c55b |
1357 | |
1358 | memset(state->errors, 0, W*H); |
f1010613 |
1359 | |
1360 | /* |
8aa366aa |
1361 | * To detect loops in the grid, we iterate through each edge |
f5512c77 |
1362 | * building up a dsf of connected components of the space |
1363 | * around the edges; if there's more than one such component, |
1364 | * we have a loop, and in particular we can then easily |
1365 | * identify and highlight every edge forming part of a loop |
1366 | * because it separates two nonequivalent regions. |
1367 | * |
8aa366aa |
1368 | * We use the `tmpdsf' scratch space in the shared clues |
9dc3c55b |
1369 | * structure, to avoid mallocing too often. |
f5512c77 |
1370 | * |
1371 | * For these purposes, the grid is considered to be divided |
1372 | * into diamond-shaped regions surrounding an orthogonal edge. |
1373 | * This means we have W*h vertical edges and w*H horizontal |
1374 | * ones; so our vertical edges are indexed in the dsf as |
1375 | * (y*W+x) (0<=y<h, 0<=x<W), and the horizontal ones as (W*h + |
1376 | * y*w+x) (0<=y<H, 0<=x<w), where (x,y) is the topmost or |
1377 | * leftmost point on the edge. |
f1010613 |
1378 | */ |
8aa366aa |
1379 | dsf = state->clues->tmpdsf; |
f5512c77 |
1380 | dsf_init(dsf, W*h + w*H); |
1381 | /* Start by identifying all the outer edges with each other. */ |
1382 | for (y = 0; y < h; y++) { |
1383 | dsf_merge(dsf, 0, y*W+0); |
1384 | dsf_merge(dsf, 0, y*W+w); |
1385 | } |
1386 | for (x = 0; x < w; x++) { |
1387 | dsf_merge(dsf, 0, W*h + 0*w+x); |
1388 | dsf_merge(dsf, 0, W*h + h*w+x); |
1389 | } |
1390 | /* Now go through the actual grid. */ |
8aa366aa |
1391 | for (y = 0; y < h; y++) |
1392 | for (x = 0; x < w; x++) { |
f5512c77 |
1393 | if (state->soln[y*w+x] >= 0) { |
8aa366aa |
1394 | /* |
f5512c77 |
1395 | * There isn't a \ in this square, so we can unify |
1396 | * the top edge with the left, and the bottom with |
1397 | * the right. |
8aa366aa |
1398 | */ |
f5512c77 |
1399 | dsf_merge(dsf, y*W+x, W*h + y*w+x); |
1400 | dsf_merge(dsf, y*W+(x+1), W*h + (y+1)*w+x); |
1401 | } |
1402 | if (state->soln[y*w+x] <= 0) { |
1403 | /* |
1404 | * There isn't a / in this square, so we can unify |
1405 | * the top edge with the right, and the bottom |
1406 | * with the left. |
1407 | */ |
1408 | dsf_merge(dsf, y*W+x, W*h + (y+1)*w+x); |
1409 | dsf_merge(dsf, y*W+(x+1), W*h + y*w+x); |
1410 | } |
1411 | } |
1412 | /* Now go through again and mark the appropriate edges as erroneous. */ |
1413 | for (y = 0; y < h; y++) |
1414 | for (x = 0; x < w; x++) { |
1415 | int erroneous = 0; |
1416 | if (state->soln[y*w+x] > 0) { |
1417 | /* |
1418 | * A / separates the top and left edges (which |
1419 | * must already have been identified with each |
1420 | * other) from the bottom and right (likewise). |
1421 | * Hence it is erroneous if and only if the top |
1422 | * and right edges are nonequivalent. |
1423 | */ |
1424 | erroneous = (dsf_canonify(dsf, y*W+(x+1)) != |
1425 | dsf_canonify(dsf, W*h + y*w+x)); |
1426 | } else if (state->soln[y*w+x] < 0) { |
1427 | /* |
1428 | * A \ separates the top and right edges (which |
1429 | * must already have been identified with each |
1430 | * other) from the bottom and left (likewise). |
1431 | * Hence it is erroneous if and only if the top |
1432 | * and left edges are nonequivalent. |
1433 | */ |
1434 | erroneous = (dsf_canonify(dsf, y*W+x) != |
1435 | dsf_canonify(dsf, W*h + y*w+x)); |
1436 | } |
1437 | if (erroneous) { |
1438 | state->errors[y*W+x] |= ERR_SQUARE; |
1439 | err = TRUE; |
1440 | } |
8aa366aa |
1441 | } |
f1010613 |
1442 | |
1443 | /* |
9dc3c55b |
1444 | * Now go through and check the degree of each clue vertex, and |
1445 | * mark it with ERR_VERTEX if it cannot be fulfilled. |
f1010613 |
1446 | */ |
1447 | for (y = 0; y < H; y++) |
9dc3c55b |
1448 | for (x = 0; x < W; x++) { |
1449 | int c; |
f1010613 |
1450 | |
1451 | if ((c = state->clues->clues[y*W+x]) < 0) |
1452 | continue; |
1453 | |
9dc3c55b |
1454 | /* |
1455 | * Check to see if there are too many connections to |
1456 | * this vertex _or_ too many non-connections. Either is |
1457 | * grounds for marking the vertex as erroneous. |
1458 | */ |
1459 | if (vertex_degree(w, h, state->soln, x, y, |
1460 | FALSE, NULL, NULL) > c || |
1461 | vertex_degree(w, h, state->soln, x, y, |
1462 | TRUE, NULL, NULL) > 4-c) { |
1463 | state->errors[y*W+x] |= ERR_VERTEX; |
1464 | err = TRUE; |
1465 | } |
1466 | } |
1467 | |
1468 | /* |
1469 | * Now our actual victory condition is that (a) none of the |
1470 | * above code marked anything as erroneous, and (b) every |
1471 | * square has an edge in it. |
1472 | */ |
f1010613 |
1473 | |
9dc3c55b |
1474 | if (err) |
1475 | return FALSE; |
f1010613 |
1476 | |
9dc3c55b |
1477 | for (y = 0; y < h; y++) |
1478 | for (x = 0; x < w; x++) |
1479 | if (state->soln[y*w+x] == 0) |
f1010613 |
1480 | return FALSE; |
f1010613 |
1481 | |
1482 | return TRUE; |
1483 | } |
1484 | |
1485 | static char *solve_game(game_state *state, game_state *currstate, |
1486 | char *aux, char **error) |
1487 | { |
1488 | int w = state->p.w, h = state->p.h; |
1489 | signed char *soln; |
1490 | int bs, ret; |
1491 | int free_soln = FALSE; |
1492 | char *move, buf[80]; |
1493 | int movelen, movesize; |
1494 | int x, y; |
1495 | |
1496 | if (aux) { |
1497 | /* |
1498 | * If we already have the solution, save ourselves some |
1499 | * time. |
1500 | */ |
1501 | soln = (signed char *)aux; |
1502 | bs = (signed char)'\\'; |
1503 | free_soln = FALSE; |
1504 | } else { |
1505 | struct solver_scratch *sc = new_scratch(w, h); |
1506 | soln = snewn(w*h, signed char); |
1507 | bs = -1; |
b926ba00 |
1508 | ret = slant_solve(w, h, state->clues->clues, soln, sc, DIFF_HARD); |
f1010613 |
1509 | free_scratch(sc); |
1510 | if (ret != 1) { |
1511 | sfree(soln); |
1512 | if (ret == 0) |
8349ac38 |
1513 | *error = "This puzzle is not self-consistent"; |
f1010613 |
1514 | else |
8349ac38 |
1515 | *error = "Unable to find a unique solution for this puzzle"; |
1516 | return NULL; |
f1010613 |
1517 | } |
1518 | free_soln = TRUE; |
1519 | } |
1520 | |
1521 | /* |
1522 | * Construct a move string which turns the current state into |
1523 | * the solved state. |
1524 | */ |
1525 | movesize = 256; |
1526 | move = snewn(movesize, char); |
1527 | movelen = 0; |
1528 | move[movelen++] = 'S'; |
1529 | move[movelen] = '\0'; |
1530 | for (y = 0; y < h; y++) |
1531 | for (x = 0; x < w; x++) { |
1532 | int v = (soln[y*w+x] == bs ? -1 : +1); |
1533 | if (state->soln[y*w+x] != v) { |
986cc2de |
1534 | int len = sprintf(buf, ";%c%d,%d", (int)(v < 0 ? '\\' : '/'), x, y); |
f1010613 |
1535 | if (movelen + len >= movesize) { |
1536 | movesize = movelen + len + 256; |
1537 | move = sresize(move, movesize, char); |
1538 | } |
1539 | strcpy(move + movelen, buf); |
1540 | movelen += len; |
1541 | } |
1542 | } |
1543 | |
1544 | if (free_soln) |
1545 | sfree(soln); |
1546 | |
1547 | return move; |
1548 | } |
1549 | |
fa3abef5 |
1550 | static int game_can_format_as_text_now(game_params *params) |
1551 | { |
1552 | return TRUE; |
1553 | } |
1554 | |
f1010613 |
1555 | static char *game_text_format(game_state *state) |
1556 | { |
1557 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
1558 | int x, y, len; |
1559 | char *ret, *p; |
1560 | |
1561 | /* |
1562 | * There are h+H rows of w+W columns. |
1563 | */ |
1564 | len = (h+H) * (w+W+1) + 1; |
1565 | ret = snewn(len, char); |
1566 | p = ret; |
1567 | |
1568 | for (y = 0; y < H; y++) { |
1569 | for (x = 0; x < W; x++) { |
1570 | if (state->clues->clues[y*W+x] >= 0) |
1571 | *p++ = state->clues->clues[y*W+x] + '0'; |
1572 | else |
1573 | *p++ = '+'; |
1574 | if (x < w) |
1575 | *p++ = '-'; |
1576 | } |
1577 | *p++ = '\n'; |
1578 | if (y < h) { |
1579 | for (x = 0; x < W; x++) { |
1580 | *p++ = '|'; |
1581 | if (x < w) { |
1582 | if (state->soln[y*w+x] != 0) |
1583 | *p++ = (state->soln[y*w+x] < 0 ? '\\' : '/'); |
1584 | else |
1585 | *p++ = ' '; |
1586 | } |
1587 | } |
1588 | *p++ = '\n'; |
1589 | } |
1590 | } |
1591 | *p++ = '\0'; |
1592 | |
1593 | assert(p - ret == len); |
1594 | return ret; |
1595 | } |
1596 | |
1597 | static game_ui *new_ui(game_state *state) |
1598 | { |
1599 | return NULL; |
1600 | } |
1601 | |
1602 | static void free_ui(game_ui *ui) |
1603 | { |
1604 | } |
1605 | |
1606 | static char *encode_ui(game_ui *ui) |
1607 | { |
1608 | return NULL; |
1609 | } |
1610 | |
1611 | static void decode_ui(game_ui *ui, char *encoding) |
1612 | { |
1613 | } |
1614 | |
1615 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
1616 | game_state *newstate) |
1617 | { |
1618 | } |
1619 | |
1620 | #define PREFERRED_TILESIZE 32 |
1621 | #define TILESIZE (ds->tilesize) |
1622 | #define BORDER TILESIZE |
1623 | #define CLUE_RADIUS (TILESIZE / 3) |
1624 | #define CLUE_TEXTSIZE (TILESIZE / 2) |
1625 | #define COORD(x) ( (x) * TILESIZE + BORDER ) |
1626 | #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 ) |
1627 | |
1628 | #define FLASH_TIME 0.30F |
1629 | |
1630 | /* |
1631 | * Bit fields in the `grid' and `todraw' elements of the drawstate. |
1632 | */ |
9dc3c55b |
1633 | #define BACKSLASH 0x00000001L |
1634 | #define FORWSLASH 0x00000002L |
1635 | #define L_T 0x00000004L |
1636 | #define ERR_L_T 0x00000008L |
1637 | #define L_B 0x00000010L |
1638 | #define ERR_L_B 0x00000020L |
1639 | #define T_L 0x00000040L |
1640 | #define ERR_T_L 0x00000080L |
1641 | #define T_R 0x00000100L |
1642 | #define ERR_T_R 0x00000200L |
1643 | #define C_TL 0x00000400L |
1644 | #define ERR_C_TL 0x00000800L |
1645 | #define FLASH 0x00001000L |
1646 | #define ERRSLASH 0x00002000L |
1647 | #define ERR_TL 0x00004000L |
1648 | #define ERR_TR 0x00008000L |
1649 | #define ERR_BL 0x00010000L |
1650 | #define ERR_BR 0x00020000L |
f1010613 |
1651 | |
1652 | struct game_drawstate { |
1653 | int tilesize; |
1654 | int started; |
9dc3c55b |
1655 | long *grid; |
1656 | long *todraw; |
f1010613 |
1657 | }; |
1658 | |
1659 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
1660 | int x, int y, int button) |
1661 | { |
1662 | int w = state->p.w, h = state->p.h; |
1663 | |
1664 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
1665 | int v; |
1666 | char buf[80]; |
1667 | |
68bf6206 |
1668 | /* |
1669 | * This is an utterly awful hack which I should really sort out |
1670 | * by means of a proper configuration mechanism. One Slant |
1671 | * player has observed that they prefer the mouse buttons to |
1672 | * function exactly the opposite way round, so here's a |
1673 | * mechanism for environment-based configuration. I cache the |
1674 | * result in a global variable - yuck! - to avoid repeated |
1675 | * lookups. |
1676 | */ |
1677 | { |
1678 | static int swap_buttons = -1; |
1679 | if (swap_buttons < 0) { |
1680 | char *env = getenv("SLANT_SWAP_BUTTONS"); |
1681 | swap_buttons = (env && (env[0] == 'y' || env[0] == 'Y')); |
1682 | } |
1683 | if (swap_buttons) { |
1684 | if (button == LEFT_BUTTON) |
1685 | button = RIGHT_BUTTON; |
1686 | else |
1687 | button = LEFT_BUTTON; |
1688 | } |
1689 | } |
1690 | |
f1010613 |
1691 | x = FROMCOORD(x); |
1692 | y = FROMCOORD(y); |
1693 | if (x < 0 || y < 0 || x >= w || y >= h) |
1694 | return NULL; |
1695 | |
1696 | if (button == LEFT_BUTTON) { |
1697 | /* |
1698 | * Left-clicking cycles blank -> \ -> / -> blank. |
1699 | */ |
1700 | v = state->soln[y*w+x] - 1; |
1701 | if (v == -2) |
1702 | v = +1; |
1703 | } else { |
1704 | /* |
1705 | * Right-clicking cycles blank -> / -> \ -> blank. |
1706 | */ |
1707 | v = state->soln[y*w+x] + 1; |
1708 | if (v == +2) |
1709 | v = -1; |
1710 | } |
1711 | |
986cc2de |
1712 | sprintf(buf, "%c%d,%d", (int)(v==-1 ? '\\' : v==+1 ? '/' : 'C'), x, y); |
f1010613 |
1713 | return dupstr(buf); |
1714 | } |
1715 | |
1716 | return NULL; |
1717 | } |
1718 | |
1719 | static game_state *execute_move(game_state *state, char *move) |
1720 | { |
1721 | int w = state->p.w, h = state->p.h; |
1722 | char c; |
1723 | int x, y, n; |
1724 | game_state *ret = dup_game(state); |
1725 | |
1726 | while (*move) { |
1727 | c = *move; |
1728 | if (c == 'S') { |
1729 | ret->used_solve = TRUE; |
1730 | move++; |
1731 | } else if (c == '\\' || c == '/' || c == 'C') { |
1732 | move++; |
1733 | if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || |
1734 | x < 0 || y < 0 || x >= w || y >= h) { |
1735 | free_game(ret); |
1736 | return NULL; |
1737 | } |
1738 | ret->soln[y*w+x] = (c == '\\' ? -1 : c == '/' ? +1 : 0); |
1739 | move += n; |
1740 | } else { |
1741 | free_game(ret); |
1742 | return NULL; |
1743 | } |
1744 | if (*move == ';') |
1745 | move++; |
1746 | else if (*move) { |
1747 | free_game(ret); |
1748 | return NULL; |
1749 | } |
1750 | } |
1751 | |
9dc3c55b |
1752 | /* |
1753 | * We never clear the `completed' flag, but we must always |
1754 | * re-run the completion check because it also highlights |
1755 | * errors in the grid. |
1756 | */ |
1757 | ret->completed = check_completion(ret) || ret->completed; |
f1010613 |
1758 | |
1759 | return ret; |
1760 | } |
1761 | |
1762 | /* ---------------------------------------------------------------------- |
1763 | * Drawing routines. |
1764 | */ |
1765 | |
1766 | static void game_compute_size(game_params *params, int tilesize, |
1767 | int *x, int *y) |
1768 | { |
1769 | /* fool the macros */ |
3466f373 |
1770 | struct dummy { int tilesize; } dummy, *ds = &dummy; |
1771 | dummy.tilesize = tilesize; |
f1010613 |
1772 | |
1773 | *x = 2 * BORDER + params->w * TILESIZE + 1; |
1774 | *y = 2 * BORDER + params->h * TILESIZE + 1; |
1775 | } |
1776 | |
dafd6cf6 |
1777 | static void game_set_size(drawing *dr, game_drawstate *ds, |
1778 | game_params *params, int tilesize) |
f1010613 |
1779 | { |
1780 | ds->tilesize = tilesize; |
1781 | } |
1782 | |
8266f3fc |
1783 | static float *game_colours(frontend *fe, int *ncolours) |
f1010613 |
1784 | { |
1785 | float *ret = snewn(3 * NCOLOURS, float); |
1786 | |
1787 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
1788 | |
1789 | ret[COL_GRID * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.7F; |
1790 | ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.7F; |
1791 | ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.7F; |
1792 | |
1793 | ret[COL_INK * 3 + 0] = 0.0F; |
1794 | ret[COL_INK * 3 + 1] = 0.0F; |
1795 | ret[COL_INK * 3 + 2] = 0.0F; |
1796 | |
e3478a4b |
1797 | ret[COL_SLANT1 * 3 + 0] = 0.0F; |
1798 | ret[COL_SLANT1 * 3 + 1] = 0.0F; |
1799 | ret[COL_SLANT1 * 3 + 2] = 0.0F; |
1800 | |
1801 | ret[COL_SLANT2 * 3 + 0] = 0.0F; |
1802 | ret[COL_SLANT2 * 3 + 1] = 0.0F; |
1803 | ret[COL_SLANT2 * 3 + 2] = 0.0F; |
1804 | |
9dc3c55b |
1805 | ret[COL_ERROR * 3 + 0] = 1.0F; |
1806 | ret[COL_ERROR * 3 + 1] = 0.0F; |
1807 | ret[COL_ERROR * 3 + 2] = 0.0F; |
1808 | |
f1010613 |
1809 | *ncolours = NCOLOURS; |
1810 | return ret; |
1811 | } |
1812 | |
dafd6cf6 |
1813 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
f1010613 |
1814 | { |
1815 | int w = state->p.w, h = state->p.h; |
1816 | int i; |
1817 | struct game_drawstate *ds = snew(struct game_drawstate); |
1818 | |
1819 | ds->tilesize = 0; |
1820 | ds->started = FALSE; |
9dc3c55b |
1821 | ds->grid = snewn((w+2)*(h+2), long); |
1822 | ds->todraw = snewn((w+2)*(h+2), long); |
1823 | for (i = 0; i < (w+2)*(h+2); i++) |
f1010613 |
1824 | ds->grid[i] = ds->todraw[i] = -1; |
1825 | |
1826 | return ds; |
1827 | } |
1828 | |
dafd6cf6 |
1829 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
f1010613 |
1830 | { |
986cc2de |
1831 | sfree(ds->todraw); |
f1010613 |
1832 | sfree(ds->grid); |
1833 | sfree(ds); |
1834 | } |
1835 | |
dafd6cf6 |
1836 | static void draw_clue(drawing *dr, game_drawstate *ds, |
1837 | int x, int y, long v, long err, int bg, int colour) |
f1010613 |
1838 | { |
1839 | char p[2]; |
dafd6cf6 |
1840 | int ccol = colour >= 0 ? colour : ((x ^ y) & 1) ? COL_SLANT1 : COL_SLANT2; |
1841 | int tcol = colour >= 0 ? colour : err ? COL_ERROR : COL_INK; |
f1010613 |
1842 | |
1843 | if (v < 0) |
1844 | return; |
1845 | |
1846 | p[0] = v + '0'; |
1847 | p[1] = '\0'; |
dafd6cf6 |
1848 | draw_circle(dr, COORD(x), COORD(y), CLUE_RADIUS, |
1849 | bg >= 0 ? bg : COL_BACKGROUND, ccol); |
1850 | draw_text(dr, COORD(x), COORD(y), FONT_VARIABLE, |
9dc3c55b |
1851 | CLUE_TEXTSIZE, ALIGN_VCENTRE|ALIGN_HCENTRE, tcol, p); |
f1010613 |
1852 | } |
1853 | |
dafd6cf6 |
1854 | static void draw_tile(drawing *dr, game_drawstate *ds, game_clues *clues, |
5788a57e |
1855 | int x, int y, long v) |
f1010613 |
1856 | { |
9dc3c55b |
1857 | int w = clues->w, h = clues->h, W = w+1 /*, H = h+1 */; |
e3478a4b |
1858 | int chesscolour = (x ^ y) & 1; |
1859 | int fscol = chesscolour ? COL_SLANT2 : COL_SLANT1; |
1860 | int bscol = chesscolour ? COL_SLANT1 : COL_SLANT2; |
f1010613 |
1861 | |
dafd6cf6 |
1862 | clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
f1010613 |
1863 | |
dafd6cf6 |
1864 | draw_rect(dr, COORD(x), COORD(y), TILESIZE, TILESIZE, |
f1010613 |
1865 | (v & FLASH) ? COL_GRID : COL_BACKGROUND); |
1866 | |
1867 | /* |
1868 | * Draw the grid lines. |
1869 | */ |
9dc3c55b |
1870 | if (x >= 0 && x < w && y >= 0) |
dafd6cf6 |
1871 | draw_rect(dr, COORD(x), COORD(y), TILESIZE+1, 1, COL_GRID); |
9dc3c55b |
1872 | if (x >= 0 && x < w && y < h) |
dafd6cf6 |
1873 | draw_rect(dr, COORD(x), COORD(y+1), TILESIZE+1, 1, COL_GRID); |
9dc3c55b |
1874 | if (y >= 0 && y < h && x >= 0) |
dafd6cf6 |
1875 | draw_rect(dr, COORD(x), COORD(y), 1, TILESIZE+1, COL_GRID); |
9dc3c55b |
1876 | if (y >= 0 && y < h && x < w) |
dafd6cf6 |
1877 | draw_rect(dr, COORD(x+1), COORD(y), 1, TILESIZE+1, COL_GRID); |
9dc3c55b |
1878 | if (x == -1 && y == -1) |
dafd6cf6 |
1879 | draw_rect(dr, COORD(x+1), COORD(y+1), 1, 1, COL_GRID); |
9dc3c55b |
1880 | if (x == -1 && y == h) |
dafd6cf6 |
1881 | draw_rect(dr, COORD(x+1), COORD(y), 1, 1, COL_GRID); |
9dc3c55b |
1882 | if (x == w && y == -1) |
dafd6cf6 |
1883 | draw_rect(dr, COORD(x), COORD(y+1), 1, 1, COL_GRID); |
9dc3c55b |
1884 | if (x == w && y == h) |
dafd6cf6 |
1885 | draw_rect(dr, COORD(x), COORD(y), 1, 1, COL_GRID); |
f1010613 |
1886 | |
1887 | /* |
1888 | * Draw the slash. |
1889 | */ |
1890 | if (v & BACKSLASH) { |
9dc3c55b |
1891 | int scol = (v & ERRSLASH) ? COL_ERROR : bscol; |
dafd6cf6 |
1892 | draw_line(dr, COORD(x), COORD(y), COORD(x+1), COORD(y+1), scol); |
1893 | draw_line(dr, COORD(x)+1, COORD(y), COORD(x+1), COORD(y+1)-1, |
9dc3c55b |
1894 | scol); |
dafd6cf6 |
1895 | draw_line(dr, COORD(x), COORD(y)+1, COORD(x+1)-1, COORD(y+1), |
9dc3c55b |
1896 | scol); |
f1010613 |
1897 | } else if (v & FORWSLASH) { |
9dc3c55b |
1898 | int scol = (v & ERRSLASH) ? COL_ERROR : fscol; |
dafd6cf6 |
1899 | draw_line(dr, COORD(x+1), COORD(y), COORD(x), COORD(y+1), scol); |
1900 | draw_line(dr, COORD(x+1)-1, COORD(y), COORD(x), COORD(y+1)-1, |
9dc3c55b |
1901 | scol); |
dafd6cf6 |
1902 | draw_line(dr, COORD(x+1), COORD(y)+1, COORD(x)+1, COORD(y+1), |
9dc3c55b |
1903 | scol); |
f1010613 |
1904 | } |
1905 | |
1906 | /* |
1907 | * Draw dots on the grid corners that appear if a slash is in a |
1908 | * neighbouring cell. |
1909 | */ |
9dc3c55b |
1910 | if (v & (L_T | BACKSLASH)) |
dafd6cf6 |
1911 | draw_rect(dr, COORD(x), COORD(y)+1, 1, 1, |
ae4bc2cf |
1912 | (v & ERR_L_T ? COL_ERROR : bscol)); |
9dc3c55b |
1913 | if (v & (L_B | FORWSLASH)) |
dafd6cf6 |
1914 | draw_rect(dr, COORD(x), COORD(y+1)-1, 1, 1, |
ae4bc2cf |
1915 | (v & ERR_L_B ? COL_ERROR : fscol)); |
9dc3c55b |
1916 | if (v & (T_L | BACKSLASH)) |
dafd6cf6 |
1917 | draw_rect(dr, COORD(x)+1, COORD(y), 1, 1, |
ae4bc2cf |
1918 | (v & ERR_T_L ? COL_ERROR : bscol)); |
9dc3c55b |
1919 | if (v & (T_R | FORWSLASH)) |
dafd6cf6 |
1920 | draw_rect(dr, COORD(x+1)-1, COORD(y), 1, 1, |
ae4bc2cf |
1921 | (v & ERR_T_R ? COL_ERROR : fscol)); |
9dc3c55b |
1922 | if (v & (C_TL | BACKSLASH)) |
dafd6cf6 |
1923 | draw_rect(dr, COORD(x), COORD(y), 1, 1, |
ae4bc2cf |
1924 | (v & ERR_C_TL ? COL_ERROR : bscol)); |
f1010613 |
1925 | |
1926 | /* |
1927 | * And finally the clues at the corners. |
1928 | */ |
9dc3c55b |
1929 | if (x >= 0 && y >= 0) |
dafd6cf6 |
1930 | draw_clue(dr, ds, x, y, clues->clues[y*W+x], v & ERR_TL, -1, -1); |
9dc3c55b |
1931 | if (x < w && y >= 0) |
dafd6cf6 |
1932 | draw_clue(dr, ds, x+1, y, clues->clues[y*W+(x+1)], v & ERR_TR, -1, -1); |
9dc3c55b |
1933 | if (x >= 0 && y < h) |
dafd6cf6 |
1934 | draw_clue(dr, ds, x, y+1, clues->clues[(y+1)*W+x], v & ERR_BL, -1, -1); |
9dc3c55b |
1935 | if (x < w && y < h) |
dafd6cf6 |
1936 | draw_clue(dr, ds, x+1, y+1, clues->clues[(y+1)*W+(x+1)], v & ERR_BR, |
1937 | -1, -1); |
f1010613 |
1938 | |
dafd6cf6 |
1939 | unclip(dr); |
1940 | draw_update(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
f1010613 |
1941 | } |
1942 | |
dafd6cf6 |
1943 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
f1010613 |
1944 | game_state *state, int dir, game_ui *ui, |
1945 | float animtime, float flashtime) |
1946 | { |
6c48bdb7 |
1947 | int w = state->p.w, h = state->p.h, W = w+1, H = h+1; |
f1010613 |
1948 | int x, y; |
1949 | int flashing; |
1950 | |
1951 | if (flashtime > 0) |
1952 | flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; |
1953 | else |
1954 | flashing = FALSE; |
1955 | |
1956 | if (!ds->started) { |
1957 | int ww, wh; |
1958 | game_compute_size(&state->p, TILESIZE, &ww, &wh); |
dafd6cf6 |
1959 | draw_rect(dr, 0, 0, ww, wh, COL_BACKGROUND); |
1960 | draw_update(dr, 0, 0, ww, wh); |
f1010613 |
1961 | ds->started = TRUE; |
1962 | } |
1963 | |
1964 | /* |
1965 | * Loop over the grid and work out where all the slashes are. |
1966 | * We need to do this because a slash in one square affects the |
1967 | * drawing of the next one along. |
1968 | */ |
9dc3c55b |
1969 | for (y = -1; y <= h; y++) |
1970 | for (x = -1; x <= w; x++) { |
1971 | if (x >= 0 && x < w && y >= 0 && y < h) |
1972 | ds->todraw[(y+1)*(w+2)+(x+1)] = flashing ? FLASH : 0; |
1973 | else |
1974 | ds->todraw[(y+1)*(w+2)+(x+1)] = 0; |
1975 | } |
f1010613 |
1976 | |
1977 | for (y = 0; y < h; y++) { |
1978 | for (x = 0; x < w; x++) { |
9dc3c55b |
1979 | int err = state->errors[y*W+x] & ERR_SQUARE; |
1980 | |
f1010613 |
1981 | if (state->soln[y*w+x] < 0) { |
9dc3c55b |
1982 | ds->todraw[(y+1)*(w+2)+(x+1)] |= BACKSLASH; |
1983 | ds->todraw[(y+2)*(w+2)+(x+1)] |= T_R; |
1984 | ds->todraw[(y+1)*(w+2)+(x+2)] |= L_B; |
1985 | ds->todraw[(y+2)*(w+2)+(x+2)] |= C_TL; |
1986 | if (err) { |
ae4bc2cf |
1987 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERRSLASH | |
1988 | ERR_T_L | ERR_L_T | ERR_C_TL; |
9dc3c55b |
1989 | ds->todraw[(y+2)*(w+2)+(x+1)] |= ERR_T_R; |
1990 | ds->todraw[(y+1)*(w+2)+(x+2)] |= ERR_L_B; |
1991 | ds->todraw[(y+2)*(w+2)+(x+2)] |= ERR_C_TL; |
1992 | } |
f1010613 |
1993 | } else if (state->soln[y*w+x] > 0) { |
9dc3c55b |
1994 | ds->todraw[(y+1)*(w+2)+(x+1)] |= FORWSLASH; |
1995 | ds->todraw[(y+1)*(w+2)+(x+2)] |= L_T | C_TL; |
1996 | ds->todraw[(y+2)*(w+2)+(x+1)] |= T_L | C_TL; |
1997 | if (err) { |
ae4bc2cf |
1998 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERRSLASH | |
1999 | ERR_L_B | ERR_T_R; |
9dc3c55b |
2000 | ds->todraw[(y+1)*(w+2)+(x+2)] |= ERR_L_T | ERR_C_TL; |
2001 | ds->todraw[(y+2)*(w+2)+(x+1)] |= ERR_T_L | ERR_C_TL; |
2002 | } |
f1010613 |
2003 | } |
2004 | } |
2005 | } |
2006 | |
9dc3c55b |
2007 | for (y = 0; y < H; y++) |
2008 | for (x = 0; x < W; x++) |
2009 | if (state->errors[y*W+x] & ERR_VERTEX) { |
2010 | ds->todraw[y*(w+2)+x] |= ERR_BR; |
2011 | ds->todraw[y*(w+2)+(x+1)] |= ERR_BL; |
2012 | ds->todraw[(y+1)*(w+2)+x] |= ERR_TR; |
2013 | ds->todraw[(y+1)*(w+2)+(x+1)] |= ERR_TL; |
2014 | } |
2015 | |
f1010613 |
2016 | /* |
2017 | * Now go through and draw the grid squares. |
2018 | */ |
9dc3c55b |
2019 | for (y = -1; y <= h; y++) { |
2020 | for (x = -1; x <= w; x++) { |
2021 | if (ds->todraw[(y+1)*(w+2)+(x+1)] != ds->grid[(y+1)*(w+2)+(x+1)]) { |
dafd6cf6 |
2022 | draw_tile(dr, ds, state->clues, x, y, |
9dc3c55b |
2023 | ds->todraw[(y+1)*(w+2)+(x+1)]); |
2024 | ds->grid[(y+1)*(w+2)+(x+1)] = ds->todraw[(y+1)*(w+2)+(x+1)]; |
f1010613 |
2025 | } |
2026 | } |
2027 | } |
2028 | } |
2029 | |
2030 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
2031 | int dir, game_ui *ui) |
2032 | { |
2033 | return 0.0F; |
2034 | } |
2035 | |
2036 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
2037 | int dir, game_ui *ui) |
2038 | { |
2039 | if (!oldstate->completed && newstate->completed && |
2040 | !oldstate->used_solve && !newstate->used_solve) |
2041 | return FLASH_TIME; |
2042 | |
2043 | return 0.0F; |
2044 | } |
2045 | |
f1010613 |
2046 | static int game_timing_state(game_state *state, game_ui *ui) |
2047 | { |
2048 | return TRUE; |
2049 | } |
2050 | |
dafd6cf6 |
2051 | static void game_print_size(game_params *params, float *x, float *y) |
2052 | { |
2053 | int pw, ph; |
2054 | |
2055 | /* |
2056 | * I'll use 6mm squares by default. |
2057 | */ |
2058 | game_compute_size(params, 600, &pw, &ph); |
2059 | *x = pw / 100.0; |
2060 | *y = ph / 100.0; |
2061 | } |
2062 | |
2063 | static void game_print(drawing *dr, game_state *state, int tilesize) |
2064 | { |
2065 | int w = state->p.w, h = state->p.h, W = w+1; |
2066 | int ink = print_mono_colour(dr, 0); |
2067 | int paper = print_mono_colour(dr, 1); |
2068 | int x, y; |
2069 | |
2070 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
2071 | game_drawstate ads, *ds = &ads; |
4413ef0f |
2072 | game_set_size(dr, ds, NULL, tilesize); |
dafd6cf6 |
2073 | |
2074 | /* |
2075 | * Border. |
2076 | */ |
2077 | print_line_width(dr, TILESIZE / 16); |
2078 | draw_rect_outline(dr, COORD(0), COORD(0), w*TILESIZE, h*TILESIZE, ink); |
2079 | |
2080 | /* |
2081 | * Grid. |
2082 | */ |
2083 | print_line_width(dr, TILESIZE / 24); |
2084 | for (x = 1; x < w; x++) |
2085 | draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), ink); |
2086 | for (y = 1; y < h; y++) |
2087 | draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), ink); |
2088 | |
2089 | /* |
2090 | * Solution. |
2091 | */ |
2092 | print_line_width(dr, TILESIZE / 12); |
2093 | for (y = 0; y < h; y++) |
2094 | for (x = 0; x < w; x++) |
2095 | if (state->soln[y*w+x]) { |
2096 | int ly, ry; |
2097 | /* |
2098 | * To prevent nasty line-ending artefacts at |
2099 | * corners, I'll do something slightly cunning |
2100 | * here. |
2101 | */ |
2102 | clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE); |
2103 | if (state->soln[y*w+x] < 0) |
2104 | ly = y-1, ry = y+2; |
2105 | else |
2106 | ry = y-1, ly = y+2; |
2107 | draw_line(dr, COORD(x-1), COORD(ly), COORD(x+2), COORD(ry), |
2108 | ink); |
2109 | unclip(dr); |
2110 | } |
2111 | |
2112 | /* |
2113 | * Clues. |
2114 | */ |
2115 | print_line_width(dr, TILESIZE / 24); |
2116 | for (y = 0; y <= h; y++) |
2117 | for (x = 0; x <= w; x++) |
2118 | draw_clue(dr, ds, x, y, state->clues->clues[y*W+x], |
2119 | FALSE, paper, ink); |
2120 | } |
2121 | |
f1010613 |
2122 | #ifdef COMBINED |
2123 | #define thegame slant |
2124 | #endif |
2125 | |
2126 | const struct game thegame = { |
750037d7 |
2127 | "Slant", "games.slant", "slant", |
f1010613 |
2128 | default_params, |
2129 | game_fetch_preset, |
2130 | decode_params, |
2131 | encode_params, |
2132 | free_params, |
2133 | dup_params, |
2134 | TRUE, game_configure, custom_params, |
2135 | validate_params, |
2136 | new_game_desc, |
2137 | validate_desc, |
2138 | new_game, |
2139 | dup_game, |
2140 | free_game, |
2141 | TRUE, solve_game, |
fa3abef5 |
2142 | TRUE, game_can_format_as_text_now, game_text_format, |
f1010613 |
2143 | new_ui, |
2144 | free_ui, |
2145 | encode_ui, |
2146 | decode_ui, |
2147 | game_changed_state, |
2148 | interpret_move, |
2149 | execute_move, |
2150 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
2151 | game_colours, |
2152 | game_new_drawstate, |
2153 | game_free_drawstate, |
2154 | game_redraw, |
2155 | game_anim_length, |
2156 | game_flash_length, |
dafd6cf6 |
2157 | TRUE, FALSE, game_print_size, game_print, |
ac9f41c4 |
2158 | FALSE, /* wants_statusbar */ |
f1010613 |
2159 | FALSE, game_timing_state, |
2705d374 |
2160 | 0, /* flags */ |
f1010613 |
2161 | }; |
b926ba00 |
2162 | |
2163 | #ifdef STANDALONE_SOLVER |
2164 | |
2165 | #include <stdarg.h> |
2166 | |
b926ba00 |
2167 | int main(int argc, char **argv) |
2168 | { |
2169 | game_params *p; |
2170 | game_state *s; |
2171 | char *id = NULL, *desc, *err; |
2172 | int grade = FALSE; |
ccda7394 |
2173 | int ret, diff, really_verbose = FALSE; |
b926ba00 |
2174 | struct solver_scratch *sc; |
2175 | |
2176 | while (--argc > 0) { |
2177 | char *p = *++argv; |
2178 | if (!strcmp(p, "-v")) { |
ccda7394 |
2179 | really_verbose = TRUE; |
b926ba00 |
2180 | } else if (!strcmp(p, "-g")) { |
2181 | grade = TRUE; |
2182 | } else if (*p == '-') { |
2183 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
2184 | return 1; |
2185 | } else { |
2186 | id = p; |
2187 | } |
2188 | } |
2189 | |
2190 | if (!id) { |
2191 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
2192 | return 1; |
2193 | } |
2194 | |
2195 | desc = strchr(id, ':'); |
2196 | if (!desc) { |
2197 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
2198 | return 1; |
2199 | } |
2200 | *desc++ = '\0'; |
2201 | |
2202 | p = default_params(); |
2203 | decode_params(p, id); |
2204 | err = validate_desc(p, desc); |
2205 | if (err) { |
2206 | fprintf(stderr, "%s: %s\n", argv[0], err); |
2207 | return 1; |
2208 | } |
2209 | s = new_game(NULL, p, desc); |
2210 | |
2211 | sc = new_scratch(p->w, p->h); |
2212 | |
ccda7394 |
2213 | /* |
2214 | * When solving an Easy puzzle, we don't want to bother the |
2215 | * user with Hard-level deductions. For this reason, we grade |
2216 | * the puzzle internally before doing anything else. |
2217 | */ |
8067a45b |
2218 | ret = -1; /* placate optimiser */ |
ccda7394 |
2219 | for (diff = 0; diff < DIFFCOUNT; diff++) { |
b926ba00 |
2220 | ret = slant_solve(p->w, p->h, s->clues->clues, |
ccda7394 |
2221 | s->soln, sc, diff); |
2222 | if (ret < 2) |
2223 | break; |
2224 | } |
2225 | |
2226 | if (diff == DIFFCOUNT) { |
2227 | if (grade) |
2228 | printf("Difficulty rating: harder than Hard, or ambiguous\n"); |
2229 | else |
2230 | printf("Unable to find a unique solution\n"); |
2231 | } else { |
2232 | if (grade) { |
b926ba00 |
2233 | if (ret == 0) |
2234 | printf("Difficulty rating: impossible (no solution exists)\n"); |
2235 | else if (ret == 1) |
ccda7394 |
2236 | printf("Difficulty rating: %s\n", slant_diffnames[diff]); |
2237 | } else { |
2238 | verbose = really_verbose; |
2239 | ret = slant_solve(p->w, p->h, s->clues->clues, |
2240 | s->soln, sc, diff); |
2241 | if (ret == 0) |
2242 | printf("Puzzle is inconsistent\n"); |
b926ba00 |
2243 | else |
ccda7394 |
2244 | fputs(game_text_format(s), stdout); |
b926ba00 |
2245 | } |
b926ba00 |
2246 | } |
2247 | |
2248 | return 0; |
2249 | } |
2250 | |
2251 | #endif |