f4afe206 |
1 | /* |
2 | * flip.c: Puzzle involving lighting up all the squares on a grid, |
3 | * where each click toggles an overlapping set of lights. |
4 | */ |
5 | |
f4afe206 |
6 | #include <stdio.h> |
7 | #include <stdlib.h> |
8 | #include <string.h> |
9 | #include <assert.h> |
10 | #include <ctype.h> |
11 | #include <math.h> |
12 | |
13 | #include "puzzles.h" |
14 | #include "tree234.h" |
15 | |
16 | enum { |
17 | COL_BACKGROUND, |
18 | COL_WRONG, |
19 | COL_RIGHT, |
20 | COL_GRID, |
21 | COL_DIAG, |
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22 | COL_HINT, |
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23 | NCOLOURS |
24 | }; |
25 | |
26 | #define PREFERRED_TILE_SIZE 48 |
27 | #define TILE_SIZE (ds->tilesize) |
28 | #define BORDER (TILE_SIZE / 2) |
29 | #define COORD(x) ( (x) * TILE_SIZE + BORDER ) |
30 | #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 ) |
31 | |
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32 | #define ANIM_TIME 0.25F |
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33 | #define FLASH_FRAME 0.07F |
34 | |
35 | /* |
36 | * Possible ways to decide which lights are toggled by each click. |
37 | * Essentially, each of these describes a means of inventing a |
38 | * matrix over GF(2). |
39 | */ |
40 | enum { |
41 | CROSSES, RANDOM |
42 | }; |
43 | |
44 | struct game_params { |
45 | int w, h; |
46 | int matrix_type; |
47 | }; |
48 | |
49 | /* |
50 | * This structure is shared between all the game_states describing |
51 | * a particular game, so it's reference-counted. |
52 | */ |
53 | struct matrix { |
54 | int refcount; |
55 | unsigned char *matrix; /* array of (w*h) by (w*h) */ |
56 | }; |
57 | |
58 | struct game_state { |
59 | int w, h; |
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60 | int moves, completed, cheated, hints_active; |
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61 | unsigned char *grid; /* array of w*h */ |
62 | struct matrix *matrix; |
63 | }; |
64 | |
65 | static game_params *default_params(void) |
66 | { |
67 | game_params *ret = snew(game_params); |
68 | |
69 | ret->w = ret->h = 5; |
70 | ret->matrix_type = CROSSES; |
71 | |
72 | return ret; |
73 | } |
74 | |
75 | static const struct game_params flip_presets[] = { |
76 | {3, 3, CROSSES}, |
77 | {4, 4, CROSSES}, |
78 | {5, 5, CROSSES}, |
79 | {3, 3, RANDOM}, |
80 | {4, 4, RANDOM}, |
81 | {5, 5, RANDOM}, |
82 | }; |
83 | |
84 | static int game_fetch_preset(int i, char **name, game_params **params) |
85 | { |
86 | game_params *ret; |
87 | char str[80]; |
88 | |
89 | if (i < 0 || i >= lenof(flip_presets)) |
90 | return FALSE; |
91 | |
92 | ret = snew(game_params); |
93 | *ret = flip_presets[i]; |
94 | |
95 | sprintf(str, "%dx%d %s", ret->w, ret->h, |
96 | ret->matrix_type == CROSSES ? "Crosses" : "Random"); |
97 | |
98 | *name = dupstr(str); |
99 | *params = ret; |
100 | return TRUE; |
101 | } |
102 | |
103 | static void free_params(game_params *params) |
104 | { |
105 | sfree(params); |
106 | } |
107 | |
108 | static game_params *dup_params(game_params *params) |
109 | { |
110 | game_params *ret = snew(game_params); |
111 | *ret = *params; /* structure copy */ |
112 | return ret; |
113 | } |
114 | |
115 | static void decode_params(game_params *ret, char const *string) |
116 | { |
117 | ret->w = ret->h = atoi(string); |
118 | while (*string && isdigit(*string)) string++; |
119 | if (*string == 'x') { |
120 | string++; |
121 | ret->h = atoi(string); |
122 | while (*string && isdigit(*string)) string++; |
123 | } |
124 | if (*string == 'r') { |
125 | string++; |
126 | ret->matrix_type = RANDOM; |
127 | } else if (*string == 'c') { |
128 | string++; |
129 | ret->matrix_type = CROSSES; |
130 | } |
131 | } |
132 | |
133 | static char *encode_params(game_params *params, int full) |
134 | { |
135 | char data[256]; |
136 | |
137 | sprintf(data, "%dx%d%s", params->w, params->h, |
138 | !full ? "" : params->matrix_type == CROSSES ? "c" : "r"); |
139 | |
140 | return dupstr(data); |
141 | } |
142 | |
143 | static config_item *game_configure(game_params *params) |
144 | { |
145 | config_item *ret = snewn(4, config_item); |
146 | char buf[80]; |
147 | |
148 | ret[0].name = "Width"; |
149 | ret[0].type = C_STRING; |
150 | sprintf(buf, "%d", params->w); |
151 | ret[0].sval = dupstr(buf); |
152 | ret[0].ival = 0; |
153 | |
154 | ret[1].name = "Height"; |
155 | ret[1].type = C_STRING; |
156 | sprintf(buf, "%d", params->h); |
157 | ret[1].sval = dupstr(buf); |
158 | ret[1].ival = 0; |
159 | |
160 | ret[2].name = "Shape type"; |
161 | ret[2].type = C_CHOICES; |
162 | ret[2].sval = ":Crosses:Random"; |
163 | ret[2].ival = params->matrix_type; |
164 | |
165 | ret[3].name = NULL; |
166 | ret[3].type = C_END; |
167 | ret[3].sval = NULL; |
168 | ret[3].ival = 0; |
169 | |
170 | return ret; |
171 | } |
172 | |
173 | static game_params *custom_params(config_item *cfg) |
174 | { |
175 | game_params *ret = snew(game_params); |
176 | |
177 | ret->w = atoi(cfg[0].sval); |
178 | ret->h = atoi(cfg[1].sval); |
179 | ret->matrix_type = cfg[2].ival; |
180 | |
181 | return ret; |
182 | } |
183 | |
184 | static char *validate_params(game_params *params) |
185 | { |
186 | if (params->w <= 0 || params->h <= 0) |
187 | return "Width and height must both be greater than zero"; |
188 | return NULL; |
189 | } |
190 | |
191 | static char *encode_bitmap(unsigned char *bmp, int len) |
192 | { |
193 | int slen = (len + 3) / 4; |
194 | char *ret; |
195 | int i; |
196 | |
197 | ret = snewn(slen + 1, char); |
198 | for (i = 0; i < slen; i++) { |
199 | int j, v; |
200 | v = 0; |
201 | for (j = 0; j < 4; j++) |
202 | if (i*4+j < len && bmp[i*4+j]) |
203 | v |= 8 >> j; |
204 | ret[i] = "0123456789abcdef"[v]; |
205 | } |
206 | ret[slen] = '\0'; |
207 | return ret; |
208 | } |
209 | |
210 | static void decode_bitmap(unsigned char *bmp, int len, char *hex) |
211 | { |
212 | int slen = (len + 3) / 4; |
213 | int i; |
214 | |
215 | for (i = 0; i < slen; i++) { |
216 | int j, v, c = hex[i]; |
217 | if (c >= '0' && c <= '9') |
218 | v = c - '0'; |
219 | else if (c >= 'A' && c <= 'F') |
220 | v = c - 'A' + 10; |
221 | else if (c >= 'a' && c <= 'f') |
222 | v = c - 'a' + 10; |
223 | else |
224 | v = 0; /* shouldn't happen */ |
225 | for (j = 0; j < 4; j++) { |
226 | if (i*4+j < len) { |
227 | if (v & (8 >> j)) |
228 | bmp[i*4+j] = 1; |
229 | else |
230 | bmp[i*4+j] = 0; |
231 | } |
232 | } |
233 | } |
234 | } |
235 | |
236 | /* |
237 | * Structure used during random matrix generation, and a compare |
238 | * function to permit storage in a tree234. |
239 | */ |
240 | struct sq { |
241 | int cx, cy; /* coords of click square */ |
242 | int x, y; /* coords of output square */ |
243 | /* |
244 | * Number of click squares which currently affect this output |
245 | * square. |
246 | */ |
247 | int coverage; |
248 | /* |
249 | * Number of output squares currently affected by this click |
250 | * square. |
251 | */ |
252 | int ominosize; |
253 | }; |
254 | #define SORT(field) do { \ |
255 | if (a->field < b->field) \ |
256 | return -1; \ |
257 | else if (a->field > b->field) \ |
258 | return +1; \ |
259 | } while (0) |
260 | /* |
261 | * Compare function for choosing the next square to add. We must |
262 | * sort by coverage, then by omino size, then everything else. |
263 | */ |
264 | static int sqcmp_pick(void *av, void *bv) |
265 | { |
266 | struct sq *a = (struct sq *)av; |
267 | struct sq *b = (struct sq *)bv; |
268 | SORT(coverage); |
269 | SORT(ominosize); |
270 | SORT(cy); |
271 | SORT(cx); |
272 | SORT(y); |
273 | SORT(x); |
274 | return 0; |
275 | } |
276 | /* |
277 | * Compare function for adjusting the coverage figures after a |
278 | * change. We sort first by coverage and output square, then by |
279 | * everything else. |
280 | */ |
281 | static int sqcmp_cov(void *av, void *bv) |
282 | { |
283 | struct sq *a = (struct sq *)av; |
284 | struct sq *b = (struct sq *)bv; |
285 | SORT(coverage); |
286 | SORT(y); |
287 | SORT(x); |
288 | SORT(ominosize); |
289 | SORT(cy); |
290 | SORT(cx); |
291 | return 0; |
292 | } |
293 | /* |
294 | * Compare function for adjusting the omino sizes after a change. |
295 | * We sort first by omino size and input square, then by everything |
296 | * else. |
297 | */ |
298 | static int sqcmp_osize(void *av, void *bv) |
299 | { |
300 | struct sq *a = (struct sq *)av; |
301 | struct sq *b = (struct sq *)bv; |
302 | SORT(ominosize); |
303 | SORT(cy); |
304 | SORT(cx); |
305 | SORT(coverage); |
306 | SORT(y); |
307 | SORT(x); |
308 | return 0; |
309 | } |
310 | static void addsq(tree234 *t, int w, int h, int cx, int cy, |
311 | int x, int y, unsigned char *matrix) |
312 | { |
313 | int wh = w * h; |
314 | struct sq *sq; |
315 | int i; |
316 | |
317 | if (x < 0 || x >= w || y < 0 || y >= h) |
318 | return; |
319 | if (abs(x-cx) > 1 || abs(y-cy) > 1) |
320 | return; |
321 | if (matrix[(cy*w+cx) * wh + y*w+x]) |
322 | return; |
323 | |
324 | sq = snew(struct sq); |
325 | sq->cx = cx; |
326 | sq->cy = cy; |
327 | sq->x = x; |
328 | sq->y = y; |
329 | sq->coverage = sq->ominosize = 0; |
330 | for (i = 0; i < wh; i++) { |
331 | if (matrix[i * wh + y*w+x]) |
332 | sq->coverage++; |
333 | if (matrix[(cy*w+cx) * wh + i]) |
334 | sq->ominosize++; |
335 | } |
336 | |
337 | if (add234(t, sq) != sq) |
338 | sfree(sq); /* already there */ |
339 | } |
340 | static void addneighbours(tree234 *t, int w, int h, int cx, int cy, |
341 | int x, int y, unsigned char *matrix) |
342 | { |
343 | addsq(t, w, h, cx, cy, x-1, y, matrix); |
344 | addsq(t, w, h, cx, cy, x+1, y, matrix); |
345 | addsq(t, w, h, cx, cy, x, y-1, matrix); |
346 | addsq(t, w, h, cx, cy, x, y+1, matrix); |
347 | } |
348 | |
349 | static char *new_game_desc(game_params *params, random_state *rs, |
c566778e |
350 | char **aux, int interactive) |
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351 | { |
352 | int w = params->w, h = params->h, wh = w * h; |
353 | int i, j; |
354 | unsigned char *matrix, *grid; |
355 | char *mbmp, *gbmp, *ret; |
356 | |
357 | matrix = snewn(wh * wh, unsigned char); |
358 | grid = snewn(wh, unsigned char); |
359 | |
360 | /* |
361 | * First set up the matrix. |
362 | */ |
363 | switch (params->matrix_type) { |
364 | case CROSSES: |
365 | for (i = 0; i < wh; i++) { |
366 | int ix = i % w, iy = i / w; |
367 | for (j = 0; j < wh; j++) { |
368 | int jx = j % w, jy = j / w; |
369 | if (abs(jx - ix) + abs(jy - iy) <= 1) |
370 | matrix[i*wh+j] = 1; |
371 | else |
372 | matrix[i*wh+j] = 0; |
373 | } |
374 | } |
375 | break; |
376 | case RANDOM: |
377 | while (1) { |
378 | tree234 *pick, *cov, *osize; |
379 | int limit; |
380 | |
381 | pick = newtree234(sqcmp_pick); |
382 | cov = newtree234(sqcmp_cov); |
383 | osize = newtree234(sqcmp_osize); |
384 | |
385 | memset(matrix, 0, wh * wh); |
386 | for (i = 0; i < wh; i++) { |
387 | matrix[i*wh+i] = 1; |
388 | } |
389 | |
390 | for (i = 0; i < wh; i++) { |
391 | int ix = i % w, iy = i / w; |
392 | addneighbours(pick, w, h, ix, iy, ix, iy, matrix); |
393 | addneighbours(cov, w, h, ix, iy, ix, iy, matrix); |
394 | addneighbours(osize, w, h, ix, iy, ix, iy, matrix); |
395 | } |
396 | |
397 | /* |
398 | * Repeatedly choose a square to add to the matrix, |
399 | * until we have enough. I'll arbitrarily choose our |
400 | * limit to be the same as the total number of set bits |
401 | * in the crosses matrix. |
402 | */ |
403 | limit = 4*wh - 2*(w+h); /* centre squares already present */ |
404 | |
405 | while (limit-- > 0) { |
406 | struct sq *sq, *sq2, sqlocal; |
407 | int k; |
408 | |
409 | /* |
410 | * Find the lowest element in the pick tree. |
411 | */ |
412 | sq = index234(pick, 0); |
413 | |
414 | /* |
415 | * Find the highest element with the same coverage |
416 | * and omino size, by setting all other elements to |
417 | * lots. |
418 | */ |
419 | sqlocal = *sq; |
420 | sqlocal.cx = sqlocal.cy = sqlocal.x = sqlocal.y = wh; |
421 | sq = findrelpos234(pick, &sqlocal, NULL, REL234_LT, &k); |
422 | assert(sq != 0); |
423 | |
424 | /* |
425 | * Pick at random from all elements up to k of the |
426 | * pick tree. |
427 | */ |
428 | k = random_upto(rs, k+1); |
429 | sq = delpos234(pick, k); |
430 | del234(cov, sq); |
431 | del234(osize, sq); |
432 | |
433 | /* |
434 | * Add this square to the matrix. |
435 | */ |
436 | matrix[(sq->cy * w + sq->cx) * wh + (sq->y * w + sq->x)] = 1; |
437 | |
438 | /* |
439 | * Correct the matrix coverage field of any sq |
440 | * which points at this output square. |
441 | */ |
442 | sqlocal = *sq; |
443 | sqlocal.cx = sqlocal.cy = sqlocal.ominosize = -1; |
444 | while ((sq2 = findrel234(cov, &sqlocal, NULL, |
445 | REL234_GT)) != NULL && |
446 | sq2->coverage == sq->coverage && |
447 | sq2->x == sq->x && sq2->y == sq->y) { |
448 | del234(pick, sq2); |
449 | del234(cov, sq2); |
450 | del234(osize, sq2); |
451 | sq2->coverage++; |
452 | add234(pick, sq2); |
453 | add234(cov, sq2); |
454 | add234(osize, sq2); |
455 | } |
456 | |
457 | /* |
458 | * Correct the omino size field of any sq which |
459 | * points at this input square. |
460 | */ |
461 | sqlocal = *sq; |
462 | sqlocal.x = sqlocal.y = sqlocal.coverage = -1; |
463 | while ((sq2 = findrel234(osize, &sqlocal, NULL, |
464 | REL234_GT)) != NULL && |
465 | sq2->ominosize == sq->ominosize && |
466 | sq2->cx == sq->cx && sq2->cy == sq->cy) { |
467 | del234(pick, sq2); |
468 | del234(cov, sq2); |
469 | del234(osize, sq2); |
470 | sq2->ominosize++; |
471 | add234(pick, sq2); |
472 | add234(cov, sq2); |
473 | add234(osize, sq2); |
474 | } |
475 | |
476 | /* |
477 | * The sq we actually picked out of the tree is |
478 | * finished with; but its neighbours now need to |
479 | * appear. |
480 | */ |
481 | addneighbours(pick, w,h, sq->cx,sq->cy, sq->x,sq->y, matrix); |
482 | addneighbours(cov, w,h, sq->cx,sq->cy, sq->x,sq->y, matrix); |
483 | addneighbours(osize, w,h, sq->cx,sq->cy, sq->x,sq->y, matrix); |
484 | sfree(sq); |
485 | } |
486 | |
487 | /* |
488 | * Free all remaining sq structures. |
489 | */ |
490 | { |
491 | struct sq *sq; |
492 | while ((sq = delpos234(pick, 0)) != NULL) |
493 | sfree(sq); |
494 | } |
495 | freetree234(pick); |
496 | freetree234(cov); |
497 | freetree234(osize); |
498 | |
499 | /* |
500 | * Finally, check to see if any two matrix rows are |
501 | * exactly identical. If so, this is not an acceptable |
502 | * matrix, and we give up and go round again. |
503 | * |
504 | * I haven't been immediately able to think of a |
505 | * plausible means of algorithmically avoiding this |
506 | * situation (by, say, making a small perturbation to |
507 | * an offending matrix), so for the moment I'm just |
508 | * going to deal with it by throwing the whole thing |
509 | * away. I suspect this will lead to scalability |
510 | * problems (since most of the things happening in |
511 | * these matrices are local, the chance of _some_ |
512 | * neighbourhood having two identical regions will |
513 | * increase with the grid area), but so far this puzzle |
514 | * seems to be really hard at large sizes so I'm not |
515 | * massively worried yet. Anyone needs this done |
516 | * better, they're welcome to submit a patch. |
517 | */ |
518 | for (i = 0; i < wh; i++) { |
519 | for (j = 0; j < wh; j++) |
520 | if (i != j && |
521 | !memcmp(matrix + i * wh, matrix + j * wh, wh)) |
522 | break; |
523 | if (j < wh) |
524 | break; |
525 | } |
526 | if (i == wh) |
527 | break; /* no matches found */ |
528 | } |
529 | break; |
530 | } |
531 | |
532 | /* |
533 | * Now invent a random initial set of lights. |
534 | * |
535 | * At first glance it looks as if it might be quite difficult |
536 | * to choose equiprobably from all soluble light sets. After |
537 | * all, soluble light sets are those in the image space of the |
538 | * transformation matrix; so first we'd have to identify that |
539 | * space and its dimension, then pick a random coordinate for |
540 | * each basis vector and recombine. Lot of fiddly matrix |
541 | * algebra there. |
542 | * |
543 | * However, vector spaces are nicely orthogonal and relieve us |
544 | * of all that difficulty. For every point in the image space, |
545 | * there are precisely as many points in the input space that |
546 | * map to it as there are elements in the kernel of the |
547 | * transformation matrix (because adding any kernel element to |
548 | * the input does not change the output, and because any two |
549 | * inputs mapping to the same output must differ by an element |
550 | * of the kernel because that's what the kernel _is_); and |
551 | * these cosets are all disjoint (obviously, since no input |
552 | * point can map to more than one output point) and cover the |
553 | * whole space (equally obviously, because no input point can |
554 | * map to fewer than one output point!). |
555 | * |
556 | * So the input space contains the same number of points for |
557 | * each point in the output space; thus, we can simply choose |
558 | * equiprobably from elements of the _input_ space, and filter |
559 | * the result through the transformation matrix in the obvious |
560 | * way, and we thereby guarantee to choose equiprobably from |
561 | * all the output points. Phew! |
562 | */ |
563 | while (1) { |
564 | memset(grid, 0, wh); |
565 | for (i = 0; i < wh; i++) { |
566 | int v = random_upto(rs, 2); |
567 | if (v) { |
568 | for (j = 0; j < wh; j++) |
569 | grid[j] ^= matrix[i*wh+j]; |
570 | } |
571 | } |
572 | /* |
573 | * Ensure we don't have the starting state already! |
574 | */ |
575 | for (i = 0; i < wh; i++) |
576 | if (grid[i]) |
577 | break; |
578 | if (i < wh) |
579 | break; |
580 | } |
581 | |
582 | /* |
583 | * Now encode the matrix and the starting grid as a game |
584 | * description. We'll do this by concatenating two great big |
585 | * hex bitmaps. |
586 | */ |
587 | mbmp = encode_bitmap(matrix, wh*wh); |
588 | gbmp = encode_bitmap(grid, wh); |
589 | ret = snewn(strlen(mbmp) + strlen(gbmp) + 2, char); |
590 | sprintf(ret, "%s,%s", mbmp, gbmp); |
591 | sfree(mbmp); |
592 | sfree(gbmp); |
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593 | sfree(matrix); |
594 | sfree(grid); |
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595 | return ret; |
596 | } |
597 | |
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598 | static char *validate_desc(game_params *params, char *desc) |
599 | { |
600 | int w = params->w, h = params->h, wh = w * h; |
601 | int mlen = (wh*wh+3)/4, glen = (wh+3)/4; |
602 | |
603 | if (strspn(desc, "0123456789abcdefABCDEF") != mlen) |
604 | return "Matrix description is wrong length"; |
605 | if (desc[mlen] != ',') |
606 | return "Expected comma after matrix description"; |
607 | if (strspn(desc+mlen+1, "0123456789abcdefABCDEF") != glen) |
608 | return "Grid description is wrong length"; |
609 | if (desc[mlen+1+glen]) |
610 | return "Unexpected data after grid description"; |
611 | |
612 | return NULL; |
613 | } |
614 | |
615 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
616 | { |
617 | int w = params->w, h = params->h, wh = w * h; |
618 | int mlen = (wh*wh+3)/4; |
619 | |
620 | game_state *state = snew(game_state); |
621 | |
622 | state->w = w; |
623 | state->h = h; |
624 | state->completed = FALSE; |
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625 | state->cheated = FALSE; |
626 | state->hints_active = FALSE; |
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627 | state->moves = 0; |
628 | state->matrix = snew(struct matrix); |
629 | state->matrix->refcount = 1; |
630 | state->matrix->matrix = snewn(wh*wh, unsigned char); |
631 | decode_bitmap(state->matrix->matrix, wh*wh, desc); |
632 | state->grid = snewn(wh, unsigned char); |
633 | decode_bitmap(state->grid, wh, desc + mlen + 1); |
634 | |
635 | return state; |
636 | } |
637 | |
638 | static game_state *dup_game(game_state *state) |
639 | { |
640 | game_state *ret = snew(game_state); |
641 | |
642 | ret->w = state->w; |
643 | ret->h = state->h; |
644 | ret->completed = state->completed; |
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645 | ret->cheated = state->cheated; |
646 | ret->hints_active = state->hints_active; |
f4afe206 |
647 | ret->moves = state->moves; |
648 | ret->matrix = state->matrix; |
649 | state->matrix->refcount++; |
650 | ret->grid = snewn(ret->w * ret->h, unsigned char); |
651 | memcpy(ret->grid, state->grid, ret->w * ret->h); |
652 | |
653 | return ret; |
654 | } |
655 | |
656 | static void free_game(game_state *state) |
657 | { |
658 | sfree(state->grid); |
659 | if (--state->matrix->refcount <= 0) { |
660 | sfree(state->matrix->matrix); |
661 | sfree(state->matrix); |
662 | } |
663 | sfree(state); |
664 | } |
665 | |
79cb09e9 |
666 | static void rowxor(unsigned char *row1, unsigned char *row2, int len) |
667 | { |
668 | int i; |
669 | for (i = 0; i < len; i++) |
670 | row1[i] ^= row2[i]; |
671 | } |
672 | |
df11cd4e |
673 | static char *solve_game(game_state *state, game_state *currstate, |
c566778e |
674 | char *aux, char **error) |
f4afe206 |
675 | { |
79cb09e9 |
676 | int w = state->w, h = state->h, wh = w * h; |
677 | unsigned char *equations, *solution, *shortest; |
678 | int *und, nund; |
679 | int rowsdone, colsdone; |
680 | int i, j, k, len, bestlen; |
df11cd4e |
681 | char *ret; |
79cb09e9 |
682 | |
683 | /* |
684 | * Set up a list of simultaneous equations. Each one is of |
685 | * length (wh+1) and has wh coefficients followed by a value. |
686 | */ |
687 | equations = snewn((wh + 1) * wh, unsigned char); |
688 | for (i = 0; i < wh; i++) { |
689 | for (j = 0; j < wh; j++) |
690 | equations[i * (wh+1) + j] = currstate->matrix->matrix[j*wh+i]; |
691 | equations[i * (wh+1) + wh] = currstate->grid[i] & 1; |
692 | } |
693 | |
694 | /* |
695 | * Perform Gaussian elimination over GF(2). |
696 | */ |
697 | rowsdone = colsdone = 0; |
698 | nund = 0; |
699 | und = snewn(wh, int); |
700 | do { |
701 | /* |
702 | * Find the leftmost column which has a 1 in it somewhere |
703 | * outside the first `rowsdone' rows. |
704 | */ |
705 | j = -1; |
706 | for (i = colsdone; i < wh; i++) { |
707 | for (j = rowsdone; j < wh; j++) |
708 | if (equations[j * (wh+1) + i]) |
709 | break; |
710 | if (j < wh) |
711 | break; /* found one */ |
712 | /* |
713 | * This is a column which will not have an equation |
714 | * controlling it. Mark it as undetermined. |
715 | */ |
716 | und[nund++] = i; |
717 | } |
718 | |
719 | /* |
720 | * If there wasn't one, then we've finished: all remaining |
721 | * equations are of the form 0 = constant. Check to see if |
722 | * any of them wants 0 to be equal to 1; this is the |
723 | * condition which indicates an insoluble problem |
724 | * (therefore _hopefully_ one typed in by a user!). |
725 | */ |
726 | if (i == wh) { |
727 | for (j = rowsdone; j < wh; j++) |
728 | if (equations[j * (wh+1) + wh]) { |
729 | *error = "No solution exists for this position"; |
730 | sfree(equations); |
5d83d8f3 |
731 | sfree(und); |
79cb09e9 |
732 | return NULL; |
733 | } |
734 | break; |
735 | } |
736 | |
737 | /* |
738 | * We've found a 1. It's in column i, and the topmost 1 in |
739 | * that column is in row j. Do a row-XOR to move it up to |
740 | * the topmost row if it isn't already there. |
741 | */ |
742 | assert(j != -1); |
743 | if (j > rowsdone) |
744 | rowxor(equations + rowsdone*(wh+1), equations + j*(wh+1), wh+1); |
745 | |
746 | /* |
747 | * Do row-XORs to eliminate that 1 from all rows below the |
748 | * topmost row. |
749 | */ |
750 | for (j = rowsdone + 1; j < wh; j++) |
751 | if (equations[j*(wh+1) + i]) |
752 | rowxor(equations + j*(wh+1), |
753 | equations + rowsdone*(wh+1), wh+1); |
754 | |
755 | /* |
756 | * Mark this row and column as done. |
757 | */ |
758 | rowsdone++; |
759 | colsdone = i+1; |
760 | |
761 | /* |
762 | * If we've done all the rows, terminate. |
763 | */ |
764 | } while (rowsdone < wh); |
765 | |
766 | /* |
767 | * If we reach here, we have the ability to produce a solution. |
768 | * So we go through _all_ possible solutions (each |
769 | * corresponding to a set of arbitrary choices of those |
770 | * components not directly determined by an equation), and pick |
771 | * one requiring the smallest number of flips. |
772 | */ |
773 | solution = snewn(wh, unsigned char); |
774 | shortest = snewn(wh, unsigned char); |
775 | memset(solution, 0, wh); |
776 | bestlen = wh + 1; |
777 | while (1) { |
778 | /* |
779 | * Find a solution based on the current values of the |
780 | * undetermined variables. |
781 | */ |
782 | for (j = rowsdone; j-- ;) { |
783 | int v; |
784 | |
785 | /* |
786 | * Find the leftmost set bit in this equation. |
787 | */ |
788 | for (i = 0; i < wh; i++) |
789 | if (equations[j * (wh+1) + i]) |
790 | break; |
791 | assert(i < wh); /* there must have been one! */ |
792 | |
793 | /* |
794 | * Compute this variable using the rest. |
795 | */ |
796 | v = equations[j * (wh+1) + wh]; |
797 | for (k = i+1; k < wh; k++) |
798 | if (equations[j * (wh+1) + k]) |
799 | v ^= solution[k]; |
800 | |
801 | solution[i] = v; |
802 | } |
803 | |
804 | /* |
805 | * Compare this solution to the current best one, and |
806 | * replace the best one if this one is shorter. |
807 | */ |
808 | len = 0; |
809 | for (i = 0; i < wh; i++) |
810 | if (solution[i]) |
811 | len++; |
812 | if (len < bestlen) { |
813 | bestlen = len; |
814 | memcpy(shortest, solution, wh); |
815 | } |
816 | |
817 | /* |
818 | * Now increment the binary number given by the |
819 | * undetermined variables: turn all 1s into 0s until we see |
820 | * a 0, at which point we turn it into a 1. |
821 | */ |
822 | for (i = 0; i < nund; i++) { |
823 | solution[und[i]] = !solution[und[i]]; |
824 | if (solution[und[i]]) |
825 | break; |
826 | } |
827 | |
828 | /* |
829 | * If we didn't find a 0 at any point, we have wrapped |
830 | * round and are back at the start, i.e. we have enumerated |
831 | * all solutions. |
832 | */ |
833 | if (i == nund) |
834 | break; |
835 | } |
836 | |
837 | /* |
df11cd4e |
838 | * We have a solution. Produce a move string encoding the |
839 | * solution. |
79cb09e9 |
840 | */ |
df11cd4e |
841 | ret = snewn(wh + 2, char); |
842 | ret[0] = 'S'; |
843 | for (i = 0; i < wh; i++) |
844 | ret[i+1] = shortest[i] ? '1' : '0'; |
845 | ret[wh+1] = '\0'; |
79cb09e9 |
846 | |
847 | sfree(shortest); |
848 | sfree(solution); |
849 | sfree(equations); |
5d83d8f3 |
850 | sfree(und); |
79cb09e9 |
851 | |
852 | return ret; |
f4afe206 |
853 | } |
854 | |
855 | static char *game_text_format(game_state *state) |
856 | { |
857 | return NULL; |
858 | } |
859 | |
860 | static game_ui *new_ui(game_state *state) |
861 | { |
862 | return NULL; |
863 | } |
864 | |
865 | static void free_ui(game_ui *ui) |
866 | { |
867 | } |
868 | |
844f605f |
869 | static char *encode_ui(game_ui *ui) |
ae8290c6 |
870 | { |
871 | return NULL; |
872 | } |
873 | |
844f605f |
874 | static void decode_ui(game_ui *ui, char *encoding) |
ae8290c6 |
875 | { |
876 | } |
877 | |
f4afe206 |
878 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
879 | game_state *newstate) |
880 | { |
881 | } |
882 | |
883 | struct game_drawstate { |
884 | int w, h, started; |
885 | unsigned char *tiles; |
886 | int tilesize; |
887 | }; |
888 | |
df11cd4e |
889 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
890 | int x, int y, int button) |
f4afe206 |
891 | { |
df11cd4e |
892 | int w = state->w, h = state->h /*, wh = w * h */; |
893 | char buf[80]; |
f4afe206 |
894 | |
895 | if (button == LEFT_BUTTON) { |
896 | int tx = FROMCOORD(x), ty = FROMCOORD(y); |
897 | if (tx >= 0 && tx < w && ty >= 0 && ty < h) { |
df11cd4e |
898 | sprintf(buf, "M%d,%d", tx, ty); |
899 | return dupstr(buf); |
900 | } |
901 | } |
902 | |
903 | return NULL; |
904 | } |
f4afe206 |
905 | |
df11cd4e |
906 | static game_state *execute_move(game_state *from, char *move) |
907 | { |
908 | int w = from->w, h = from->h, wh = w * h; |
909 | game_state *ret; |
910 | int x, y; |
911 | |
912 | if (move[0] == 'S' && strlen(move) == wh+1) { |
913 | int i; |
914 | |
915 | ret = dup_game(from); |
916 | ret->hints_active = TRUE; |
917 | ret->cheated = TRUE; |
918 | for (i = 0; i < wh; i++) { |
919 | ret->grid[i] &= ~2; |
920 | if (move[i+1] != '0') |
921 | ret->grid[i] |= 2; |
922 | } |
923 | return ret; |
924 | } else if (move[0] == 'M' && |
925 | sscanf(move+1, "%d,%d", &x, &y) == 2 && |
926 | x >= 0 && x < w && y >= 0 && y < h) { |
927 | int i, j, done; |
f4afe206 |
928 | |
df11cd4e |
929 | ret = dup_game(from); |
f4afe206 |
930 | |
df11cd4e |
931 | if (!ret->completed) |
932 | ret->moves++; |
f4afe206 |
933 | |
df11cd4e |
934 | i = y * w + x; |
f4afe206 |
935 | |
df11cd4e |
936 | done = TRUE; |
937 | for (j = 0; j < wh; j++) { |
938 | ret->grid[j] ^= ret->matrix->matrix[i*wh+j]; |
939 | if (ret->grid[j] & 1) |
940 | done = FALSE; |
941 | } |
942 | ret->grid[i] ^= 2; /* toggle hint */ |
943 | if (done) { |
944 | ret->completed = TRUE; |
945 | ret->hints_active = FALSE; |
946 | } |
f4afe206 |
947 | |
df11cd4e |
948 | return ret; |
949 | } else |
950 | return NULL; /* can't parse move string */ |
f4afe206 |
951 | } |
952 | |
953 | /* ---------------------------------------------------------------------- |
954 | * Drawing routines. |
955 | */ |
956 | |
957 | static void game_size(game_params *params, game_drawstate *ds, |
958 | int *x, int *y, int expand) |
959 | { |
960 | int tsx, tsy, ts; |
961 | /* |
962 | * Each window dimension equals the tile size times one more |
963 | * than the grid dimension (the border is half the width of the |
964 | * tiles). |
965 | */ |
966 | tsx = *x / (params->w + 1); |
967 | tsy = *y / (params->h + 1); |
968 | ts = min(tsx, tsy); |
969 | if (expand) |
970 | ds->tilesize = ts; |
971 | else |
972 | ds->tilesize = min(ts, PREFERRED_TILE_SIZE); |
973 | |
974 | *x = TILE_SIZE * params->w + 2 * BORDER; |
975 | *y = TILE_SIZE * params->h + 2 * BORDER; |
976 | } |
977 | |
978 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
979 | { |
980 | float *ret = snewn(3 * NCOLOURS, float); |
981 | |
982 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
983 | |
984 | ret[COL_WRONG * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] / 3; |
985 | ret[COL_WRONG * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] / 3; |
986 | ret[COL_WRONG * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] / 3; |
987 | |
988 | ret[COL_RIGHT * 3 + 0] = 1.0F; |
989 | ret[COL_RIGHT * 3 + 1] = 1.0F; |
990 | ret[COL_RIGHT * 3 + 2] = 1.0F; |
991 | |
992 | ret[COL_GRID * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] / 1.5F; |
993 | ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] / 1.5F; |
994 | ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] / 1.5F; |
995 | |
996 | ret[COL_DIAG * 3 + 0] = ret[COL_GRID * 3 + 0]; |
997 | ret[COL_DIAG * 3 + 1] = ret[COL_GRID * 3 + 1]; |
998 | ret[COL_DIAG * 3 + 2] = ret[COL_GRID * 3 + 2]; |
999 | |
79cb09e9 |
1000 | ret[COL_HINT * 3 + 0] = 1.0F; |
1001 | ret[COL_HINT * 3 + 1] = 0.0F; |
1002 | ret[COL_HINT * 3 + 2] = 0.0F; |
1003 | |
f4afe206 |
1004 | *ncolours = NCOLOURS; |
1005 | return ret; |
1006 | } |
1007 | |
1008 | static game_drawstate *game_new_drawstate(game_state *state) |
1009 | { |
1010 | struct game_drawstate *ds = snew(struct game_drawstate); |
1011 | int i; |
1012 | |
1013 | ds->started = FALSE; |
1014 | ds->w = state->w; |
1015 | ds->h = state->h; |
1016 | ds->tiles = snewn(ds->w*ds->h, unsigned char); |
1017 | ds->tilesize = 0; /* haven't decided yet */ |
1018 | for (i = 0; i < ds->w*ds->h; i++) |
1019 | ds->tiles[i] = -1; |
1020 | |
1021 | return ds; |
1022 | } |
1023 | |
1024 | static void game_free_drawstate(game_drawstate *ds) |
1025 | { |
1026 | sfree(ds->tiles); |
1027 | sfree(ds); |
1028 | } |
1029 | |
1030 | static void draw_tile(frontend *fe, game_drawstate *ds, |
d1044751 |
1031 | game_state *state, int x, int y, int tile, int anim, |
1032 | float animtime) |
f4afe206 |
1033 | { |
1034 | int w = ds->w, h = ds->h, wh = w * h; |
1035 | int bx = x * TILE_SIZE + BORDER, by = y * TILE_SIZE + BORDER; |
1036 | int i, j; |
1037 | |
1038 | clip(fe, bx+1, by+1, TILE_SIZE-1, TILE_SIZE-1); |
1039 | |
1040 | draw_rect(fe, bx+1, by+1, TILE_SIZE-1, TILE_SIZE-1, |
d1044751 |
1041 | anim ? COL_BACKGROUND : tile & 1 ? COL_WRONG : COL_RIGHT); |
1042 | if (anim) { |
1043 | /* |
1044 | * Draw a polygon indicating that the square is diagonally |
1045 | * flipping over. |
1046 | */ |
1047 | int coords[8], colour; |
1048 | |
1049 | coords[0] = bx + TILE_SIZE; |
1050 | coords[1] = by; |
1051 | coords[2] = bx + TILE_SIZE * animtime; |
1052 | coords[3] = by + TILE_SIZE * animtime; |
1053 | coords[4] = bx; |
1054 | coords[5] = by + TILE_SIZE; |
1055 | coords[6] = bx + TILE_SIZE - TILE_SIZE * animtime; |
1056 | coords[7] = by + TILE_SIZE - TILE_SIZE * animtime; |
1057 | |
1058 | colour = (tile & 1 ? COL_WRONG : COL_RIGHT); |
1059 | if (animtime < 0.5) |
1060 | colour = COL_WRONG + COL_RIGHT - colour; |
1061 | |
1062 | draw_polygon(fe, coords, 4, TRUE, colour); |
1063 | draw_polygon(fe, coords, 4, FALSE, COL_GRID); |
1064 | } |
f4afe206 |
1065 | |
1066 | /* |
1067 | * Draw a little diagram in the tile which indicates which |
1068 | * surrounding tiles flip when this one is clicked. |
1069 | */ |
1070 | for (i = 0; i < h; i++) |
1071 | for (j = 0; j < w; j++) |
1072 | if (state->matrix->matrix[(y*w+x)*wh + i*w+j]) { |
1073 | int ox = j - x, oy = i - y; |
1074 | int td = TILE_SIZE / 16; |
1075 | int cx = (bx + TILE_SIZE/2) + (2 * ox - 1) * td; |
1076 | int cy = (by + TILE_SIZE/2) + (2 * oy - 1) * td; |
1077 | if (ox == 0 && oy == 0) |
1078 | draw_rect(fe, cx, cy, 2*td+1, 2*td+1, COL_DIAG); |
1079 | else { |
1080 | draw_line(fe, cx, cy, cx+2*td, cy, COL_DIAG); |
1081 | draw_line(fe, cx, cy+2*td, cx+2*td, cy+2*td, COL_DIAG); |
1082 | draw_line(fe, cx, cy, cx, cy+2*td, COL_DIAG); |
1083 | draw_line(fe, cx+2*td, cy, cx+2*td, cy+2*td, COL_DIAG); |
1084 | } |
1085 | } |
1086 | |
79cb09e9 |
1087 | /* |
5f6050b4 |
1088 | * Draw a hint rectangle if required. |
79cb09e9 |
1089 | */ |
1090 | if (tile & 2) { |
5f6050b4 |
1091 | int x1 = bx + TILE_SIZE / 20, x2 = bx + TILE_SIZE - TILE_SIZE / 20; |
1092 | int y1 = by + TILE_SIZE / 20, y2 = by + TILE_SIZE - TILE_SIZE / 20; |
1093 | int i = 3; |
1094 | while (i--) { |
1095 | draw_line(fe, x1, y1, x2, y1, COL_HINT); |
1096 | draw_line(fe, x1, y2, x2, y2, COL_HINT); |
1097 | draw_line(fe, x1, y1, x1, y2, COL_HINT); |
1098 | draw_line(fe, x2, y1, x2, y2, COL_HINT); |
1099 | x1++, y1++, x2--, y2--; |
1100 | } |
79cb09e9 |
1101 | } |
1102 | |
f4afe206 |
1103 | unclip(fe); |
1104 | |
1105 | draw_update(fe, bx+1, by+1, TILE_SIZE-1, TILE_SIZE-1); |
1106 | } |
1107 | |
1108 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
1109 | game_state *state, int dir, game_ui *ui, |
1110 | float animtime, float flashtime) |
1111 | { |
1112 | int w = ds->w, h = ds->h, wh = w * h; |
1113 | int i, flashframe; |
1114 | |
1115 | if (!ds->started) { |
1116 | draw_rect(fe, 0, 0, TILE_SIZE * w + 2 * BORDER, |
1117 | TILE_SIZE * h + 2 * BORDER, COL_BACKGROUND); |
1118 | |
1119 | /* |
1120 | * Draw the grid lines. |
1121 | */ |
1122 | for (i = 0; i <= w; i++) |
1123 | draw_line(fe, i * TILE_SIZE + BORDER, BORDER, |
1124 | i * TILE_SIZE + BORDER, h * TILE_SIZE + BORDER, |
1125 | COL_GRID); |
1126 | for (i = 0; i <= h; i++) |
1127 | draw_line(fe, BORDER, i * TILE_SIZE + BORDER, |
1128 | w * TILE_SIZE + BORDER, i * TILE_SIZE + BORDER, |
1129 | COL_GRID); |
1130 | |
1131 | draw_update(fe, 0, 0, TILE_SIZE * w + 2 * BORDER, |
1132 | TILE_SIZE * h + 2 * BORDER); |
1133 | |
1134 | ds->started = TRUE; |
1135 | } |
1136 | |
1137 | if (flashtime) |
1138 | flashframe = flashtime / FLASH_FRAME; |
1139 | else |
1140 | flashframe = -1; |
1141 | |
d1044751 |
1142 | animtime /= ANIM_TIME; /* scale it so it goes from 0 to 1 */ |
1143 | |
f4afe206 |
1144 | for (i = 0; i < wh; i++) { |
1145 | int x = i % w, y = i / w; |
1146 | int fx, fy, fd; |
1147 | int v = state->grid[i]; |
d1044751 |
1148 | int vv; |
f4afe206 |
1149 | |
1150 | if (flashframe >= 0) { |
1151 | fx = (w+1)/2 - min(x+1, w-x); |
1152 | fy = (h+1)/2 - min(y+1, h-y); |
1153 | fd = max(fx, fy); |
1154 | if (fd == flashframe) |
1155 | v |= 1; |
1156 | else if (fd == flashframe - 1) |
1157 | v &= ~1; |
1158 | } |
d1044751 |
1159 | |
79cb09e9 |
1160 | if (!state->hints_active) |
1161 | v &= ~2; |
1162 | |
d1044751 |
1163 | if (oldstate && state->grid[i] != oldstate->grid[i]) |
1164 | vv = 255; /* means `animated' */ |
1165 | else |
1166 | vv = v; |
1167 | |
1168 | if (ds->tiles[i] == 255 || vv == 255 || ds->tiles[i] != vv) { |
1169 | draw_tile(fe, ds, state, x, y, v, vv == 255, animtime); |
1170 | ds->tiles[i] = vv; |
f4afe206 |
1171 | } |
1172 | } |
1173 | |
1174 | { |
1175 | char buf[256]; |
1176 | |
79cb09e9 |
1177 | sprintf(buf, "%sMoves: %d", |
1178 | (state->completed ? |
1179 | (state->cheated ? "Auto-solved. " : "COMPLETED! ") : |
1180 | (state->cheated ? "Auto-solver used. " : "")), |
f4afe206 |
1181 | state->moves); |
1182 | |
1183 | status_bar(fe, buf); |
1184 | } |
1185 | } |
1186 | |
1187 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1188 | int dir, game_ui *ui) |
1189 | { |
d1044751 |
1190 | return ANIM_TIME; |
f4afe206 |
1191 | } |
1192 | |
1193 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
1194 | int dir, game_ui *ui) |
1195 | { |
1196 | if (!oldstate->completed && newstate->completed) |
1197 | return FLASH_FRAME * (max((newstate->w+1)/2, (newstate->h+1)/2)+1); |
1198 | |
1199 | return 0.0F; |
1200 | } |
1201 | |
1202 | static int game_wants_statusbar(void) |
1203 | { |
1204 | return TRUE; |
1205 | } |
1206 | |
1207 | static int game_timing_state(game_state *state) |
1208 | { |
1209 | return TRUE; |
1210 | } |
1211 | |
1212 | #ifdef COMBINED |
1213 | #define thegame flip |
1214 | #endif |
1215 | |
1216 | const struct game thegame = { |
5d8c6c55 |
1217 | "Flip", "games.flip", |
f4afe206 |
1218 | default_params, |
1219 | game_fetch_preset, |
1220 | decode_params, |
1221 | encode_params, |
1222 | free_params, |
1223 | dup_params, |
1224 | TRUE, game_configure, custom_params, |
1225 | validate_params, |
1226 | new_game_desc, |
f4afe206 |
1227 | validate_desc, |
1228 | new_game, |
1229 | dup_game, |
1230 | free_game, |
79cb09e9 |
1231 | TRUE, solve_game, |
f4afe206 |
1232 | FALSE, game_text_format, |
1233 | new_ui, |
1234 | free_ui, |
ae8290c6 |
1235 | encode_ui, |
1236 | decode_ui, |
f4afe206 |
1237 | game_changed_state, |
df11cd4e |
1238 | interpret_move, |
1239 | execute_move, |
f4afe206 |
1240 | game_size, |
1241 | game_colours, |
1242 | game_new_drawstate, |
1243 | game_free_drawstate, |
1244 | game_redraw, |
1245 | game_anim_length, |
1246 | game_flash_length, |
1247 | game_wants_statusbar, |
1248 | FALSE, game_timing_state, |
1249 | 0, /* mouse_priorities */ |
1250 | }; |