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Palm fixes for Loopy from James H: a #ifdef SLOW_SYSTEM, and an
[sgt/puzzles] / loopy.c
1 /*
2 * loopy.c: An implementation of the Nikoli game 'Loop the loop'.
3 * (c) Mike Pinna, 2005
4 *
5 * vim: set shiftwidth=4 :set textwidth=80:
6 */
7
8 /*
9 * TODO:
10 *
11 * - setting very high recursion depth seems to cause memory
12 * munching: are we recursing before checking completion, by any
13 * chance?
14 *
15 * - there's an interesting deductive technique which makes use of
16 * topology rather than just graph theory. Each _square_ in the
17 * grid is either inside or outside the loop; you can tell that
18 * two squares are on the same side of the loop if they're
19 * separated by an x (or, more generally, by a path crossing no
20 * LINE_UNKNOWNs and an even number of LINE_YESes), and on the
21 * opposite side of the loop if they're separated by a line (or
22 * an odd number of LINE_YESes and no LINE_UNKNOWNs). Oh, and
23 * any square separated from the outside of the grid by a
24 * LINE_YES or a LINE_NO is on the inside or outside
25 * respectively. So if you can track this for all squares, you
26 * can occasionally spot that two squares are separated by a
27 * LINE_UNKNOWN but their relative insideness is known, and
28 * therefore deduce the state of the edge between them.
29 * + An efficient way to track this would be by augmenting the
30 * disjoint set forest data structure. Each element, along
31 * with a pointer to a parent member of its equivalence
32 * class, would also carry a one-bit field indicating whether
33 * it was equal or opposite to its parent. Then you could
34 * keep flipping a bit as you ascended the tree during
35 * dsf_canonify(), and hence you'd be able to return the
36 * relationship of the input value to its ultimate parent
37 * (and also you could then get all those bits right when you
38 * went back up the tree rewriting). So you'd be able to
39 * query whether any two elements were known-equal,
40 * known-opposite, or not-known, and you could add new
41 * equalities or oppositenesses to increase your knowledge.
42 * (Of course the algorithm would have to fail an assertion
43 * if you tried to tell it two things it already knew to be
44 * opposite were equal, or vice versa!)
45 */
46
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <assert.h>
51 #include <ctype.h>
52 #include <math.h>
53
54 #include "puzzles.h"
55 #include "tree234.h"
56
57 #define PREFERRED_TILE_SIZE 32
58 #define TILE_SIZE (ds->tilesize)
59 #define LINEWIDTH TILE_SIZE / 16
60 #define BORDER (TILE_SIZE / 2)
61
62 #define FLASH_TIME 0.4F
63
64 #define HL_COUNT(state) ((state)->w * ((state)->h + 1))
65 #define VL_COUNT(state) (((state)->w + 1) * (state)->h)
66 #define DOT_COUNT(state) (((state)->w + 1) * ((state)->h + 1))
67 #define SQUARE_COUNT(state) ((state)->w * (state)->h)
68
69 #define ABOVE_SQUARE(state, i, j) ((state)->hl[(i) + (state)->w * (j)])
70 #define BELOW_SQUARE(state, i, j) ABOVE_SQUARE(state, i, (j)+1)
71
72 #define LEFTOF_SQUARE(state, i, j) ((state)->vl[(i) + ((state)->w + 1) * (j)])
73 #define RIGHTOF_SQUARE(state, i, j) LEFTOF_SQUARE(state, (i)+1, j)
74
75 #define LEGAL_DOT(state, i, j) ((i) >= 0 && (j) >= 0 && \
76 (i) <= (state)->w && (j) <= (state)->h)
77
78 /*
79 * These macros return rvalues only, but can cope with being passed
80 * out-of-range coordinates.
81 */
82 #define ABOVE_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j <= 0) ? \
83 LINE_NO : LV_ABOVE_DOT(state, i, j))
84 #define BELOW_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j >= (state)->h) ? \
85 LINE_NO : LV_BELOW_DOT(state, i, j))
86
87 #define LEFTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i <= 0) ? \
88 LINE_NO : LV_LEFTOF_DOT(state, i, j))
89 #define RIGHTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i >= (state)->w)?\
90 LINE_NO : LV_RIGHTOF_DOT(state, i, j))
91
92 /*
93 * These macros expect to be passed valid coordinates, and return
94 * lvalues.
95 */
96 #define LV_BELOW_DOT(state, i, j) ((state)->vl[(i) + ((state)->w + 1) * (j)])
97 #define LV_ABOVE_DOT(state, i, j) LV_BELOW_DOT(state, i, (j)-1)
98
99 #define LV_RIGHTOF_DOT(state, i, j) ((state)->hl[(i) + (state)->w * (j)])
100 #define LV_LEFTOF_DOT(state, i, j) LV_RIGHTOF_DOT(state, (i)-1, j)
101
102 #define CLUE_AT(state, i, j) ((i < 0 || i >= (state)->w || \
103 j < 0 || j >= (state)->h) ? \
104 ' ' : LV_CLUE_AT(state, i, j))
105
106 #define LV_CLUE_AT(state, i, j) ((state)->clues[(i) + (state)->w * (j)])
107
108 #define OPP(dir) (dir == LINE_UNKNOWN ? LINE_UNKNOWN : \
109 dir == LINE_YES ? LINE_NO : LINE_YES)
110
111 static char *game_text_format(game_state *state);
112
113 enum {
114 COL_BACKGROUND,
115 COL_FOREGROUND,
116 COL_HIGHLIGHT,
117 NCOLOURS
118 };
119
120 enum line_state { LINE_UNKNOWN, LINE_YES, LINE_NO };
121
122 enum direction { UP, DOWN, LEFT, RIGHT };
123
124 struct game_params {
125 int w, h, rec;
126 };
127
128 struct game_state {
129 int w, h;
130
131 /* Put ' ' in a square that doesn't get a clue */
132 char *clues;
133
134 /* Arrays of line states, stored left-to-right, top-to-bottom */
135 char *hl, *vl;
136
137 int solved;
138 int cheated;
139
140 int recursion_depth;
141 };
142
143 static game_state *dup_game(game_state *state)
144 {
145 game_state *ret = snew(game_state);
146
147 ret->h = state->h;
148 ret->w = state->w;
149 ret->solved = state->solved;
150 ret->cheated = state->cheated;
151
152 ret->clues = snewn(SQUARE_COUNT(state), char);
153 memcpy(ret->clues, state->clues, SQUARE_COUNT(state));
154
155 ret->hl = snewn(HL_COUNT(state), char);
156 memcpy(ret->hl, state->hl, HL_COUNT(state));
157
158 ret->vl = snewn(VL_COUNT(state), char);
159 memcpy(ret->vl, state->vl, VL_COUNT(state));
160
161 ret->recursion_depth = state->recursion_depth;
162
163 return ret;
164 }
165
166 static void free_game(game_state *state)
167 {
168 if (state) {
169 sfree(state->clues);
170 sfree(state->hl);
171 sfree(state->vl);
172 sfree(state);
173 }
174 }
175
176 enum solver_status {
177 SOLVER_SOLVED, /* This is the only solution the solver could find */
178 SOLVER_MISTAKE, /* This is definitely not a solution */
179 SOLVER_AMBIGUOUS, /* This _might_ be an ambiguous solution */
180 SOLVER_INCOMPLETE /* This may be a partial solution */
181 };
182
183 typedef struct solver_state {
184 game_state *state;
185 /* XXX dot_atleastone[i,j, dline] is equivalent to */
186 /* dot_atmostone[i,j,OPP_DLINE(dline)] */
187 char *dot_atleastone;
188 char *dot_atmostone;
189 /* char *dline_identical; */
190 int recursion_remaining;
191 enum solver_status solver_status;
192 int *dotdsf, *looplen;
193 } solver_state;
194
195 static solver_state *new_solver_state(game_state *state) {
196 solver_state *ret = snew(solver_state);
197 int i;
198
199 ret->state = dup_game(state);
200
201 ret->dot_atmostone = snewn(DOT_COUNT(state), char);
202 memset(ret->dot_atmostone, 0, DOT_COUNT(state));
203 ret->dot_atleastone = snewn(DOT_COUNT(state), char);
204 memset(ret->dot_atleastone, 0, DOT_COUNT(state));
205
206 #if 0
207 dline_identical = snewn(DOT_COUNT(state), char);
208 memset(dline_identical, 0, DOT_COUNT(state));
209 #endif
210
211 ret->recursion_remaining = state->recursion_depth;
212 ret->solver_status = SOLVER_INCOMPLETE; /* XXX This may be a lie */
213
214 ret->dotdsf = snewn(DOT_COUNT(state), int);
215 ret->looplen = snewn(DOT_COUNT(state), int);
216 for (i = 0; i < DOT_COUNT(state); i++) {
217 ret->dotdsf[i] = i;
218 ret->looplen[i] = 1;
219 }
220
221 return ret;
222 }
223
224 static void free_solver_state(solver_state *sstate) {
225 if (sstate) {
226 free_game(sstate->state);
227 sfree(sstate->dot_atleastone);
228 sfree(sstate->dot_atmostone);
229 /* sfree(sstate->dline_identical); */
230 sfree(sstate->dotdsf);
231 sfree(sstate->looplen);
232 sfree(sstate);
233 }
234 }
235
236 static solver_state *dup_solver_state(solver_state *sstate) {
237 game_state *state;
238
239 solver_state *ret = snew(solver_state);
240
241 ret->state = state = dup_game(sstate->state);
242
243 ret->dot_atmostone = snewn(DOT_COUNT(state), char);
244 memcpy(ret->dot_atmostone, sstate->dot_atmostone, DOT_COUNT(state));
245
246 ret->dot_atleastone = snewn(DOT_COUNT(state), char);
247 memcpy(ret->dot_atleastone, sstate->dot_atleastone, DOT_COUNT(state));
248
249 #if 0
250 ret->dline_identical = snewn((state->w + 1) * (state->h + 1), char);
251 memcpy(ret->dline_identical, state->dot_atmostone,
252 (state->w + 1) * (state->h + 1));
253 #endif
254
255 ret->recursion_remaining = sstate->recursion_remaining;
256 ret->solver_status = sstate->solver_status;
257
258 ret->dotdsf = snewn(DOT_COUNT(state), int);
259 ret->looplen = snewn(DOT_COUNT(state), int);
260 memcpy(ret->dotdsf, sstate->dotdsf, DOT_COUNT(state) * sizeof(int));
261 memcpy(ret->looplen, sstate->looplen, DOT_COUNT(state) * sizeof(int));
262
263 return ret;
264 }
265
266 /*
267 * Merge two dots due to the existence of an edge between them.
268 * Updates the dsf tracking equivalence classes, and keeps track of
269 * the length of path each dot is currently a part of.
270 */
271 static void merge_dots(solver_state *sstate, int x1, int y1, int x2, int y2)
272 {
273 int i, j, len;
274
275 i = y1 * (sstate->state->w + 1) + x1;
276 j = y2 * (sstate->state->w + 1) + x2;
277
278 i = dsf_canonify(sstate->dotdsf, i);
279 j = dsf_canonify(sstate->dotdsf, j);
280
281 if (i != j) {
282 len = sstate->looplen[i] + sstate->looplen[j];
283 dsf_merge(sstate->dotdsf, i, j);
284 i = dsf_canonify(sstate->dotdsf, i);
285 sstate->looplen[i] = len;
286 }
287 }
288
289 /* Count the number of lines of a particular type currently going into the
290 * given dot. Lines going off the edge of the board are assumed fixed no. */
291 static int dot_order(const game_state* state, int i, int j, char line_type)
292 {
293 int n = 0;
294
295 if (i > 0) {
296 if (LEFTOF_DOT(state, i, j) == line_type)
297 ++n;
298 } else {
299 if (line_type == LINE_NO)
300 ++n;
301 }
302 if (i < state->w) {
303 if (RIGHTOF_DOT(state, i, j) == line_type)
304 ++n;
305 } else {
306 if (line_type == LINE_NO)
307 ++n;
308 }
309 if (j > 0) {
310 if (ABOVE_DOT(state, i, j) == line_type)
311 ++n;
312 } else {
313 if (line_type == LINE_NO)
314 ++n;
315 }
316 if (j < state->h) {
317 if (BELOW_DOT(state, i, j) == line_type)
318 ++n;
319 } else {
320 if (line_type == LINE_NO)
321 ++n;
322 }
323
324 return n;
325 }
326 /* Count the number of lines of a particular type currently surrounding the
327 * given square */
328 static int square_order(const game_state* state, int i, int j, char line_type)
329 {
330 int n = 0;
331
332 if (ABOVE_SQUARE(state, i, j) == line_type)
333 ++n;
334 if (BELOW_SQUARE(state, i, j) == line_type)
335 ++n;
336 if (LEFTOF_SQUARE(state, i, j) == line_type)
337 ++n;
338 if (RIGHTOF_SQUARE(state, i, j) == line_type)
339 ++n;
340
341 return n;
342 }
343
344 /* Set all lines bordering a dot of type old_type to type new_type */
345 static void dot_setall(game_state *state, int i, int j,
346 char old_type, char new_type)
347 {
348 /* printf("dot_setall([%d,%d], %d, %d)\n", i, j, old_type, new_type); */
349 if (i > 0 && LEFTOF_DOT(state, i, j) == old_type)
350 LV_LEFTOF_DOT(state, i, j) = new_type;
351 if (i < state->w && RIGHTOF_DOT(state, i, j) == old_type)
352 LV_RIGHTOF_DOT(state, i, j) = new_type;
353 if (j > 0 && ABOVE_DOT(state, i, j) == old_type)
354 LV_ABOVE_DOT(state, i, j) = new_type;
355 if (j < state->h && BELOW_DOT(state, i, j) == old_type)
356 LV_BELOW_DOT(state, i, j) = new_type;
357 }
358 /* Set all lines bordering a square of type old_type to type new_type */
359 static void square_setall(game_state *state, int i, int j,
360 char old_type, char new_type)
361 {
362 if (ABOVE_SQUARE(state, i, j) == old_type)
363 ABOVE_SQUARE(state, i, j) = new_type;
364 if (BELOW_SQUARE(state, i, j) == old_type)
365 BELOW_SQUARE(state, i, j) = new_type;
366 if (LEFTOF_SQUARE(state, i, j) == old_type)
367 LEFTOF_SQUARE(state, i, j) = new_type;
368 if (RIGHTOF_SQUARE(state, i, j) == old_type)
369 RIGHTOF_SQUARE(state, i, j) = new_type;
370 }
371
372 static game_params *default_params(void)
373 {
374 game_params *ret = snew(game_params);
375
376 #ifdef SLOW_SYSTEM
377 ret->h = 4;
378 ret->w = 4;
379 #else
380 ret->h = 10;
381 ret->w = 10;
382 #endif
383 ret->rec = 0;
384
385 return ret;
386 }
387
388 static game_params *dup_params(game_params *params)
389 {
390 game_params *ret = snew(game_params);
391 *ret = *params; /* structure copy */
392 return ret;
393 }
394
395 static const struct {
396 char *desc;
397 game_params params;
398 } loopy_presets[] = {
399 { "4x4 Easy", { 4, 4, 0 } },
400 { "4x4 Hard", { 4, 4, 2 } },
401 { "7x7 Easy", { 7, 7, 0 } },
402 { "7x7 Hard", { 7, 7, 2 } },
403 { "10x10 Easy", { 10, 10, 0 } },
404 #ifndef SLOW_SYSTEM
405 { "10x10 Hard", { 10, 10, 2 } },
406 { "15x15 Easy", { 15, 15, 0 } },
407 { "30x20 Easy", { 30, 20, 0 } }
408 #endif
409 };
410
411 static int game_fetch_preset(int i, char **name, game_params **params)
412 {
413 game_params tmppar;
414
415 if (i < 0 || i >= lenof(loopy_presets))
416 return FALSE;
417
418 tmppar = loopy_presets[i].params;
419 *params = dup_params(&tmppar);
420 *name = dupstr(loopy_presets[i].desc);
421
422 return TRUE;
423 }
424
425 static void free_params(game_params *params)
426 {
427 sfree(params);
428 }
429
430 static void decode_params(game_params *params, char const *string)
431 {
432 params->h = params->w = atoi(string);
433 params->rec = 0;
434 while (*string && isdigit((unsigned char)*string)) string++;
435 if (*string == 'x') {
436 string++;
437 params->h = atoi(string);
438 while (*string && isdigit((unsigned char)*string)) string++;
439 }
440 if (*string == 'r') {
441 string++;
442 params->rec = atoi(string);
443 while (*string && isdigit((unsigned char)*string)) string++;
444 }
445 }
446
447 static char *encode_params(game_params *params, int full)
448 {
449 char str[80];
450 sprintf(str, "%dx%d", params->w, params->h);
451 if (full)
452 sprintf(str + strlen(str), "r%d", params->rec);
453 return dupstr(str);
454 }
455
456 static config_item *game_configure(game_params *params)
457 {
458 config_item *ret;
459 char buf[80];
460
461 ret = snewn(4, config_item);
462
463 ret[0].name = "Width";
464 ret[0].type = C_STRING;
465 sprintf(buf, "%d", params->w);
466 ret[0].sval = dupstr(buf);
467 ret[0].ival = 0;
468
469 ret[1].name = "Height";
470 ret[1].type = C_STRING;
471 sprintf(buf, "%d", params->h);
472 ret[1].sval = dupstr(buf);
473 ret[1].ival = 0;
474
475 ret[2].name = "Recursion depth";
476 ret[2].type = C_STRING;
477 sprintf(buf, "%d", params->rec);
478 ret[2].sval = dupstr(buf);
479 ret[2].ival = 0;
480
481 ret[3].name = NULL;
482 ret[3].type = C_END;
483 ret[3].sval = NULL;
484 ret[3].ival = 0;
485
486 return ret;
487 }
488
489 static game_params *custom_params(config_item *cfg)
490 {
491 game_params *ret = snew(game_params);
492
493 ret->w = atoi(cfg[0].sval);
494 ret->h = atoi(cfg[1].sval);
495 ret->rec = atoi(cfg[2].sval);
496
497 return ret;
498 }
499
500 static char *validate_params(game_params *params, int full)
501 {
502 if (params->w < 4 || params->h < 4)
503 return "Width and height must both be at least 4";
504 if (params->rec < 0)
505 return "Recursion depth can't be negative";
506 return NULL;
507 }
508
509 /* We're going to store a list of current candidate squares for lighting.
510 * Each square gets a 'score', which tells us how adding that square right
511 * now would affect the length of the solution loop. We're trying to
512 * maximise that quantity so will bias our random selection of squares to
513 * light towards those with high scores */
514 struct square {
515 int score;
516 unsigned long random;
517 int x, y;
518 };
519
520 static int get_square_cmpfn(void *v1, void *v2)
521 {
522 struct square *s1 = (struct square *)v1;
523 struct square *s2 = (struct square *)v2;
524 int r;
525
526 r = s1->x - s2->x;
527 if (r)
528 return r;
529
530 r = s1->y - s2->y;
531 if (r)
532 return r;
533
534 return 0;
535 }
536
537 static int square_sort_cmpfn(void *v1, void *v2)
538 {
539 struct square *s1 = (struct square *)v1;
540 struct square *s2 = (struct square *)v2;
541 int r;
542
543 r = s2->score - s1->score;
544 if (r) {
545 return r;
546 }
547
548 if (s1->random < s2->random)
549 return -1;
550 else if (s1->random > s2->random)
551 return 1;
552
553 /*
554 * It's _just_ possible that two squares might have been given
555 * the same random value. In that situation, fall back to
556 * comparing based on the coordinates. This introduces a tiny
557 * directional bias, but not a significant one.
558 */
559 return get_square_cmpfn(v1, v2);
560 }
561
562 static void print_tree(tree234 *tree)
563 {
564 #if 0
565 int i = 0;
566 struct square *s;
567 printf("Print tree:\n");
568 while (i < count234(tree)) {
569 s = (struct square *)index234(tree, i);
570 assert(s);
571 printf(" [%d,%d], %d, %d\n", s->x, s->y, s->score, s->random);
572 ++i;
573 }
574 #endif
575 }
576
577 enum { SQUARE_LIT, SQUARE_UNLIT };
578
579 #define SQUARE_STATE(i, j) \
580 (((i) < 0 || (i) >= params->w || \
581 (j) < 0 || (j) >= params->h) ? \
582 SQUARE_UNLIT : LV_SQUARE_STATE(i,j))
583
584 #define LV_SQUARE_STATE(i, j) board[(i) + params->w * (j)]
585
586 static void print_board(const game_params *params, const char *board)
587 {
588 #if 0
589 int i,j;
590
591 printf(" ");
592 for (i = 0; i < params->w; i++) {
593 printf("%d", i%10);
594 }
595 printf("\n");
596 for (j = 0; j < params->h; j++) {
597 printf("%d", j%10);
598 for (i = 0; i < params->w; i++) {
599 printf("%c", SQUARE_STATE(i, j) ? ' ' : 'O');
600 }
601 printf("\n");
602 }
603 #endif
604 }
605
606 static char *new_fullyclued_board(game_params *params, random_state *rs)
607 {
608 char *clues;
609 char *board;
610 int i, j, a, b, c;
611 game_state s;
612 game_state *state = &s;
613 int board_area = SQUARE_COUNT(params);
614 int t;
615
616 struct square *square, *tmpsquare, *sq;
617 struct square square_pos;
618
619 /* These will contain exactly the same information, sorted into different
620 * orders */
621 tree234 *lightable_squares_sorted, *lightable_squares_gettable;
622
623 #define SQUARE_REACHABLE(i,j) \
624 (t = (SQUARE_STATE(i-1, j) == SQUARE_LIT || \
625 SQUARE_STATE(i+1, j) == SQUARE_LIT || \
626 SQUARE_STATE(i, j-1) == SQUARE_LIT || \
627 SQUARE_STATE(i, j+1) == SQUARE_LIT), \
628 /* printf("SQUARE_REACHABLE(%d,%d) = %d\n", i, j, t), */ \
629 t)
630
631
632 /* One situation in which we may not light a square is if that'll leave one
633 * square above/below and one left/right of us unlit, separated by a lit
634 * square diagnonal from us */
635 #define SQUARE_DIAGONAL_VIOLATION(i, j, h, v) \
636 (t = (SQUARE_STATE((i)+(h), (j)) == SQUARE_UNLIT && \
637 SQUARE_STATE((i), (j)+(v)) == SQUARE_UNLIT && \
638 SQUARE_STATE((i)+(h), (j)+(v)) == SQUARE_LIT), \
639 /* t ? printf("SQUARE_DIAGONAL_VIOLATION(%d, %d, %d, %d)\n",
640 i, j, h, v) : 0,*/ \
641 t)
642
643 /* We also may not light a square if it will form a loop of lit squares
644 * around some unlit squares, as then the game soln won't have a single
645 * loop */
646 #define SQUARE_LOOP_VIOLATION(i, j, lit1, lit2) \
647 (SQUARE_STATE((i)+1, (j)) == lit1 && \
648 SQUARE_STATE((i)-1, (j)) == lit1 && \
649 SQUARE_STATE((i), (j)+1) == lit2 && \
650 SQUARE_STATE((i), (j)-1) == lit2)
651
652 #define CAN_LIGHT_SQUARE(i, j) \
653 (SQUARE_REACHABLE(i, j) && \
654 !SQUARE_DIAGONAL_VIOLATION(i, j, -1, -1) && \
655 !SQUARE_DIAGONAL_VIOLATION(i, j, +1, -1) && \
656 !SQUARE_DIAGONAL_VIOLATION(i, j, -1, +1) && \
657 !SQUARE_DIAGONAL_VIOLATION(i, j, +1, +1) && \
658 !SQUARE_LOOP_VIOLATION(i, j, SQUARE_LIT, SQUARE_UNLIT) && \
659 !SQUARE_LOOP_VIOLATION(i, j, SQUARE_UNLIT, SQUARE_LIT))
660
661 #define IS_LIGHTING_CANDIDATE(i, j) \
662 (SQUARE_STATE(i, j) == SQUARE_UNLIT && \
663 CAN_LIGHT_SQUARE(i,j))
664
665 /* The 'score' of a square reflects its current desirability for selection
666 * as the next square to light. We want to encourage moving into uncharted
667 * areas so we give scores according to how many of the square's neighbours
668 * are currently unlit. */
669
670 /* UNLIT SCORE
671 * 3 2
672 * 2 0
673 * 1 -2
674 */
675 #define SQUARE_SCORE(i,j) \
676 (2*((SQUARE_STATE(i-1, j) == SQUARE_UNLIT) + \
677 (SQUARE_STATE(i+1, j) == SQUARE_UNLIT) + \
678 (SQUARE_STATE(i, j-1) == SQUARE_UNLIT) + \
679 (SQUARE_STATE(i, j+1) == SQUARE_UNLIT)) - 4)
680
681 /* When a square gets lit, this defines how far away from that square we
682 * need to go recomputing scores */
683 #define SCORE_DISTANCE 1
684
685 board = snewn(board_area, char);
686 clues = snewn(board_area, char);
687
688 state->h = params->h;
689 state->w = params->w;
690 state->clues = clues;
691
692 /* Make a board */
693 memset(board, SQUARE_UNLIT, board_area);
694
695 /* Seed the board with a single lit square near the middle */
696 i = params->w / 2;
697 j = params->h / 2;
698 if (params->w & 1 && random_bits(rs, 1))
699 ++i;
700 if (params->h & 1 && random_bits(rs, 1))
701 ++j;
702
703 LV_SQUARE_STATE(i, j) = SQUARE_LIT;
704
705 /* We need a way of favouring squares that will increase our loopiness.
706 * We do this by maintaining a list of all candidate squares sorted by
707 * their score and choose randomly from that with appropriate skew.
708 * In order to avoid consistently biasing towards particular squares, we
709 * need the sort order _within_ each group of scores to be completely
710 * random. But it would be abusing the hospitality of the tree234 data
711 * structure if our comparison function were nondeterministic :-). So with
712 * each square we associate a random number that does not change during a
713 * particular run of the generator, and use that as a secondary sort key.
714 * Yes, this means we will be biased towards particular random squares in
715 * any one run but that doesn't actually matter. */
716
717 lightable_squares_sorted = newtree234(square_sort_cmpfn);
718 lightable_squares_gettable = newtree234(get_square_cmpfn);
719 #define ADD_SQUARE(s) \
720 do { \
721 /* printf("ADD SQUARE: [%d,%d], %d, %d\n",
722 s->x, s->y, s->score, s->random);*/ \
723 sq = add234(lightable_squares_sorted, s); \
724 assert(sq == s); \
725 sq = add234(lightable_squares_gettable, s); \
726 assert(sq == s); \
727 } while (0)
728
729 #define REMOVE_SQUARE(s) \
730 do { \
731 /* printf("DELETE SQUARE: [%d,%d], %d, %d\n",
732 s->x, s->y, s->score, s->random);*/ \
733 sq = del234(lightable_squares_sorted, s); \
734 assert(sq); \
735 sq = del234(lightable_squares_gettable, s); \
736 assert(sq); \
737 } while (0)
738
739 #define HANDLE_DIR(a, b) \
740 square = snew(struct square); \
741 square->x = (i)+(a); \
742 square->y = (j)+(b); \
743 square->score = 2; \
744 square->random = random_bits(rs, 31); \
745 ADD_SQUARE(square);
746 HANDLE_DIR(-1, 0);
747 HANDLE_DIR( 1, 0);
748 HANDLE_DIR( 0,-1);
749 HANDLE_DIR( 0, 1);
750 #undef HANDLE_DIR
751
752 /* Light squares one at a time until the board is interesting enough */
753 while (TRUE)
754 {
755 /* We have count234(lightable_squares) possibilities, and in
756 * lightable_squares_sorted they are sorted with the most desirable
757 * first. */
758 c = count234(lightable_squares_sorted);
759 if (c == 0)
760 break;
761 assert(c == count234(lightable_squares_gettable));
762
763 /* Check that the best square available is any good */
764 square = (struct square *)index234(lightable_squares_sorted, 0);
765 assert(square);
766
767 if (square->score <= 0)
768 break;
769
770 print_tree(lightable_squares_sorted);
771 assert(square->score == SQUARE_SCORE(square->x, square->y));
772 assert(SQUARE_STATE(square->x, square->y) == SQUARE_UNLIT);
773 assert(square->x >= 0 && square->x < params->w);
774 assert(square->y >= 0 && square->y < params->h);
775 /* printf("LIGHT SQUARE: [%d,%d], score = %d\n", square->x, square->y, square->score); */
776
777 /* Update data structures */
778 LV_SQUARE_STATE(square->x, square->y) = SQUARE_LIT;
779 REMOVE_SQUARE(square);
780
781 print_board(params, board);
782
783 /* We might have changed the score of any squares up to 2 units away in
784 * any direction */
785 for (b = -SCORE_DISTANCE; b <= SCORE_DISTANCE; b++) {
786 for (a = -SCORE_DISTANCE; a <= SCORE_DISTANCE; a++) {
787 if (!a && !b)
788 continue;
789 square_pos.x = square->x + a;
790 square_pos.y = square->y + b;
791 /* printf("Refreshing score for [%d,%d]:\n", square_pos.x, square_pos.y); */
792 if (square_pos.x < 0 || square_pos.x >= params->w ||
793 square_pos.y < 0 || square_pos.y >= params->h) {
794 /* printf(" Out of bounds\n"); */
795 continue;
796 }
797 tmpsquare = find234(lightable_squares_gettable, &square_pos,
798 NULL);
799 if (tmpsquare) {
800 /* printf(" Removing\n"); */
801 assert(tmpsquare->x == square_pos.x);
802 assert(tmpsquare->y == square_pos.y);
803 assert(SQUARE_STATE(tmpsquare->x, tmpsquare->y) ==
804 SQUARE_UNLIT);
805 REMOVE_SQUARE(tmpsquare);
806 } else {
807 /* printf(" Creating\n"); */
808 tmpsquare = snew(struct square);
809 tmpsquare->x = square_pos.x;
810 tmpsquare->y = square_pos.y;
811 tmpsquare->random = random_bits(rs, 31);
812 }
813 tmpsquare->score = SQUARE_SCORE(tmpsquare->x, tmpsquare->y);
814
815 if (IS_LIGHTING_CANDIDATE(tmpsquare->x, tmpsquare->y)) {
816 /* printf(" Adding\n"); */
817 ADD_SQUARE(tmpsquare);
818 } else {
819 /* printf(" Destroying\n"); */
820 sfree(tmpsquare);
821 }
822 }
823 }
824 sfree(square);
825 /* printf("\n\n"); */
826 }
827
828 while ((square = delpos234(lightable_squares_gettable, 0)) != NULL)
829 sfree(square);
830 freetree234(lightable_squares_gettable);
831 freetree234(lightable_squares_sorted);
832
833 /* Copy out all the clues */
834 for (j = 0; j < params->h; ++j) {
835 for (i = 0; i < params->w; ++i) {
836 c = SQUARE_STATE(i, j);
837 LV_CLUE_AT(state, i, j) = '0';
838 if (SQUARE_STATE(i-1, j) != c) ++LV_CLUE_AT(state, i, j);
839 if (SQUARE_STATE(i+1, j) != c) ++LV_CLUE_AT(state, i, j);
840 if (SQUARE_STATE(i, j-1) != c) ++LV_CLUE_AT(state, i, j);
841 if (SQUARE_STATE(i, j+1) != c) ++LV_CLUE_AT(state, i, j);
842 }
843 }
844
845 sfree(board);
846 return clues;
847 }
848
849 static solver_state *solve_game_rec(const solver_state *sstate);
850
851 static int game_has_unique_soln(const game_state *state)
852 {
853 int ret;
854 solver_state *sstate_new;
855 solver_state *sstate = new_solver_state((game_state *)state);
856
857 sstate_new = solve_game_rec(sstate);
858
859 ret = (sstate_new->solver_status == SOLVER_SOLVED);
860
861 free_solver_state(sstate_new);
862 free_solver_state(sstate);
863
864 return ret;
865 }
866
867 /* Remove clues one at a time at random. */
868 static game_state *remove_clues(game_state *state, random_state *rs)
869 {
870 int *square_list, squares;
871 game_state *ret = dup_game(state), *saved_ret;
872 int n;
873
874 /* We need to remove some clues. We'll do this by forming a list of all
875 * available equivalence classes, shuffling it, then going along one at a
876 * time clearing every member of each equivalence class, where removing a
877 * class doesn't render the board unsolvable. */
878 squares = state->w * state->h;
879 square_list = snewn(squares, int);
880 for (n = 0; n < squares; ++n) {
881 square_list[n] = n;
882 }
883
884 shuffle(square_list, squares, sizeof(int), rs);
885
886 for (n = 0; n < squares; ++n) {
887 saved_ret = dup_game(ret);
888 LV_CLUE_AT(ret, square_list[n] % state->w,
889 square_list[n] / state->w) = ' ';
890 if (game_has_unique_soln(ret)) {
891 free_game(saved_ret);
892 } else {
893 free_game(ret);
894 ret = saved_ret;
895 }
896 }
897 sfree(square_list);
898
899 return ret;
900 }
901
902 static char *validate_desc(game_params *params, char *desc);
903
904 static char *new_game_desc(game_params *params, random_state *rs,
905 char **aux, int interactive)
906 {
907 /* solution and description both use run-length encoding in obvious ways */
908 char *retval;
909 char *description = snewn(SQUARE_COUNT(params) + 1, char);
910 char *dp = description;
911 int i, j;
912 int empty_count;
913 game_state *state = snew(game_state), *state_new;
914
915 state->h = params->h;
916 state->w = params->w;
917
918 state->hl = snewn(HL_COUNT(params), char);
919 state->vl = snewn(VL_COUNT(params), char);
920 memset(state->hl, LINE_UNKNOWN, HL_COUNT(params));
921 memset(state->vl, LINE_UNKNOWN, VL_COUNT(params));
922
923 state->solved = state->cheated = FALSE;
924 state->recursion_depth = params->rec;
925
926 /* Get a new random solvable board with all its clues filled in. Yes, this
927 * can loop for ever if the params are suitably unfavourable, but
928 * preventing games smaller than 4x4 seems to stop this happening */
929 do {
930 state->clues = new_fullyclued_board(params, rs);
931 } while (!game_has_unique_soln(state));
932
933 state_new = remove_clues(state, rs);
934 free_game(state);
935 state = state_new;
936
937 empty_count = 0;
938 for (j = 0; j < params->h; ++j) {
939 for (i = 0; i < params->w; ++i) {
940 if (CLUE_AT(state, i, j) == ' ') {
941 if (empty_count > 25) {
942 dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
943 empty_count = 0;
944 }
945 empty_count++;
946 } else {
947 if (empty_count) {
948 dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
949 empty_count = 0;
950 }
951 dp += sprintf(dp, "%c", (int)(CLUE_AT(state, i, j)));
952 }
953 }
954 }
955 if (empty_count)
956 dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
957
958 free_game(state);
959 retval = dupstr(description);
960 sfree(description);
961
962 assert(!validate_desc(params, retval));
963
964 return retval;
965 }
966
967 /* We require that the params pass the test in validate_params and that the
968 * description fills the entire game area */
969 static char *validate_desc(game_params *params, char *desc)
970 {
971 int count = 0;
972
973 for (; *desc; ++desc) {
974 if (*desc >= '0' && *desc <= '9') {
975 count++;
976 continue;
977 }
978 if (*desc >= 'a') {
979 count += *desc - 'a' + 1;
980 continue;
981 }
982 return "Unknown character in description";
983 }
984
985 if (count < SQUARE_COUNT(params))
986 return "Description too short for board size";
987 if (count > SQUARE_COUNT(params))
988 return "Description too long for board size";
989
990 return NULL;
991 }
992
993 static game_state *new_game(midend *me, game_params *params, char *desc)
994 {
995 int i,j;
996 game_state *state = snew(game_state);
997 int empties_to_make = 0;
998 int n;
999 const char *dp = desc;
1000
1001 state->recursion_depth = params->rec;
1002
1003 state->h = params->h;
1004 state->w = params->w;
1005
1006 state->clues = snewn(SQUARE_COUNT(params), char);
1007 state->hl = snewn(HL_COUNT(params), char);
1008 state->vl = snewn(VL_COUNT(params), char);
1009
1010 state->solved = state->cheated = FALSE;
1011
1012 for (j = 0 ; j < params->h; ++j) {
1013 for (i = 0 ; i < params->w; ++i) {
1014 if (empties_to_make) {
1015 empties_to_make--;
1016 LV_CLUE_AT(state, i, j) = ' ';
1017 continue;
1018 }
1019
1020 assert(*dp);
1021 n = *dp - '0';
1022 if (n >=0 && n < 10) {
1023 LV_CLUE_AT(state, i, j) = *dp;
1024 } else {
1025 n = *dp - 'a' + 1;
1026 assert(n > 0);
1027 LV_CLUE_AT(state, i, j) = ' ';
1028 empties_to_make = n - 1;
1029 }
1030 ++dp;
1031 }
1032 }
1033
1034 memset(state->hl, LINE_UNKNOWN, HL_COUNT(params));
1035 memset(state->vl, LINE_UNKNOWN, VL_COUNT(params));
1036
1037 return state;
1038 }
1039
1040 enum { LOOP_NONE=0, LOOP_SOLN, LOOP_NOT_SOLN };
1041
1042 /* Starting at dot [i,j] moves around 'state' removing lines until it's clear
1043 * whether or not the starting dot was on a loop. Returns boolean specifying
1044 * whether a loop was found. loop_status calls this and assumes that if state
1045 * has any lines set, this function will always remove at least one. */
1046 static int destructively_find_loop(game_state *state)
1047 {
1048 int a, b, i, j, new_i, new_j, n;
1049 char *lp;
1050
1051 lp = (char *)memchr(state->hl, LINE_YES, HL_COUNT(state));
1052 if (!lp) {
1053 /* We know we're going to return false but we have to fulfil our
1054 * contract */
1055 lp = (char *)memchr(state->vl, LINE_YES, VL_COUNT(state));
1056 if (lp)
1057 *lp = LINE_NO;
1058
1059 return FALSE;
1060 }
1061
1062 n = lp - state->hl;
1063
1064 i = n % state->w;
1065 j = n / state->w;
1066
1067 assert(i + j * state->w == n); /* because I'm feeling stupid */
1068 /* Save start position */
1069 a = i;
1070 b = j;
1071
1072 /* Delete one line from the potential loop */
1073 if (LEFTOF_DOT(state, i, j) == LINE_YES) {
1074 LV_LEFTOF_DOT(state, i, j) = LINE_NO;
1075 i--;
1076 } else if (ABOVE_DOT(state, i, j) == LINE_YES) {
1077 LV_ABOVE_DOT(state, i, j) = LINE_NO;
1078 j--;
1079 } else if (RIGHTOF_DOT(state, i, j) == LINE_YES) {
1080 LV_RIGHTOF_DOT(state, i, j) = LINE_NO;
1081 i++;
1082 } else if (BELOW_DOT(state, i, j) == LINE_YES) {
1083 LV_BELOW_DOT(state, i, j) = LINE_NO;
1084 j++;
1085 } else {
1086 return FALSE;
1087 }
1088
1089 do {
1090 /* From the current position of [i,j] there needs to be exactly one
1091 * line */
1092 new_i = new_j = -1;
1093
1094 #define HANDLE_DIR(dir_dot, x, y) \
1095 if (dir_dot(state, i, j) == LINE_YES) { \
1096 if (new_i != -1 || new_j != -1) \
1097 return FALSE; \
1098 new_i = (i)+(x); \
1099 new_j = (j)+(y); \
1100 LV_##dir_dot(state, i, j) = LINE_NO; \
1101 }
1102 HANDLE_DIR(ABOVE_DOT, 0, -1);
1103 HANDLE_DIR(BELOW_DOT, 0, +1);
1104 HANDLE_DIR(LEFTOF_DOT, -1, 0);
1105 HANDLE_DIR(RIGHTOF_DOT, +1, 0);
1106 #undef HANDLE_DIR
1107 if (new_i == -1 || new_j == -1) {
1108 return FALSE;
1109 }
1110
1111 i = new_i;
1112 j = new_j;
1113 } while (i != a || j != b);
1114
1115 return TRUE;
1116 }
1117
1118 static int loop_status(game_state *state)
1119 {
1120 int i, j, n;
1121 game_state *tmpstate;
1122 int loop_found = FALSE, non_loop_found = FALSE, any_lines_found = FALSE;
1123
1124 #define BAD_LOOP_FOUND \
1125 do { free_game(tmpstate); return LOOP_NOT_SOLN; } while(0)
1126
1127 /* Repeatedly look for loops until we either run out of lines to consider
1128 * or discover for sure that the board fails on the grounds of having no
1129 * loop */
1130 tmpstate = dup_game(state);
1131
1132 while (TRUE) {
1133 if (!memchr(tmpstate->hl, LINE_YES, HL_COUNT(tmpstate)) &&
1134 !memchr(tmpstate->vl, LINE_YES, VL_COUNT(tmpstate))) {
1135 break;
1136 }
1137 any_lines_found = TRUE;
1138
1139 if (loop_found)
1140 BAD_LOOP_FOUND;
1141 if (destructively_find_loop(tmpstate)) {
1142 loop_found = TRUE;
1143 if (non_loop_found)
1144 BAD_LOOP_FOUND;
1145 } else {
1146 non_loop_found = TRUE;
1147 }
1148 }
1149
1150 free_game(tmpstate);
1151
1152 if (!any_lines_found)
1153 return LOOP_NONE;
1154
1155 if (non_loop_found) {
1156 assert(!loop_found); /* should have dealt with this already */
1157 return LOOP_NONE;
1158 }
1159
1160 /* Check that every clue is satisfied */
1161 for (j = 0; j < state->h; ++j) {
1162 for (i = 0; i < state->w; ++i) {
1163 n = CLUE_AT(state, i, j);
1164 if (n != ' ') {
1165 if (square_order(state, i, j, LINE_YES) != n - '0') {
1166 return LOOP_NOT_SOLN;
1167 }
1168 }
1169 }
1170 }
1171
1172 return LOOP_SOLN;
1173 }
1174
1175 /* Sums the lengths of the numbers in range [0,n) */
1176 /* See equivalent function in solo.c for justification of this. */
1177 static int len_0_to_n(int n)
1178 {
1179 int len = 1; /* Counting 0 as a bit of a special case */
1180 int i;
1181
1182 for (i = 1; i < n; i *= 10) {
1183 len += max(n - i, 0);
1184 }
1185
1186 return len;
1187 }
1188
1189 static char *encode_solve_move(const game_state *state)
1190 {
1191 int len, i, j;
1192 char *ret, *p;
1193 /* This is going to return a string representing the moves needed to set
1194 * every line in a grid to be the same as the ones in 'state'. The exact
1195 * length of this string is predictable. */
1196
1197 len = 1; /* Count the 'S' prefix */
1198 /* Numbers in horizontal lines */
1199 /* Horizontal lines, x position */
1200 len += len_0_to_n(state->w) * (state->h + 1);
1201 /* Horizontal lines, y position */
1202 len += len_0_to_n(state->h + 1) * (state->w);
1203 /* Vertical lines, y position */
1204 len += len_0_to_n(state->h) * (state->w + 1);
1205 /* Vertical lines, x position */
1206 len += len_0_to_n(state->w + 1) * (state->h);
1207 /* For each line we also have two letters and a comma */
1208 len += 3 * (HL_COUNT(state) + VL_COUNT(state));
1209
1210 ret = snewn(len + 1, char);
1211 p = ret;
1212
1213 p += sprintf(p, "S");
1214
1215 for (j = 0; j < state->h + 1; ++j) {
1216 for (i = 0; i < state->w; ++i) {
1217 switch (RIGHTOF_DOT(state, i, j)) {
1218 case LINE_YES:
1219 p += sprintf(p, "%d,%dhy", i, j);
1220 break;
1221 case LINE_NO:
1222 p += sprintf(p, "%d,%dhn", i, j);
1223 break;
1224 /* default: */
1225 /* I'm going to forgive this because I think the results
1226 * are cute. */
1227 /* assert(!"Solver produced incomplete solution!"); */
1228 }
1229 }
1230 }
1231
1232 for (j = 0; j < state->h; ++j) {
1233 for (i = 0; i < state->w + 1; ++i) {
1234 switch (BELOW_DOT(state, i, j)) {
1235 case LINE_YES:
1236 p += sprintf(p, "%d,%dvy", i, j);
1237 break;
1238 case LINE_NO:
1239 p += sprintf(p, "%d,%dvn", i, j);
1240 break;
1241 /* default: */
1242 /* I'm going to forgive this because I think the results
1243 * are cute. */
1244 /* assert(!"Solver produced incomplete solution!"); */
1245 }
1246 }
1247 }
1248
1249 /* No point in doing sums like that if they're going to be wrong */
1250 assert(strlen(ret) <= (size_t)len);
1251 return ret;
1252 }
1253
1254 /* BEGIN SOLVER IMPLEMENTATION */
1255
1256 /* For each pair of lines through each dot we store a bit for whether
1257 * exactly one of those lines is ON, and in separate arrays we store whether
1258 * at least one is on and whether at most 1 is on. (If we know both or
1259 * neither is on that's already stored more directly.) That's six bits per
1260 * dot. Bit number n represents the lines shown in dot_type_dirs[n]. */
1261
1262 enum dline {
1263 DLINE_VERT = 0,
1264 DLINE_HORIZ = 1,
1265 DLINE_UL = 2,
1266 DLINE_DR = 3,
1267 DLINE_UR = 4,
1268 DLINE_DL = 5
1269 };
1270
1271 #define OPP_DLINE(dline) (dline ^ 1)
1272
1273
1274 #define SQUARE_DLINES \
1275 HANDLE_DLINE(DLINE_UL, RIGHTOF_SQUARE, BELOW_SQUARE, 1, 1); \
1276 HANDLE_DLINE(DLINE_UR, LEFTOF_SQUARE, BELOW_SQUARE, 0, 1); \
1277 HANDLE_DLINE(DLINE_DL, RIGHTOF_SQUARE, ABOVE_SQUARE, 1, 0); \
1278 HANDLE_DLINE(DLINE_DR, LEFTOF_SQUARE, ABOVE_SQUARE, 0, 0);
1279
1280 #define DOT_DLINES \
1281 HANDLE_DLINE(DLINE_VERT, ABOVE_DOT, BELOW_DOT); \
1282 HANDLE_DLINE(DLINE_HORIZ, LEFTOF_DOT, RIGHTOF_DOT); \
1283 HANDLE_DLINE(DLINE_UL, ABOVE_DOT, LEFTOF_DOT); \
1284 HANDLE_DLINE(DLINE_UR, ABOVE_DOT, RIGHTOF_DOT); \
1285 HANDLE_DLINE(DLINE_DL, BELOW_DOT, LEFTOF_DOT); \
1286 HANDLE_DLINE(DLINE_DR, BELOW_DOT, RIGHTOF_DOT);
1287
1288 static void array_setall(char *array, char from, char to, int len)
1289 {
1290 char *p = array, *p_old = p;
1291 int len_remaining = len;
1292
1293 while ((p = memchr(p, from, len_remaining))) {
1294 *p = to;
1295 len_remaining -= p - p_old;
1296 p_old = p;
1297 }
1298 }
1299
1300
1301 static int game_states_equal(const game_state *state1,
1302 const game_state *state2)
1303 {
1304 /* This deliberately doesn't check _all_ fields, just the ones that make a
1305 * game state 'interesting' from the POV of the solver */
1306 /* XXX review this */
1307 if (state1 == state2)
1308 return 1;
1309
1310 if (!state1 || !state2)
1311 return 0;
1312
1313 if (state1->w != state2->w || state1->h != state2->h)
1314 return 0;
1315
1316 if (memcmp(state1->hl, state2->hl, HL_COUNT(state1)))
1317 return 0;
1318
1319 if (memcmp(state1->vl, state2->vl, VL_COUNT(state1)))
1320 return 0;
1321
1322 return 1;
1323 }
1324
1325 static int solver_states_equal(const solver_state *sstate1,
1326 const solver_state *sstate2)
1327 {
1328 if (!sstate1) {
1329 if (!sstate2)
1330 return TRUE;
1331 else
1332 return FALSE;
1333 }
1334
1335 if (!game_states_equal(sstate1->state, sstate2->state)) {
1336 return 0;
1337 }
1338
1339 /* XXX fields missing, needs review */
1340 /* XXX we're deliberately not looking at solver_state as it's only a cache */
1341
1342 if (memcmp(sstate1->dot_atleastone, sstate2->dot_atleastone,
1343 DOT_COUNT(sstate1->state))) {
1344 return 0;
1345 }
1346
1347 if (memcmp(sstate1->dot_atmostone, sstate2->dot_atmostone,
1348 DOT_COUNT(sstate1->state))) {
1349 return 0;
1350 }
1351
1352 /* handle dline_identical here */
1353
1354 return 1;
1355 }
1356
1357 static void dot_setall_dlines(solver_state *sstate, enum dline dl, int i, int j,
1358 enum line_state line_old, enum line_state line_new)
1359 {
1360 game_state *state = sstate->state;
1361
1362 /* First line in dline */
1363 switch (dl) {
1364 case DLINE_UL:
1365 case DLINE_UR:
1366 case DLINE_VERT:
1367 if (j > 0 && ABOVE_DOT(state, i, j) == line_old)
1368 LV_ABOVE_DOT(state, i, j) = line_new;
1369 break;
1370 case DLINE_DL:
1371 case DLINE_DR:
1372 if (j <= (state)->h && BELOW_DOT(state, i, j) == line_old)
1373 LV_BELOW_DOT(state, i, j) = line_new;
1374 break;
1375 case DLINE_HORIZ:
1376 if (i > 0 && LEFTOF_DOT(state, i, j) == line_old)
1377 LV_LEFTOF_DOT(state, i, j) = line_new;
1378 break;
1379 }
1380
1381 /* Second line in dline */
1382 switch (dl) {
1383 case DLINE_UL:
1384 case DLINE_DL:
1385 if (i > 0 && LEFTOF_DOT(state, i, j) == line_old)
1386 LV_LEFTOF_DOT(state, i, j) = line_new;
1387 break;
1388 case DLINE_UR:
1389 case DLINE_DR:
1390 case DLINE_HORIZ:
1391 if (i <= (state)->w && RIGHTOF_DOT(state, i, j) == line_old)
1392 LV_RIGHTOF_DOT(state, i, j) = line_new;
1393 break;
1394 case DLINE_VERT:
1395 if (j <= (state)->h && BELOW_DOT(state, i, j) == line_old)
1396 LV_BELOW_DOT(state, i, j) = line_new;
1397 break;
1398 }
1399 }
1400
1401 static void update_solver_status(solver_state *sstate)
1402 {
1403 if (sstate->solver_status == SOLVER_INCOMPLETE) {
1404 switch (loop_status(sstate->state)) {
1405 case LOOP_NONE:
1406 sstate->solver_status = SOLVER_INCOMPLETE;
1407 break;
1408 case LOOP_SOLN:
1409 if (sstate->solver_status != SOLVER_AMBIGUOUS)
1410 sstate->solver_status = SOLVER_SOLVED;
1411 break;
1412 case LOOP_NOT_SOLN:
1413 sstate->solver_status = SOLVER_MISTAKE;
1414 break;
1415 }
1416 }
1417 }
1418
1419
1420 /* This will return a dynamically allocated solver_state containing the (more)
1421 * solved grid */
1422 static solver_state *solve_game_rec(const solver_state *sstate_start)
1423 {
1424 int i, j;
1425 int current_yes, current_no, desired;
1426 solver_state *sstate, *sstate_saved, *sstate_tmp;
1427 int t;
1428 /* char *text; */
1429 solver_state *sstate_rec_solved;
1430 int recursive_soln_count;
1431
1432 #if 0
1433 printf("solve_game_rec: recursion_remaining = %d\n",
1434 sstate_start->recursion_remaining);
1435 #endif
1436
1437 sstate = dup_solver_state((solver_state *)sstate_start);
1438
1439 #if 0
1440 text = game_text_format(sstate->state);
1441 printf("%s\n", text);
1442 sfree(text);
1443 #endif
1444
1445 #define RETURN_IF_SOLVED \
1446 do { \
1447 update_solver_status(sstate); \
1448 if (sstate->solver_status != SOLVER_INCOMPLETE) { \
1449 free_solver_state(sstate_saved); \
1450 return sstate; \
1451 } \
1452 } while (0)
1453
1454 sstate_saved = NULL;
1455 RETURN_IF_SOLVED;
1456
1457 nonrecursive_solver:
1458
1459 while (1) {
1460 sstate_saved = dup_solver_state(sstate);
1461
1462 /* First we do the 'easy' work, that might cause concrete results */
1463
1464 /* Per-square deductions */
1465 for (j = 0; j < sstate->state->h; ++j) {
1466 for (i = 0; i < sstate->state->w; ++i) {
1467 /* Begin rules that look at the clue (if there is one) */
1468 desired = CLUE_AT(sstate->state, i, j);
1469 if (desired == ' ')
1470 continue;
1471 desired = desired - '0';
1472 current_yes = square_order(sstate->state, i, j, LINE_YES);
1473 current_no = square_order(sstate->state, i, j, LINE_NO);
1474
1475 if (desired <= current_yes) {
1476 square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_NO);
1477 continue;
1478 }
1479
1480 if (4 - desired <= current_no) {
1481 square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_YES);
1482 }
1483 }
1484 }
1485
1486 RETURN_IF_SOLVED;
1487
1488 /* Per-dot deductions */
1489 for (j = 0; j < sstate->state->h + 1; ++j) {
1490 for (i = 0; i < sstate->state->w + 1; ++i) {
1491 switch (dot_order(sstate->state, i, j, LINE_YES)) {
1492 case 0:
1493 if (dot_order(sstate->state, i, j, LINE_NO) == 3) {
1494 dot_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_NO);
1495 }
1496 break;
1497 case 1:
1498 switch (dot_order(sstate->state, i, j, LINE_NO)) {
1499 #define H1(dline, dir1_dot, dir2_dot, dot_howmany) \
1500 if (dir1_dot(sstate->state, i, j) == LINE_UNKNOWN) { \
1501 if (dir2_dot(sstate->state, i, j) == LINE_UNKNOWN){ \
1502 sstate->dot_howmany \
1503 [i + (sstate->state->w + 1) * j] |= 1<<dline; \
1504 } \
1505 }
1506 case 1:
1507 #define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
1508 H1(dline, dir1_dot, dir2_dot, dot_atleastone)
1509 /* 1 yes, 1 no, so exactly one of unknowns is yes */
1510 DOT_DLINES;
1511 #undef HANDLE_DLINE
1512 /* fall through */
1513 case 0:
1514 #define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
1515 H1(dline, dir1_dot, dir2_dot, dot_atmostone)
1516 /* 1 yes, fewer than 2 no, so at most one of
1517 * unknowns is yes */
1518 DOT_DLINES;
1519 #undef HANDLE_DLINE
1520 #undef H1
1521 break;
1522 case 2: /* 1 yes, 2 no */
1523 dot_setall(sstate->state, i, j,
1524 LINE_UNKNOWN, LINE_YES);
1525 break;
1526 }
1527 break;
1528 case 2:
1529 case 3:
1530 dot_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_NO);
1531 }
1532 #define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
1533 if (sstate->dot_atleastone \
1534 [i + (sstate->state->w + 1) * j] & 1<<dline) { \
1535 sstate->dot_atmostone \
1536 [i + (sstate->state->w + 1) * j] |= 1<<OPP_DLINE(dline); \
1537 }
1538 /* If at least one of a dline in a dot is YES, at most one of
1539 * the opposite dline to that dot must be YES. */
1540 DOT_DLINES;
1541 #undef HANDLE_DLINE
1542 }
1543 }
1544
1545 /* More obscure per-square operations */
1546 for (j = 0; j < sstate->state->h; ++j) {
1547 for (i = 0; i < sstate->state->w; ++i) {
1548 #define H1(dline, dir1_sq, dir2_sq, a, b, dot_howmany, line_query, line_set) \
1549 if (sstate->dot_howmany[i+a + (sstate->state->w + 1) * (j+b)] &\
1550 1<<dline) { \
1551 t = dir1_sq(sstate->state, i, j); \
1552 if (t == line_query) \
1553 dir2_sq(sstate->state, i, j) = line_set; \
1554 else { \
1555 t = dir2_sq(sstate->state, i, j); \
1556 if (t == line_query) \
1557 dir1_sq(sstate->state, i, j) = line_set; \
1558 } \
1559 }
1560 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1561 H1(dline, dir1_sq, dir2_sq, a, b, dot_atmostone, \
1562 LINE_YES, LINE_NO)
1563 /* If at most one of the DLINE is on, and one is definitely on,
1564 * set the other to definitely off */
1565 SQUARE_DLINES;
1566 #undef HANDLE_DLINE
1567
1568 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1569 H1(dline, dir1_sq, dir2_sq, a, b, dot_atleastone, \
1570 LINE_NO, LINE_YES)
1571 /* If at least one of the DLINE is on, and one is definitely
1572 * off, set the other to definitely on */
1573 SQUARE_DLINES;
1574 #undef HANDLE_DLINE
1575 #undef H1
1576
1577 switch (CLUE_AT(sstate->state, i, j)) {
1578 case '0':
1579 case '1':
1580 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1581 /* At most one of any DLINE can be set */ \
1582 sstate->dot_atmostone \
1583 [i+a + (sstate->state->w + 1) * (j+b)] |= 1<<dline; \
1584 /* This DLINE provides enough YESes to solve the clue */\
1585 if (sstate->dot_atleastone \
1586 [i+a + (sstate->state->w + 1) * (j+b)] & \
1587 1<<dline) { \
1588 dot_setall_dlines(sstate, OPP_DLINE(dline), \
1589 i+(1-a), j+(1-b), \
1590 LINE_UNKNOWN, LINE_NO); \
1591 }
1592 SQUARE_DLINES;
1593 #undef HANDLE_DLINE
1594 break;
1595 case '2':
1596 #define H1(dline, dot_at1one, dot_at2one, a, b) \
1597 if (sstate->dot_at1one \
1598 [i+a + (sstate->state->w + 1) * (j+b)] & \
1599 1<<dline) { \
1600 sstate->dot_at2one \
1601 [i+(1-a) + (sstate->state->w + 1) * (j+(1-b))] |= \
1602 1<<OPP_DLINE(dline); \
1603 }
1604 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1605 H1(dline, dot_atleastone, dot_atmostone, a, b); \
1606 H1(dline, dot_atmostone, dot_atleastone, a, b);
1607 /* If at least one of one DLINE is set, at most one of
1608 * the opposing one is and vice versa */
1609 SQUARE_DLINES;
1610 #undef HANDLE_DLINE
1611 #undef H1
1612 break;
1613 case '3':
1614 case '4':
1615 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1616 /* At least one of any DLINE can be set */ \
1617 sstate->dot_atleastone \
1618 [i+a + (sstate->state->w + 1) * (j+b)] |= 1<<dline; \
1619 /* This DLINE provides enough NOs to solve the clue */ \
1620 if (sstate->dot_atmostone \
1621 [i+a + (sstate->state->w + 1) * (j+b)] & \
1622 1<<dline) { \
1623 dot_setall_dlines(sstate, OPP_DLINE(dline), \
1624 i+(1-a), j+(1-b), \
1625 LINE_UNKNOWN, LINE_YES); \
1626 }
1627 SQUARE_DLINES;
1628 #undef HANDLE_DLINE
1629 break;
1630 }
1631 }
1632 }
1633
1634 if (solver_states_equal(sstate, sstate_saved)) {
1635 int edgecount = 0, clues = 0, satclues = 0, sm1clues = 0;
1636 int d;
1637
1638 /*
1639 * Go through the grid and update for all the new edges.
1640 * Since merge_dots() is idempotent, the simplest way to
1641 * do this is just to update for _all_ the edges.
1642 *
1643 * Also, while we're here, we count the edges, count the
1644 * clues, count the satisfied clues, and count the
1645 * satisfied-minus-one clues.
1646 */
1647 for (j = 0; j <= sstate->state->h; ++j) {
1648 for (i = 0; i <= sstate->state->w; ++i) {
1649 if (RIGHTOF_DOT(sstate->state, i, j) == LINE_YES) {
1650 merge_dots(sstate, i, j, i+1, j);
1651 edgecount++;
1652 }
1653 if (BELOW_DOT(sstate->state, i, j) == LINE_YES) {
1654 merge_dots(sstate, i, j, i, j+1);
1655 edgecount++;
1656 }
1657
1658 if (CLUE_AT(sstate->state, i, j) != ' ') {
1659 int c = CLUE_AT(sstate->state, i, j) - '0';
1660 int o = square_order(sstate->state, i, j, LINE_YES);
1661 if (o == c)
1662 satclues++;
1663 else if (o == c-1)
1664 sm1clues++;
1665 clues++;
1666 }
1667 }
1668 }
1669
1670 /*
1671 * Now go through looking for LINE_UNKNOWN edges which
1672 * connect two dots that are already in the same
1673 * equivalence class. If we find one, test to see if the
1674 * loop it would create is a solution.
1675 */
1676 for (j = 0; j <= sstate->state->h; ++j) {
1677 for (i = 0; i <= sstate->state->w; ++i) {
1678 for (d = 0; d < 2; d++) {
1679 int i2, j2, eqclass, val;
1680
1681 if (d == 0) {
1682 if (RIGHTOF_DOT(sstate->state, i, j) !=
1683 LINE_UNKNOWN)
1684 continue;
1685 i2 = i+1;
1686 j2 = j;
1687 } else {
1688 if (BELOW_DOT(sstate->state, i, j) !=
1689 LINE_UNKNOWN)
1690 continue;
1691 i2 = i;
1692 j2 = j+1;
1693 }
1694
1695 eqclass = dsf_canonify(sstate->dotdsf,
1696 j * (sstate->state->w+1) + i);
1697 if (eqclass != dsf_canonify(sstate->dotdsf,
1698 j2 * (sstate->state->w+1) +
1699 i2))
1700 continue;
1701
1702 val = LINE_NO; /* loop is bad until proven otherwise */
1703
1704 /*
1705 * This edge would form a loop. Next
1706 * question: how long would the loop be?
1707 * Would it equal the total number of edges
1708 * (plus the one we'd be adding if we added
1709 * it)?
1710 */
1711 if (sstate->looplen[eqclass] == edgecount + 1) {
1712 int sm1_nearby;
1713 int cx, cy;
1714
1715 /*
1716 * This edge would form a loop which
1717 * took in all the edges in the entire
1718 * grid. So now we need to work out
1719 * whether it would be a valid solution
1720 * to the puzzle, which means we have to
1721 * check if it satisfies all the clues.
1722 * This means that every clue must be
1723 * either satisfied or satisfied-minus-
1724 * 1, and also that the number of
1725 * satisfied-minus-1 clues must be at
1726 * most two and they must lie on either
1727 * side of this edge.
1728 */
1729 sm1_nearby = 0;
1730 cx = i - (j2-j);
1731 cy = j - (i2-i);
1732 if (CLUE_AT(sstate->state, cx,cy) != ' ' &&
1733 square_order(sstate->state, cx,cy, LINE_YES) ==
1734 CLUE_AT(sstate->state, cx,cy) - '0' - 1)
1735 sm1_nearby++;
1736 if (CLUE_AT(sstate->state, i, j) != ' ' &&
1737 square_order(sstate->state, i, j, LINE_YES) ==
1738 CLUE_AT(sstate->state, i, j) - '0' - 1)
1739 sm1_nearby++;
1740 if (sm1clues == sm1_nearby &&
1741 sm1clues + satclues == clues)
1742 val = LINE_YES; /* loop is good! */
1743 }
1744
1745 /*
1746 * Right. Now we know that adding this edge
1747 * would form a loop, and we know whether
1748 * that loop would be a viable solution or
1749 * not.
1750 *
1751 * If adding this edge produces a solution,
1752 * then we know we've found _a_ solution but
1753 * we don't know that it's _the_ solution -
1754 * if it were provably the solution then
1755 * we'd have deduced this edge some time ago
1756 * without the need to do loop detection. So
1757 * in this state we return SOLVER_AMBIGUOUS,
1758 * which has the effect that hitting Solve
1759 * on a user-provided puzzle will fill in a
1760 * solution but using the solver to
1761 * construct new puzzles won't consider this
1762 * a reasonable deduction for the user to
1763 * make.
1764 */
1765 if (d == 0)
1766 LV_RIGHTOF_DOT(sstate->state, i, j) = val;
1767 else
1768 LV_BELOW_DOT(sstate->state, i, j) = val;
1769 if (val == LINE_YES) {
1770 sstate->solver_status = SOLVER_AMBIGUOUS;
1771 goto finished_loop_checking;
1772 }
1773 }
1774 }
1775 }
1776
1777 finished_loop_checking:
1778
1779 RETURN_IF_SOLVED;
1780 }
1781
1782 if (solver_states_equal(sstate, sstate_saved)) {
1783 /* Solver has stopped making progress so we terminate */
1784 free_solver_state(sstate_saved);
1785 break;
1786 }
1787
1788 free_solver_state(sstate_saved);
1789 }
1790
1791 if (sstate->solver_status == SOLVER_SOLVED ||
1792 sstate->solver_status == SOLVER_AMBIGUOUS) {
1793 /* s/LINE_UNKNOWN/LINE_NO/g */
1794 array_setall(sstate->state->hl, LINE_UNKNOWN, LINE_NO,
1795 HL_COUNT(sstate->state));
1796 array_setall(sstate->state->vl, LINE_UNKNOWN, LINE_NO,
1797 VL_COUNT(sstate->state));
1798 return sstate;
1799 }
1800
1801 /* Perform recursive calls */
1802 if (sstate->recursion_remaining) {
1803 sstate->recursion_remaining--;
1804
1805 sstate_saved = dup_solver_state(sstate);
1806
1807 recursive_soln_count = 0;
1808 sstate_rec_solved = NULL;
1809
1810 /* Memory management:
1811 * sstate_saved won't be modified but needs to be freed when we have
1812 * finished with it.
1813 * sstate is expected to contain our 'best' solution by the time we
1814 * finish this section of code. It's the thing we'll try adding lines
1815 * to, seeing if they make it more solvable.
1816 * If sstate_rec_solved is non-NULL, it will supersede sstate
1817 * eventually. sstate_tmp should not hold a value persistently.
1818 */
1819
1820 /* NB SOLVER_AMBIGUOUS is like SOLVER_SOLVED except the solver is aware
1821 * of the possibility of additional solutions. So as soon as we have a
1822 * SOLVER_AMBIGUOUS we can safely propagate it back to our caller, but
1823 * if we get a SOLVER_SOLVED we want to keep trying in case we find
1824 * further solutions and have to mark it ambiguous.
1825 */
1826
1827 #define DO_RECURSIVE_CALL(dir_dot) \
1828 if (dir_dot(sstate->state, i, j) == LINE_UNKNOWN) { \
1829 debug(("Trying " #dir_dot " at [%d,%d]\n", i, j)); \
1830 LV_##dir_dot(sstate->state, i, j) = LINE_YES; \
1831 sstate_tmp = solve_game_rec(sstate); \
1832 switch (sstate_tmp->solver_status) { \
1833 case SOLVER_AMBIGUOUS: \
1834 debug(("Solver ambiguous, returning\n")); \
1835 sstate_rec_solved = sstate_tmp; \
1836 goto finished_recursion; \
1837 case SOLVER_SOLVED: \
1838 switch (++recursive_soln_count) { \
1839 case 1: \
1840 debug(("One solution found\n")); \
1841 sstate_rec_solved = sstate_tmp; \
1842 break; \
1843 case 2: \
1844 debug(("Ambiguous solutions found\n")); \
1845 free_solver_state(sstate_tmp); \
1846 sstate_rec_solved->solver_status = SOLVER_AMBIGUOUS;\
1847 goto finished_recursion; \
1848 default: \
1849 assert(!"recursive_soln_count out of range"); \
1850 break; \
1851 } \
1852 break; \
1853 case SOLVER_MISTAKE: \
1854 debug(("Non-solution found\n")); \
1855 free_solver_state(sstate_tmp); \
1856 free_solver_state(sstate_saved); \
1857 LV_##dir_dot(sstate->state, i, j) = LINE_NO; \
1858 goto nonrecursive_solver; \
1859 case SOLVER_INCOMPLETE: \
1860 debug(("Recursive step inconclusive\n")); \
1861 free_solver_state(sstate_tmp); \
1862 break; \
1863 } \
1864 free_solver_state(sstate); \
1865 sstate = dup_solver_state(sstate_saved); \
1866 }
1867
1868 for (j = 0; j < sstate->state->h + 1; ++j) {
1869 for (i = 0; i < sstate->state->w + 1; ++i) {
1870 /* Only perform recursive calls on 'loose ends' */
1871 if (dot_order(sstate->state, i, j, LINE_YES) == 1) {
1872 if (LEFTOF_DOT(sstate->state, i, j) == LINE_UNKNOWN)
1873 DO_RECURSIVE_CALL(LEFTOF_DOT);
1874 if (RIGHTOF_DOT(sstate->state, i, j) == LINE_UNKNOWN)
1875 DO_RECURSIVE_CALL(RIGHTOF_DOT);
1876 if (ABOVE_DOT(sstate->state, i, j) == LINE_UNKNOWN)
1877 DO_RECURSIVE_CALL(ABOVE_DOT);
1878 if (BELOW_DOT(sstate->state, i, j) == LINE_UNKNOWN)
1879 DO_RECURSIVE_CALL(BELOW_DOT);
1880 }
1881 }
1882 }
1883
1884 finished_recursion:
1885
1886 if (sstate_rec_solved) {
1887 free_solver_state(sstate);
1888 sstate = sstate_rec_solved;
1889 }
1890 }
1891
1892 return sstate;
1893 }
1894
1895 /* XXX bits of solver that may come in handy one day */
1896 #if 0
1897 #define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
1898 /* dline from this dot that's entirely unknown must have
1899 * both lines identical */ \
1900 if (dir1_dot(sstate->state, i, j) == LINE_UNKNOWN && \
1901 dir2_dot(sstate->state, i, j) == LINE_UNKNOWN) { \
1902 sstate->dline_identical[i + (sstate->state->w + 1) * j] |= \
1903 1<<dline; \
1904 } else if (sstate->dline_identical[i +
1905 (sstate->state->w + 1) * j] &\
1906 1<<dline) { \
1907 /* If they're identical and one is known do the obvious
1908 * thing */ \
1909 t = dir1_dot(sstate->state, i, j); \
1910 if (t != LINE_UNKNOWN) \
1911 dir2_dot(sstate->state, i, j) = t; \
1912 else { \
1913 t = dir2_dot(sstate->state, i, j); \
1914 if (t != LINE_UNKNOWN) \
1915 dir1_dot(sstate->state, i, j) = t; \
1916 } \
1917 } \
1918 DOT_DLINES;
1919 #undef HANDLE_DLINE
1920 #endif
1921
1922 #if 0
1923 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1924 if (sstate->dline_identical[i+a + \
1925 (sstate->state->w + 1) * (j+b)] &\
1926 1<<dline) { \
1927 dir1_sq(sstate->state, i, j) = LINE_YES; \
1928 dir2_sq(sstate->state, i, j) = LINE_YES; \
1929 }
1930 /* If two lines are the same they must be on */
1931 SQUARE_DLINES;
1932 #undef HANDLE_DLINE
1933 #endif
1934
1935
1936 #if 0
1937 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1938 if (sstate->dot_atmostone[i+a + (sstate->state->w + 1) * (j+b)] & \
1939 1<<dline) { \
1940 if (square_order(sstate->state, i, j, LINE_UNKNOWN) - 1 == \
1941 CLUE_AT(sstate->state, i, j) - '0') { \
1942 square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_YES); \
1943 /* XXX the following may overwrite known data! */ \
1944 dir1_sq(sstate->state, i, j) = LINE_UNKNOWN; \
1945 dir2_sq(sstate->state, i, j) = LINE_UNKNOWN; \
1946 } \
1947 }
1948 SQUARE_DLINES;
1949 #undef HANDLE_DLINE
1950 #endif
1951
1952 #if 0
1953 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
1954 if (sstate->dline_identical[i+a +
1955 (sstate->state->w + 1) * (j+b)] &\
1956 1<<dline) { \
1957 dir1_sq(sstate->state, i, j) = LINE_NO; \
1958 dir2_sq(sstate->state, i, j) = LINE_NO; \
1959 }
1960 /* If two lines are the same they must be off */
1961 SQUARE_DLINES;
1962 #undef HANDLE_DLINE
1963 #endif
1964
1965 static char *solve_game(game_state *state, game_state *currstate,
1966 char *aux, char **error)
1967 {
1968 char *soln = NULL;
1969 solver_state *sstate, *new_sstate;
1970
1971 sstate = new_solver_state(state);
1972 new_sstate = solve_game_rec(sstate);
1973
1974 if (new_sstate->solver_status == SOLVER_SOLVED) {
1975 soln = encode_solve_move(new_sstate->state);
1976 } else if (new_sstate->solver_status == SOLVER_AMBIGUOUS) {
1977 soln = encode_solve_move(new_sstate->state);
1978 /**error = "Solver found ambiguous solutions"; */
1979 } else {
1980 soln = encode_solve_move(new_sstate->state);
1981 /**error = "Solver failed"; */
1982 }
1983
1984 free_solver_state(new_sstate);
1985 free_solver_state(sstate);
1986
1987 return soln;
1988 }
1989
1990 static char *game_text_format(game_state *state)
1991 {
1992 int i, j;
1993 int len;
1994 char *ret, *rp;
1995
1996 len = (2 * state->w + 2) * (2 * state->h + 1);
1997 rp = ret = snewn(len + 1, char);
1998
1999 #define DRAW_HL \
2000 switch (ABOVE_SQUARE(state, i, j)) { \
2001 case LINE_YES: \
2002 rp += sprintf(rp, " -"); \
2003 break; \
2004 case LINE_NO: \
2005 rp += sprintf(rp, " x"); \
2006 break; \
2007 case LINE_UNKNOWN: \
2008 rp += sprintf(rp, " "); \
2009 break; \
2010 default: \
2011 assert(!"Illegal line state for HL");\
2012 }
2013
2014 #define DRAW_VL \
2015 switch (LEFTOF_SQUARE(state, i, j)) {\
2016 case LINE_YES: \
2017 rp += sprintf(rp, "|"); \
2018 break; \
2019 case LINE_NO: \
2020 rp += sprintf(rp, "x"); \
2021 break; \
2022 case LINE_UNKNOWN: \
2023 rp += sprintf(rp, " "); \
2024 break; \
2025 default: \
2026 assert(!"Illegal line state for VL");\
2027 }
2028
2029 for (j = 0; j < state->h; ++j) {
2030 for (i = 0; i < state->w; ++i) {
2031 DRAW_HL;
2032 }
2033 rp += sprintf(rp, " \n");
2034 for (i = 0; i < state->w; ++i) {
2035 DRAW_VL;
2036 rp += sprintf(rp, "%c", (int)(CLUE_AT(state, i, j)));
2037 }
2038 DRAW_VL;
2039 rp += sprintf(rp, "\n");
2040 }
2041 for (i = 0; i < state->w; ++i) {
2042 DRAW_HL;
2043 }
2044 rp += sprintf(rp, " \n");
2045
2046 assert(strlen(ret) == len);
2047 return ret;
2048 }
2049
2050 static game_ui *new_ui(game_state *state)
2051 {
2052 return NULL;
2053 }
2054
2055 static void free_ui(game_ui *ui)
2056 {
2057 }
2058
2059 static char *encode_ui(game_ui *ui)
2060 {
2061 return NULL;
2062 }
2063
2064 static void decode_ui(game_ui *ui, char *encoding)
2065 {
2066 }
2067
2068 static void game_changed_state(game_ui *ui, game_state *oldstate,
2069 game_state *newstate)
2070 {
2071 }
2072
2073 struct game_drawstate {
2074 int started;
2075 int tilesize;
2076 int flashing;
2077 char *hl, *vl;
2078 };
2079
2080 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
2081 int x, int y, int button)
2082 {
2083 int hl_selected;
2084 int i, j, p, q;
2085 char *ret, buf[80];
2086 char button_char = ' ';
2087 enum line_state old_state;
2088
2089 button &= ~MOD_MASK;
2090
2091 /* Around each line is a diamond-shaped region where points within that
2092 * region are closer to this line than any other. We assume any click
2093 * within a line's diamond was meant for that line. It would all be a lot
2094 * simpler if the / and % operators respected modulo arithmetic properly
2095 * for negative numbers. */
2096
2097 x -= BORDER;
2098 y -= BORDER;
2099
2100 /* Get the coordinates of the square the click was in */
2101 i = (x + TILE_SIZE) / TILE_SIZE - 1;
2102 j = (y + TILE_SIZE) / TILE_SIZE - 1;
2103
2104 /* Get the precise position inside square [i,j] */
2105 p = (x + TILE_SIZE) % TILE_SIZE;
2106 q = (y + TILE_SIZE) % TILE_SIZE;
2107
2108 /* After this bit of magic [i,j] will correspond to the point either above
2109 * or to the left of the line selected */
2110 if (p > q) {
2111 if (TILE_SIZE - p > q) {
2112 hl_selected = TRUE;
2113 } else {
2114 hl_selected = FALSE;
2115 ++i;
2116 }
2117 } else {
2118 if (TILE_SIZE - q > p) {
2119 hl_selected = FALSE;
2120 } else {
2121 hl_selected = TRUE;
2122 ++j;
2123 }
2124 }
2125
2126 if (i < 0 || j < 0)
2127 return NULL;
2128
2129 if (hl_selected) {
2130 if (i >= state->w || j >= state->h + 1)
2131 return NULL;
2132 } else {
2133 if (i >= state->w + 1 || j >= state->h)
2134 return NULL;
2135 }
2136
2137 /* I think it's only possible to play this game with mouse clicks, sorry */
2138 /* Maybe will add mouse drag support some time */
2139 if (hl_selected)
2140 old_state = RIGHTOF_DOT(state, i, j);
2141 else
2142 old_state = BELOW_DOT(state, i, j);
2143
2144 switch (button) {
2145 case LEFT_BUTTON:
2146 switch (old_state) {
2147 case LINE_UNKNOWN:
2148 button_char = 'y';
2149 break;
2150 case LINE_YES:
2151 case LINE_NO:
2152 button_char = 'u';
2153 break;
2154 }
2155 break;
2156 case MIDDLE_BUTTON:
2157 button_char = 'u';
2158 break;
2159 case RIGHT_BUTTON:
2160 switch (old_state) {
2161 case LINE_UNKNOWN:
2162 button_char = 'n';
2163 break;
2164 case LINE_NO:
2165 case LINE_YES:
2166 button_char = 'u';
2167 break;
2168 }
2169 break;
2170 default:
2171 return NULL;
2172 }
2173
2174
2175 sprintf(buf, "%d,%d%c%c", i, j, (int)(hl_selected ? 'h' : 'v'), (int)button_char);
2176 ret = dupstr(buf);
2177
2178 return ret;
2179 }
2180
2181 static game_state *execute_move(game_state *state, char *move)
2182 {
2183 int i, j;
2184 game_state *newstate = dup_game(state);
2185
2186 if (move[0] == 'S') {
2187 move++;
2188 newstate->cheated = TRUE;
2189 }
2190
2191 while (*move) {
2192 i = atoi(move);
2193 move = strchr(move, ',');
2194 if (!move)
2195 goto fail;
2196 j = atoi(++move);
2197 move += strspn(move, "1234567890");
2198 switch (*(move++)) {
2199 case 'h':
2200 if (i >= newstate->w || j > newstate->h)
2201 goto fail;
2202 switch (*(move++)) {
2203 case 'y':
2204 LV_RIGHTOF_DOT(newstate, i, j) = LINE_YES;
2205 break;
2206 case 'n':
2207 LV_RIGHTOF_DOT(newstate, i, j) = LINE_NO;
2208 break;
2209 case 'u':
2210 LV_RIGHTOF_DOT(newstate, i, j) = LINE_UNKNOWN;
2211 break;
2212 default:
2213 goto fail;
2214 }
2215 break;
2216 case 'v':
2217 if (i > newstate->w || j >= newstate->h)
2218 goto fail;
2219 switch (*(move++)) {
2220 case 'y':
2221 LV_BELOW_DOT(newstate, i, j) = LINE_YES;
2222 break;
2223 case 'n':
2224 LV_BELOW_DOT(newstate, i, j) = LINE_NO;
2225 break;
2226 case 'u':
2227 LV_BELOW_DOT(newstate, i, j) = LINE_UNKNOWN;
2228 break;
2229 default:
2230 goto fail;
2231 }
2232 break;
2233 default:
2234 goto fail;
2235 }
2236 }
2237
2238 /*
2239 * Check for completion.
2240 */
2241 i = 0; /* placate optimiser */
2242 for (j = 0; j <= newstate->h; j++) {
2243 for (i = 0; i < newstate->w; i++)
2244 if (LV_RIGHTOF_DOT(newstate, i, j) == LINE_YES)
2245 break;
2246 if (i < newstate->w)
2247 break;
2248 }
2249 if (j <= newstate->h) {
2250 int prevdir = 'R';
2251 int x = i, y = j;
2252 int looplen, count;
2253
2254 /*
2255 * We've found a horizontal edge at (i,j). Follow it round
2256 * to see if it's part of a loop.
2257 */
2258 looplen = 0;
2259 while (1) {
2260 int order = dot_order(newstate, x, y, LINE_YES);
2261 if (order != 2)
2262 goto completion_check_done;
2263
2264 if (LEFTOF_DOT(newstate, x, y) == LINE_YES && prevdir != 'L') {
2265 x--;
2266 prevdir = 'R';
2267 } else if (RIGHTOF_DOT(newstate, x, y) == LINE_YES &&
2268 prevdir != 'R') {
2269 x++;
2270 prevdir = 'L';
2271 } else if (ABOVE_DOT(newstate, x, y) == LINE_YES &&
2272 prevdir != 'U') {
2273 y--;
2274 prevdir = 'D';
2275 } else if (BELOW_DOT(newstate, x, y) == LINE_YES &&
2276 prevdir != 'D') {
2277 y++;
2278 prevdir = 'U';
2279 } else {
2280 assert(!"Can't happen"); /* dot_order guarantees success */
2281 }
2282
2283 looplen++;
2284
2285 if (x == i && y == j)
2286 break;
2287 }
2288
2289 if (x != i || y != j || looplen == 0)
2290 goto completion_check_done;
2291
2292 /*
2293 * We've traced our way round a loop, and we know how many
2294 * line segments were involved. Count _all_ the line
2295 * segments in the grid, to see if the loop includes them
2296 * all.
2297 */
2298 count = 0;
2299 for (j = 0; j <= newstate->h; j++)
2300 for (i = 0; i <= newstate->w; i++)
2301 count += ((RIGHTOF_DOT(newstate, i, j) == LINE_YES) +
2302 (BELOW_DOT(newstate, i, j) == LINE_YES));
2303 assert(count >= looplen);
2304 if (count != looplen)
2305 goto completion_check_done;
2306
2307 /*
2308 * The grid contains one closed loop and nothing else.
2309 * Check that all the clues are satisfied.
2310 */
2311 for (j = 0; j < newstate->h; ++j) {
2312 for (i = 0; i < newstate->w; ++i) {
2313 int n = CLUE_AT(newstate, i, j);
2314 if (n != ' ') {
2315 if (square_order(newstate, i, j, LINE_YES) != n - '0') {
2316 goto completion_check_done;
2317 }
2318 }
2319 }
2320 }
2321
2322 /*
2323 * Completed!
2324 */
2325 newstate->solved = TRUE;
2326 }
2327
2328 completion_check_done:
2329 return newstate;
2330
2331 fail:
2332 free_game(newstate);
2333 return NULL;
2334 }
2335
2336 /* ----------------------------------------------------------------------
2337 * Drawing routines.
2338 */
2339
2340 #define SIZE(d) ((d) * TILE_SIZE + 2 * BORDER + 1)
2341
2342 static void game_compute_size(game_params *params, int tilesize,
2343 int *x, int *y)
2344 {
2345 struct { int tilesize; } ads, *ds = &ads;
2346 ads.tilesize = tilesize;
2347
2348 *x = SIZE(params->w);
2349 *y = SIZE(params->h);
2350 }
2351
2352 static void game_set_size(drawing *dr, game_drawstate *ds,
2353 game_params *params, int tilesize)
2354 {
2355 ds->tilesize = tilesize;
2356 }
2357
2358 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
2359 {
2360 float *ret = snewn(4 * NCOLOURS, float);
2361
2362 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
2363
2364 ret[COL_FOREGROUND * 3 + 0] = 0.0F;
2365 ret[COL_FOREGROUND * 3 + 1] = 0.0F;
2366 ret[COL_FOREGROUND * 3 + 2] = 0.0F;
2367
2368 ret[COL_HIGHLIGHT * 3 + 0] = 1.0F;
2369 ret[COL_HIGHLIGHT * 3 + 1] = 1.0F;
2370 ret[COL_HIGHLIGHT * 3 + 2] = 1.0F;
2371
2372 *ncolours = NCOLOURS;
2373 return ret;
2374 }
2375
2376 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
2377 {
2378 struct game_drawstate *ds = snew(struct game_drawstate);
2379
2380 ds->tilesize = 0;
2381 ds->started = 0;
2382 ds->hl = snewn(HL_COUNT(state), char);
2383 ds->vl = snewn(VL_COUNT(state), char);
2384 ds->flashing = 0;
2385
2386 memset(ds->hl, LINE_UNKNOWN, HL_COUNT(state));
2387 memset(ds->vl, LINE_UNKNOWN, VL_COUNT(state));
2388
2389 return ds;
2390 }
2391
2392 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2393 {
2394 sfree(ds->hl);
2395 sfree(ds->vl);
2396 sfree(ds);
2397 }
2398
2399 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
2400 game_state *state, int dir, game_ui *ui,
2401 float animtime, float flashtime)
2402 {
2403 int i, j;
2404 int w = state->w, h = state->h;
2405 char c[2];
2406 int line_colour, flash_changed;
2407
2408 if (!ds->started) {
2409 /*
2410 * The initial contents of the window are not guaranteed and
2411 * can vary with front ends. To be on the safe side, all games
2412 * should start by drawing a big background-colour rectangle
2413 * covering the whole window.
2414 */
2415 draw_rect(dr, 0, 0, SIZE(state->w), SIZE(state->h), COL_BACKGROUND);
2416
2417 /* Draw dots */
2418 for (j = 0; j < h + 1; ++j) {
2419 for (i = 0; i < w + 1; ++i) {
2420 draw_rect(dr,
2421 BORDER + i * TILE_SIZE - LINEWIDTH/2,
2422 BORDER + j * TILE_SIZE - LINEWIDTH/2,
2423 LINEWIDTH, LINEWIDTH, COL_FOREGROUND);
2424 }
2425 }
2426
2427 /* Draw clues */
2428 for (j = 0; j < h; ++j) {
2429 for (i = 0; i < w; ++i) {
2430 c[0] = CLUE_AT(state, i, j);
2431 c[1] = '\0';
2432 draw_text(dr,
2433 BORDER + i * TILE_SIZE + TILE_SIZE/2,
2434 BORDER + j * TILE_SIZE + TILE_SIZE/2,
2435 FONT_VARIABLE, TILE_SIZE/2,
2436 ALIGN_VCENTRE | ALIGN_HCENTRE, COL_FOREGROUND, c);
2437 }
2438 }
2439 draw_update(dr, 0, 0,
2440 state->w * TILE_SIZE + 2*BORDER + 1,
2441 state->h * TILE_SIZE + 2*BORDER + 1);
2442 ds->started = TRUE;
2443 }
2444
2445 if (flashtime > 0 &&
2446 (flashtime <= FLASH_TIME/3 ||
2447 flashtime >= FLASH_TIME*2/3)) {
2448 flash_changed = !ds->flashing;
2449 ds->flashing = TRUE;
2450 line_colour = COL_HIGHLIGHT;
2451 } else {
2452 flash_changed = ds->flashing;
2453 ds->flashing = FALSE;
2454 line_colour = COL_FOREGROUND;
2455 }
2456
2457 #define CROSS_SIZE (3 * LINEWIDTH / 2)
2458
2459 #define CLEAR_VL(i, j) do { \
2460 draw_rect(dr, \
2461 BORDER + i * TILE_SIZE - CROSS_SIZE, \
2462 BORDER + j * TILE_SIZE + LINEWIDTH/2, \
2463 CROSS_SIZE * 2, \
2464 TILE_SIZE - LINEWIDTH, \
2465 COL_BACKGROUND); \
2466 draw_update(dr, \
2467 BORDER + i * TILE_SIZE - CROSS_SIZE, \
2468 BORDER + j * TILE_SIZE - CROSS_SIZE, \
2469 CROSS_SIZE*2, \
2470 TILE_SIZE + CROSS_SIZE*2); \
2471 } while (0)
2472
2473 #define CLEAR_HL(i, j) do { \
2474 draw_rect(dr, \
2475 BORDER + i * TILE_SIZE + LINEWIDTH/2, \
2476 BORDER + j * TILE_SIZE - CROSS_SIZE, \
2477 TILE_SIZE - LINEWIDTH, \
2478 CROSS_SIZE * 2, \
2479 COL_BACKGROUND); \
2480 draw_update(dr, \
2481 BORDER + i * TILE_SIZE - CROSS_SIZE, \
2482 BORDER + j * TILE_SIZE - CROSS_SIZE, \
2483 TILE_SIZE + CROSS_SIZE*2, \
2484 CROSS_SIZE*2); \
2485 } while (0)
2486
2487 /* Vertical lines */
2488 for (j = 0; j < h; ++j) {
2489 for (i = 0; i < w + 1; ++i) {
2490 switch (BELOW_DOT(state, i, j)) {
2491 case LINE_UNKNOWN:
2492 if (ds->vl[i + (w + 1) * j] != BELOW_DOT(state, i, j)) {
2493 CLEAR_VL(i, j);
2494 }
2495 break;
2496 case LINE_YES:
2497 if (ds->vl[i + (w + 1) * j] != BELOW_DOT(state, i, j) ||
2498 flash_changed) {
2499 CLEAR_VL(i, j);
2500 draw_rect(dr,
2501 BORDER + i * TILE_SIZE - LINEWIDTH/2,
2502 BORDER + j * TILE_SIZE + LINEWIDTH/2,
2503 LINEWIDTH, TILE_SIZE - LINEWIDTH,
2504 line_colour);
2505 }
2506 break;
2507 case LINE_NO:
2508 if (ds->vl[i + (w + 1) * j] != BELOW_DOT(state, i, j)) {
2509 CLEAR_VL(i, j);
2510 draw_line(dr,
2511 BORDER + i * TILE_SIZE - CROSS_SIZE,
2512 BORDER + j * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
2513 BORDER + i * TILE_SIZE + CROSS_SIZE - 1,
2514 BORDER + j * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
2515 COL_FOREGROUND);
2516 draw_line(dr,
2517 BORDER + i * TILE_SIZE + CROSS_SIZE - 1,
2518 BORDER + j * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
2519 BORDER + i * TILE_SIZE - CROSS_SIZE,
2520 BORDER + j * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
2521 COL_FOREGROUND);
2522 }
2523 break;
2524 }
2525 ds->vl[i + (w + 1) * j] = BELOW_DOT(state, i, j);
2526 }
2527 }
2528
2529 /* Horizontal lines */
2530 for (j = 0; j < h + 1; ++j) {
2531 for (i = 0; i < w; ++i) {
2532 switch (RIGHTOF_DOT(state, i, j)) {
2533 case LINE_UNKNOWN:
2534 if (ds->hl[i + w * j] != RIGHTOF_DOT(state, i, j)) {
2535 CLEAR_HL(i, j);
2536 }
2537 break;
2538 case LINE_YES:
2539 if (ds->hl[i + w * j] != RIGHTOF_DOT(state, i, j) ||
2540 flash_changed) {
2541 CLEAR_HL(i, j);
2542 draw_rect(dr,
2543 BORDER + i * TILE_SIZE + LINEWIDTH/2,
2544 BORDER + j * TILE_SIZE - LINEWIDTH/2,
2545 TILE_SIZE - LINEWIDTH, LINEWIDTH,
2546 line_colour);
2547 break;
2548 }
2549 case LINE_NO:
2550 if (ds->hl[i + w * j] != RIGHTOF_DOT(state, i, j)) {
2551 CLEAR_HL(i, j);
2552 draw_line(dr,
2553 BORDER + i * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
2554 BORDER + j * TILE_SIZE + CROSS_SIZE - 1,
2555 BORDER + i * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
2556 BORDER + j * TILE_SIZE - CROSS_SIZE,
2557 COL_FOREGROUND);
2558 draw_line(dr,
2559 BORDER + i * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
2560 BORDER + j * TILE_SIZE - CROSS_SIZE,
2561 BORDER + i * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
2562 BORDER + j * TILE_SIZE + CROSS_SIZE - 1,
2563 COL_FOREGROUND);
2564 break;
2565 }
2566 }
2567 ds->hl[i + w * j] = RIGHTOF_DOT(state, i, j);
2568 }
2569 }
2570 }
2571
2572 static float game_anim_length(game_state *oldstate, game_state *newstate,
2573 int dir, game_ui *ui)
2574 {
2575 return 0.0F;
2576 }
2577
2578 static float game_flash_length(game_state *oldstate, game_state *newstate,
2579 int dir, game_ui *ui)
2580 {
2581 if (!oldstate->solved && newstate->solved &&
2582 !oldstate->cheated && !newstate->cheated) {
2583 return FLASH_TIME;
2584 }
2585
2586 return 0.0F;
2587 }
2588
2589 static int game_wants_statusbar(void)
2590 {
2591 return FALSE;
2592 }
2593
2594 static int game_timing_state(game_state *state, game_ui *ui)
2595 {
2596 return TRUE;
2597 }
2598
2599 static void game_print_size(game_params *params, float *x, float *y)
2600 {
2601 int pw, ph;
2602
2603 /*
2604 * I'll use 7mm squares by default.
2605 */
2606 game_compute_size(params, 700, &pw, &ph);
2607 *x = pw / 100.0F;
2608 *y = ph / 100.0F;
2609 }
2610
2611 static void game_print(drawing *dr, game_state *state, int tilesize)
2612 {
2613 int w = state->w, h = state->h;
2614 int ink = print_mono_colour(dr, 0);
2615 int x, y;
2616 game_drawstate ads, *ds = &ads;
2617 ds->tilesize = tilesize;
2618
2619 /*
2620 * Dots. I'll deliberately make the dots a bit wider than the
2621 * lines, so you can still see them. (And also because it's
2622 * annoyingly tricky to make them _exactly_ the same size...)
2623 */
2624 for (y = 0; y <= h; y++)
2625 for (x = 0; x <= w; x++)
2626 draw_circle(dr, BORDER + x * TILE_SIZE, BORDER + y * TILE_SIZE,
2627 LINEWIDTH, ink, ink);
2628
2629 /*
2630 * Clues.
2631 */
2632 for (y = 0; y < h; y++)
2633 for (x = 0; x < w; x++)
2634 if (CLUE_AT(state, x, y) != ' ') {
2635 char c[2];
2636
2637 c[0] = CLUE_AT(state, x, y);
2638 c[1] = '\0';
2639 draw_text(dr,
2640 BORDER + x * TILE_SIZE + TILE_SIZE/2,
2641 BORDER + y * TILE_SIZE + TILE_SIZE/2,
2642 FONT_VARIABLE, TILE_SIZE/2,
2643 ALIGN_VCENTRE | ALIGN_HCENTRE, ink, c);
2644 }
2645
2646 /*
2647 * Lines. (At the moment, I'm not bothering with crosses.)
2648 */
2649 for (y = 0; y <= h; y++)
2650 for (x = 0; x < w; x++)
2651 if (RIGHTOF_DOT(state, x, y) == LINE_YES)
2652 draw_rect(dr, BORDER + x * TILE_SIZE,
2653 BORDER + y * TILE_SIZE - LINEWIDTH/2,
2654 TILE_SIZE, (LINEWIDTH/2) * 2 + 1, ink);
2655 for (y = 0; y < h; y++)
2656 for (x = 0; x <= w; x++)
2657 if (BELOW_DOT(state, x, y) == LINE_YES)
2658 draw_rect(dr, BORDER + x * TILE_SIZE - LINEWIDTH/2,
2659 BORDER + y * TILE_SIZE,
2660 (LINEWIDTH/2) * 2 + 1, TILE_SIZE, ink);
2661 }
2662
2663 #ifdef COMBINED
2664 #define thegame loopy
2665 #endif
2666
2667 const struct game thegame = {
2668 "Loopy", "games.loopy",
2669 default_params,
2670 game_fetch_preset,
2671 decode_params,
2672 encode_params,
2673 free_params,
2674 dup_params,
2675 TRUE, game_configure, custom_params,
2676 validate_params,
2677 new_game_desc,
2678 validate_desc,
2679 new_game,
2680 dup_game,
2681 free_game,
2682 1, solve_game,
2683 TRUE, game_text_format,
2684 new_ui,
2685 free_ui,
2686 encode_ui,
2687 decode_ui,
2688 game_changed_state,
2689 interpret_move,
2690 execute_move,
2691 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
2692 game_colours,
2693 game_new_drawstate,
2694 game_free_drawstate,
2695 game_redraw,
2696 game_anim_length,
2697 game_flash_length,
2698 TRUE, FALSE, game_print_size, game_print,
2699 game_wants_statusbar,
2700 FALSE, game_timing_state,
2701 0, /* mouse_priorities */
2702 };
Simon Tatham's portable puzzles collection; import of svn://svn.tartarus.org/sgt/puzzles