86e60e3d |
1 | /* |
2 | * tents.c: Puzzle involving placing tents next to trees subject to |
3 | * some confusing conditions. |
4 | * |
5 | * TODO: |
e8df451f |
6 | * |
86e60e3d |
7 | * - it might be nice to make setter-provided tent/nontent clues |
8 | * inviolable? |
9 | * * on the other hand, this would introduce considerable extra |
10 | * complexity and size into the game state; also inviolable |
11 | * clues would have to be marked as such somehow, in an |
12 | * intrusive and annoying manner. Since they're never |
13 | * generated by _my_ generator, I'm currently more inclined |
14 | * not to bother. |
15 | * |
16 | * - more difficult levels at the top end? |
17 | * * for example, sometimes we can deduce that two BLANKs in |
18 | * the same row are each adjacent to the same unattached tree |
19 | * and to nothing else, implying that they can't both be |
20 | * tents; this enables us to rule out some extra combinations |
21 | * in the row-based deduction loop, and hence deduce more |
22 | * from the number in that row than we could otherwise do. |
23 | * * that by itself doesn't seem worth implementing a new |
24 | * difficulty level for, but if I can find a few more things |
25 | * like that then it might become worthwhile. |
26 | * * I wonder if there's a sensible heuristic for where to |
27 | * guess which would make a recursive solver viable? |
28 | */ |
29 | |
30 | #include <stdio.h> |
31 | #include <stdlib.h> |
32 | #include <string.h> |
33 | #include <assert.h> |
34 | #include <ctype.h> |
35 | #include <math.h> |
36 | |
37 | #include "puzzles.h" |
38 | #include "maxflow.h" |
39 | |
40 | /* |
41 | * Design discussion |
42 | * ----------------- |
43 | * |
44 | * The rules of this puzzle as available on the WWW are poorly |
45 | * specified. The bits about tents having to be orthogonally |
46 | * adjacent to trees, tents not being even diagonally adjacent to |
47 | * one another, and the number of tents in each row and column |
48 | * being given are simple enough; the difficult bit is the |
49 | * tent-to-tree matching. |
50 | * |
51 | * Some sources use simplistic wordings such as `each tree is |
52 | * exactly connected to only one tent', which is extremely unclear: |
53 | * it's easy to read erroneously as `each tree is _orthogonally |
54 | * adjacent_ to exactly one tent', which is definitely incorrect. |
55 | * Even the most coherent sources I've found don't do a much better |
56 | * job of stating the rule. |
57 | * |
58 | * A more precise statement of the rule is that it must be possible |
59 | * to find a bijection f between tents and trees such that each |
60 | * tree T is orthogonally adjacent to the tent f(T), but that a |
61 | * tent is permitted to be adjacent to other trees in addition to |
62 | * its own. This slightly non-obvious criterion is what gives this |
63 | * puzzle most of its subtlety. |
64 | * |
65 | * However, there's a particularly subtle ambiguity left over. Is |
66 | * the bijection between tents and trees required to be _unique_? |
67 | * In other words, is that bijection conceptually something the |
68 | * player should be able to exhibit as part of the solution (even |
69 | * if they aren't actually required to do so)? Or is it sufficient |
70 | * to have a unique _placement_ of the tents which gives rise to at |
71 | * least one suitable bijection? |
72 | * |
73 | * The puzzle shown to the right of this .T. 2 *T* 2 |
74 | * paragraph illustrates the problem. There T.T 0 -> T-T 0 |
75 | * are two distinct bijections available. .T. 2 *T* 2 |
76 | * The answer to the above question will |
77 | * determine whether it's a valid puzzle. 202 202 |
78 | * |
79 | * This is an important question, because it affects both the |
80 | * player and the generator. Eventually I found all the instances |
81 | * of this puzzle I could Google up, solved them all by hand, and |
82 | * verified that in all cases the tree/tent matching was uniquely |
83 | * determined given the tree and tent positions. Therefore, the |
84 | * puzzle as implemented in this source file takes the following |
85 | * policy: |
86 | * |
87 | * - When checking a user-supplied solution for correctness, only |
88 | * verify that there exists _at least_ one matching. |
89 | * - When generating a puzzle, enforce that there must be |
90 | * _exactly_ one. |
91 | * |
92 | * Algorithmic implications |
93 | * ------------------------ |
94 | * |
95 | * Another way of phrasing the tree/tent matching criterion is to |
96 | * say that the bipartite adjacency graph between trees and tents |
97 | * has a perfect matching. That is, if you construct a graph which |
98 | * has a vertex per tree and a vertex per tent, and an edge between |
99 | * any tree and tent which are orthogonally adjacent, it is |
100 | * possible to find a set of N edges of that graph (where N is the |
101 | * number of trees and also the number of tents) which between them |
102 | * connect every tree to every tent. |
103 | * |
104 | * The most efficient known algorithms for finding such a matching |
105 | * given a graph, as far as I'm aware, are the Munkres assignment |
106 | * algorithm (also known as the Hungarian algorithm) and the |
107 | * Ford-Fulkerson algorithm (for finding optimal flows in |
108 | * networks). Each of these takes O(N^3) running time; so we're |
109 | * talking O(N^3) time to verify any candidate solution to this |
110 | * puzzle. That's just about OK if you're doing it once per mouse |
111 | * click (and in fact not even that, since the sensible thing to do |
112 | * is check all the _other_ puzzle criteria and only wade into this |
113 | * quagmire if none are violated); but if the solver had to keep |
114 | * doing N^3 work internally, then it would probably end up with |
115 | * more like N^5 or N^6 running time, and grid generation would |
116 | * become very clunky. |
117 | * |
118 | * Fortunately, I've been able to prove a very useful property of |
119 | * _unique_ perfect matchings, by adapting the proof of Hall's |
120 | * Marriage Theorem. For those unaware of Hall's Theorem, I'll |
121 | * recap it and its proof: it states that a bipartite graph |
122 | * contains a perfect matching iff every set of vertices on the |
123 | * left side of the graph have a neighbourhood _at least_ as big on |
124 | * the right. |
125 | * |
126 | * This condition is obviously satisfied if a perfect matching does |
127 | * exist; each left-side node has a distinct right-side node which |
128 | * is the one assigned to it by the matching, and thus any set of n |
129 | * left vertices must have a combined neighbourhood containing at |
130 | * least the n corresponding right vertices, and possibly others |
131 | * too. Alternatively, imagine if you had (say) three left-side |
132 | * nodes all of which were connected to only two right-side nodes |
133 | * between them: any perfect matching would have to assign one of |
134 | * those two right nodes to each of the three left nodes, and still |
135 | * give the three left nodes a different right node each. This is |
136 | * of course impossible. |
137 | * |
138 | * To prove the converse (that if every subset of left vertices |
139 | * satisfies the Hall condition then a perfect matching exists), |
140 | * consider trying to find a proper subset of the left vertices |
141 | * which _exactly_ satisfies the Hall condition: that is, its right |
142 | * neighbourhood is precisely the same size as it. If we can find |
143 | * such a subset, then we can split the bipartite graph into two |
144 | * smaller ones: one consisting of the left subset and its right |
145 | * neighbourhood, the other consisting of everything else. Edges |
146 | * from the left side of the former graph to the right side of the |
147 | * latter do not exist, by construction; edges from the right side |
148 | * of the former to the left of the latter cannot be part of any |
149 | * perfect matching because otherwise the left subset would not be |
150 | * left with enough distinct right vertices to connect to (this is |
151 | * exactly the same deduction used in Solo's set analysis). You can |
152 | * then prove (left as an exercise) that both these smaller graphs |
153 | * still satisfy the Hall condition, and therefore the proof will |
154 | * follow by induction. |
155 | * |
156 | * There's one other possibility, which is the case where _no_ |
157 | * proper subset of the left vertices has a right neighbourhood of |
158 | * exactly the same size. That is, every left subset has a strictly |
159 | * _larger_ right neighbourhood. In this situation, we can simply |
160 | * remove an _arbitrary_ edge from the graph. This cannot reduce |
161 | * the size of any left subset's right neighbourhood by more than |
162 | * one, so if all neighbourhoods were strictly bigger than they |
163 | * needed to be initially, they must now still be _at least as big_ |
164 | * as they need to be. So we can keep throwing out arbitrary edges |
165 | * until we find a set which exactly satisfies the Hall condition, |
166 | * and then proceed as above. [] |
167 | * |
168 | * That's Hall's theorem. I now build on this by examining the |
169 | * circumstances in which a bipartite graph can have a _unique_ |
170 | * perfect matching. It is clear that in the second case, where no |
171 | * left subset exactly satisfies the Hall condition and so we can |
172 | * remove an arbitrary edge, there cannot be a unique perfect |
173 | * matching: given one perfect matching, we choose our arbitrary |
174 | * removed edge to be one of those contained in it, and then we can |
175 | * still find a perfect matching in the remaining graph, which will |
176 | * be a distinct perfect matching in the original. |
177 | * |
178 | * So it is a necessary condition for a unique perfect matching |
179 | * that there must be at least one proper left subset which |
180 | * _exactly_ satisfies the Hall condition. But now consider the |
181 | * smaller graph constructed by taking that left subset and its |
182 | * neighbourhood: if the graph as a whole had a unique perfect |
183 | * matching, then so must this smaller one, which means we can find |
184 | * a proper left subset _again_, and so on. Repeating this process |
185 | * must eventually reduce us to a graph with only one left-side |
186 | * vertex (so there are no proper subsets at all); this vertex must |
187 | * be connected to only one right-side vertex, and hence must be so |
188 | * in the original graph as well (by construction). So we can |
189 | * discard this vertex pair from the graph, and any other edges |
190 | * that involved it (which will by construction be from other left |
191 | * vertices only), and the resulting smaller graph still has a |
192 | * unique perfect matching which means we can do the same thing |
193 | * again. |
194 | * |
195 | * In other words, given any bipartite graph with a unique perfect |
196 | * matching, we can find that matching by the following extremely |
197 | * simple algorithm: |
198 | * |
199 | * - Find a left-side vertex which is only connected to one |
200 | * right-side vertex. |
201 | * - Assign those vertices to one another, and therefore discard |
202 | * any other edges connecting to that right vertex. |
203 | * - Repeat until all vertices have been matched. |
204 | * |
205 | * This algorithm can be run in O(V+E) time (where V is the number |
206 | * of vertices and E is the number of edges in the graph), and the |
207 | * only way it can fail is if there is not a unique perfect |
208 | * matching (either because there is no matching at all, or because |
209 | * it isn't unique; but it can't distinguish those cases). |
210 | * |
211 | * Thus, the internal solver in this source file can be confident |
212 | * that if the tree/tent matching is uniquely determined by the |
213 | * tree and tent positions, it can find it using only this kind of |
214 | * obvious and simple operation: assign a tree to a tent if it |
215 | * cannot possibly belong to any other tent, and vice versa. If the |
216 | * solver were _only_ trying to determine the matching, even that |
217 | * `vice versa' wouldn't be required; but it can come in handy when |
218 | * not all the tents have been placed yet. I can therefore be |
219 | * reasonably confident that as long as my solver doesn't need to |
220 | * cope with grids that have a non-unique matching, it will also |
221 | * not need to do anything complicated like set analysis between |
222 | * trees and tents. |
223 | */ |
224 | |
225 | /* |
226 | * In standalone solver mode, `verbose' is a variable which can be |
227 | * set by command-line option; in debugging mode it's simply always |
228 | * true. |
229 | */ |
230 | #if defined STANDALONE_SOLVER |
231 | #define SOLVER_DIAGNOSTICS |
232 | int verbose = FALSE; |
233 | #elif defined SOLVER_DIAGNOSTICS |
234 | #define verbose TRUE |
235 | #endif |
236 | |
237 | /* |
238 | * Difficulty levels. I do some macro ickery here to ensure that my |
239 | * enum and the various forms of my name list always match up. |
240 | */ |
241 | #define DIFFLIST(A) \ |
242 | A(EASY,Easy,e) \ |
243 | A(TRICKY,Tricky,t) |
244 | #define ENUM(upper,title,lower) DIFF_ ## upper, |
245 | #define TITLE(upper,title,lower) #title, |
246 | #define ENCODE(upper,title,lower) #lower |
247 | #define CONFIG(upper,title,lower) ":" #title |
248 | enum { DIFFLIST(ENUM) DIFFCOUNT }; |
249 | static char const *const tents_diffnames[] = { DIFFLIST(TITLE) }; |
250 | static char const tents_diffchars[] = DIFFLIST(ENCODE); |
251 | #define DIFFCONFIG DIFFLIST(CONFIG) |
252 | |
253 | enum { |
254 | COL_BACKGROUND, |
255 | COL_GRID, |
256 | COL_GRASS, |
257 | COL_TREETRUNK, |
258 | COL_TREELEAF, |
259 | COL_TENT, |
2a27ffcf |
260 | COL_ERROR, |
261 | COL_ERRTEXT, |
e8df451f |
262 | COL_ERRTRUNK, |
86e60e3d |
263 | NCOLOURS |
264 | }; |
265 | |
266 | enum { BLANK, TREE, TENT, NONTENT, MAGIC }; |
267 | |
268 | struct game_params { |
269 | int w, h; |
270 | int diff; |
271 | }; |
272 | |
273 | struct numbers { |
274 | int refcount; |
275 | int *numbers; |
276 | }; |
277 | |
278 | struct game_state { |
279 | game_params p; |
280 | char *grid; |
281 | struct numbers *numbers; |
282 | int completed, used_solve; |
283 | }; |
284 | |
285 | static game_params *default_params(void) |
286 | { |
287 | game_params *ret = snew(game_params); |
288 | |
289 | ret->w = ret->h = 8; |
290 | ret->diff = DIFF_EASY; |
291 | |
292 | return ret; |
293 | } |
294 | |
295 | static const struct game_params tents_presets[] = { |
296 | {8, 8, DIFF_EASY}, |
297 | {8, 8, DIFF_TRICKY}, |
298 | {10, 10, DIFF_EASY}, |
299 | {10, 10, DIFF_TRICKY}, |
300 | {15, 15, DIFF_EASY}, |
301 | {15, 15, DIFF_TRICKY}, |
302 | }; |
303 | |
304 | static int game_fetch_preset(int i, char **name, game_params **params) |
305 | { |
306 | game_params *ret; |
307 | char str[80]; |
308 | |
309 | if (i < 0 || i >= lenof(tents_presets)) |
310 | return FALSE; |
311 | |
312 | ret = snew(game_params); |
313 | *ret = tents_presets[i]; |
314 | |
315 | sprintf(str, "%dx%d %s", ret->w, ret->h, tents_diffnames[ret->diff]); |
316 | |
317 | *name = dupstr(str); |
318 | *params = ret; |
319 | return TRUE; |
320 | } |
321 | |
322 | static void free_params(game_params *params) |
323 | { |
324 | sfree(params); |
325 | } |
326 | |
327 | static game_params *dup_params(game_params *params) |
328 | { |
329 | game_params *ret = snew(game_params); |
330 | *ret = *params; /* structure copy */ |
331 | return ret; |
332 | } |
333 | |
334 | static void decode_params(game_params *params, char const *string) |
335 | { |
336 | params->w = params->h = atoi(string); |
337 | while (*string && isdigit((unsigned char)*string)) string++; |
338 | if (*string == 'x') { |
339 | string++; |
340 | params->h = atoi(string); |
341 | while (*string && isdigit((unsigned char)*string)) string++; |
342 | } |
343 | if (*string == 'd') { |
344 | int i; |
345 | string++; |
346 | for (i = 0; i < DIFFCOUNT; i++) |
347 | if (*string == tents_diffchars[i]) |
348 | params->diff = i; |
349 | if (*string) string++; |
350 | } |
351 | } |
352 | |
353 | static char *encode_params(game_params *params, int full) |
354 | { |
355 | char buf[120]; |
356 | |
357 | sprintf(buf, "%dx%d", params->w, params->h); |
358 | if (full) |
359 | sprintf(buf + strlen(buf), "d%c", |
360 | tents_diffchars[params->diff]); |
361 | return dupstr(buf); |
362 | } |
363 | |
364 | static config_item *game_configure(game_params *params) |
365 | { |
366 | config_item *ret; |
367 | char buf[80]; |
368 | |
369 | ret = snewn(4, config_item); |
370 | |
371 | ret[0].name = "Width"; |
372 | ret[0].type = C_STRING; |
373 | sprintf(buf, "%d", params->w); |
374 | ret[0].sval = dupstr(buf); |
375 | ret[0].ival = 0; |
376 | |
377 | ret[1].name = "Height"; |
378 | ret[1].type = C_STRING; |
379 | sprintf(buf, "%d", params->h); |
380 | ret[1].sval = dupstr(buf); |
381 | ret[1].ival = 0; |
382 | |
383 | ret[2].name = "Difficulty"; |
384 | ret[2].type = C_CHOICES; |
385 | ret[2].sval = DIFFCONFIG; |
386 | ret[2].ival = params->diff; |
387 | |
388 | ret[3].name = NULL; |
389 | ret[3].type = C_END; |
390 | ret[3].sval = NULL; |
391 | ret[3].ival = 0; |
392 | |
393 | return ret; |
394 | } |
395 | |
396 | static game_params *custom_params(config_item *cfg) |
397 | { |
398 | game_params *ret = snew(game_params); |
399 | |
400 | ret->w = atoi(cfg[0].sval); |
401 | ret->h = atoi(cfg[1].sval); |
402 | ret->diff = cfg[2].ival; |
403 | |
404 | return ret; |
405 | } |
406 | |
407 | static char *validate_params(game_params *params, int full) |
408 | { |
e4b6a85b |
409 | /* |
410 | * Generating anything under 4x4 runs into trouble of one kind |
411 | * or another. |
412 | */ |
413 | if (params->w < 4 || params->h < 4) |
414 | return "Width and height must both be at least four"; |
86e60e3d |
415 | return NULL; |
416 | } |
417 | |
418 | /* |
419 | * Scratch space for solver. |
420 | */ |
421 | enum { N, U, L, R, D, MAXDIR }; /* link directions */ |
422 | #define dx(d) ( ((d)==R) - ((d)==L) ) |
423 | #define dy(d) ( ((d)==D) - ((d)==U) ) |
424 | #define F(d) ( U + D - (d) ) |
425 | struct solver_scratch { |
426 | char *links; /* mapping between trees and tents */ |
427 | int *locs; |
428 | char *place, *mrows, *trows; |
429 | }; |
430 | |
431 | static struct solver_scratch *new_scratch(int w, int h) |
432 | { |
433 | struct solver_scratch *ret = snew(struct solver_scratch); |
434 | |
435 | ret->links = snewn(w*h, char); |
436 | ret->locs = snewn(max(w, h), int); |
437 | ret->place = snewn(max(w, h), char); |
438 | ret->mrows = snewn(3 * max(w, h), char); |
439 | ret->trows = snewn(3 * max(w, h), char); |
440 | |
441 | return ret; |
442 | } |
443 | |
444 | static void free_scratch(struct solver_scratch *sc) |
445 | { |
446 | sfree(sc->trows); |
447 | sfree(sc->mrows); |
448 | sfree(sc->place); |
449 | sfree(sc->locs); |
450 | sfree(sc->links); |
451 | sfree(sc); |
452 | } |
453 | |
454 | /* |
455 | * Solver. Returns 0 for impossibility, 1 for success, 2 for |
456 | * ambiguity or failure to converge. |
457 | */ |
458 | static int tents_solve(int w, int h, const char *grid, int *numbers, |
459 | char *soln, struct solver_scratch *sc, int diff) |
460 | { |
461 | int x, y, d, i, j; |
72c15821 |
462 | char *mrow, *trow, *trow1, *trow2; |
86e60e3d |
463 | |
464 | /* |
465 | * Set up solver data. |
466 | */ |
467 | memset(sc->links, N, w*h); |
468 | |
469 | /* |
470 | * Set up solution array. |
471 | */ |
472 | memcpy(soln, grid, w*h); |
473 | |
474 | /* |
475 | * Main solver loop. |
476 | */ |
477 | while (1) { |
478 | int done_something = FALSE; |
479 | |
480 | /* |
481 | * Any tent which has only one unattached tree adjacent to |
482 | * it can be tied to that tree. |
483 | */ |
484 | for (y = 0; y < h; y++) |
485 | for (x = 0; x < w; x++) |
486 | if (soln[y*w+x] == TENT && !sc->links[y*w+x]) { |
487 | int linkd = 0; |
488 | |
489 | for (d = 1; d < MAXDIR; d++) { |
490 | int x2 = x + dx(d), y2 = y + dy(d); |
491 | if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h && |
492 | soln[y2*w+x2] == TREE && |
493 | !sc->links[y2*w+x2]) { |
494 | if (linkd) |
495 | break; /* found more than one */ |
496 | else |
497 | linkd = d; |
498 | } |
499 | } |
500 | |
501 | if (d == MAXDIR && linkd == 0) { |
502 | #ifdef SOLVER_DIAGNOSTICS |
503 | if (verbose) |
504 | printf("tent at %d,%d cannot link to anything\n", |
505 | x, y); |
506 | #endif |
507 | return 0; /* no solution exists */ |
508 | } else if (d == MAXDIR) { |
509 | int x2 = x + dx(linkd), y2 = y + dy(linkd); |
510 | |
511 | #ifdef SOLVER_DIAGNOSTICS |
512 | if (verbose) |
513 | printf("tent at %d,%d can only link to tree at" |
514 | " %d,%d\n", x, y, x2, y2); |
515 | #endif |
516 | |
517 | sc->links[y*w+x] = linkd; |
518 | sc->links[y2*w+x2] = F(linkd); |
519 | done_something = TRUE; |
520 | } |
521 | } |
522 | |
523 | if (done_something) |
524 | continue; |
525 | if (diff < 0) |
526 | break; /* don't do anything else! */ |
527 | |
528 | /* |
529 | * Mark a blank square as NONTENT if it is not orthogonally |
530 | * adjacent to any unmatched tree. |
531 | */ |
532 | for (y = 0; y < h; y++) |
533 | for (x = 0; x < w; x++) |
534 | if (soln[y*w+x] == BLANK) { |
535 | int can_be_tent = FALSE; |
536 | |
537 | for (d = 1; d < MAXDIR; d++) { |
538 | int x2 = x + dx(d), y2 = y + dy(d); |
539 | if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h && |
540 | soln[y2*w+x2] == TREE && |
541 | !sc->links[y2*w+x2]) |
542 | can_be_tent = TRUE; |
543 | } |
544 | |
545 | if (!can_be_tent) { |
546 | #ifdef SOLVER_DIAGNOSTICS |
547 | if (verbose) |
548 | printf("%d,%d cannot be a tent (no adjacent" |
549 | " unmatched tree)\n", x, y); |
550 | #endif |
551 | soln[y*w+x] = NONTENT; |
552 | done_something = TRUE; |
553 | } |
554 | } |
555 | |
556 | if (done_something) |
557 | continue; |
558 | |
559 | /* |
560 | * Mark a blank square as NONTENT if it is (perhaps |
561 | * diagonally) adjacent to any other tent. |
562 | */ |
563 | for (y = 0; y < h; y++) |
564 | for (x = 0; x < w; x++) |
565 | if (soln[y*w+x] == BLANK) { |
566 | int dx, dy, imposs = FALSE; |
567 | |
568 | for (dy = -1; dy <= +1; dy++) |
569 | for (dx = -1; dx <= +1; dx++) |
570 | if (dy || dx) { |
571 | int x2 = x + dx, y2 = y + dy; |
572 | if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h && |
573 | soln[y2*w+x2] == TENT) |
574 | imposs = TRUE; |
575 | } |
576 | |
577 | if (imposs) { |
578 | #ifdef SOLVER_DIAGNOSTICS |
579 | if (verbose) |
580 | printf("%d,%d cannot be a tent (adjacent tent)\n", |
581 | x, y); |
582 | #endif |
583 | soln[y*w+x] = NONTENT; |
584 | done_something = TRUE; |
585 | } |
586 | } |
587 | |
588 | if (done_something) |
589 | continue; |
590 | |
591 | /* |
592 | * Any tree which has exactly one {unattached tent, BLANK} |
593 | * adjacent to it must have its tent in that square. |
594 | */ |
595 | for (y = 0; y < h; y++) |
596 | for (x = 0; x < w; x++) |
597 | if (soln[y*w+x] == TREE && !sc->links[y*w+x]) { |
598 | int linkd = 0, linkd2 = 0, nd = 0; |
599 | |
600 | for (d = 1; d < MAXDIR; d++) { |
601 | int x2 = x + dx(d), y2 = y + dy(d); |
602 | if (!(x2 >= 0 && x2 < w && y2 >= 0 && y2 < h)) |
603 | continue; |
604 | if (soln[y2*w+x2] == BLANK || |
605 | (soln[y2*w+x2] == TENT && !sc->links[y2*w+x2])) { |
606 | if (linkd) |
607 | linkd2 = d; |
608 | else |
609 | linkd = d; |
610 | nd++; |
611 | } |
612 | } |
613 | |
614 | if (nd == 0) { |
615 | #ifdef SOLVER_DIAGNOSTICS |
616 | if (verbose) |
617 | printf("tree at %d,%d cannot link to anything\n", |
618 | x, y); |
619 | #endif |
620 | return 0; /* no solution exists */ |
621 | } else if (nd == 1) { |
622 | int x2 = x + dx(linkd), y2 = y + dy(linkd); |
623 | |
624 | #ifdef SOLVER_DIAGNOSTICS |
625 | if (verbose) |
626 | printf("tree at %d,%d can only link to tent at" |
627 | " %d,%d\n", x, y, x2, y2); |
628 | #endif |
629 | soln[y2*w+x2] = TENT; |
630 | sc->links[y*w+x] = linkd; |
631 | sc->links[y2*w+x2] = F(linkd); |
632 | done_something = TRUE; |
633 | } else if (nd == 2 && (!dx(linkd) != !dx(linkd2)) && |
634 | diff >= DIFF_TRICKY) { |
635 | /* |
636 | * If there are two possible places where |
637 | * this tree's tent can go, and they are |
638 | * diagonally separated rather than being |
639 | * on opposite sides of the tree, then the |
640 | * square (other than the tree square) |
641 | * which is adjacent to both of them must |
642 | * be a non-tent. |
643 | */ |
644 | int x2 = x + dx(linkd) + dx(linkd2); |
645 | int y2 = y + dy(linkd) + dy(linkd2); |
646 | assert(x2 >= 0 && x2 < w && y2 >= 0 && y2 < h); |
647 | if (soln[y2*w+x2] == BLANK) { |
648 | #ifdef SOLVER_DIAGNOSTICS |
649 | if (verbose) |
650 | printf("possible tent locations for tree at" |
651 | " %d,%d rule out tent at %d,%d\n", |
652 | x, y, x2, y2); |
653 | #endif |
654 | soln[y2*w+x2] = NONTENT; |
655 | done_something = TRUE; |
656 | } |
657 | } |
658 | } |
659 | |
660 | if (done_something) |
661 | continue; |
662 | |
663 | /* |
664 | * If localised deductions about the trees and tents |
665 | * themselves haven't helped us, it's time to resort to the |
666 | * numbers round the grid edge. For each row and column, we |
667 | * go through all possible combinations of locations for |
668 | * the unplaced tents, rule out any which have adjacent |
669 | * tents, and spot any square which is given the same state |
670 | * by all remaining combinations. |
671 | */ |
672 | for (i = 0; i < w+h; i++) { |
673 | int start, step, len, start1, start2, n, k; |
674 | |
675 | if (i < w) { |
676 | /* |
677 | * This is the number for a column. |
678 | */ |
679 | start = i; |
680 | step = w; |
681 | len = h; |
682 | if (i > 0) |
683 | start1 = start - 1; |
684 | else |
685 | start1 = -1; |
686 | if (i+1 < w) |
687 | start2 = start + 1; |
688 | else |
689 | start2 = -1; |
690 | } else { |
691 | /* |
692 | * This is the number for a row. |
693 | */ |
694 | start = (i-w)*w; |
695 | step = 1; |
696 | len = w; |
697 | if (i > w) |
698 | start1 = start - w; |
699 | else |
700 | start1 = -1; |
701 | if (i+1 < w+h) |
702 | start2 = start + w; |
703 | else |
704 | start2 = -1; |
705 | } |
706 | |
707 | if (diff < DIFF_TRICKY) { |
708 | /* |
709 | * In Easy mode, we don't look at the effect of one |
710 | * row on the next (i.e. ruling out a square if all |
711 | * possibilities for an adjacent row place a tent |
712 | * next to it). |
713 | */ |
714 | start1 = start2 = -1; |
715 | } |
716 | |
717 | k = numbers[i]; |
718 | |
719 | /* |
720 | * Count and store the locations of the free squares, |
721 | * and also count the number of tents already placed. |
722 | */ |
723 | n = 0; |
724 | for (j = 0; j < len; j++) { |
725 | if (soln[start+j*step] == TENT) |
726 | k--; /* one fewer tent to place */ |
727 | else if (soln[start+j*step] == BLANK) |
728 | sc->locs[n++] = j; |
729 | } |
730 | |
731 | if (n == 0) |
732 | continue; /* nothing left to do here */ |
733 | |
734 | /* |
735 | * Now we know we're placing k tents in n squares. Set |
736 | * up the first possibility. |
737 | */ |
738 | for (j = 0; j < n; j++) |
739 | sc->place[j] = (j < k ? TENT : NONTENT); |
740 | |
741 | /* |
742 | * We're aiming to find squares in this row which are |
743 | * invariant over all valid possibilities. Thus, we |
744 | * maintain the current state of that invariance. We |
745 | * start everything off at MAGIC to indicate that it |
746 | * hasn't been set up yet. |
747 | */ |
748 | mrow = sc->mrows; |
86e60e3d |
749 | trow = sc->trows; |
750 | trow1 = sc->trows + len; |
751 | trow2 = sc->trows + 2*len; |
752 | memset(mrow, MAGIC, 3*len); |
753 | |
754 | /* |
755 | * And iterate over all possibilities. |
756 | */ |
757 | while (1) { |
758 | int p, valid; |
759 | |
760 | /* |
761 | * See if this possibility is valid. The only way |
762 | * it can fail to be valid is if it contains two |
763 | * adjacent tents. (Other forms of invalidity, such |
764 | * as containing a tent adjacent to one already |
765 | * placed, will have been dealt with already by |
766 | * other parts of the solver.) |
767 | */ |
768 | valid = TRUE; |
769 | for (j = 0; j+1 < n; j++) |
770 | if (sc->place[j] == TENT && |
771 | sc->place[j+1] == TENT && |
772 | sc->locs[j+1] == sc->locs[j]+1) { |
773 | valid = FALSE; |
774 | break; |
775 | } |
776 | |
777 | if (valid) { |
778 | /* |
779 | * Merge this valid combination into mrow. |
780 | */ |
781 | memset(trow, MAGIC, len); |
782 | memset(trow+len, BLANK, 2*len); |
783 | for (j = 0; j < n; j++) { |
784 | trow[sc->locs[j]] = sc->place[j]; |
785 | if (sc->place[j] == TENT) { |
786 | int jj; |
787 | for (jj = sc->locs[j]-1; jj <= sc->locs[j]+1; jj++) |
788 | if (jj >= 0 && jj < len) |
789 | trow1[jj] = trow2[jj] = NONTENT; |
790 | } |
791 | } |
792 | |
793 | for (j = 0; j < 3*len; j++) { |
794 | if (trow[j] == MAGIC) |
795 | continue; |
796 | if (mrow[j] == MAGIC || mrow[j] == trow[j]) { |
797 | /* |
798 | * Either this is the first valid |
799 | * placement we've found at all, or |
800 | * this square's contents are |
801 | * consistent with every previous valid |
802 | * combination. |
803 | */ |
804 | mrow[j] = trow[j]; |
805 | } else { |
806 | /* |
807 | * This square's contents fail to match |
808 | * what they were in a different |
809 | * combination, so we cannot deduce |
810 | * anything about this square. |
811 | */ |
812 | mrow[j] = BLANK; |
813 | } |
814 | } |
815 | } |
816 | |
817 | /* |
818 | * Find the next combination of k choices from n. |
819 | * We do this by finding the rightmost tent which |
820 | * can be moved one place right, doing so, and |
821 | * shunting all tents to the right of that as far |
822 | * left as they can go. |
823 | */ |
824 | p = 0; |
825 | for (j = n-1; j > 0; j--) { |
826 | if (sc->place[j] == TENT) |
827 | p++; |
828 | if (sc->place[j] == NONTENT && sc->place[j-1] == TENT) { |
829 | sc->place[j-1] = NONTENT; |
830 | sc->place[j] = TENT; |
831 | while (p--) |
832 | sc->place[++j] = TENT; |
833 | while (++j < n) |
834 | sc->place[j] = NONTENT; |
835 | break; |
836 | } |
837 | } |
838 | if (j <= 0) |
839 | break; /* we've finished */ |
840 | } |
841 | |
842 | /* |
843 | * It's just possible that _no_ placement was valid, in |
844 | * which case we have an internally inconsistent |
845 | * puzzle. |
846 | */ |
847 | if (mrow[sc->locs[0]] == MAGIC) |
848 | return 0; /* inconsistent */ |
849 | |
850 | /* |
851 | * Now go through mrow and see if there's anything |
852 | * we've deduced which wasn't already mentioned in soln. |
853 | */ |
854 | for (j = 0; j < len; j++) { |
855 | int whichrow; |
856 | |
857 | for (whichrow = 0; whichrow < 3; whichrow++) { |
858 | char *mthis = mrow + whichrow * len; |
859 | int tstart = (whichrow == 0 ? start : |
860 | whichrow == 1 ? start1 : start2); |
861 | if (tstart >= 0 && |
862 | mthis[j] != MAGIC && mthis[j] != BLANK && |
863 | soln[tstart+j*step] == BLANK) { |
864 | int pos = tstart+j*step; |
865 | |
866 | #ifdef SOLVER_DIAGNOSTICS |
867 | if (verbose) |
868 | printf("%s %d forces %s at %d,%d\n", |
869 | step==1 ? "row" : "column", |
870 | step==1 ? start/w : start, |
9d8d4f9f |
871 | mthis[j] == TENT ? "tent" : "non-tent", |
86e60e3d |
872 | pos % w, pos / w); |
873 | #endif |
874 | soln[pos] = mthis[j]; |
875 | done_something = TRUE; |
876 | } |
877 | } |
878 | } |
879 | } |
880 | |
881 | if (done_something) |
882 | continue; |
883 | |
884 | if (!done_something) |
885 | break; |
886 | } |
887 | |
888 | /* |
889 | * The solver has nothing further it can do. Return 1 if both |
890 | * soln and sc->links are completely filled in, or 2 otherwise. |
891 | */ |
892 | for (y = 0; y < h; y++) |
893 | for (x = 0; x < w; x++) { |
894 | if (soln[y*w+x] == BLANK) |
895 | return 2; |
896 | if (soln[y*w+x] != NONTENT && sc->links[y*w+x] == 0) |
897 | return 2; |
898 | } |
899 | |
900 | return 1; |
901 | } |
902 | |
903 | static char *new_game_desc(game_params *params, random_state *rs, |
904 | char **aux, int interactive) |
905 | { |
906 | int w = params->w, h = params->h; |
907 | int ntrees = w * h / 5; |
908 | char *grid = snewn(w*h, char); |
909 | char *puzzle = snewn(w*h, char); |
910 | int *numbers = snewn(w+h, int); |
911 | char *soln = snewn(w*h, char); |
e4b6a85b |
912 | int *temp = snewn(2*w*h, int); |
86e60e3d |
913 | int maxedges = ntrees*4 + w*h; |
914 | int *edges = snewn(2*maxedges, int); |
915 | int *capacity = snewn(maxedges, int); |
916 | int *flow = snewn(maxedges, int); |
917 | struct solver_scratch *sc = new_scratch(w, h); |
918 | char *ret, *p; |
919 | int i, j, nedges; |
920 | |
921 | /* |
922 | * Since this puzzle has many global deductions and doesn't |
923 | * permit limited clue sets, generating grids for this puzzle |
924 | * is hard enough that I see no better option than to simply |
925 | * generate a solution and see if it's unique and has the |
926 | * required difficulty. This turns out to be computationally |
927 | * plausible as well. |
928 | * |
929 | * We chose our tree count (hence also tent count) by dividing |
930 | * the total grid area by five above. Why five? Well, w*h/4 is |
931 | * the maximum number of tents you can _possibly_ fit into the |
932 | * grid without violating the separation criterion, and to |
933 | * achieve that you are constrained to a very small set of |
934 | * possible layouts (the obvious one with a tent at every |
935 | * (even,even) coordinate, and trivial variations thereon). So |
936 | * if we reduce the tent count a bit more, we enable more |
937 | * random-looking placement; 5 turns out to be a plausible |
938 | * figure which yields sensible puzzles. Increasing the tent |
939 | * count would give puzzles whose solutions were too regimented |
940 | * and could be solved by the use of that knowledge (and would |
941 | * also take longer to find a viable placement); decreasing it |
942 | * would make the grids emptier and more boring. |
943 | * |
944 | * Actually generating a grid is a matter of first placing the |
945 | * tents, and then placing the trees by the use of maxflow |
946 | * (finding a distinct square adjacent to every tent). We do it |
947 | * this way round because otherwise satisfying the tent |
948 | * separation condition would become onerous: most randomly |
949 | * chosen tent layouts do not satisfy this condition, so we'd |
950 | * have gone to a lot of work before finding that a candidate |
951 | * layout was unusable. Instead, we place the tents first and |
952 | * ensure they meet the separation criterion _before_ doing |
953 | * lots of computation; this works much better. |
954 | * |
955 | * The maxflow algorithm is not randomised, so employed naively |
956 | * it would give rise to grids with clear structure and |
957 | * directional bias. Hence, I assign the network nodes as seen |
e4b6a85b |
958 | * by maxflow to be a _random_ permutation of the squares of |
959 | * the grid, so that any bias shown by maxflow towards |
960 | * low-numbered nodes is turned into a random bias. |
86e60e3d |
961 | * |
962 | * This generation strategy can fail at many points, including |
963 | * as early as tent placement (if you get a bad random order in |
964 | * which to greedily try the grid squares, you won't even |
965 | * manage to find enough mutually non-adjacent squares to put |
966 | * the tents in). Then it can fail if maxflow doesn't manage to |
967 | * find a good enough matching (i.e. the tent placements don't |
968 | * admit any adequate tree placements); and finally it can fail |
969 | * if the solver finds that the problem has the wrong |
970 | * difficulty (including being actually non-unique). All of |
971 | * these, however, are insufficiently frequent to cause |
972 | * trouble. |
973 | */ |
974 | |
e4b6a85b |
975 | if (params->diff > DIFF_EASY && params->w <= 4 && params->h <= 4) |
976 | params->diff = DIFF_EASY; /* downgrade to prevent tight loop */ |
977 | |
86e60e3d |
978 | while (1) { |
979 | /* |
e4b6a85b |
980 | * Arrange the grid squares into a random order. |
86e60e3d |
981 | */ |
982 | for (i = 0; i < w*h; i++) |
983 | temp[i] = i; |
984 | shuffle(temp, w*h, sizeof(*temp), rs); |
86e60e3d |
985 | |
986 | /* |
987 | * The first `ntrees' entries in temp which we can get |
988 | * without making two tents adjacent will be the tent |
989 | * locations. |
990 | */ |
991 | memset(grid, BLANK, w*h); |
992 | j = ntrees; |
993 | for (i = 0; i < w*h && j > 0; i++) { |
994 | int x = temp[i] % w, y = temp[i] / w; |
995 | int dy, dx, ok = TRUE; |
996 | |
997 | for (dy = -1; dy <= +1; dy++) |
998 | for (dx = -1; dx <= +1; dx++) |
999 | if (x+dx >= 0 && x+dx < w && |
1000 | y+dy >= 0 && y+dy < h && |
1001 | grid[(y+dy)*w+(x+dx)] == TENT) |
1002 | ok = FALSE; |
1003 | |
1004 | if (ok) { |
1005 | grid[temp[i]] = TENT; |
1006 | j--; |
1007 | } |
1008 | } |
1009 | if (j > 0) |
1010 | continue; /* couldn't place all the tents */ |
1011 | |
1012 | /* |
1013 | * Now we build up the list of graph edges. |
1014 | */ |
1015 | nedges = 0; |
1016 | for (i = 0; i < w*h; i++) { |
1017 | if (grid[temp[i]] == TENT) { |
1018 | for (j = 0; j < w*h; j++) { |
1019 | if (grid[temp[j]] != TENT) { |
1020 | int xi = temp[i] % w, yi = temp[i] / w; |
1021 | int xj = temp[j] % w, yj = temp[j] / w; |
1022 | if (abs(xi-xj) + abs(yi-yj) == 1) { |
1023 | edges[nedges*2] = i; |
1024 | edges[nedges*2+1] = j; |
1025 | capacity[nedges] = 1; |
1026 | nedges++; |
1027 | } |
1028 | } |
1029 | } |
1030 | } else { |
1031 | /* |
1032 | * Special node w*h is the sink node; any non-tent node |
1033 | * has an edge going to it. |
1034 | */ |
1035 | edges[nedges*2] = i; |
1036 | edges[nedges*2+1] = w*h; |
1037 | capacity[nedges] = 1; |
1038 | nedges++; |
1039 | } |
1040 | } |
1041 | |
1042 | /* |
1043 | * Special node w*h+1 is the source node, with an edge going to |
1044 | * every tent. |
1045 | */ |
1046 | for (i = 0; i < w*h; i++) { |
1047 | if (grid[temp[i]] == TENT) { |
1048 | edges[nedges*2] = w*h+1; |
1049 | edges[nedges*2+1] = i; |
1050 | capacity[nedges] = 1; |
1051 | nedges++; |
1052 | } |
1053 | } |
1054 | |
1055 | assert(nedges <= maxedges); |
1056 | |
1057 | /* |
1058 | * Now we're ready to call the maxflow algorithm to place the |
1059 | * trees. |
1060 | */ |
1061 | j = maxflow(w*h+2, w*h+1, w*h, nedges, edges, capacity, flow, NULL); |
1062 | |
1063 | if (j < ntrees) |
1064 | continue; /* couldn't place all the tents */ |
1065 | |
1066 | /* |
1067 | * We've placed the trees. Now we need to work out _where_ |
1068 | * we've placed them, which is a matter of reading back out |
1069 | * from the `flow' array. |
1070 | */ |
1071 | for (i = 0; i < nedges; i++) { |
1072 | if (edges[2*i] < w*h && edges[2*i+1] < w*h && flow[i] > 0) |
1073 | grid[temp[edges[2*i+1]]] = TREE; |
1074 | } |
1075 | |
1076 | /* |
1077 | * I think it looks ugly if there isn't at least one of |
1078 | * _something_ (tent or tree) in each row and each column |
1079 | * of the grid. This doesn't give any information away |
1080 | * since a completely empty row/column is instantly obvious |
1081 | * from the clues (it has no trees and a zero). |
1082 | */ |
1083 | for (i = 0; i < w; i++) { |
1084 | for (j = 0; j < h; j++) { |
1085 | if (grid[j*w+i] != BLANK) |
1086 | break; /* found something in this column */ |
1087 | } |
1088 | if (j == h) |
1089 | break; /* found empty column */ |
1090 | } |
1091 | if (i < w) |
1092 | continue; /* a column was empty */ |
1093 | |
1094 | for (j = 0; j < h; j++) { |
1095 | for (i = 0; i < w; i++) { |
1096 | if (grid[j*w+i] != BLANK) |
1097 | break; /* found something in this row */ |
1098 | } |
1099 | if (i == w) |
1100 | break; /* found empty row */ |
1101 | } |
1102 | if (j < h) |
1103 | continue; /* a row was empty */ |
1104 | |
1105 | /* |
1106 | * Now set up the numbers round the edge. |
1107 | */ |
1108 | for (i = 0; i < w; i++) { |
1109 | int n = 0; |
1110 | for (j = 0; j < h; j++) |
1111 | if (grid[j*w+i] == TENT) |
1112 | n++; |
1113 | numbers[i] = n; |
1114 | } |
1115 | for (i = 0; i < h; i++) { |
1116 | int n = 0; |
1117 | for (j = 0; j < w; j++) |
1118 | if (grid[i*w+j] == TENT) |
1119 | n++; |
1120 | numbers[w+i] = n; |
1121 | } |
1122 | |
1123 | /* |
1124 | * And now actually solve the puzzle, to see whether it's |
1125 | * unique and has the required difficulty. |
1126 | */ |
1127 | for (i = 0; i < w*h; i++) |
1128 | puzzle[i] = grid[i] == TREE ? TREE : BLANK; |
1129 | i = tents_solve(w, h, puzzle, numbers, soln, sc, params->diff-1); |
1130 | j = tents_solve(w, h, puzzle, numbers, soln, sc, params->diff); |
1131 | |
1132 | /* |
1133 | * We expect solving with difficulty params->diff to have |
1134 | * succeeded (otherwise the problem is too hard), and |
1135 | * solving with diff-1 to have failed (otherwise it's too |
1136 | * easy). |
1137 | */ |
1138 | if (i == 2 && j == 1) |
1139 | break; |
1140 | } |
1141 | |
1142 | /* |
1143 | * That's it. Encode as a game ID. |
1144 | */ |
1145 | ret = snewn((w+h)*40 + ntrees + (w*h)/26 + 1, char); |
1146 | p = ret; |
1147 | j = 0; |
1148 | for (i = 0; i <= w*h; i++) { |
1149 | int c = (i < w*h ? grid[i] == TREE : 1); |
1150 | if (c) { |
1151 | *p++ = (j == 0 ? '_' : j-1 + 'a'); |
1152 | j = 0; |
1153 | } else { |
1154 | j++; |
1155 | while (j > 25) { |
1156 | *p++ = 'z'; |
1157 | j -= 25; |
1158 | } |
1159 | } |
1160 | } |
1161 | for (i = 0; i < w+h; i++) |
1162 | p += sprintf(p, ",%d", numbers[i]); |
1163 | *p++ = '\0'; |
1164 | ret = sresize(ret, p - ret, char); |
1165 | |
1166 | /* |
1167 | * And encode the solution as an aux_info. |
1168 | */ |
1169 | *aux = snewn(ntrees * 40, char); |
1170 | p = *aux; |
1171 | *p++ = 'S'; |
1172 | for (i = 0; i < w*h; i++) |
1173 | if (grid[i] == TENT) |
1174 | p += sprintf(p, ";T%d,%d", i%w, i/w); |
1175 | *p++ = '\0'; |
1176 | *aux = sresize(*aux, p - *aux, char); |
1177 | |
1178 | free_scratch(sc); |
1179 | sfree(flow); |
1180 | sfree(capacity); |
1181 | sfree(edges); |
1182 | sfree(temp); |
1183 | sfree(soln); |
1184 | sfree(numbers); |
1185 | sfree(puzzle); |
1186 | sfree(grid); |
1187 | |
1188 | return ret; |
1189 | } |
1190 | |
1191 | static char *validate_desc(game_params *params, char *desc) |
1192 | { |
1193 | int w = params->w, h = params->h; |
1194 | int area, i; |
1195 | |
1196 | area = 0; |
1197 | while (*desc && *desc != ',') { |
1198 | if (*desc == '_') |
1199 | area++; |
1200 | else if (*desc >= 'a' && *desc < 'z') |
1201 | area += *desc - 'a' + 2; |
1202 | else if (*desc == 'z') |
1203 | area += 25; |
1204 | else if (*desc == '!' || *desc == '-') |
1205 | /* do nothing */; |
1206 | else |
1207 | return "Invalid character in grid specification"; |
1208 | |
1209 | desc++; |
1210 | } |
724b4a49 |
1211 | if (area < w * h + 1) |
1212 | return "Not enough data to fill grid"; |
1213 | else if (area > w * h + 1) |
1214 | return "Too much data to fill grid"; |
86e60e3d |
1215 | |
1216 | for (i = 0; i < w+h; i++) { |
1217 | if (!*desc) |
1218 | return "Not enough numbers given after grid specification"; |
1219 | else if (*desc != ',') |
1220 | return "Invalid character in number list"; |
1221 | desc++; |
1222 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
1223 | } |
1224 | |
1225 | if (*desc) |
1226 | return "Unexpected additional data at end of game description"; |
1227 | return NULL; |
1228 | } |
1229 | |
1230 | static game_state *new_game(midend *me, game_params *params, char *desc) |
1231 | { |
1232 | int w = params->w, h = params->h; |
1233 | game_state *state = snew(game_state); |
1234 | int i; |
1235 | |
1236 | state->p = *params; /* structure copy */ |
1237 | state->grid = snewn(w*h, char); |
1238 | state->numbers = snew(struct numbers); |
1239 | state->numbers->refcount = 1; |
1240 | state->numbers->numbers = snewn(w+h, int); |
1241 | state->completed = state->used_solve = FALSE; |
1242 | |
1243 | i = 0; |
1244 | memset(state->grid, BLANK, w*h); |
1245 | |
1246 | while (*desc) { |
1247 | int run, type; |
1248 | |
1249 | type = TREE; |
1250 | |
1251 | if (*desc == '_') |
1252 | run = 0; |
1253 | else if (*desc >= 'a' && *desc < 'z') |
1254 | run = *desc - ('a'-1); |
1255 | else if (*desc == 'z') { |
1256 | run = 25; |
1257 | type = BLANK; |
1258 | } else { |
1259 | assert(*desc == '!' || *desc == '-'); |
1260 | run = -1; |
1261 | type = (*desc == '!' ? TENT : NONTENT); |
1262 | } |
1263 | |
1264 | desc++; |
1265 | |
1266 | i += run; |
1267 | assert(i >= 0 && i <= w*h); |
1268 | if (i == w*h) { |
1269 | assert(type == TREE); |
1270 | break; |
1271 | } else { |
1272 | if (type != BLANK) |
1273 | state->grid[i++] = type; |
1274 | } |
1275 | } |
1276 | |
1277 | for (i = 0; i < w+h; i++) { |
1278 | assert(*desc == ','); |
1279 | desc++; |
1280 | state->numbers->numbers[i] = atoi(desc); |
1281 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
1282 | } |
1283 | |
1284 | assert(!*desc); |
1285 | |
1286 | return state; |
1287 | } |
1288 | |
1289 | static game_state *dup_game(game_state *state) |
1290 | { |
1291 | int w = state->p.w, h = state->p.h; |
1292 | game_state *ret = snew(game_state); |
1293 | |
1294 | ret->p = state->p; /* structure copy */ |
1295 | ret->grid = snewn(w*h, char); |
1296 | memcpy(ret->grid, state->grid, w*h); |
1297 | ret->numbers = state->numbers; |
1298 | state->numbers->refcount++; |
1299 | ret->completed = state->completed; |
1300 | ret->used_solve = state->used_solve; |
1301 | |
1302 | return ret; |
1303 | } |
1304 | |
1305 | static void free_game(game_state *state) |
1306 | { |
1307 | if (--state->numbers->refcount <= 0) { |
1308 | sfree(state->numbers->numbers); |
1309 | sfree(state->numbers); |
1310 | } |
1311 | sfree(state->grid); |
1312 | sfree(state); |
1313 | } |
1314 | |
1315 | static char *solve_game(game_state *state, game_state *currstate, |
1316 | char *aux, char **error) |
1317 | { |
1318 | int w = state->p.w, h = state->p.h; |
1319 | |
1320 | if (aux) { |
1321 | /* |
1322 | * If we already have the solution, save ourselves some |
1323 | * time. |
1324 | */ |
1325 | return dupstr(aux); |
1326 | } else { |
1327 | struct solver_scratch *sc = new_scratch(w, h); |
1328 | char *soln; |
1329 | int ret; |
1330 | char *move, *p; |
1331 | int i; |
1332 | |
1333 | soln = snewn(w*h, char); |
1334 | ret = tents_solve(w, h, state->grid, state->numbers->numbers, |
1335 | soln, sc, DIFFCOUNT-1); |
1336 | free_scratch(sc); |
1337 | if (ret != 1) { |
1338 | sfree(soln); |
1339 | if (ret == 0) |
1340 | *error = "This puzzle is not self-consistent"; |
1341 | else |
1342 | *error = "Unable to find a unique solution for this puzzle"; |
1343 | return NULL; |
1344 | } |
1345 | |
1346 | /* |
1347 | * Construct a move string which turns the current state |
1348 | * into the solved state. |
1349 | */ |
1350 | move = snewn(w*h * 40, char); |
1351 | p = move; |
1352 | *p++ = 'S'; |
1353 | for (i = 0; i < w*h; i++) |
1354 | if (soln[i] == TENT) |
1355 | p += sprintf(p, ";T%d,%d", i%w, i/w); |
1356 | *p++ = '\0'; |
1357 | move = sresize(move, p - move, char); |
1358 | |
1359 | sfree(soln); |
1360 | |
1361 | return move; |
1362 | } |
1363 | } |
1364 | |
fa3abef5 |
1365 | static int game_can_format_as_text_now(game_params *params) |
1366 | { |
1367 | return TRUE; |
1368 | } |
1369 | |
86e60e3d |
1370 | static char *game_text_format(game_state *state) |
1371 | { |
1372 | int w = state->p.w, h = state->p.h; |
1373 | char *ret, *p; |
1374 | int x, y; |
1375 | |
1376 | /* |
1377 | * FIXME: We currently do not print the numbers round the edges |
1378 | * of the grid. I need to work out a sensible way of doing this |
1379 | * even when the column numbers exceed 9. |
1380 | * |
1381 | * In the absence of those numbers, the result size is h lines |
1382 | * of w+1 characters each, plus a NUL. |
1383 | * |
1384 | * This function is currently only used by the standalone |
1385 | * solver; until I make it look more sensible, I won't enable |
1386 | * it in the main game structure. |
1387 | */ |
1388 | ret = snewn(h*(w+1) + 1, char); |
1389 | p = ret; |
1390 | for (y = 0; y < h; y++) { |
1391 | for (x = 0; x < w; x++) { |
1392 | *p = (state->grid[y*w+x] == BLANK ? '.' : |
1393 | state->grid[y*w+x] == TREE ? 'T' : |
1394 | state->grid[y*w+x] == TENT ? '*' : |
1395 | state->grid[y*w+x] == NONTENT ? '-' : '?'); |
1396 | p++; |
1397 | } |
1398 | *p++ = '\n'; |
1399 | } |
1400 | *p++ = '\0'; |
1401 | |
1402 | return ret; |
1403 | } |
1404 | |
565394e7 |
1405 | struct game_ui { |
1406 | int dsx, dsy; /* coords of drag start */ |
1407 | int dex, dey; /* coords of drag end */ |
1408 | int drag_button; /* -1 for none, or a button code */ |
1409 | int drag_ok; /* dragged off the window, to cancel */ |
505ea4e5 |
1410 | |
1411 | int cx, cy, cdisp; /* cursor position, and ?display. */ |
565394e7 |
1412 | }; |
1413 | |
86e60e3d |
1414 | static game_ui *new_ui(game_state *state) |
1415 | { |
565394e7 |
1416 | game_ui *ui = snew(game_ui); |
1417 | ui->dsx = ui->dsy = -1; |
1418 | ui->dex = ui->dey = -1; |
1419 | ui->drag_button = -1; |
1420 | ui->drag_ok = FALSE; |
505ea4e5 |
1421 | ui->cx = ui->cy = ui->cdisp = 0; |
565394e7 |
1422 | return ui; |
86e60e3d |
1423 | } |
1424 | |
1425 | static void free_ui(game_ui *ui) |
1426 | { |
565394e7 |
1427 | sfree(ui); |
86e60e3d |
1428 | } |
1429 | |
1430 | static char *encode_ui(game_ui *ui) |
1431 | { |
1432 | return NULL; |
1433 | } |
1434 | |
1435 | static void decode_ui(game_ui *ui, char *encoding) |
1436 | { |
1437 | } |
1438 | |
1439 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
1440 | game_state *newstate) |
1441 | { |
1442 | } |
1443 | |
1444 | struct game_drawstate { |
1445 | int tilesize; |
1446 | int started; |
1447 | game_params p; |
2a27ffcf |
1448 | int *drawn, *numbersdrawn; |
505ea4e5 |
1449 | int cx, cy; /* last-drawn cursor pos, or (-1,-1) if absent. */ |
86e60e3d |
1450 | }; |
1451 | |
1452 | #define PREFERRED_TILESIZE 32 |
1453 | #define TILESIZE (ds->tilesize) |
1454 | #define TLBORDER (TILESIZE/2) |
1455 | #define BRBORDER (TILESIZE*3/2) |
1456 | #define COORD(x) ( (x) * TILESIZE + TLBORDER ) |
1457 | #define FROMCOORD(x) ( ((x) - TLBORDER + TILESIZE) / TILESIZE - 1 ) |
1458 | |
1459 | #define FLASH_TIME 0.30F |
1460 | |
565394e7 |
1461 | static int drag_xform(game_ui *ui, int x, int y, int v) |
1462 | { |
1463 | int xmin, ymin, xmax, ymax; |
1464 | |
1465 | xmin = min(ui->dsx, ui->dex); |
1466 | xmax = max(ui->dsx, ui->dex); |
1467 | ymin = min(ui->dsy, ui->dey); |
1468 | ymax = max(ui->dsy, ui->dey); |
1469 | |
80e7e37c |
1470 | #ifndef STYLUS_BASED |
565394e7 |
1471 | /* |
1472 | * Left-dragging has no effect, so we treat a left-drag as a |
1473 | * single click on dsx,dsy. |
1474 | */ |
1475 | if (ui->drag_button == LEFT_BUTTON) { |
1476 | xmin = xmax = ui->dsx; |
1477 | ymin = ymax = ui->dsy; |
1478 | } |
80e7e37c |
1479 | #endif |
565394e7 |
1480 | |
1481 | if (x < xmin || x > xmax || y < ymin || y > ymax) |
1482 | return v; /* no change outside drag area */ |
1483 | |
1484 | if (v == TREE) |
1485 | return v; /* trees are inviolate always */ |
1486 | |
1487 | if (xmin == xmax && ymin == ymax) { |
1488 | /* |
1489 | * Results of a simple click. Left button sets blanks to |
1490 | * tents; right button sets blanks to non-tents; either |
1491 | * button clears a non-blank square. |
80e7e37c |
1492 | * If stylus-based however, it loops instead. |
565394e7 |
1493 | */ |
1494 | if (ui->drag_button == LEFT_BUTTON) |
80e7e37c |
1495 | #ifdef STYLUS_BASED |
1496 | v = (v == BLANK ? TENT : (v == TENT ? NONTENT : BLANK)); |
1497 | else |
1498 | v = (v == BLANK ? NONTENT : (v == NONTENT ? TENT : BLANK)); |
1499 | #else |
565394e7 |
1500 | v = (v == BLANK ? TENT : BLANK); |
1501 | else |
1502 | v = (v == BLANK ? NONTENT : BLANK); |
80e7e37c |
1503 | #endif |
565394e7 |
1504 | } else { |
1505 | /* |
1506 | * Results of a drag. Left-dragging has no effect. |
1507 | * Right-dragging sets all blank squares to non-tents and |
1508 | * has no effect on anything else. |
1509 | */ |
1510 | if (ui->drag_button == RIGHT_BUTTON) |
1511 | v = (v == BLANK ? NONTENT : v); |
1512 | else |
80e7e37c |
1513 | #ifdef STYLUS_BASED |
1514 | v = (v == BLANK ? NONTENT : v); |
1515 | #else |
565394e7 |
1516 | /* do nothing */; |
80e7e37c |
1517 | #endif |
565394e7 |
1518 | } |
1519 | |
1520 | return v; |
1521 | } |
1522 | |
86e60e3d |
1523 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
1524 | int x, int y, int button) |
1525 | { |
1526 | int w = state->p.w, h = state->p.h; |
505ea4e5 |
1527 | char tmpbuf[80]; |
86e60e3d |
1528 | |
1529 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
86e60e3d |
1530 | x = FROMCOORD(x); |
1531 | y = FROMCOORD(y); |
1532 | if (x < 0 || y < 0 || x >= w || y >= h) |
1533 | return NULL; |
1534 | |
565394e7 |
1535 | ui->drag_button = button; |
1536 | ui->dsx = ui->dex = x; |
1537 | ui->dsy = ui->dey = y; |
1538 | ui->drag_ok = TRUE; |
505ea4e5 |
1539 | ui->cdisp = 0; |
565394e7 |
1540 | return ""; /* ui updated */ |
1541 | } |
86e60e3d |
1542 | |
565394e7 |
1543 | if ((IS_MOUSE_DRAG(button) || IS_MOUSE_RELEASE(button)) && |
1544 | ui->drag_button > 0) { |
1545 | int xmin, ymin, xmax, ymax; |
505ea4e5 |
1546 | char *buf, *sep; |
565394e7 |
1547 | int buflen, bufsize, tmplen; |
1548 | |
1549 | x = FROMCOORD(x); |
1550 | y = FROMCOORD(y); |
1551 | if (x < 0 || y < 0 || x >= w || y >= h) { |
1552 | ui->drag_ok = FALSE; |
86e60e3d |
1553 | } else { |
565394e7 |
1554 | /* |
1555 | * Drags are limited to one row or column. Hence, we |
1556 | * work out which coordinate is closer to the drag |
1557 | * start, and move it _to_ the drag start. |
1558 | */ |
1559 | if (abs(x - ui->dsx) < abs(y - ui->dsy)) |
1560 | x = ui->dsx; |
1561 | else |
1562 | y = ui->dsy; |
1563 | |
1564 | ui->dex = x; |
1565 | ui->dey = y; |
1566 | |
1567 | ui->drag_ok = TRUE; |
86e60e3d |
1568 | } |
1569 | |
565394e7 |
1570 | if (IS_MOUSE_DRAG(button)) |
1571 | return ""; /* ui updated */ |
1572 | |
1573 | /* |
1574 | * The drag has been released. Enact it. |
1575 | */ |
1576 | if (!ui->drag_ok) { |
1577 | ui->drag_button = -1; |
1578 | return ""; /* drag was just cancelled */ |
1579 | } |
1580 | |
1581 | xmin = min(ui->dsx, ui->dex); |
1582 | xmax = max(ui->dsx, ui->dex); |
1583 | ymin = min(ui->dsy, ui->dey); |
1584 | ymax = max(ui->dsy, ui->dey); |
1585 | assert(0 <= xmin && xmin <= xmax && xmax < w); |
e4b6a85b |
1586 | assert(0 <= ymin && ymin <= ymax && ymax < h); |
565394e7 |
1587 | |
1588 | buflen = 0; |
1589 | bufsize = 256; |
1590 | buf = snewn(bufsize, char); |
1591 | sep = ""; |
1592 | for (y = ymin; y <= ymax; y++) |
1593 | for (x = xmin; x <= xmax; x++) { |
1594 | int v = drag_xform(ui, x, y, state->grid[y*w+x]); |
1595 | if (state->grid[y*w+x] != v) { |
1596 | tmplen = sprintf(tmpbuf, "%s%c%d,%d", sep, |
626cd8ac |
1597 | (int)(v == BLANK ? 'B' : |
1598 | v == TENT ? 'T' : 'N'), |
565394e7 |
1599 | x, y); |
1600 | sep = ";"; |
1601 | |
1602 | if (buflen + tmplen >= bufsize) { |
1603 | bufsize = buflen + tmplen + 256; |
1604 | buf = sresize(buf, bufsize, char); |
1605 | } |
1606 | |
1607 | strcpy(buf+buflen, tmpbuf); |
1608 | buflen += tmplen; |
1609 | } |
1610 | } |
1611 | |
1612 | ui->drag_button = -1; /* drag is terminated */ |
1613 | |
1614 | if (buflen == 0) { |
1615 | sfree(buf); |
1616 | return ""; /* ui updated (drag was terminated) */ |
1617 | } else { |
1618 | buf[buflen] = '\0'; |
1619 | return buf; |
1620 | } |
86e60e3d |
1621 | } |
1622 | |
505ea4e5 |
1623 | if (IS_CURSOR_MOVE(button)) { |
1624 | move_cursor(button, &ui->cx, &ui->cy, w, h, 0); |
1625 | ui->cdisp = 1; |
1626 | return ""; |
1627 | } |
1628 | if (ui->cdisp) { |
1629 | char rep = 0; |
1630 | int v = state->grid[ui->cy*w+ui->cx]; |
1631 | |
1632 | if (v != TREE) { |
1633 | #ifdef SINGLE_CURSOR_SELECT |
1634 | if (button == CURSOR_SELECT) |
1635 | /* SELECT cycles T, N, B */ |
1636 | rep = v == BLANK ? 'T' : v == TENT ? 'N' : 'B'; |
1637 | #else |
1638 | if (button == CURSOR_SELECT) |
1639 | rep = v == BLANK ? 'T' : 'B'; |
1640 | else if (button == CURSOR_SELECT2) |
1641 | rep = v == BLANK ? 'N' : 'B'; |
1642 | else if (button == 'T' || button == 'N' || button == 'B') |
1643 | rep = (char)button; |
1644 | #endif |
1645 | } |
1646 | |
1647 | if (rep) { |
1648 | sprintf(tmpbuf, "%c%d,%d", (int)rep, ui->cx, ui->cy); |
1649 | return dupstr(tmpbuf); |
1650 | } |
1651 | } else if (IS_CURSOR_SELECT(button)) { |
1652 | ui->cdisp = 1; |
1653 | return ""; |
1654 | } |
1655 | |
86e60e3d |
1656 | return NULL; |
1657 | } |
1658 | |
1659 | static game_state *execute_move(game_state *state, char *move) |
1660 | { |
1661 | int w = state->p.w, h = state->p.h; |
1662 | char c; |
1663 | int x, y, m, n, i, j; |
1664 | game_state *ret = dup_game(state); |
1665 | |
1666 | while (*move) { |
1667 | c = *move; |
1668 | if (c == 'S') { |
1669 | int i; |
1670 | ret->used_solve = TRUE; |
1671 | /* |
1672 | * Set all non-tree squares to NONTENT. The rest of the |
1673 | * solve move will fill the tents in over the top. |
1674 | */ |
1675 | for (i = 0; i < w*h; i++) |
1676 | if (ret->grid[i] != TREE) |
1677 | ret->grid[i] = NONTENT; |
1678 | move++; |
1679 | } else if (c == 'B' || c == 'T' || c == 'N') { |
1680 | move++; |
1681 | if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || |
1682 | x < 0 || y < 0 || x >= w || y >= h) { |
1683 | free_game(ret); |
1684 | return NULL; |
1685 | } |
1686 | if (ret->grid[y*w+x] == TREE) { |
1687 | free_game(ret); |
1688 | return NULL; |
1689 | } |
1690 | ret->grid[y*w+x] = (c == 'B' ? BLANK : c == 'T' ? TENT : NONTENT); |
1691 | move += n; |
1692 | } else { |
1693 | free_game(ret); |
1694 | return NULL; |
1695 | } |
1696 | if (*move == ';') |
1697 | move++; |
1698 | else if (*move) { |
1699 | free_game(ret); |
1700 | return NULL; |
1701 | } |
1702 | } |
1703 | |
1704 | /* |
1705 | * Check for completion. |
1706 | */ |
1707 | for (i = n = m = 0; i < w*h; i++) { |
1708 | if (ret->grid[i] == TENT) |
1709 | n++; |
1710 | else if (ret->grid[i] == TREE) |
1711 | m++; |
1712 | } |
1713 | if (n == m) { |
1714 | int nedges, maxedges, *edges, *capacity, *flow; |
1715 | |
1716 | /* |
1717 | * We have the right number of tents, which is a |
1718 | * precondition for the game being complete. Now check that |
1719 | * the numbers add up. |
1720 | */ |
1721 | for (i = 0; i < w; i++) { |
1722 | n = 0; |
1723 | for (j = 0; j < h; j++) |
1724 | if (ret->grid[j*w+i] == TENT) |
1725 | n++; |
1726 | if (ret->numbers->numbers[i] != n) |
1727 | goto completion_check_done; |
1728 | } |
1729 | for (i = 0; i < h; i++) { |
1730 | n = 0; |
1731 | for (j = 0; j < w; j++) |
1732 | if (ret->grid[i*w+j] == TENT) |
1733 | n++; |
1734 | if (ret->numbers->numbers[w+i] != n) |
1735 | goto completion_check_done; |
1736 | } |
1737 | /* |
1738 | * Also, check that no two tents are adjacent. |
1739 | */ |
1740 | for (y = 0; y < h; y++) |
1741 | for (x = 0; x < w; x++) { |
1742 | if (x+1 < w && |
1743 | ret->grid[y*w+x] == TENT && ret->grid[y*w+x+1] == TENT) |
1744 | goto completion_check_done; |
1745 | if (y+1 < h && |
1746 | ret->grid[y*w+x] == TENT && ret->grid[(y+1)*w+x] == TENT) |
1747 | goto completion_check_done; |
1748 | if (x+1 < w && y+1 < h) { |
1749 | if (ret->grid[y*w+x] == TENT && |
1750 | ret->grid[(y+1)*w+(x+1)] == TENT) |
1751 | goto completion_check_done; |
1752 | if (ret->grid[(y+1)*w+x] == TENT && |
1753 | ret->grid[y*w+(x+1)] == TENT) |
1754 | goto completion_check_done; |
1755 | } |
1756 | } |
1757 | |
1758 | /* |
1759 | * OK; we have the right number of tents, they match the |
1760 | * numeric clues, and they satisfy the non-adjacency |
1761 | * criterion. Finally, we need to verify that they can be |
1762 | * placed in a one-to-one matching with the trees such that |
1763 | * every tent is orthogonally adjacent to its tree. |
1764 | * |
1765 | * This bit is where the hard work comes in: we have to do |
1766 | * it by finding such a matching using maxflow. |
1767 | * |
1768 | * So we construct a network with one special source node, |
1769 | * one special sink node, one node per tent, and one node |
1770 | * per tree. |
1771 | */ |
1772 | maxedges = 6 * m; |
1773 | edges = snewn(2 * maxedges, int); |
1774 | capacity = snewn(maxedges, int); |
1775 | flow = snewn(maxedges, int); |
1776 | nedges = 0; |
1777 | /* |
1778 | * Node numbering: |
1779 | * |
1780 | * 0..w*h trees/tents |
1781 | * w*h source |
1782 | * w*h+1 sink |
1783 | */ |
1784 | for (y = 0; y < h; y++) |
1785 | for (x = 0; x < w; x++) |
1786 | if (ret->grid[y*w+x] == TREE) { |
1787 | int d; |
1788 | |
1789 | /* |
1790 | * Here we use the direction enum declared for |
1791 | * the solver. We make use of the fact that the |
1792 | * directions are declared in the order |
1793 | * U,L,R,D, meaning that we go through the four |
1794 | * neighbours of any square in numerically |
1795 | * increasing order. |
1796 | */ |
1797 | for (d = 1; d < MAXDIR; d++) { |
1798 | int x2 = x + dx(d), y2 = y + dy(d); |
1799 | if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h && |
1800 | ret->grid[y2*w+x2] == TENT) { |
1801 | assert(nedges < maxedges); |
1802 | edges[nedges*2] = y*w+x; |
1803 | edges[nedges*2+1] = y2*w+x2; |
1804 | capacity[nedges] = 1; |
1805 | nedges++; |
1806 | } |
1807 | } |
1808 | } else if (ret->grid[y*w+x] == TENT) { |
1809 | assert(nedges < maxedges); |
1810 | edges[nedges*2] = y*w+x; |
1811 | edges[nedges*2+1] = w*h+1; /* edge going to sink */ |
1812 | capacity[nedges] = 1; |
1813 | nedges++; |
1814 | } |
1815 | for (y = 0; y < h; y++) |
1816 | for (x = 0; x < w; x++) |
1817 | if (ret->grid[y*w+x] == TREE) { |
1818 | assert(nedges < maxedges); |
1819 | edges[nedges*2] = w*h; /* edge coming from source */ |
1820 | edges[nedges*2+1] = y*w+x; |
1821 | capacity[nedges] = 1; |
1822 | nedges++; |
1823 | } |
1824 | n = maxflow(w*h+2, w*h, w*h+1, nedges, edges, capacity, flow, NULL); |
1825 | |
1826 | sfree(flow); |
1827 | sfree(capacity); |
1828 | sfree(edges); |
1829 | |
1830 | if (n != m) |
1831 | goto completion_check_done; |
1832 | |
1833 | /* |
1834 | * We haven't managed to fault the grid on any count. Score! |
1835 | */ |
1836 | ret->completed = TRUE; |
1837 | } |
1838 | completion_check_done: |
1839 | |
1840 | return ret; |
1841 | } |
1842 | |
1843 | /* ---------------------------------------------------------------------- |
1844 | * Drawing routines. |
1845 | */ |
1846 | |
1847 | static void game_compute_size(game_params *params, int tilesize, |
1848 | int *x, int *y) |
1849 | { |
1850 | /* fool the macros */ |
3466f373 |
1851 | struct dummy { int tilesize; } dummy, *ds = &dummy; |
1852 | dummy.tilesize = tilesize; |
86e60e3d |
1853 | |
1854 | *x = TLBORDER + BRBORDER + TILESIZE * params->w; |
1855 | *y = TLBORDER + BRBORDER + TILESIZE * params->h; |
1856 | } |
1857 | |
1858 | static void game_set_size(drawing *dr, game_drawstate *ds, |
1859 | game_params *params, int tilesize) |
1860 | { |
1861 | ds->tilesize = tilesize; |
1862 | } |
1863 | |
8266f3fc |
1864 | static float *game_colours(frontend *fe, int *ncolours) |
86e60e3d |
1865 | { |
1866 | float *ret = snewn(3 * NCOLOURS, float); |
1867 | |
1868 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
1869 | |
1870 | ret[COL_GRID * 3 + 0] = 0.0F; |
1871 | ret[COL_GRID * 3 + 1] = 0.0F; |
1872 | ret[COL_GRID * 3 + 2] = 0.0F; |
1873 | |
1874 | ret[COL_GRASS * 3 + 0] = 0.7F; |
1875 | ret[COL_GRASS * 3 + 1] = 1.0F; |
1876 | ret[COL_GRASS * 3 + 2] = 0.5F; |
1877 | |
1878 | ret[COL_TREETRUNK * 3 + 0] = 0.6F; |
1879 | ret[COL_TREETRUNK * 3 + 1] = 0.4F; |
1880 | ret[COL_TREETRUNK * 3 + 2] = 0.0F; |
1881 | |
1882 | ret[COL_TREELEAF * 3 + 0] = 0.0F; |
1883 | ret[COL_TREELEAF * 3 + 1] = 0.7F; |
1884 | ret[COL_TREELEAF * 3 + 2] = 0.0F; |
1885 | |
1886 | ret[COL_TENT * 3 + 0] = 0.8F; |
1887 | ret[COL_TENT * 3 + 1] = 0.7F; |
1888 | ret[COL_TENT * 3 + 2] = 0.0F; |
1889 | |
2a27ffcf |
1890 | ret[COL_ERROR * 3 + 0] = 1.0F; |
1891 | ret[COL_ERROR * 3 + 1] = 0.0F; |
1892 | ret[COL_ERROR * 3 + 2] = 0.0F; |
1893 | |
1894 | ret[COL_ERRTEXT * 3 + 0] = 1.0F; |
1895 | ret[COL_ERRTEXT * 3 + 1] = 1.0F; |
1896 | ret[COL_ERRTEXT * 3 + 2] = 1.0F; |
1897 | |
e8df451f |
1898 | ret[COL_ERRTRUNK * 3 + 0] = 0.6F; |
1899 | ret[COL_ERRTRUNK * 3 + 1] = 0.0F; |
1900 | ret[COL_ERRTRUNK * 3 + 2] = 0.0F; |
1901 | |
86e60e3d |
1902 | *ncolours = NCOLOURS; |
1903 | return ret; |
1904 | } |
1905 | |
1906 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
1907 | { |
1908 | int w = state->p.w, h = state->p.h; |
1909 | struct game_drawstate *ds = snew(struct game_drawstate); |
2a27ffcf |
1910 | int i; |
86e60e3d |
1911 | |
1912 | ds->tilesize = 0; |
1913 | ds->started = FALSE; |
1914 | ds->p = state->p; /* structure copy */ |
2a27ffcf |
1915 | ds->drawn = snewn(w*h, int); |
1916 | for (i = 0; i < w*h; i++) |
1917 | ds->drawn[i] = MAGIC; |
1918 | ds->numbersdrawn = snewn(w+h, int); |
1919 | for (i = 0; i < w+h; i++) |
1920 | ds->numbersdrawn[i] = 2; |
505ea4e5 |
1921 | ds->cx = ds->cy = -1; |
86e60e3d |
1922 | |
1923 | return ds; |
1924 | } |
1925 | |
1926 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
1927 | { |
1928 | sfree(ds->drawn); |
2a27ffcf |
1929 | sfree(ds->numbersdrawn); |
86e60e3d |
1930 | sfree(ds); |
1931 | } |
1932 | |
2a27ffcf |
1933 | enum { |
1934 | ERR_ADJ_TOPLEFT = 4, |
1935 | ERR_ADJ_TOP, |
1936 | ERR_ADJ_TOPRIGHT, |
1937 | ERR_ADJ_LEFT, |
1938 | ERR_ADJ_RIGHT, |
1939 | ERR_ADJ_BOTLEFT, |
1940 | ERR_ADJ_BOT, |
1941 | ERR_ADJ_BOTRIGHT, |
1942 | ERR_OVERCOMMITTED |
1943 | }; |
1944 | |
271cf5c1 |
1945 | static int *find_errors(game_state *state, char *grid) |
2a27ffcf |
1946 | { |
1947 | int w = state->p.w, h = state->p.h; |
1948 | int *ret = snewn(w*h + w + h, int); |
1949 | int *tmp = snewn(w*h*2, int), *dsf = tmp + w*h; |
1950 | int x, y; |
1951 | |
1952 | /* |
7463d8ef |
1953 | * This function goes through a grid and works out where to |
1954 | * highlight play errors in red. The aim is that it should |
1955 | * produce at least one error highlight for any complete grid |
1956 | * (or complete piece of grid) violating a puzzle constraint, so |
1957 | * that a grid containing no BLANK squares is either a win or is |
1958 | * marked up in some way that indicates why not. |
1959 | * |
1960 | * So it's easy enough to highlight errors in the numeric clues |
1961 | * - just light up any row or column number which is not |
1962 | * fulfilled - and it's just as easy to highlight adjacent |
1963 | * tents. The difficult bit is highlighting failures in the |
1964 | * tent/tree matching criterion. |
1965 | * |
1966 | * A natural approach would seem to be to apply the maxflow |
1967 | * algorithm to find the tent/tree matching; if this fails, it |
1968 | * must necessarily terminate with a min-cut which can be |
1969 | * reinterpreted as some set of trees which have too few tents |
1970 | * between them (or vice versa). However, it's bad for |
1971 | * localising errors, because it's not easy to make the |
1972 | * algorithm narrow down to the _smallest_ such set of trees: if |
1973 | * trees A and B have only one tent between them, for instance, |
1974 | * it might perfectly well highlight not only A and B but also |
1975 | * trees C and D which are correctly matched on the far side of |
1976 | * the grid, on the grounds that those four trees between them |
1977 | * have only three tents. |
1978 | * |
1979 | * Also, that approach fares badly when you introduce the |
1980 | * additional requirement that incomplete grids should have |
1981 | * errors highlighted only when they can be proved to be errors |
26dac649 |
1982 | * - so that trees should not be marked as having too few tents |
1983 | * if there are enough BLANK squares remaining around them that |
1984 | * could be turned into the missing tents (to do so would be |
1985 | * patronising, since the overwhelming likelihood is not that |
1986 | * the player has forgotten to put a tree there but that they |
1987 | * have merely not put one there _yet_). However, tents with too |
1988 | * few trees can be marked immediately, since those are |
1989 | * definitely player error. |
7463d8ef |
1990 | * |
1991 | * So I adopt an alternative approach, which is to consider the |
1992 | * bipartite adjacency graph between trees and tents |
1993 | * ('bipartite' in the sense that for these purposes I |
1994 | * deliberately ignore two adjacent trees or two adjacent |
1995 | * tents), divide that graph up into its connected components |
1996 | * using a dsf, and look for components which contain different |
1997 | * numbers of trees and tents. This allows me to highlight |
1998 | * groups of tents with too few trees between them immediately, |
1999 | * and then in order to find groups of trees with too few tents |
2000 | * I redo the same process but counting BLANKs as potential |
2001 | * tents (so that the only trees highlighted are those |
2002 | * surrounded by enough NONTENTs to make it impossible to give |
2003 | * them enough tents). |
2004 | * |
2005 | * However, this technique is incomplete: it is not a sufficient |
2006 | * condition for the existence of a perfect matching that every |
2007 | * connected component of the graph has the same number of tents |
2008 | * and trees. An example of a graph which satisfies the latter |
2009 | * condition but still has no perfect matching is |
2010 | * |
2011 | * A B C |
2012 | * | / ,/| |
2013 | * | / ,'/ | |
2014 | * | / ,' / | |
2015 | * |/,' / | |
2016 | * 1 2 3 |
2017 | * |
2018 | * which can be realised in Tents as |
2019 | * |
2020 | * B |
2021 | * A 1 C 2 |
2022 | * 3 |
2023 | * |
2024 | * The matching-error highlighter described above will not mark |
2025 | * this construction as erroneous. However, something else will: |
2026 | * the three tents in the above diagram (let us suppose A,B,C |
2027 | * are the tents, though it doesn't matter which) contain two |
2028 | * diagonally adjacent pairs. So there will be _an_ error |
2029 | * highlighted for the above layout, even though not all types |
2030 | * of error will be highlighted. |
2031 | * |
2032 | * And in fact we can prove that this will always be the case: |
2033 | * that the shortcomings of the matching-error highlighter will |
2034 | * always be made up for by the easy tent adjacency highlighter. |
2035 | * |
2036 | * Lemma: Let G be a bipartite graph between n trees and n |
2037 | * tents, which is connected, and in which no tree has degree |
2038 | * more than two (but a tent may). Then G has a perfect matching. |
2039 | * |
2040 | * (Note: in the statement and proof of the Lemma I will |
2041 | * consistently use 'tree' to indicate a type of graph vertex as |
2042 | * opposed to a tent, and not to indicate a tree in the graph- |
2043 | * theoretic sense.) |
2044 | * |
2045 | * Proof: |
2046 | * |
2047 | * If we can find a tent of degree 1 joined to a tree of degree |
2048 | * 2, then any perfect matching must pair that tent with that |
2049 | * tree. Hence, we can remove both, leaving a smaller graph G' |
2050 | * which still satisfies all the conditions of the Lemma, and |
2051 | * which has a perfect matching iff G does. |
2052 | * |
2053 | * So, wlog, we may assume G contains no tent of degree 1 joined |
2054 | * to a tree of degree 2; if it does, we can reduce it as above. |
2055 | * |
2056 | * If G has no tent of degree 1 at all, then every tent has |
2057 | * degree at least two, so there are at least 2n edges in the |
2058 | * graph. But every tree has degree at most two, so there are at |
2059 | * most 2n edges. Hence there must be exactly 2n edges, so every |
2060 | * tree and every tent must have degree exactly two, which means |
2061 | * that the whole graph consists of a single loop (by |
2062 | * connectedness), and therefore certainly has a perfect |
2063 | * matching. |
2064 | * |
2065 | * Alternatively, if G does have a tent of degree 1 but it is |
2066 | * not connected to a tree of degree 2, then the tree it is |
2067 | * connected to must have degree 1 - and, by connectedness, that |
2068 | * must mean that that tent and that tree between them form the |
2069 | * entire graph. This trivial graph has a trivial perfect |
2070 | * matching. [] |
2071 | * |
2072 | * That proves the lemma. Hence, in any case where the matching- |
2073 | * error highlighter fails to highlight an erroneous component |
2074 | * (because it has the same number of tents as trees, but they |
2075 | * cannot be matched up), the above lemma tells us that there |
2076 | * must be a tree with degree more than 2, i.e. a tree |
2077 | * orthogonally adjacent to at least three tents. But in that |
2078 | * case, there must be some pair of those three tents which are |
2079 | * diagonally adjacent to each other, so the tent-adjacency |
2080 | * highlighter will necessarily show an error. So any filled |
2081 | * layout in Tents which is not a correct solution to the puzzle |
2082 | * must have _some_ error highlighted by the subroutine below. |
2083 | * |
2084 | * (Of course it would be nicer if we could highlight all |
2085 | * errors: in the above example layout, we would like to |
2086 | * highlight tents A,B as having too few trees between them, and |
2087 | * trees 2,3 as having too few tents, in addition to marking the |
2088 | * adjacency problems. But I can't immediately think of any way |
2089 | * to find the smallest sets of such tents and trees without an |
2090 | * O(2^N) loop over all subsets of a given component.) |
2091 | */ |
2092 | |
2093 | /* |
2a27ffcf |
2094 | * ret[0] through to ret[w*h-1] give error markers for the grid |
2095 | * squares. After that, ret[w*h] to ret[w*h+w-1] give error |
2096 | * markers for the column numbers, and ret[w*h+w] to |
2097 | * ret[w*h+w+h-1] for the row numbers. |
2098 | */ |
2099 | |
2100 | /* |
2101 | * Spot tent-adjacency violations. |
2102 | */ |
2103 | for (x = 0; x < w*h; x++) |
2104 | ret[x] = 0; |
2105 | for (y = 0; y < h; y++) { |
2106 | for (x = 0; x < w; x++) { |
2107 | if (y+1 < h && x+1 < w && |
271cf5c1 |
2108 | ((grid[y*w+x] == TENT && |
2109 | grid[(y+1)*w+(x+1)] == TENT) || |
2110 | (grid[(y+1)*w+x] == TENT && |
2111 | grid[y*w+(x+1)] == TENT))) { |
2a27ffcf |
2112 | ret[y*w+x] |= 1 << ERR_ADJ_BOTRIGHT; |
2113 | ret[(y+1)*w+x] |= 1 << ERR_ADJ_TOPRIGHT; |
2114 | ret[y*w+(x+1)] |= 1 << ERR_ADJ_BOTLEFT; |
2115 | ret[(y+1)*w+(x+1)] |= 1 << ERR_ADJ_TOPLEFT; |
2116 | } |
2117 | if (y+1 < h && |
271cf5c1 |
2118 | grid[y*w+x] == TENT && |
2119 | grid[(y+1)*w+x] == TENT) { |
2a27ffcf |
2120 | ret[y*w+x] |= 1 << ERR_ADJ_BOT; |
2121 | ret[(y+1)*w+x] |= 1 << ERR_ADJ_TOP; |
2122 | } |
2123 | if (x+1 < w && |
271cf5c1 |
2124 | grid[y*w+x] == TENT && |
2125 | grid[y*w+(x+1)] == TENT) { |
2a27ffcf |
2126 | ret[y*w+x] |= 1 << ERR_ADJ_RIGHT; |
2127 | ret[y*w+(x+1)] |= 1 << ERR_ADJ_LEFT; |
2128 | } |
2129 | } |
2130 | } |
2131 | |
2132 | /* |
2133 | * Spot numeric clue violations. |
2134 | */ |
2135 | for (x = 0; x < w; x++) { |
2136 | int tents = 0, maybetents = 0; |
2137 | for (y = 0; y < h; y++) { |
271cf5c1 |
2138 | if (grid[y*w+x] == TENT) |
2a27ffcf |
2139 | tents++; |
271cf5c1 |
2140 | else if (grid[y*w+x] == BLANK) |
2a27ffcf |
2141 | maybetents++; |
2142 | } |
2143 | ret[w*h+x] = (tents > state->numbers->numbers[x] || |
2144 | tents + maybetents < state->numbers->numbers[x]); |
2145 | } |
2146 | for (y = 0; y < h; y++) { |
2147 | int tents = 0, maybetents = 0; |
2148 | for (x = 0; x < w; x++) { |
271cf5c1 |
2149 | if (grid[y*w+x] == TENT) |
2a27ffcf |
2150 | tents++; |
271cf5c1 |
2151 | else if (grid[y*w+x] == BLANK) |
2a27ffcf |
2152 | maybetents++; |
2153 | } |
2154 | ret[w*h+w+y] = (tents > state->numbers->numbers[w+y] || |
2155 | tents + maybetents < state->numbers->numbers[w+y]); |
2156 | } |
2157 | |
2158 | /* |
2159 | * Identify groups of tents with too few trees between them, |
2160 | * which we do by constructing the connected components of the |
2161 | * bipartite adjacency graph between tents and trees |
2162 | * ('bipartite' in the sense that we deliberately ignore |
2163 | * adjacency between tents or between trees), and highlighting |
2164 | * all the tents in any component which has a smaller tree |
2165 | * count. |
2166 | */ |
2167 | dsf_init(dsf, w*h); |
2168 | /* Construct the equivalence classes. */ |
2169 | for (y = 0; y < h; y++) { |
2170 | for (x = 0; x < w-1; x++) { |
271cf5c1 |
2171 | if ((grid[y*w+x] == TREE && grid[y*w+x+1] == TENT) || |
2172 | (grid[y*w+x] == TENT && grid[y*w+x+1] == TREE)) |
2a27ffcf |
2173 | dsf_merge(dsf, y*w+x, y*w+x+1); |
2174 | } |
2175 | } |
2176 | for (y = 0; y < h-1; y++) { |
2177 | for (x = 0; x < w; x++) { |
271cf5c1 |
2178 | if ((grid[y*w+x] == TREE && grid[(y+1)*w+x] == TENT) || |
2179 | (grid[y*w+x] == TENT && grid[(y+1)*w+x] == TREE)) |
2a27ffcf |
2180 | dsf_merge(dsf, y*w+x, (y+1)*w+x); |
2181 | } |
2182 | } |
2183 | /* Count up the tent/tree difference in each one. */ |
2184 | for (x = 0; x < w*h; x++) |
2185 | tmp[x] = 0; |
2186 | for (x = 0; x < w*h; x++) { |
2187 | y = dsf_canonify(dsf, x); |
271cf5c1 |
2188 | if (grid[x] == TREE) |
2a27ffcf |
2189 | tmp[y]++; |
271cf5c1 |
2190 | else if (grid[x] == TENT) |
2a27ffcf |
2191 | tmp[y]--; |
2192 | } |
2193 | /* And highlight any tent belonging to an equivalence class with |
2194 | * a score less than zero. */ |
2195 | for (x = 0; x < w*h; x++) { |
2196 | y = dsf_canonify(dsf, x); |
271cf5c1 |
2197 | if (grid[x] == TENT && tmp[y] < 0) |
2a27ffcf |
2198 | ret[x] |= 1 << ERR_OVERCOMMITTED; |
2199 | } |
2200 | |
2201 | /* |
2202 | * Identify groups of trees with too few tents between them. |
2203 | * This is done similarly, except that we now count BLANK as |
2204 | * equivalent to TENT, i.e. we only highlight such trees when |
2205 | * the user hasn't even left _room_ to provide tents for them |
2206 | * all. (Otherwise, we'd highlight all trees red right at the |
2207 | * start of the game, before the user had done anything wrong!) |
2208 | */ |
2209 | #define TENT(x) ((x)==TENT || (x)==BLANK) |
2210 | dsf_init(dsf, w*h); |
2211 | /* Construct the equivalence classes. */ |
2212 | for (y = 0; y < h; y++) { |
2213 | for (x = 0; x < w-1; x++) { |
271cf5c1 |
2214 | if ((grid[y*w+x] == TREE && TENT(grid[y*w+x+1])) || |
2215 | (TENT(grid[y*w+x]) && grid[y*w+x+1] == TREE)) |
2a27ffcf |
2216 | dsf_merge(dsf, y*w+x, y*w+x+1); |
2217 | } |
2218 | } |
2219 | for (y = 0; y < h-1; y++) { |
2220 | for (x = 0; x < w; x++) { |
271cf5c1 |
2221 | if ((grid[y*w+x] == TREE && TENT(grid[(y+1)*w+x])) || |
2222 | (TENT(grid[y*w+x]) && grid[(y+1)*w+x] == TREE)) |
2a27ffcf |
2223 | dsf_merge(dsf, y*w+x, (y+1)*w+x); |
2224 | } |
2225 | } |
2226 | /* Count up the tent/tree difference in each one. */ |
2227 | for (x = 0; x < w*h; x++) |
2228 | tmp[x] = 0; |
2229 | for (x = 0; x < w*h; x++) { |
2230 | y = dsf_canonify(dsf, x); |
271cf5c1 |
2231 | if (grid[x] == TREE) |
2a27ffcf |
2232 | tmp[y]++; |
271cf5c1 |
2233 | else if (TENT(grid[x])) |
2a27ffcf |
2234 | tmp[y]--; |
2235 | } |
2236 | /* And highlight any tree belonging to an equivalence class with |
2237 | * a score more than zero. */ |
2238 | for (x = 0; x < w*h; x++) { |
2239 | y = dsf_canonify(dsf, x); |
271cf5c1 |
2240 | if (grid[x] == TREE && tmp[y] > 0) |
2a27ffcf |
2241 | ret[x] |= 1 << ERR_OVERCOMMITTED; |
2242 | } |
2243 | #undef TENT |
2244 | |
2245 | sfree(tmp); |
2246 | return ret; |
2247 | } |
2248 | |
2249 | static void draw_err_adj(drawing *dr, game_drawstate *ds, int x, int y) |
2250 | { |
2251 | int coords[8]; |
2252 | int yext, xext; |
2253 | |
2254 | /* |
2255 | * Draw a diamond. |
2256 | */ |
2257 | coords[0] = x - TILESIZE*2/5; |
2258 | coords[1] = y; |
2259 | coords[2] = x; |
2260 | coords[3] = y - TILESIZE*2/5; |
2261 | coords[4] = x + TILESIZE*2/5; |
2262 | coords[5] = y; |
2263 | coords[6] = x; |
2264 | coords[7] = y + TILESIZE*2/5; |
2265 | draw_polygon(dr, coords, 4, COL_ERROR, COL_GRID); |
2266 | |
2267 | /* |
2268 | * Draw an exclamation mark in the diamond. This turns out to |
2269 | * look unpleasantly off-centre if done via draw_text, so I do |
2270 | * it by hand on the basis that exclamation marks aren't that |
2271 | * difficult to draw... |
2272 | */ |
2273 | xext = TILESIZE/16; |
2274 | yext = TILESIZE*2/5 - (xext*2+2); |
2275 | draw_rect(dr, x-xext, y-yext, xext*2+1, yext*2+1 - (xext*3), |
2276 | COL_ERRTEXT); |
2277 | draw_rect(dr, x-xext, y+yext-xext*2+1, xext*2+1, xext*2, COL_ERRTEXT); |
2278 | } |
2279 | |
86e60e3d |
2280 | static void draw_tile(drawing *dr, game_drawstate *ds, |
505ea4e5 |
2281 | int x, int y, int v, int cur, int printing) |
86e60e3d |
2282 | { |
2a27ffcf |
2283 | int err; |
86e60e3d |
2284 | int tx = COORD(x), ty = COORD(y); |
2285 | int cx = tx + TILESIZE/2, cy = ty + TILESIZE/2; |
2286 | |
2a27ffcf |
2287 | err = v & ~15; |
2288 | v &= 15; |
86e60e3d |
2289 | |
2a27ffcf |
2290 | clip(dr, tx, ty, TILESIZE, TILESIZE); |
2291 | |
2292 | if (!printing) { |
2293 | draw_rect(dr, tx, ty, TILESIZE, TILESIZE, COL_GRID); |
86e60e3d |
2294 | draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, |
2295 | (v == BLANK ? COL_BACKGROUND : COL_GRASS)); |
2a27ffcf |
2296 | } |
86e60e3d |
2297 | |
2298 | if (v == TREE) { |
2299 | int i; |
2300 | |
2301 | (printing ? draw_rect_outline : draw_rect) |
2302 | (dr, cx-TILESIZE/15, ty+TILESIZE*3/10, |
2303 | 2*(TILESIZE/15)+1, (TILESIZE*9/10 - TILESIZE*3/10), |
e8df451f |
2304 | (err & (1<<ERR_OVERCOMMITTED) ? COL_ERRTRUNK : COL_TREETRUNK)); |
86e60e3d |
2305 | |
2306 | for (i = 0; i < (printing ? 2 : 1); i++) { |
2a27ffcf |
2307 | int col = (i == 1 ? COL_BACKGROUND : |
2308 | (err & (1<<ERR_OVERCOMMITTED) ? COL_ERROR : |
2309 | COL_TREELEAF)); |
86e60e3d |
2310 | int sub = i * (TILESIZE/32); |
2311 | draw_circle(dr, cx, ty+TILESIZE*4/10, TILESIZE/4 - sub, |
2312 | col, col); |
2313 | draw_circle(dr, cx+TILESIZE/5, ty+TILESIZE/4, TILESIZE/8 - sub, |
2314 | col, col); |
2315 | draw_circle(dr, cx-TILESIZE/5, ty+TILESIZE/4, TILESIZE/8 - sub, |
2316 | col, col); |
2317 | draw_circle(dr, cx+TILESIZE/4, ty+TILESIZE*6/13, TILESIZE/8 - sub, |
2318 | col, col); |
2319 | draw_circle(dr, cx-TILESIZE/4, ty+TILESIZE*6/13, TILESIZE/8 - sub, |
2320 | col, col); |
2321 | } |
2322 | } else if (v == TENT) { |
2323 | int coords[6]; |
2a27ffcf |
2324 | int col; |
86e60e3d |
2325 | coords[0] = cx - TILESIZE/3; |
2326 | coords[1] = cy + TILESIZE/3; |
2327 | coords[2] = cx + TILESIZE/3; |
2328 | coords[3] = cy + TILESIZE/3; |
2329 | coords[4] = cx; |
2330 | coords[5] = cy - TILESIZE/3; |
2a27ffcf |
2331 | col = (err & (1<<ERR_OVERCOMMITTED) ? COL_ERROR : COL_TENT); |
2332 | draw_polygon(dr, coords, 3, (printing ? -1 : col), col); |
86e60e3d |
2333 | } |
2334 | |
2a27ffcf |
2335 | if (err & (1 << ERR_ADJ_TOPLEFT)) |
2336 | draw_err_adj(dr, ds, tx, ty); |
2337 | if (err & (1 << ERR_ADJ_TOP)) |
2338 | draw_err_adj(dr, ds, tx+TILESIZE/2, ty); |
2339 | if (err & (1 << ERR_ADJ_TOPRIGHT)) |
2340 | draw_err_adj(dr, ds, tx+TILESIZE, ty); |
2341 | if (err & (1 << ERR_ADJ_LEFT)) |
2342 | draw_err_adj(dr, ds, tx, ty+TILESIZE/2); |
2343 | if (err & (1 << ERR_ADJ_RIGHT)) |
2344 | draw_err_adj(dr, ds, tx+TILESIZE, ty+TILESIZE/2); |
2345 | if (err & (1 << ERR_ADJ_BOTLEFT)) |
2346 | draw_err_adj(dr, ds, tx, ty+TILESIZE); |
2347 | if (err & (1 << ERR_ADJ_BOT)) |
2348 | draw_err_adj(dr, ds, tx+TILESIZE/2, ty+TILESIZE); |
2349 | if (err & (1 << ERR_ADJ_BOTRIGHT)) |
2350 | draw_err_adj(dr, ds, tx+TILESIZE, ty+TILESIZE); |
2351 | |
505ea4e5 |
2352 | if (cur) { |
2353 | int coff = TILESIZE/8; |
2354 | draw_rect_outline(dr, tx + coff, ty + coff, |
fe5d2401 |
2355 | TILESIZE - coff*2 + 1, TILESIZE - coff*2 + 1, |
2356 | COL_GRID); |
505ea4e5 |
2357 | } |
2358 | |
86e60e3d |
2359 | unclip(dr); |
2360 | draw_update(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1); |
2361 | } |
2362 | |
2363 | /* |
2364 | * Internal redraw function, used for printing as well as drawing. |
2365 | */ |
2366 | static void int_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
2367 | game_state *state, int dir, game_ui *ui, |
2368 | float animtime, float flashtime, int printing) |
2369 | { |
2370 | int w = state->p.w, h = state->p.h; |
2371 | int x, y, flashing; |
505ea4e5 |
2372 | int cx = -1, cy = -1; |
2373 | int cmoved = 0; |
271cf5c1 |
2374 | char *tmpgrid; |
2a27ffcf |
2375 | int *errors; |
505ea4e5 |
2376 | |
2377 | if (ui) { |
2378 | if (ui->cdisp) { cx = ui->cx; cy = ui->cy; } |
2379 | if (cx != ds->cx || cy != ds->cy) cmoved = 1; |
2380 | } |
86e60e3d |
2381 | |
2382 | if (printing || !ds->started) { |
2383 | if (!printing) { |
2384 | int ww, wh; |
2385 | game_compute_size(&state->p, TILESIZE, &ww, &wh); |
2386 | draw_rect(dr, 0, 0, ww, wh, COL_BACKGROUND); |
2387 | draw_update(dr, 0, 0, ww, wh); |
2388 | ds->started = TRUE; |
2389 | } |
2390 | |
2391 | if (printing) |
2392 | print_line_width(dr, TILESIZE/64); |
2393 | |
2394 | /* |
2395 | * Draw the grid. |
2396 | */ |
2397 | for (y = 0; y <= h; y++) |
2398 | draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), COL_GRID); |
2399 | for (x = 0; x <= w; x++) |
2400 | draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), COL_GRID); |
86e60e3d |
2401 | } |
2402 | |
2403 | if (flashtime > 0) |
2404 | flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; |
2405 | else |
2406 | flashing = FALSE; |
2407 | |
2408 | /* |
271cf5c1 |
2409 | * Find errors. For this we use _part_ of the information from a |
2410 | * currently active drag: we transform dsx,dsy but not anything |
2411 | * else. (This seems to strike a good compromise between having |
2412 | * the error highlights respond instantly to single clicks, but |
26dac649 |
2413 | * not giving constant feedback during a right-drag.) |
2a27ffcf |
2414 | */ |
271cf5c1 |
2415 | if (ui && ui->drag_button >= 0) { |
2416 | tmpgrid = snewn(w*h, char); |
2417 | memcpy(tmpgrid, state->grid, w*h); |
2418 | tmpgrid[ui->dsy * w + ui->dsx] = |
2419 | drag_xform(ui, ui->dsx, ui->dsy, tmpgrid[ui->dsy * w + ui->dsx]); |
2420 | errors = find_errors(state, tmpgrid); |
2421 | sfree(tmpgrid); |
2422 | } else { |
2423 | errors = find_errors(state, state->grid); |
2424 | } |
2a27ffcf |
2425 | |
2426 | /* |
86e60e3d |
2427 | * Draw the grid. |
2428 | */ |
2a27ffcf |
2429 | for (y = 0; y < h; y++) { |
86e60e3d |
2430 | for (x = 0; x < w; x++) { |
2431 | int v = state->grid[y*w+x]; |
505ea4e5 |
2432 | int credraw = 0; |
86e60e3d |
2433 | |
565394e7 |
2434 | /* |
2435 | * We deliberately do not take drag_ok into account |
2436 | * here, because user feedback suggests that it's |
2437 | * marginally nicer not to have the drag effects |
2438 | * flickering on and off disconcertingly. |
2439 | */ |
5bcb1aa3 |
2440 | if (ui && ui->drag_button >= 0) |
565394e7 |
2441 | v = drag_xform(ui, x, y, v); |
2442 | |
86e60e3d |
2443 | if (flashing && (v == TREE || v == TENT)) |
2444 | v = NONTENT; |
2445 | |
505ea4e5 |
2446 | if (cmoved) { |
2447 | if ((x == cx && y == cy) || |
2448 | (x == ds->cx && y == ds->cy)) credraw = 1; |
2449 | } |
2450 | |
2a27ffcf |
2451 | v |= errors[y*w+x]; |
2452 | |
505ea4e5 |
2453 | if (printing || ds->drawn[y*w+x] != v || credraw) { |
2454 | draw_tile(dr, ds, x, y, v, (x == cx && y == cy), printing); |
86e60e3d |
2455 | if (!printing) |
2456 | ds->drawn[y*w+x] = v; |
2457 | } |
2458 | } |
2a27ffcf |
2459 | } |
2460 | |
2461 | /* |
2462 | * Draw (or redraw, if their error-highlighted state has |
2463 | * changed) the numbers. |
2464 | */ |
2465 | for (x = 0; x < w; x++) { |
69147c34 |
2466 | if (printing || ds->numbersdrawn[x] != errors[w*h+x]) { |
2a27ffcf |
2467 | char buf[80]; |
2468 | draw_rect(dr, COORD(x), COORD(h)+1, TILESIZE, BRBORDER-1, |
2469 | COL_BACKGROUND); |
2470 | sprintf(buf, "%d", state->numbers->numbers[x]); |
2471 | draw_text(dr, COORD(x) + TILESIZE/2, COORD(h+1), |
2472 | FONT_VARIABLE, TILESIZE/2, ALIGN_HCENTRE|ALIGN_VNORMAL, |
2473 | (errors[w*h+x] ? COL_ERROR : COL_GRID), buf); |
2474 | draw_update(dr, COORD(x), COORD(h)+1, TILESIZE, BRBORDER-1); |
69147c34 |
2475 | if (!printing) |
2476 | ds->numbersdrawn[x] = errors[w*h+x]; |
2a27ffcf |
2477 | } |
2478 | } |
2479 | for (y = 0; y < h; y++) { |
69147c34 |
2480 | if (printing || ds->numbersdrawn[w+y] != errors[w*h+w+y]) { |
2a27ffcf |
2481 | char buf[80]; |
2482 | draw_rect(dr, COORD(w)+1, COORD(y), BRBORDER-1, TILESIZE, |
2483 | COL_BACKGROUND); |
2484 | sprintf(buf, "%d", state->numbers->numbers[w+y]); |
2485 | draw_text(dr, COORD(w+1), COORD(y) + TILESIZE/2, |
2486 | FONT_VARIABLE, TILESIZE/2, ALIGN_HRIGHT|ALIGN_VCENTRE, |
2487 | (errors[w*h+w+y] ? COL_ERROR : COL_GRID), buf); |
2488 | draw_update(dr, COORD(w)+1, COORD(y), BRBORDER-1, TILESIZE); |
69147c34 |
2489 | if (!printing) |
2490 | ds->numbersdrawn[w+y] = errors[w*h+w+y]; |
2a27ffcf |
2491 | } |
2492 | } |
2493 | |
2494 | if (cmoved) { |
2495 | ds->cx = cx; |
2496 | ds->cy = cy; |
2497 | } |
2498 | |
2499 | sfree(errors); |
86e60e3d |
2500 | } |
2501 | |
2502 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
2503 | game_state *state, int dir, game_ui *ui, |
2504 | float animtime, float flashtime) |
2505 | { |
2506 | int_redraw(dr, ds, oldstate, state, dir, ui, animtime, flashtime, FALSE); |
2507 | } |
2508 | |
2509 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
2510 | int dir, game_ui *ui) |
2511 | { |
2512 | return 0.0F; |
2513 | } |
2514 | |
2515 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
2516 | int dir, game_ui *ui) |
2517 | { |
2518 | if (!oldstate->completed && newstate->completed && |
2519 | !oldstate->used_solve && !newstate->used_solve) |
2520 | return FLASH_TIME; |
2521 | |
2522 | return 0.0F; |
2523 | } |
2524 | |
1cea529f |
2525 | static int game_status(game_state *state) |
4496362f |
2526 | { |
1cea529f |
2527 | return state->completed ? +1 : 0; |
4496362f |
2528 | } |
2529 | |
86e60e3d |
2530 | static int game_timing_state(game_state *state, game_ui *ui) |
2531 | { |
2532 | return TRUE; |
2533 | } |
2534 | |
2535 | static void game_print_size(game_params *params, float *x, float *y) |
2536 | { |
2537 | int pw, ph; |
2538 | |
2539 | /* |
2540 | * I'll use 6mm squares by default. |
2541 | */ |
2542 | game_compute_size(params, 600, &pw, &ph); |
505ea4e5 |
2543 | *x = pw / 100.0F; |
2544 | *y = ph / 100.0F; |
86e60e3d |
2545 | } |
2546 | |
2547 | static void game_print(drawing *dr, game_state *state, int tilesize) |
2548 | { |
2549 | int c; |
2550 | |
2551 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
2552 | game_drawstate ads, *ds = &ads; |
2553 | game_set_size(dr, ds, NULL, tilesize); |
2554 | |
2555 | c = print_mono_colour(dr, 1); assert(c == COL_BACKGROUND); |
2556 | c = print_mono_colour(dr, 0); assert(c == COL_GRID); |
2557 | c = print_mono_colour(dr, 1); assert(c == COL_GRASS); |
2558 | c = print_mono_colour(dr, 0); assert(c == COL_TREETRUNK); |
2559 | c = print_mono_colour(dr, 0); assert(c == COL_TREELEAF); |
2560 | c = print_mono_colour(dr, 0); assert(c == COL_TENT); |
2561 | |
2562 | int_redraw(dr, ds, NULL, state, +1, NULL, 0.0F, 0.0F, TRUE); |
2563 | } |
2564 | |
2565 | #ifdef COMBINED |
2566 | #define thegame tents |
2567 | #endif |
2568 | |
2569 | const struct game thegame = { |
750037d7 |
2570 | "Tents", "games.tents", "tents", |
86e60e3d |
2571 | default_params, |
2572 | game_fetch_preset, |
2573 | decode_params, |
2574 | encode_params, |
2575 | free_params, |
2576 | dup_params, |
2577 | TRUE, game_configure, custom_params, |
2578 | validate_params, |
2579 | new_game_desc, |
2580 | validate_desc, |
2581 | new_game, |
2582 | dup_game, |
2583 | free_game, |
2584 | TRUE, solve_game, |
fa3abef5 |
2585 | FALSE, game_can_format_as_text_now, game_text_format, |
86e60e3d |
2586 | new_ui, |
2587 | free_ui, |
2588 | encode_ui, |
2589 | decode_ui, |
2590 | game_changed_state, |
2591 | interpret_move, |
2592 | execute_move, |
2593 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
2594 | game_colours, |
2595 | game_new_drawstate, |
2596 | game_free_drawstate, |
2597 | game_redraw, |
2598 | game_anim_length, |
2599 | game_flash_length, |
1cea529f |
2600 | game_status, |
86e60e3d |
2601 | TRUE, FALSE, game_print_size, game_print, |
ac9f41c4 |
2602 | FALSE, /* wants_statusbar */ |
86e60e3d |
2603 | FALSE, game_timing_state, |
cb0c7d4a |
2604 | REQUIRE_RBUTTON, /* flags */ |
86e60e3d |
2605 | }; |
2606 | |
2607 | #ifdef STANDALONE_SOLVER |
2608 | |
2609 | #include <stdarg.h> |
2610 | |
2611 | int main(int argc, char **argv) |
2612 | { |
2613 | game_params *p; |
2614 | game_state *s, *s2; |
2615 | char *id = NULL, *desc, *err; |
2616 | int grade = FALSE; |
2617 | int ret, diff, really_verbose = FALSE; |
2618 | struct solver_scratch *sc; |
2619 | |
2620 | while (--argc > 0) { |
2621 | char *p = *++argv; |
2622 | if (!strcmp(p, "-v")) { |
2623 | really_verbose = TRUE; |
2624 | } else if (!strcmp(p, "-g")) { |
2625 | grade = TRUE; |
2626 | } else if (*p == '-') { |
2627 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
2628 | return 1; |
2629 | } else { |
2630 | id = p; |
2631 | } |
2632 | } |
2633 | |
2634 | if (!id) { |
2635 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
2636 | return 1; |
2637 | } |
2638 | |
2639 | desc = strchr(id, ':'); |
2640 | if (!desc) { |
2641 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
2642 | return 1; |
2643 | } |
2644 | *desc++ = '\0'; |
2645 | |
2646 | p = default_params(); |
2647 | decode_params(p, id); |
2648 | err = validate_desc(p, desc); |
2649 | if (err) { |
2650 | fprintf(stderr, "%s: %s\n", argv[0], err); |
2651 | return 1; |
2652 | } |
2653 | s = new_game(NULL, p, desc); |
2654 | s2 = new_game(NULL, p, desc); |
2655 | |
2656 | sc = new_scratch(p->w, p->h); |
2657 | |
2658 | /* |
2659 | * When solving an Easy puzzle, we don't want to bother the |
2660 | * user with Hard-level deductions. For this reason, we grade |
2661 | * the puzzle internally before doing anything else. |
2662 | */ |
2663 | ret = -1; /* placate optimiser */ |
2664 | for (diff = 0; diff < DIFFCOUNT; diff++) { |
2665 | ret = tents_solve(p->w, p->h, s->grid, s->numbers->numbers, |
2666 | s2->grid, sc, diff); |
2667 | if (ret < 2) |
2668 | break; |
2669 | } |
2670 | |
2671 | if (diff == DIFFCOUNT) { |
2672 | if (grade) |
2673 | printf("Difficulty rating: too hard to solve internally\n"); |
2674 | else |
2675 | printf("Unable to find a unique solution\n"); |
2676 | } else { |
2677 | if (grade) { |
2678 | if (ret == 0) |
2679 | printf("Difficulty rating: impossible (no solution exists)\n"); |
2680 | else if (ret == 1) |
2681 | printf("Difficulty rating: %s\n", tents_diffnames[diff]); |
2682 | } else { |
2683 | verbose = really_verbose; |
2684 | ret = tents_solve(p->w, p->h, s->grid, s->numbers->numbers, |
2685 | s2->grid, sc, diff); |
2686 | if (ret == 0) |
2687 | printf("Puzzle is inconsistent\n"); |
2688 | else |
2689 | fputs(game_text_format(s2), stdout); |
2690 | } |
2691 | } |
2692 | |
2693 | return 0; |
2694 | } |
2695 | |
2696 | #endif |
505ea4e5 |
2697 | |
2698 | /* vim: set shiftwidth=4 tabstop=8: */ |