4 * An implementation of the Nikoli game 'Loop the loop'.
5 * (c) Mike Pinna, 2005, 2006
6 * Substantially rewritten to allowing for more general types of grid.
7 * (c) Lambros Lambrou 2008
9 * vim: set shiftwidth=4 :set textwidth=80:
13 * Possible future solver enhancements:
15 * - There's an interesting deductive technique which makes use
16 * of topology rather than just graph theory. Each _face_ in
17 * the grid is either inside or outside the loop; you can tell
18 * that two faces are on the same side of the loop if they're
19 * separated by a LINE_NO (or, more generally, by a path
20 * crossing no LINE_UNKNOWNs and an even number of LINE_YESes),
21 * and on the opposite side of the loop if they're separated by
22 * a LINE_YES (or an odd number of LINE_YESes and no
23 * LINE_UNKNOWNs). Oh, and any face separated from the outside
24 * of the grid by a LINE_YES or a LINE_NO is on the inside or
25 * outside respectively. So if you can track this for all
26 * faces, you figure out the state of the line between a pair
27 * once their relative insideness is known.
28 * + The way I envisage this working is simply to keep an edsf
29 * of all _faces_, which indicates whether they're on
30 * opposite sides of the loop from one another. We also
31 * include a special entry in the edsf for the infinite
33 * + So, the simple way to do this is to just go through the
34 * edges: every time we see an edge in a state other than
35 * LINE_UNKNOWN which separates two faces that aren't in the
36 * same edsf class, we can rectify that by merging the
37 * classes. Then, conversely, an edge in LINE_UNKNOWN state
38 * which separates two faces that _are_ in the same edsf
39 * class can immediately have its state determined.
40 * + But you can go one better, if you're prepared to loop
41 * over all _pairs_ of edges. Suppose we have edges A and B,
42 * which respectively separate faces A1,A2 and B1,B2.
43 * Suppose that A,B are in the same edge-edsf class and that
44 * A1,B1 (wlog) are in the same face-edsf class; then we can
45 * immediately place A2,B2 into the same face-edsf class (as
46 * each other, not as A1 and A2) one way round or the other.
47 * And conversely again, if A1,B1 are in the same face-edsf
48 * class and so are A2,B2, then we can put A,B into the same
50 * * Of course, this deduction requires a quadratic-time
51 * loop over all pairs of edges in the grid, so it should
52 * be reserved until there's nothing easier left to be
55 * - The generalised grid support has made me (SGT) notice a
56 * possible extension to the loop-avoidance code. When you have
57 * a path of connected edges such that no other edges at all
58 * are incident on any vertex in the middle of the path - or,
59 * alternatively, such that any such edges are already known to
60 * be LINE_NO - then you know those edges are either all
61 * LINE_YES or all LINE_NO. Hence you can mentally merge the
62 * entire path into a single long curly edge for the purposes
63 * of loop avoidance, and look directly at whether or not the
64 * extreme endpoints of the path are connected by some other
65 * route. I find this coming up fairly often when I play on the
66 * octagonal grid setting, so it might be worth implementing in
69 * - (Just a speed optimisation.) Consider some todo list queue where every
70 * time we modify something we mark it for consideration by other bits of
71 * the solver, to save iteration over things that have already been done.
87 /* Debugging options */
95 /* ----------------------------------------------------------------------
96 * Struct, enum and function declarations
111 grid *game_grid; /* ref-counted (internally) */
113 /* Put -1 in a face that doesn't get a clue */
116 /* Array of line states, to store whether each line is
117 * YES, NO or UNKNOWN */
120 unsigned char *line_errors;
125 /* Used in game_text_format(), so that it knows what type of
126 * grid it's trying to render as ASCII text. */
131 SOLVER_SOLVED, /* This is the only solution the solver could find */
132 SOLVER_MISTAKE, /* This is definitely not a solution */
133 SOLVER_AMBIGUOUS, /* This _might_ be an ambiguous solution */
134 SOLVER_INCOMPLETE /* This may be a partial solution */
137 /* ------ Solver state ------ */
138 typedef struct solver_state {
140 enum solver_status solver_status;
141 /* NB looplen is the number of dots that are joined together at a point, ie a
142 * looplen of 1 means there are no lines to a particular dot */
145 /* Difficulty level of solver. Used by solver functions that want to
146 * vary their behaviour depending on the requested difficulty level. */
152 char *face_yes_count;
154 char *dot_solved, *face_solved;
157 /* Information for Normal level deductions:
158 * For each dline, store a bitmask for whether we know:
159 * (bit 0) at least one is YES
160 * (bit 1) at most one is YES */
163 /* Hard level information */
168 * Difficulty levels. I do some macro ickery here to ensure that my
169 * enum and the various forms of my name list always match up.
172 #define DIFFLIST(A) \
177 #define ENUM(upper,title,lower) DIFF_ ## upper,
178 #define TITLE(upper,title,lower) #title,
179 #define ENCODE(upper,title,lower) #lower
180 #define CONFIG(upper,title,lower) ":" #title
181 enum { DIFFLIST(ENUM) DIFF_MAX };
182 static char const *const diffnames[] = { DIFFLIST(TITLE) };
183 static char const diffchars[] = DIFFLIST(ENCODE);
184 #define DIFFCONFIG DIFFLIST(CONFIG)
187 * Solver routines, sorted roughly in order of computational cost.
188 * The solver will run the faster deductions first, and slower deductions are
189 * only invoked when the faster deductions are unable to make progress.
190 * Each function is associated with a difficulty level, so that the generated
191 * puzzles are solvable by applying only the functions with the chosen
192 * difficulty level or lower.
194 #define SOLVERLIST(A) \
195 A(trivial_deductions, DIFF_EASY) \
196 A(dline_deductions, DIFF_NORMAL) \
197 A(linedsf_deductions, DIFF_HARD) \
198 A(loop_deductions, DIFF_EASY)
199 #define SOLVER_FN_DECL(fn,diff) static int fn(solver_state *);
200 #define SOLVER_FN(fn,diff) &fn,
201 #define SOLVER_DIFF(fn,diff) diff,
202 SOLVERLIST(SOLVER_FN_DECL)
203 static int (*(solver_fns[]))(solver_state *) = { SOLVERLIST(SOLVER_FN) };
204 static int const solver_diffs[] = { SOLVERLIST(SOLVER_DIFF) };
205 static const int NUM_SOLVERS = sizeof(solver_diffs)/sizeof(*solver_diffs);
213 /* line_drawstate is the same as line_state, but with the extra ERROR
214 * possibility. The drawing code copies line_state to line_drawstate,
215 * except in the case that the line is an error. */
216 enum line_state { LINE_YES, LINE_UNKNOWN, LINE_NO };
217 enum line_drawstate { DS_LINE_YES, DS_LINE_UNKNOWN,
218 DS_LINE_NO, DS_LINE_ERROR };
220 #define OPP(line_state) \
224 struct game_drawstate {
231 char *clue_satisfied;
234 static char *validate_desc(game_params *params, char *desc);
235 static int dot_order(const game_state* state, int i, char line_type);
236 static int face_order(const game_state* state, int i, char line_type);
237 static solver_state *solve_game_rec(const solver_state *sstate);
240 static void check_caches(const solver_state* sstate);
242 #define check_caches(s)
245 /* ------- List of grid generators ------- */
246 #define GRIDLIST(A) \
247 A(Squares,GRID_SQUARE,3,3) \
248 A(Triangular,GRID_TRIANGULAR,3,3) \
249 A(Honeycomb,GRID_HONEYCOMB,3,3) \
250 A(Snub-Square,GRID_SNUBSQUARE,3,3) \
251 A(Cairo,GRID_CAIRO,3,4) \
252 A(Great-Hexagonal,GRID_GREATHEXAGONAL,3,3) \
253 A(Octagonal,GRID_OCTAGONAL,3,3) \
254 A(Kites,GRID_KITE,3,3) \
255 A(Floret,GRID_FLORET,1,2) \
256 A(Dodecagonal,GRID_DODECAGONAL,2,2) \
257 A(Great-Dodecagonal,GRID_GREATDODECAGONAL,2,2) \
258 A(Penrose (kite/dart),GRID_PENROSE_P2,3,3) \
259 A(Penrose (rhombs),GRID_PENROSE_P3,3,3)
261 #define GRID_NAME(title,type,amin,omin) #title,
262 #define GRID_CONFIG(title,type,amin,omin) ":" #title
263 #define GRID_TYPE(title,type,amin,omin) type,
264 #define GRID_SIZES(title,type,amin,omin) \
266 "Width and height for this grid type must both be at least " #amin, \
267 "At least one of width and height for this grid type must be at least " #omin,},
268 static char const *const gridnames[] = { GRIDLIST(GRID_NAME) };
269 #define GRID_CONFIGS GRIDLIST(GRID_CONFIG)
270 static grid_type grid_types[] = { GRIDLIST(GRID_TYPE) };
271 #define NUM_GRID_TYPES (sizeof(grid_types) / sizeof(grid_types[0]))
272 static const struct {
275 } grid_size_limits[] = { GRIDLIST(GRID_SIZES) };
277 /* Generates a (dynamically allocated) new grid, according to the
278 * type and size requested in params. Does nothing if the grid is already
280 static grid *loopy_generate_grid(game_params *params, char *grid_desc)
282 return grid_new(grid_types[params->type], params->w, params->h, grid_desc);
285 /* ----------------------------------------------------------------------
289 /* General constants */
290 #define PREFERRED_TILE_SIZE 32
291 #define BORDER(tilesize) ((tilesize) / 2)
292 #define FLASH_TIME 0.5F
294 #define BIT_SET(field, bit) ((field) & (1<<(bit)))
296 #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
297 ((field) |= (1<<(bit)), TRUE))
299 #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
300 ((field) &= ~(1<<(bit)), TRUE) : FALSE)
302 #define CLUE2CHAR(c) \
303 ((c < 0) ? ' ' : c < 10 ? c + '0' : c - 10 + 'A')
305 /* ----------------------------------------------------------------------
306 * General struct manipulation and other straightforward code
309 static game_state *dup_game(game_state *state)
311 game_state *ret = snew(game_state);
313 ret->game_grid = state->game_grid;
314 ret->game_grid->refcount++;
316 ret->solved = state->solved;
317 ret->cheated = state->cheated;
319 ret->clues = snewn(state->game_grid->num_faces, signed char);
320 memcpy(ret->clues, state->clues, state->game_grid->num_faces);
322 ret->lines = snewn(state->game_grid->num_edges, char);
323 memcpy(ret->lines, state->lines, state->game_grid->num_edges);
325 ret->line_errors = snewn(state->game_grid->num_edges, unsigned char);
326 memcpy(ret->line_errors, state->line_errors, state->game_grid->num_edges);
328 ret->grid_type = state->grid_type;
332 static void free_game(game_state *state)
335 grid_free(state->game_grid);
338 sfree(state->line_errors);
343 static solver_state *new_solver_state(game_state *state, int diff) {
345 int num_dots = state->game_grid->num_dots;
346 int num_faces = state->game_grid->num_faces;
347 int num_edges = state->game_grid->num_edges;
348 solver_state *ret = snew(solver_state);
350 ret->state = dup_game(state);
352 ret->solver_status = SOLVER_INCOMPLETE;
355 ret->dotdsf = snew_dsf(num_dots);
356 ret->looplen = snewn(num_dots, int);
358 for (i = 0; i < num_dots; i++) {
362 ret->dot_solved = snewn(num_dots, char);
363 ret->face_solved = snewn(num_faces, char);
364 memset(ret->dot_solved, FALSE, num_dots);
365 memset(ret->face_solved, FALSE, num_faces);
367 ret->dot_yes_count = snewn(num_dots, char);
368 memset(ret->dot_yes_count, 0, num_dots);
369 ret->dot_no_count = snewn(num_dots, char);
370 memset(ret->dot_no_count, 0, num_dots);
371 ret->face_yes_count = snewn(num_faces, char);
372 memset(ret->face_yes_count, 0, num_faces);
373 ret->face_no_count = snewn(num_faces, char);
374 memset(ret->face_no_count, 0, num_faces);
376 if (diff < DIFF_NORMAL) {
379 ret->dlines = snewn(2*num_edges, char);
380 memset(ret->dlines, 0, 2*num_edges);
383 if (diff < DIFF_HARD) {
386 ret->linedsf = snew_dsf(state->game_grid->num_edges);
392 static void free_solver_state(solver_state *sstate) {
394 free_game(sstate->state);
395 sfree(sstate->dotdsf);
396 sfree(sstate->looplen);
397 sfree(sstate->dot_solved);
398 sfree(sstate->face_solved);
399 sfree(sstate->dot_yes_count);
400 sfree(sstate->dot_no_count);
401 sfree(sstate->face_yes_count);
402 sfree(sstate->face_no_count);
404 /* OK, because sfree(NULL) is a no-op */
405 sfree(sstate->dlines);
406 sfree(sstate->linedsf);
412 static solver_state *dup_solver_state(const solver_state *sstate) {
413 game_state *state = sstate->state;
414 int num_dots = state->game_grid->num_dots;
415 int num_faces = state->game_grid->num_faces;
416 int num_edges = state->game_grid->num_edges;
417 solver_state *ret = snew(solver_state);
419 ret->state = state = dup_game(sstate->state);
421 ret->solver_status = sstate->solver_status;
422 ret->diff = sstate->diff;
424 ret->dotdsf = snewn(num_dots, int);
425 ret->looplen = snewn(num_dots, int);
426 memcpy(ret->dotdsf, sstate->dotdsf,
427 num_dots * sizeof(int));
428 memcpy(ret->looplen, sstate->looplen,
429 num_dots * sizeof(int));
431 ret->dot_solved = snewn(num_dots, char);
432 ret->face_solved = snewn(num_faces, char);
433 memcpy(ret->dot_solved, sstate->dot_solved, num_dots);
434 memcpy(ret->face_solved, sstate->face_solved, num_faces);
436 ret->dot_yes_count = snewn(num_dots, char);
437 memcpy(ret->dot_yes_count, sstate->dot_yes_count, num_dots);
438 ret->dot_no_count = snewn(num_dots, char);
439 memcpy(ret->dot_no_count, sstate->dot_no_count, num_dots);
441 ret->face_yes_count = snewn(num_faces, char);
442 memcpy(ret->face_yes_count, sstate->face_yes_count, num_faces);
443 ret->face_no_count = snewn(num_faces, char);
444 memcpy(ret->face_no_count, sstate->face_no_count, num_faces);
446 if (sstate->dlines) {
447 ret->dlines = snewn(2*num_edges, char);
448 memcpy(ret->dlines, sstate->dlines,
454 if (sstate->linedsf) {
455 ret->linedsf = snewn(num_edges, int);
456 memcpy(ret->linedsf, sstate->linedsf,
457 num_edges * sizeof(int));
465 static game_params *default_params(void)
467 game_params *ret = snew(game_params);
476 ret->diff = DIFF_EASY;
482 static game_params *dup_params(game_params *params)
484 game_params *ret = snew(game_params);
486 *ret = *params; /* structure copy */
490 static const game_params presets[] = {
492 { 7, 7, DIFF_EASY, 0 },
493 { 7, 7, DIFF_NORMAL, 0 },
494 { 7, 7, DIFF_HARD, 0 },
495 { 7, 7, DIFF_HARD, 1 },
496 { 7, 7, DIFF_HARD, 2 },
497 { 5, 5, DIFF_HARD, 3 },
498 { 7, 7, DIFF_HARD, 4 },
499 { 5, 4, DIFF_HARD, 5 },
500 { 5, 5, DIFF_HARD, 6 },
501 { 5, 5, DIFF_HARD, 7 },
502 { 3, 3, DIFF_HARD, 8 },
503 { 3, 3, DIFF_HARD, 9 },
504 { 3, 3, DIFF_HARD, 10 },
505 { 6, 6, DIFF_HARD, 11 },
506 { 6, 6, DIFF_HARD, 12 },
508 { 7, 7, DIFF_EASY, 0 },
509 { 10, 10, DIFF_EASY, 0 },
510 { 7, 7, DIFF_NORMAL, 0 },
511 { 10, 10, DIFF_NORMAL, 0 },
512 { 7, 7, DIFF_HARD, 0 },
513 { 10, 10, DIFF_HARD, 0 },
514 { 10, 10, DIFF_HARD, 1 },
515 { 12, 10, DIFF_HARD, 2 },
516 { 7, 7, DIFF_HARD, 3 },
517 { 9, 9, DIFF_HARD, 4 },
518 { 5, 4, DIFF_HARD, 5 },
519 { 7, 7, DIFF_HARD, 6 },
520 { 5, 5, DIFF_HARD, 7 },
521 { 5, 5, DIFF_HARD, 8 },
522 { 5, 4, DIFF_HARD, 9 },
523 { 5, 4, DIFF_HARD, 10 },
524 { 10, 10, DIFF_HARD, 11 },
525 { 10, 10, DIFF_HARD, 12 }
529 static int game_fetch_preset(int i, char **name, game_params **params)
534 if (i < 0 || i >= lenof(presets))
537 tmppar = snew(game_params);
538 *tmppar = presets[i];
540 sprintf(buf, "%dx%d %s - %s", tmppar->h, tmppar->w,
541 gridnames[tmppar->type], diffnames[tmppar->diff]);
547 static void free_params(game_params *params)
552 static void decode_params(game_params *params, char const *string)
554 params->h = params->w = atoi(string);
555 params->diff = DIFF_EASY;
556 while (*string && isdigit((unsigned char)*string)) string++;
557 if (*string == 'x') {
559 params->h = atoi(string);
560 while (*string && isdigit((unsigned char)*string)) string++;
562 if (*string == 't') {
564 params->type = atoi(string);
565 while (*string && isdigit((unsigned char)*string)) string++;
567 if (*string == 'd') {
570 for (i = 0; i < DIFF_MAX; i++)
571 if (*string == diffchars[i])
573 if (*string) string++;
577 static char *encode_params(game_params *params, int full)
580 sprintf(str, "%dx%dt%d", params->w, params->h, params->type);
582 sprintf(str + strlen(str), "d%c", diffchars[params->diff]);
586 static config_item *game_configure(game_params *params)
591 ret = snewn(5, config_item);
593 ret[0].name = "Width";
594 ret[0].type = C_STRING;
595 sprintf(buf, "%d", params->w);
596 ret[0].sval = dupstr(buf);
599 ret[1].name = "Height";
600 ret[1].type = C_STRING;
601 sprintf(buf, "%d", params->h);
602 ret[1].sval = dupstr(buf);
605 ret[2].name = "Grid type";
606 ret[2].type = C_CHOICES;
607 ret[2].sval = GRID_CONFIGS;
608 ret[2].ival = params->type;
610 ret[3].name = "Difficulty";
611 ret[3].type = C_CHOICES;
612 ret[3].sval = DIFFCONFIG;
613 ret[3].ival = params->diff;
623 static game_params *custom_params(config_item *cfg)
625 game_params *ret = snew(game_params);
627 ret->w = atoi(cfg[0].sval);
628 ret->h = atoi(cfg[1].sval);
629 ret->type = cfg[2].ival;
630 ret->diff = cfg[3].ival;
635 static char *validate_params(game_params *params, int full)
637 if (params->type < 0 || params->type >= NUM_GRID_TYPES)
638 return "Illegal grid type";
639 if (params->w < grid_size_limits[params->type].amin ||
640 params->h < grid_size_limits[params->type].amin)
641 return grid_size_limits[params->type].aerr;
642 if (params->w < grid_size_limits[params->type].omin &&
643 params->h < grid_size_limits[params->type].omin)
644 return grid_size_limits[params->type].oerr;
647 * This shouldn't be able to happen at all, since decode_params
648 * and custom_params will never generate anything that isn't
651 assert(params->diff < DIFF_MAX);
656 /* Returns a newly allocated string describing the current puzzle */
657 static char *state_to_text(const game_state *state)
659 grid *g = state->game_grid;
661 int num_faces = g->num_faces;
662 char *description = snewn(num_faces + 1, char);
663 char *dp = description;
667 for (i = 0; i < num_faces; i++) {
668 if (state->clues[i] < 0) {
669 if (empty_count > 25) {
670 dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
676 dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
679 dp += sprintf(dp, "%c", (int)CLUE2CHAR(state->clues[i]));
684 dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
686 retval = dupstr(description);
692 #define GRID_DESC_SEP '_'
694 /* Splits up a (optional) grid_desc from the game desc. Returns the
695 * grid_desc (which needs freeing) and updates the desc pointer to
696 * start of real desc, or returns NULL if no desc. */
697 static char *extract_grid_desc(char **desc)
699 char *sep = strchr(*desc, GRID_DESC_SEP), *gd;
702 if (!sep) return NULL;
704 gd_len = sep - (*desc);
705 gd = snewn(gd_len+1, char);
706 memcpy(gd, *desc, gd_len);
714 /* We require that the params pass the test in validate_params and that the
715 * description fills the entire game area */
716 static char *validate_desc(game_params *params, char *desc)
720 char *grid_desc, *ret;
722 /* It's pretty inefficient to do this just for validation. All we need to
723 * know is the precise number of faces. */
724 grid_desc = extract_grid_desc(&desc);
725 ret = grid_validate_desc(grid_types[params->type], params->w, params->h, grid_desc);
728 g = loopy_generate_grid(params, grid_desc);
729 if (grid_desc) sfree(grid_desc);
731 for (; *desc; ++desc) {
732 if ((*desc >= '0' && *desc <= '9') || (*desc >= 'A' && *desc <= 'Z')) {
737 count += *desc - 'a' + 1;
740 return "Unknown character in description";
743 if (count < g->num_faces)
744 return "Description too short for board size";
745 if (count > g->num_faces)
746 return "Description too long for board size";
753 /* Sums the lengths of the numbers in range [0,n) */
754 /* See equivalent function in solo.c for justification of this. */
755 static int len_0_to_n(int n)
757 int len = 1; /* Counting 0 as a bit of a special case */
760 for (i = 1; i < n; i *= 10) {
761 len += max(n - i, 0);
767 static char *encode_solve_move(const game_state *state)
772 int num_edges = state->game_grid->num_edges;
774 /* This is going to return a string representing the moves needed to set
775 * every line in a grid to be the same as the ones in 'state'. The exact
776 * length of this string is predictable. */
778 len = 1; /* Count the 'S' prefix */
779 /* Numbers in all lines */
780 len += len_0_to_n(num_edges);
781 /* For each line we also have a letter */
784 ret = snewn(len + 1, char);
787 p += sprintf(p, "S");
789 for (i = 0; i < num_edges; i++) {
790 switch (state->lines[i]) {
792 p += sprintf(p, "%dy", i);
795 p += sprintf(p, "%dn", i);
800 /* No point in doing sums like that if they're going to be wrong */
801 assert(strlen(ret) <= (size_t)len);
805 static game_ui *new_ui(game_state *state)
810 static void free_ui(game_ui *ui)
814 static char *encode_ui(game_ui *ui)
819 static void decode_ui(game_ui *ui, char *encoding)
823 static void game_changed_state(game_ui *ui, game_state *oldstate,
824 game_state *newstate)
828 static void game_compute_size(game_params *params, int tilesize,
831 int grid_width, grid_height, rendered_width, rendered_height;
834 grid_compute_size(grid_types[params->type], params->w, params->h,
835 &g_tilesize, &grid_width, &grid_height);
837 /* multiply first to minimise rounding error on integer division */
838 rendered_width = grid_width * tilesize / g_tilesize;
839 rendered_height = grid_height * tilesize / g_tilesize;
840 *x = rendered_width + 2 * BORDER(tilesize) + 1;
841 *y = rendered_height + 2 * BORDER(tilesize) + 1;
844 static void game_set_size(drawing *dr, game_drawstate *ds,
845 game_params *params, int tilesize)
847 ds->tilesize = tilesize;
850 static float *game_colours(frontend *fe, int *ncolours)
852 float *ret = snewn(4 * NCOLOURS, float);
854 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
856 ret[COL_FOREGROUND * 3 + 0] = 0.0F;
857 ret[COL_FOREGROUND * 3 + 1] = 0.0F;
858 ret[COL_FOREGROUND * 3 + 2] = 0.0F;
861 * We want COL_LINEUNKNOWN to be a yellow which is a bit darker
862 * than the background. (I previously set it to 0.8,0.8,0, but
863 * found that this went badly with the 0.8,0.8,0.8 favoured as a
864 * background by the Java frontend.)
866 ret[COL_LINEUNKNOWN * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.9F;
867 ret[COL_LINEUNKNOWN * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.9F;
868 ret[COL_LINEUNKNOWN * 3 + 2] = 0.0F;
870 ret[COL_HIGHLIGHT * 3 + 0] = 1.0F;
871 ret[COL_HIGHLIGHT * 3 + 1] = 1.0F;
872 ret[COL_HIGHLIGHT * 3 + 2] = 1.0F;
874 ret[COL_MISTAKE * 3 + 0] = 1.0F;
875 ret[COL_MISTAKE * 3 + 1] = 0.0F;
876 ret[COL_MISTAKE * 3 + 2] = 0.0F;
878 ret[COL_SATISFIED * 3 + 0] = 0.0F;
879 ret[COL_SATISFIED * 3 + 1] = 0.0F;
880 ret[COL_SATISFIED * 3 + 2] = 0.0F;
882 /* We want the faint lines to be a bit darker than the background.
883 * Except if the background is pretty dark already; then it ought to be a
884 * bit lighter. Oy vey.
886 ret[COL_FAINT * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.9F;
887 ret[COL_FAINT * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.9F;
888 ret[COL_FAINT * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.9F;
890 *ncolours = NCOLOURS;
894 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
896 struct game_drawstate *ds = snew(struct game_drawstate);
897 int num_faces = state->game_grid->num_faces;
898 int num_edges = state->game_grid->num_edges;
903 ds->lines = snewn(num_edges, char);
904 ds->clue_error = snewn(num_faces, char);
905 ds->clue_satisfied = snewn(num_faces, char);
906 ds->textx = snewn(num_faces, int);
907 ds->texty = snewn(num_faces, int);
910 memset(ds->lines, LINE_UNKNOWN, num_edges);
911 memset(ds->clue_error, 0, num_faces);
912 memset(ds->clue_satisfied, 0, num_faces);
913 for (i = 0; i < num_faces; i++)
914 ds->textx[i] = ds->texty[i] = -1;
919 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
923 sfree(ds->clue_error);
924 sfree(ds->clue_satisfied);
929 static int game_timing_state(game_state *state, game_ui *ui)
934 static float game_anim_length(game_state *oldstate, game_state *newstate,
935 int dir, game_ui *ui)
940 static int game_can_format_as_text_now(game_params *params)
942 if (params->type != 0)
947 static char *game_text_format(game_state *state)
953 grid *g = state->game_grid;
956 assert(state->grid_type == 0);
958 /* Work out the basic size unit */
959 f = g->faces; /* first face */
960 assert(f->order == 4);
961 /* The dots are ordered clockwise, so the two opposite
962 * corners are guaranteed to span the square */
963 cell_size = abs(f->dots[0]->x - f->dots[2]->x);
965 w = (g->highest_x - g->lowest_x) / cell_size;
966 h = (g->highest_y - g->lowest_y) / cell_size;
968 /* Create a blank "canvas" to "draw" on */
971 ret = snewn(W * H + 1, char);
972 for (y = 0; y < H; y++) {
973 for (x = 0; x < W-1; x++) {
976 ret[y*W + W-1] = '\n';
980 /* Fill in edge info */
981 for (i = 0; i < g->num_edges; i++) {
982 grid_edge *e = g->edges + i;
983 /* Cell coordinates, from (0,0) to (w-1,h-1) */
984 int x1 = (e->dot1->x - g->lowest_x) / cell_size;
985 int x2 = (e->dot2->x - g->lowest_x) / cell_size;
986 int y1 = (e->dot1->y - g->lowest_y) / cell_size;
987 int y2 = (e->dot2->y - g->lowest_y) / cell_size;
988 /* Midpoint, in canvas coordinates (canvas coordinates are just twice
989 * cell coordinates) */
992 switch (state->lines[i]) {
994 ret[y*W + x] = (y1 == y2) ? '-' : '|';
1000 break; /* already a space */
1002 assert(!"Illegal line state");
1007 for (i = 0; i < g->num_faces; i++) {
1011 assert(f->order == 4);
1012 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1013 x1 = (f->dots[0]->x - g->lowest_x) / cell_size;
1014 x2 = (f->dots[2]->x - g->lowest_x) / cell_size;
1015 y1 = (f->dots[0]->y - g->lowest_y) / cell_size;
1016 y2 = (f->dots[2]->y - g->lowest_y) / cell_size;
1017 /* Midpoint, in canvas coordinates */
1020 ret[y*W + x] = CLUE2CHAR(state->clues[i]);
1025 /* ----------------------------------------------------------------------
1030 static void check_caches(const solver_state* sstate)
1033 const game_state *state = sstate->state;
1034 const grid *g = state->game_grid;
1036 for (i = 0; i < g->num_dots; i++) {
1037 assert(dot_order(state, i, LINE_YES) == sstate->dot_yes_count[i]);
1038 assert(dot_order(state, i, LINE_NO) == sstate->dot_no_count[i]);
1041 for (i = 0; i < g->num_faces; i++) {
1042 assert(face_order(state, i, LINE_YES) == sstate->face_yes_count[i]);
1043 assert(face_order(state, i, LINE_NO) == sstate->face_no_count[i]);
1048 #define check_caches(s) \
1050 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
1054 #endif /* DEBUG_CACHES */
1056 /* ----------------------------------------------------------------------
1057 * Solver utility functions
1060 /* Sets the line (with index i) to the new state 'line_new', and updates
1061 * the cached counts of any affected faces and dots.
1062 * Returns TRUE if this actually changed the line's state. */
1063 static int solver_set_line(solver_state *sstate, int i,
1064 enum line_state line_new
1066 , const char *reason
1070 game_state *state = sstate->state;
1074 assert(line_new != LINE_UNKNOWN);
1076 check_caches(sstate);
1078 if (state->lines[i] == line_new) {
1079 return FALSE; /* nothing changed */
1081 state->lines[i] = line_new;
1084 fprintf(stderr, "solver: set line [%d] to %s (%s)\n",
1085 i, line_new == LINE_YES ? "YES" : "NO",
1089 g = state->game_grid;
1092 /* Update the cache for both dots and both faces affected by this. */
1093 if (line_new == LINE_YES) {
1094 sstate->dot_yes_count[e->dot1 - g->dots]++;
1095 sstate->dot_yes_count[e->dot2 - g->dots]++;
1097 sstate->face_yes_count[e->face1 - g->faces]++;
1100 sstate->face_yes_count[e->face2 - g->faces]++;
1103 sstate->dot_no_count[e->dot1 - g->dots]++;
1104 sstate->dot_no_count[e->dot2 - g->dots]++;
1106 sstate->face_no_count[e->face1 - g->faces]++;
1109 sstate->face_no_count[e->face2 - g->faces]++;
1113 check_caches(sstate);
1118 #define solver_set_line(a, b, c) \
1119 solver_set_line(a, b, c, __FUNCTION__)
1123 * Merge two dots due to the existence of an edge between them.
1124 * Updates the dsf tracking equivalence classes, and keeps track of
1125 * the length of path each dot is currently a part of.
1126 * Returns TRUE if the dots were already linked, ie if they are part of a
1127 * closed loop, and false otherwise.
1129 static int merge_dots(solver_state *sstate, int edge_index)
1132 grid *g = sstate->state->game_grid;
1133 grid_edge *e = g->edges + edge_index;
1135 i = e->dot1 - g->dots;
1136 j = e->dot2 - g->dots;
1138 i = dsf_canonify(sstate->dotdsf, i);
1139 j = dsf_canonify(sstate->dotdsf, j);
1144 len = sstate->looplen[i] + sstate->looplen[j];
1145 dsf_merge(sstate->dotdsf, i, j);
1146 i = dsf_canonify(sstate->dotdsf, i);
1147 sstate->looplen[i] = len;
1152 /* Merge two lines because the solver has deduced that they must be either
1153 * identical or opposite. Returns TRUE if this is new information, otherwise
1155 static int merge_lines(solver_state *sstate, int i, int j, int inverse
1157 , const char *reason
1163 assert(i < sstate->state->game_grid->num_edges);
1164 assert(j < sstate->state->game_grid->num_edges);
1166 i = edsf_canonify(sstate->linedsf, i, &inv_tmp);
1168 j = edsf_canonify(sstate->linedsf, j, &inv_tmp);
1171 edsf_merge(sstate->linedsf, i, j, inverse);
1175 fprintf(stderr, "%s [%d] [%d] %s(%s)\n",
1177 inverse ? "inverse " : "", reason);
1184 #define merge_lines(a, b, c, d) \
1185 merge_lines(a, b, c, d, __FUNCTION__)
1188 /* Count the number of lines of a particular type currently going into the
1190 static int dot_order(const game_state* state, int dot, char line_type)
1193 grid *g = state->game_grid;
1194 grid_dot *d = g->dots + dot;
1197 for (i = 0; i < d->order; i++) {
1198 grid_edge *e = d->edges[i];
1199 if (state->lines[e - g->edges] == line_type)
1205 /* Count the number of lines of a particular type currently surrounding the
1207 static int face_order(const game_state* state, int face, char line_type)
1210 grid *g = state->game_grid;
1211 grid_face *f = g->faces + face;
1214 for (i = 0; i < f->order; i++) {
1215 grid_edge *e = f->edges[i];
1216 if (state->lines[e - g->edges] == line_type)
1222 /* Set all lines bordering a dot of type old_type to type new_type
1223 * Return value tells caller whether this function actually did anything */
1224 static int dot_setall(solver_state *sstate, int dot,
1225 char old_type, char new_type)
1227 int retval = FALSE, r;
1228 game_state *state = sstate->state;
1233 if (old_type == new_type)
1236 g = state->game_grid;
1239 for (i = 0; i < d->order; i++) {
1240 int line_index = d->edges[i] - g->edges;
1241 if (state->lines[line_index] == old_type) {
1242 r = solver_set_line(sstate, line_index, new_type);
1250 /* Set all lines bordering a face of type old_type to type new_type */
1251 static int face_setall(solver_state *sstate, int face,
1252 char old_type, char new_type)
1254 int retval = FALSE, r;
1255 game_state *state = sstate->state;
1260 if (old_type == new_type)
1263 g = state->game_grid;
1264 f = g->faces + face;
1266 for (i = 0; i < f->order; i++) {
1267 int line_index = f->edges[i] - g->edges;
1268 if (state->lines[line_index] == old_type) {
1269 r = solver_set_line(sstate, line_index, new_type);
1277 /* ----------------------------------------------------------------------
1278 * Loop generation and clue removal
1281 static void add_full_clues(game_state *state, random_state *rs)
1283 signed char *clues = state->clues;
1284 grid *g = state->game_grid;
1285 char *board = snewn(g->num_faces, char);
1288 generate_loop(g, board, rs, NULL, NULL);
1290 /* Fill out all the clues by initialising to 0, then iterating over
1291 * all edges and incrementing each clue as we find edges that border
1292 * between BLACK/WHITE faces. While we're at it, we verify that the
1293 * algorithm does work, and there aren't any GREY faces still there. */
1294 memset(clues, 0, g->num_faces);
1295 for (i = 0; i < g->num_edges; i++) {
1296 grid_edge *e = g->edges + i;
1297 grid_face *f1 = e->face1;
1298 grid_face *f2 = e->face2;
1299 enum face_colour c1 = FACE_COLOUR(f1);
1300 enum face_colour c2 = FACE_COLOUR(f2);
1301 assert(c1 != FACE_GREY);
1302 assert(c2 != FACE_GREY);
1304 if (f1) clues[f1 - g->faces]++;
1305 if (f2) clues[f2 - g->faces]++;
1312 static int game_has_unique_soln(const game_state *state, int diff)
1315 solver_state *sstate_new;
1316 solver_state *sstate = new_solver_state((game_state *)state, diff);
1318 sstate_new = solve_game_rec(sstate);
1320 assert(sstate_new->solver_status != SOLVER_MISTAKE);
1321 ret = (sstate_new->solver_status == SOLVER_SOLVED);
1323 free_solver_state(sstate_new);
1324 free_solver_state(sstate);
1330 /* Remove clues one at a time at random. */
1331 static game_state *remove_clues(game_state *state, random_state *rs,
1335 int num_faces = state->game_grid->num_faces;
1336 game_state *ret = dup_game(state), *saved_ret;
1339 /* We need to remove some clues. We'll do this by forming a list of all
1340 * available clues, shuffling it, then going along one at a
1341 * time clearing each clue in turn for which doing so doesn't render the
1342 * board unsolvable. */
1343 face_list = snewn(num_faces, int);
1344 for (n = 0; n < num_faces; ++n) {
1348 shuffle(face_list, num_faces, sizeof(int), rs);
1350 for (n = 0; n < num_faces; ++n) {
1351 saved_ret = dup_game(ret);
1352 ret->clues[face_list[n]] = -1;
1354 if (game_has_unique_soln(ret, diff)) {
1355 free_game(saved_ret);
1367 static char *new_game_desc(game_params *params, random_state *rs,
1368 char **aux, int interactive)
1370 /* solution and description both use run-length encoding in obvious ways */
1371 char *retval, *game_desc, *grid_desc;
1373 game_state *state = snew(game_state);
1374 game_state *state_new;
1376 grid_desc = grid_new_desc(grid_types[params->type], params->w, params->h, rs);
1377 state->game_grid = g = loopy_generate_grid(params, grid_desc);
1379 state->clues = snewn(g->num_faces, signed char);
1380 state->lines = snewn(g->num_edges, char);
1381 state->line_errors = snewn(g->num_edges, unsigned char);
1383 state->grid_type = params->type;
1387 memset(state->lines, LINE_UNKNOWN, g->num_edges);
1388 memset(state->line_errors, 0, g->num_edges);
1390 state->solved = state->cheated = FALSE;
1392 /* Get a new random solvable board with all its clues filled in. Yes, this
1393 * can loop for ever if the params are suitably unfavourable, but
1394 * preventing games smaller than 4x4 seems to stop this happening */
1396 add_full_clues(state, rs);
1397 } while (!game_has_unique_soln(state, params->diff));
1399 state_new = remove_clues(state, rs, params->diff);
1404 if (params->diff > 0 && game_has_unique_soln(state, params->diff-1)) {
1406 fprintf(stderr, "Rejecting board, it is too easy\n");
1408 goto newboard_please;
1411 game_desc = state_to_text(state);
1416 retval = snewn(strlen(grid_desc) + 1 + strlen(game_desc) + 1, char);
1417 sprintf(retval, "%s%c%s", grid_desc, (int)GRID_DESC_SEP, game_desc);
1424 assert(!validate_desc(params, retval));
1429 static game_state *new_game(midend *me, game_params *params, char *desc)
1432 game_state *state = snew(game_state);
1433 int empties_to_make = 0;
1438 int num_faces, num_edges;
1440 grid_desc = extract_grid_desc(&desc);
1441 state->game_grid = g = loopy_generate_grid(params, grid_desc);
1442 if (grid_desc) sfree(grid_desc);
1446 num_faces = g->num_faces;
1447 num_edges = g->num_edges;
1449 state->clues = snewn(num_faces, signed char);
1450 state->lines = snewn(num_edges, char);
1451 state->line_errors = snewn(num_edges, unsigned char);
1453 state->solved = state->cheated = FALSE;
1455 state->grid_type = params->type;
1457 for (i = 0; i < num_faces; i++) {
1458 if (empties_to_make) {
1460 state->clues[i] = -1;
1466 n2 = *dp - 'A' + 10;
1467 if (n >= 0 && n < 10) {
1468 state->clues[i] = n;
1469 } else if (n2 >= 10 && n2 < 36) {
1470 state->clues[i] = n2;
1474 state->clues[i] = -1;
1475 empties_to_make = n - 1;
1480 memset(state->lines, LINE_UNKNOWN, num_edges);
1481 memset(state->line_errors, 0, num_edges);
1485 /* Calculates the line_errors data, and checks if the current state is a
1487 static int check_completion(game_state *state)
1489 grid *g = state->game_grid;
1491 int num_faces = g->num_faces;
1493 int infinite_area, finite_area;
1494 int loops_found = 0;
1495 int found_edge_not_in_loop = FALSE;
1497 memset(state->line_errors, 0, g->num_edges);
1499 /* LL implementation of SGT's idea:
1500 * A loop will partition the grid into an inside and an outside.
1501 * If there is more than one loop, the grid will be partitioned into
1502 * even more distinct regions. We can therefore track equivalence of
1503 * faces, by saying that two faces are equivalent when there is a non-YES
1504 * edge between them.
1505 * We could keep track of the number of connected components, by counting
1506 * the number of dsf-merges that aren't no-ops.
1507 * But we're only interested in 3 separate cases:
1508 * no loops, one loop, more than one loop.
1510 * No loops: all faces are equivalent to the infinite face.
1511 * One loop: only two equivalence classes - finite and infinite.
1512 * >= 2 loops: there are 2 distinct finite regions.
1514 * So we simply make two passes through all the edges.
1515 * In the first pass, we dsf-merge the two faces bordering each non-YES
1517 * In the second pass, we look for YES-edges bordering:
1518 * a) two non-equivalent faces.
1519 * b) two non-equivalent faces, and one of them is part of a different
1520 * finite area from the first finite area we've seen.
1522 * An occurrence of a) means there is at least one loop.
1523 * An occurrence of b) means there is more than one loop.
1524 * Edges satisfying a) are marked as errors.
1526 * While we're at it, we set a flag if we find a YES edge that is not
1528 * This information will help decide, if there's a single loop, whether it
1529 * is a candidate for being a solution (that is, all YES edges are part of
1532 * If there is a candidate loop, we then go through all clues and check
1533 * they are all satisfied. If so, we have found a solution and we can
1534 * unmark all line_errors.
1537 /* Infinite face is at the end - its index is num_faces.
1538 * This macro is just to make this obvious! */
1539 #define INF_FACE num_faces
1540 dsf = snewn(num_faces + 1, int);
1541 dsf_init(dsf, num_faces + 1);
1544 for (i = 0; i < g->num_edges; i++) {
1545 grid_edge *e = g->edges + i;
1546 int f1 = e->face1 ? e->face1 - g->faces : INF_FACE;
1547 int f2 = e->face2 ? e->face2 - g->faces : INF_FACE;
1548 if (state->lines[i] != LINE_YES)
1549 dsf_merge(dsf, f1, f2);
1553 infinite_area = dsf_canonify(dsf, INF_FACE);
1555 for (i = 0; i < g->num_edges; i++) {
1556 grid_edge *e = g->edges + i;
1557 int f1 = e->face1 ? e->face1 - g->faces : INF_FACE;
1558 int can1 = dsf_canonify(dsf, f1);
1559 int f2 = e->face2 ? e->face2 - g->faces : INF_FACE;
1560 int can2 = dsf_canonify(dsf, f2);
1561 if (state->lines[i] != LINE_YES) continue;
1564 /* Faces are equivalent, so this edge not part of a loop */
1565 found_edge_not_in_loop = TRUE;
1568 state->line_errors[i] = TRUE;
1569 if (loops_found == 0) loops_found = 1;
1571 /* Don't bother with further checks if we've already found 2 loops */
1572 if (loops_found == 2) continue;
1574 if (finite_area == -1) {
1575 /* Found our first finite area */
1576 if (can1 != infinite_area)
1582 /* Have we found a second area? */
1583 if (finite_area != -1) {
1584 if (can1 != infinite_area && can1 != finite_area) {
1588 if (can2 != infinite_area && can2 != finite_area) {
1595 printf("loops_found = %d\n", loops_found);
1596 printf("found_edge_not_in_loop = %s\n",
1597 found_edge_not_in_loop ? "TRUE" : "FALSE");
1600 sfree(dsf); /* No longer need the dsf */
1602 /* Have we found a candidate loop? */
1603 if (loops_found == 1 && !found_edge_not_in_loop) {
1604 /* Yes, so check all clues are satisfied */
1605 int found_clue_violation = FALSE;
1606 for (i = 0; i < num_faces; i++) {
1607 int c = state->clues[i];
1609 if (face_order(state, i, LINE_YES) != c) {
1610 found_clue_violation = TRUE;
1616 if (!found_clue_violation) {
1617 /* The loop is good */
1618 memset(state->line_errors, 0, g->num_edges);
1619 return TRUE; /* No need to bother checking for dot violations */
1623 /* Check for dot violations */
1624 for (i = 0; i < g->num_dots; i++) {
1625 int yes = dot_order(state, i, LINE_YES);
1626 int unknown = dot_order(state, i, LINE_UNKNOWN);
1627 if ((yes == 1 && unknown == 0) || (yes >= 3)) {
1628 /* violation, so mark all YES edges as errors */
1629 grid_dot *d = g->dots + i;
1631 for (j = 0; j < d->order; j++) {
1632 int e = d->edges[j] - g->edges;
1633 if (state->lines[e] == LINE_YES)
1634 state->line_errors[e] = TRUE;
1641 /* ----------------------------------------------------------------------
1644 * Our solver modes operate as follows. Each mode also uses the modes above it.
1647 * Just implement the rules of the game.
1649 * Normal and Tricky Modes
1650 * For each (adjacent) pair of lines through each dot we store a bit for
1651 * whether at least one of them is on and whether at most one is on. (If we
1652 * know both or neither is on that's already stored more directly.)
1655 * Use edsf data structure to make equivalence classes of lines that are
1656 * known identical to or opposite to one another.
1661 * For general grids, we consider "dlines" to be pairs of lines joined
1662 * at a dot. The lines must be adjacent around the dot, so we can think of
1663 * a dline as being a dot+face combination. Or, a dot+edge combination where
1664 * the second edge is taken to be the next clockwise edge from the dot.
1665 * Original loopy code didn't have this extra restriction of the lines being
1666 * adjacent. From my tests with square grids, this extra restriction seems to
1667 * take little, if anything, away from the quality of the puzzles.
1668 * A dline can be uniquely identified by an edge/dot combination, given that
1669 * a dline-pair always goes clockwise around its common dot. The edge/dot
1670 * combination can be represented by an edge/bool combination - if bool is
1671 * TRUE, use edge->dot1 else use edge->dot2. So the total number of dlines is
1672 * exactly twice the number of edges in the grid - although the dlines
1673 * spanning the infinite face are not all that useful to the solver.
1674 * Note that, by convention, a dline goes clockwise around its common dot,
1675 * which means the dline goes anti-clockwise around its common face.
1678 /* Helper functions for obtaining an index into an array of dlines, given
1679 * various information. We assume the grid layout conventions about how
1680 * the various lists are interleaved - see grid_make_consistent() for
1683 /* i points to the first edge of the dline pair, reading clockwise around
1685 static int dline_index_from_dot(grid *g, grid_dot *d, int i)
1687 grid_edge *e = d->edges[i];
1692 if (i2 == d->order) i2 = 0;
1695 ret = 2 * (e - g->edges) + ((e->dot1 == d) ? 1 : 0);
1697 printf("dline_index_from_dot: d=%d,i=%d, edges [%d,%d] - %d\n",
1698 (int)(d - g->dots), i, (int)(e - g->edges),
1699 (int)(e2 - g->edges), ret);
1703 /* i points to the second edge of the dline pair, reading clockwise around
1704 * the face. That is, the edges of the dline, starting at edge{i}, read
1705 * anti-clockwise around the face. By layout conventions, the common dot
1706 * of the dline will be f->dots[i] */
1707 static int dline_index_from_face(grid *g, grid_face *f, int i)
1709 grid_edge *e = f->edges[i];
1710 grid_dot *d = f->dots[i];
1715 if (i2 < 0) i2 += f->order;
1718 ret = 2 * (e - g->edges) + ((e->dot1 == d) ? 1 : 0);
1720 printf("dline_index_from_face: f=%d,i=%d, edges [%d,%d] - %d\n",
1721 (int)(f - g->faces), i, (int)(e - g->edges),
1722 (int)(e2 - g->edges), ret);
1726 static int is_atleastone(const char *dline_array, int index)
1728 return BIT_SET(dline_array[index], 0);
1730 static int set_atleastone(char *dline_array, int index)
1732 return SET_BIT(dline_array[index], 0);
1734 static int is_atmostone(const char *dline_array, int index)
1736 return BIT_SET(dline_array[index], 1);
1738 static int set_atmostone(char *dline_array, int index)
1740 return SET_BIT(dline_array[index], 1);
1743 static void array_setall(char *array, char from, char to, int len)
1745 char *p = array, *p_old = p;
1746 int len_remaining = len;
1748 while ((p = memchr(p, from, len_remaining))) {
1750 len_remaining -= p - p_old;
1755 /* Helper, called when doing dline dot deductions, in the case where we
1756 * have 4 UNKNOWNs, and two of them (adjacent) have *exactly* one YES between
1757 * them (because of dline atmostone/atleastone).
1758 * On entry, edge points to the first of these two UNKNOWNs. This function
1759 * will find the opposite UNKNOWNS (if they are adjacent to one another)
1760 * and set their corresponding dline to atleastone. (Setting atmostone
1761 * already happens in earlier dline deductions) */
1762 static int dline_set_opp_atleastone(solver_state *sstate,
1763 grid_dot *d, int edge)
1765 game_state *state = sstate->state;
1766 grid *g = state->game_grid;
1769 for (opp = 0; opp < N; opp++) {
1770 int opp_dline_index;
1771 if (opp == edge || opp == edge+1 || opp == edge-1)
1773 if (opp == 0 && edge == N-1)
1775 if (opp == N-1 && edge == 0)
1778 if (opp2 == N) opp2 = 0;
1779 /* Check if opp, opp2 point to LINE_UNKNOWNs */
1780 if (state->lines[d->edges[opp] - g->edges] != LINE_UNKNOWN)
1782 if (state->lines[d->edges[opp2] - g->edges] != LINE_UNKNOWN)
1784 /* Found opposite UNKNOWNS and they're next to each other */
1785 opp_dline_index = dline_index_from_dot(g, d, opp);
1786 return set_atleastone(sstate->dlines, opp_dline_index);
1792 /* Set pairs of lines around this face which are known to be identical, to
1793 * the given line_state */
1794 static int face_setall_identical(solver_state *sstate, int face_index,
1795 enum line_state line_new)
1797 /* can[dir] contains the canonical line associated with the line in
1798 * direction dir from the square in question. Similarly inv[dir] is
1799 * whether or not the line in question is inverse to its canonical
1802 game_state *state = sstate->state;
1803 grid *g = state->game_grid;
1804 grid_face *f = g->faces + face_index;
1807 int can1, can2, inv1, inv2;
1809 for (i = 0; i < N; i++) {
1810 int line1_index = f->edges[i] - g->edges;
1811 if (state->lines[line1_index] != LINE_UNKNOWN)
1813 for (j = i + 1; j < N; j++) {
1814 int line2_index = f->edges[j] - g->edges;
1815 if (state->lines[line2_index] != LINE_UNKNOWN)
1818 /* Found two UNKNOWNS */
1819 can1 = edsf_canonify(sstate->linedsf, line1_index, &inv1);
1820 can2 = edsf_canonify(sstate->linedsf, line2_index, &inv2);
1821 if (can1 == can2 && inv1 == inv2) {
1822 solver_set_line(sstate, line1_index, line_new);
1823 solver_set_line(sstate, line2_index, line_new);
1830 /* Given a dot or face, and a count of LINE_UNKNOWNs, find them and
1831 * return the edge indices into e. */
1832 static void find_unknowns(game_state *state,
1833 grid_edge **edge_list, /* Edge list to search (from a face or a dot) */
1834 int expected_count, /* Number of UNKNOWNs (comes from solver's cache) */
1835 int *e /* Returned edge indices */)
1838 grid *g = state->game_grid;
1839 while (c < expected_count) {
1840 int line_index = *edge_list - g->edges;
1841 if (state->lines[line_index] == LINE_UNKNOWN) {
1849 /* If we have a list of edges, and we know whether the number of YESs should
1850 * be odd or even, and there are only a few UNKNOWNs, we can do some simple
1851 * linedsf deductions. This can be used for both face and dot deductions.
1852 * Returns the difficulty level of the next solver that should be used,
1853 * or DIFF_MAX if no progress was made. */
1854 static int parity_deductions(solver_state *sstate,
1855 grid_edge **edge_list, /* Edge list (from a face or a dot) */
1856 int total_parity, /* Expected number of YESs modulo 2 (either 0 or 1) */
1859 game_state *state = sstate->state;
1860 int diff = DIFF_MAX;
1861 int *linedsf = sstate->linedsf;
1863 if (unknown_count == 2) {
1864 /* Lines are known alike/opposite, depending on inv. */
1866 find_unknowns(state, edge_list, 2, e);
1867 if (merge_lines(sstate, e[0], e[1], total_parity))
1868 diff = min(diff, DIFF_HARD);
1869 } else if (unknown_count == 3) {
1871 int can[3]; /* canonical edges */
1872 int inv[3]; /* whether can[x] is inverse to e[x] */
1873 find_unknowns(state, edge_list, 3, e);
1874 can[0] = edsf_canonify(linedsf, e[0], inv);
1875 can[1] = edsf_canonify(linedsf, e[1], inv+1);
1876 can[2] = edsf_canonify(linedsf, e[2], inv+2);
1877 if (can[0] == can[1]) {
1878 if (solver_set_line(sstate, e[2], (total_parity^inv[0]^inv[1]) ?
1879 LINE_YES : LINE_NO))
1880 diff = min(diff, DIFF_EASY);
1882 if (can[0] == can[2]) {
1883 if (solver_set_line(sstate, e[1], (total_parity^inv[0]^inv[2]) ?
1884 LINE_YES : LINE_NO))
1885 diff = min(diff, DIFF_EASY);
1887 if (can[1] == can[2]) {
1888 if (solver_set_line(sstate, e[0], (total_parity^inv[1]^inv[2]) ?
1889 LINE_YES : LINE_NO))
1890 diff = min(diff, DIFF_EASY);
1892 } else if (unknown_count == 4) {
1894 int can[4]; /* canonical edges */
1895 int inv[4]; /* whether can[x] is inverse to e[x] */
1896 find_unknowns(state, edge_list, 4, e);
1897 can[0] = edsf_canonify(linedsf, e[0], inv);
1898 can[1] = edsf_canonify(linedsf, e[1], inv+1);
1899 can[2] = edsf_canonify(linedsf, e[2], inv+2);
1900 can[3] = edsf_canonify(linedsf, e[3], inv+3);
1901 if (can[0] == can[1]) {
1902 if (merge_lines(sstate, e[2], e[3], total_parity^inv[0]^inv[1]))
1903 diff = min(diff, DIFF_HARD);
1904 } else if (can[0] == can[2]) {
1905 if (merge_lines(sstate, e[1], e[3], total_parity^inv[0]^inv[2]))
1906 diff = min(diff, DIFF_HARD);
1907 } else if (can[0] == can[3]) {
1908 if (merge_lines(sstate, e[1], e[2], total_parity^inv[0]^inv[3]))
1909 diff = min(diff, DIFF_HARD);
1910 } else if (can[1] == can[2]) {
1911 if (merge_lines(sstate, e[0], e[3], total_parity^inv[1]^inv[2]))
1912 diff = min(diff, DIFF_HARD);
1913 } else if (can[1] == can[3]) {
1914 if (merge_lines(sstate, e[0], e[2], total_parity^inv[1]^inv[3]))
1915 diff = min(diff, DIFF_HARD);
1916 } else if (can[2] == can[3]) {
1917 if (merge_lines(sstate, e[0], e[1], total_parity^inv[2]^inv[3]))
1918 diff = min(diff, DIFF_HARD);
1926 * These are the main solver functions.
1928 * Their return values are diff values corresponding to the lowest mode solver
1929 * that would notice the work that they have done. For example if the normal
1930 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
1931 * easy mode solver might be able to make progress using that. It doesn't make
1932 * sense for one of them to return a diff value higher than that of the
1935 * Each function returns the lowest value it can, as early as possible, in
1936 * order to try and pass as much work as possible back to the lower level
1937 * solvers which progress more quickly.
1940 /* PROPOSED NEW DESIGN:
1941 * We have a work queue consisting of 'events' notifying us that something has
1942 * happened that a particular solver mode might be interested in. For example
1943 * the hard mode solver might do something that helps the normal mode solver at
1944 * dot [x,y] in which case it will enqueue an event recording this fact. Then
1945 * we pull events off the work queue, and hand each in turn to the solver that
1946 * is interested in them. If a solver reports that it failed we pass the same
1947 * event on to progressively more advanced solvers and the loop detector. Once
1948 * we've exhausted an event, or it has helped us progress, we drop it and
1949 * continue to the next one. The events are sorted first in order of solver
1950 * complexity (easy first) then order of insertion (oldest first).
1951 * Once we run out of events we loop over each permitted solver in turn
1952 * (easiest first) until either a deduction is made (and an event therefore
1953 * emerges) or no further deductions can be made (in which case we've failed).
1956 * * How do we 'loop over' a solver when both dots and squares are concerned.
1957 * Answer: first all squares then all dots.
1960 static int trivial_deductions(solver_state *sstate)
1962 int i, current_yes, current_no;
1963 game_state *state = sstate->state;
1964 grid *g = state->game_grid;
1965 int diff = DIFF_MAX;
1967 /* Per-face deductions */
1968 for (i = 0; i < g->num_faces; i++) {
1969 grid_face *f = g->faces + i;
1971 if (sstate->face_solved[i])
1974 current_yes = sstate->face_yes_count[i];
1975 current_no = sstate->face_no_count[i];
1977 if (current_yes + current_no == f->order) {
1978 sstate->face_solved[i] = TRUE;
1982 if (state->clues[i] < 0)
1986 * This code checks whether the numeric clue on a face is so
1987 * large as to permit all its remaining LINE_UNKNOWNs to be
1988 * filled in as LINE_YES, or alternatively so small as to
1989 * permit them all to be filled in as LINE_NO.
1992 if (state->clues[i] < current_yes) {
1993 sstate->solver_status = SOLVER_MISTAKE;
1996 if (state->clues[i] == current_yes) {
1997 if (face_setall(sstate, i, LINE_UNKNOWN, LINE_NO))
1998 diff = min(diff, DIFF_EASY);
1999 sstate->face_solved[i] = TRUE;
2003 if (f->order - state->clues[i] < current_no) {
2004 sstate->solver_status = SOLVER_MISTAKE;
2007 if (f->order - state->clues[i] == current_no) {
2008 if (face_setall(sstate, i, LINE_UNKNOWN, LINE_YES))
2009 diff = min(diff, DIFF_EASY);
2010 sstate->face_solved[i] = TRUE;
2014 if (f->order - state->clues[i] == current_no + 1 &&
2015 f->order - current_yes - current_no > 2) {
2017 * One small refinement to the above: we also look for any
2018 * adjacent pair of LINE_UNKNOWNs around the face with
2019 * some LINE_YES incident on it from elsewhere. If we find
2020 * one, then we know that pair of LINE_UNKNOWNs can't
2021 * _both_ be LINE_YES, and hence that pushes us one line
2022 * closer to being able to determine all the rest.
2024 int j, k, e1, e2, e, d;
2026 for (j = 0; j < f->order; j++) {
2027 e1 = f->edges[j] - g->edges;
2028 e2 = f->edges[j+1 < f->order ? j+1 : 0] - g->edges;
2030 if (g->edges[e1].dot1 == g->edges[e2].dot1 ||
2031 g->edges[e1].dot1 == g->edges[e2].dot2) {
2032 d = g->edges[e1].dot1 - g->dots;
2034 assert(g->edges[e1].dot2 == g->edges[e2].dot1 ||
2035 g->edges[e1].dot2 == g->edges[e2].dot2);
2036 d = g->edges[e1].dot2 - g->dots;
2039 if (state->lines[e1] == LINE_UNKNOWN &&
2040 state->lines[e2] == LINE_UNKNOWN) {
2041 for (k = 0; k < g->dots[d].order; k++) {
2042 int e = g->dots[d].edges[k] - g->edges;
2043 if (state->lines[e] == LINE_YES)
2044 goto found; /* multi-level break */
2052 * If we get here, we've found such a pair of edges, and
2053 * they're e1 and e2.
2055 for (j = 0; j < f->order; j++) {
2056 e = f->edges[j] - g->edges;
2057 if (state->lines[e] == LINE_UNKNOWN && e != e1 && e != e2) {
2058 int r = solver_set_line(sstate, e, LINE_YES);
2060 diff = min(diff, DIFF_EASY);
2066 check_caches(sstate);
2068 /* Per-dot deductions */
2069 for (i = 0; i < g->num_dots; i++) {
2070 grid_dot *d = g->dots + i;
2071 int yes, no, unknown;
2073 if (sstate->dot_solved[i])
2076 yes = sstate->dot_yes_count[i];
2077 no = sstate->dot_no_count[i];
2078 unknown = d->order - yes - no;
2082 sstate->dot_solved[i] = TRUE;
2083 } else if (unknown == 1) {
2084 dot_setall(sstate, i, LINE_UNKNOWN, LINE_NO);
2085 diff = min(diff, DIFF_EASY);
2086 sstate->dot_solved[i] = TRUE;
2088 } else if (yes == 1) {
2090 sstate->solver_status = SOLVER_MISTAKE;
2092 } else if (unknown == 1) {
2093 dot_setall(sstate, i, LINE_UNKNOWN, LINE_YES);
2094 diff = min(diff, DIFF_EASY);
2096 } else if (yes == 2) {
2098 dot_setall(sstate, i, LINE_UNKNOWN, LINE_NO);
2099 diff = min(diff, DIFF_EASY);
2101 sstate->dot_solved[i] = TRUE;
2103 sstate->solver_status = SOLVER_MISTAKE;
2108 check_caches(sstate);
2113 static int dline_deductions(solver_state *sstate)
2115 game_state *state = sstate->state;
2116 grid *g = state->game_grid;
2117 char *dlines = sstate->dlines;
2119 int diff = DIFF_MAX;
2121 /* ------ Face deductions ------ */
2123 /* Given a set of dline atmostone/atleastone constraints, need to figure
2124 * out if we can deduce any further info. For more general faces than
2125 * squares, this turns out to be a tricky problem.
2126 * The approach taken here is to define (per face) NxN matrices:
2127 * "maxs" and "mins".
2128 * The entries maxs(j,k) and mins(j,k) define the upper and lower limits
2129 * for the possible number of edges that are YES between positions j and k
2130 * going clockwise around the face. Can think of j and k as marking dots
2131 * around the face (recall the labelling scheme: edge0 joins dot0 to dot1,
2132 * edge1 joins dot1 to dot2 etc).
2133 * Trivially, mins(j,j) = maxs(j,j) = 0, and we don't even bother storing
2134 * these. mins(j,j+1) and maxs(j,j+1) are determined by whether edge{j}
2135 * is YES, NO or UNKNOWN. mins(j,j+2) and maxs(j,j+2) are related to
2136 * the dline atmostone/atleastone status for edges j and j+1.
2138 * Then we calculate the remaining entries recursively. We definitely
2140 * mins(j,k) >= { mins(j,u) + mins(u,k) } for any u between j and k.
2141 * This is because any valid placement of YESs between j and k must give
2142 * a valid placement between j and u, and also between u and k.
2143 * I believe it's sufficient to use just the two values of u:
2144 * j+1 and j+2. Seems to work well in practice - the bounds we compute
2145 * are rigorous, even if they might not be best-possible.
2147 * Once we have maxs and mins calculated, we can make inferences about
2148 * each dline{j,j+1} by looking at the possible complementary edge-counts
2149 * mins(j+2,j) and maxs(j+2,j) and comparing these with the face clue.
2150 * As well as dlines, we can make similar inferences about single edges.
2151 * For example, consider a pentagon with clue 3, and we know at most one
2152 * of (edge0, edge1) is YES, and at most one of (edge2, edge3) is YES.
2153 * We could then deduce edge4 is YES, because maxs(0,4) would be 2, so
2154 * that final edge would have to be YES to make the count up to 3.
2157 /* Much quicker to allocate arrays on the stack than the heap, so
2158 * define the largest possible face size, and base our array allocations
2159 * on that. We check this with an assertion, in case someone decides to
2160 * make a grid which has larger faces than this. Note, this algorithm
2161 * could get quite expensive if there are many large faces. */
2162 #define MAX_FACE_SIZE 12
2164 for (i = 0; i < g->num_faces; i++) {
2165 int maxs[MAX_FACE_SIZE][MAX_FACE_SIZE];
2166 int mins[MAX_FACE_SIZE][MAX_FACE_SIZE];
2167 grid_face *f = g->faces + i;
2170 int clue = state->clues[i];
2171 assert(N <= MAX_FACE_SIZE);
2172 if (sstate->face_solved[i])
2174 if (clue < 0) continue;
2176 /* Calculate the (j,j+1) entries */
2177 for (j = 0; j < N; j++) {
2178 int edge_index = f->edges[j] - g->edges;
2180 enum line_state line1 = state->lines[edge_index];
2181 enum line_state line2;
2185 maxs[j][k] = (line1 == LINE_NO) ? 0 : 1;
2186 mins[j][k] = (line1 == LINE_YES) ? 1 : 0;
2187 /* Calculate the (j,j+2) entries */
2188 dline_index = dline_index_from_face(g, f, k);
2189 edge_index = f->edges[k] - g->edges;
2190 line2 = state->lines[edge_index];
2196 if (line1 == LINE_NO) tmp--;
2197 if (line2 == LINE_NO) tmp--;
2198 if (tmp == 2 && is_atmostone(dlines, dline_index))
2204 if (line1 == LINE_YES) tmp++;
2205 if (line2 == LINE_YES) tmp++;
2206 if (tmp == 0 && is_atleastone(dlines, dline_index))
2211 /* Calculate the (j,j+m) entries for m between 3 and N-1 */
2212 for (m = 3; m < N; m++) {
2213 for (j = 0; j < N; j++) {
2221 maxs[j][k] = maxs[j][u] + maxs[u][k];
2222 mins[j][k] = mins[j][u] + mins[u][k];
2223 tmp = maxs[j][v] + maxs[v][k];
2224 maxs[j][k] = min(maxs[j][k], tmp);
2225 tmp = mins[j][v] + mins[v][k];
2226 mins[j][k] = max(mins[j][k], tmp);
2230 /* See if we can make any deductions */
2231 for (j = 0; j < N; j++) {
2233 grid_edge *e = f->edges[j];
2234 int line_index = e - g->edges;
2237 if (state->lines[line_index] != LINE_UNKNOWN)
2242 /* minimum YESs in the complement of this edge */
2243 if (mins[k][j] > clue) {
2244 sstate->solver_status = SOLVER_MISTAKE;
2247 if (mins[k][j] == clue) {
2248 /* setting this edge to YES would make at least
2249 * (clue+1) edges - contradiction */
2250 solver_set_line(sstate, line_index, LINE_NO);
2251 diff = min(diff, DIFF_EASY);
2253 if (maxs[k][j] < clue - 1) {
2254 sstate->solver_status = SOLVER_MISTAKE;
2257 if (maxs[k][j] == clue - 1) {
2258 /* Only way to satisfy the clue is to set edge{j} as YES */
2259 solver_set_line(sstate, line_index, LINE_YES);
2260 diff = min(diff, DIFF_EASY);
2263 /* More advanced deduction that allows propagation along diagonal
2264 * chains of faces connected by dots, for example, 3-2-...-2-3
2265 * in square grids. */
2266 if (sstate->diff >= DIFF_TRICKY) {
2267 /* Now see if we can make dline deduction for edges{j,j+1} */
2269 if (state->lines[e - g->edges] != LINE_UNKNOWN)
2270 /* Only worth doing this for an UNKNOWN,UNKNOWN pair.
2271 * Dlines where one of the edges is known, are handled in the
2275 dline_index = dline_index_from_face(g, f, k);
2279 /* minimum YESs in the complement of this dline */
2280 if (mins[k][j] > clue - 2) {
2281 /* Adding 2 YESs would break the clue */
2282 if (set_atmostone(dlines, dline_index))
2283 diff = min(diff, DIFF_NORMAL);
2285 /* maximum YESs in the complement of this dline */
2286 if (maxs[k][j] < clue) {
2287 /* Adding 2 NOs would mean not enough YESs */
2288 if (set_atleastone(dlines, dline_index))
2289 diff = min(diff, DIFF_NORMAL);
2295 if (diff < DIFF_NORMAL)
2298 /* ------ Dot deductions ------ */
2300 for (i = 0; i < g->num_dots; i++) {
2301 grid_dot *d = g->dots + i;
2303 int yes, no, unknown;
2305 if (sstate->dot_solved[i])
2307 yes = sstate->dot_yes_count[i];
2308 no = sstate->dot_no_count[i];
2309 unknown = N - yes - no;
2311 for (j = 0; j < N; j++) {
2314 int line1_index, line2_index;
2315 enum line_state line1, line2;
2318 dline_index = dline_index_from_dot(g, d, j);
2319 line1_index = d->edges[j] - g->edges;
2320 line2_index = d->edges[k] - g->edges;
2321 line1 = state->lines[line1_index];
2322 line2 = state->lines[line2_index];
2324 /* Infer dline state from line state */
2325 if (line1 == LINE_NO || line2 == LINE_NO) {
2326 if (set_atmostone(dlines, dline_index))
2327 diff = min(diff, DIFF_NORMAL);
2329 if (line1 == LINE_YES || line2 == LINE_YES) {
2330 if (set_atleastone(dlines, dline_index))
2331 diff = min(diff, DIFF_NORMAL);
2333 /* Infer line state from dline state */
2334 if (is_atmostone(dlines, dline_index)) {
2335 if (line1 == LINE_YES && line2 == LINE_UNKNOWN) {
2336 solver_set_line(sstate, line2_index, LINE_NO);
2337 diff = min(diff, DIFF_EASY);
2339 if (line2 == LINE_YES && line1 == LINE_UNKNOWN) {
2340 solver_set_line(sstate, line1_index, LINE_NO);
2341 diff = min(diff, DIFF_EASY);
2344 if (is_atleastone(dlines, dline_index)) {
2345 if (line1 == LINE_NO && line2 == LINE_UNKNOWN) {
2346 solver_set_line(sstate, line2_index, LINE_YES);
2347 diff = min(diff, DIFF_EASY);
2349 if (line2 == LINE_NO && line1 == LINE_UNKNOWN) {
2350 solver_set_line(sstate, line1_index, LINE_YES);
2351 diff = min(diff, DIFF_EASY);
2354 /* Deductions that depend on the numbers of lines.
2355 * Only bother if both lines are UNKNOWN, otherwise the
2356 * easy-mode solver (or deductions above) would have taken
2358 if (line1 != LINE_UNKNOWN || line2 != LINE_UNKNOWN)
2361 if (yes == 0 && unknown == 2) {
2362 /* Both these unknowns must be identical. If we know
2363 * atmostone or atleastone, we can make progress. */
2364 if (is_atmostone(dlines, dline_index)) {
2365 solver_set_line(sstate, line1_index, LINE_NO);
2366 solver_set_line(sstate, line2_index, LINE_NO);
2367 diff = min(diff, DIFF_EASY);
2369 if (is_atleastone(dlines, dline_index)) {
2370 solver_set_line(sstate, line1_index, LINE_YES);
2371 solver_set_line(sstate, line2_index, LINE_YES);
2372 diff = min(diff, DIFF_EASY);
2376 if (set_atmostone(dlines, dline_index))
2377 diff = min(diff, DIFF_NORMAL);
2379 if (set_atleastone(dlines, dline_index))
2380 diff = min(diff, DIFF_NORMAL);
2384 /* More advanced deduction that allows propagation along diagonal
2385 * chains of faces connected by dots, for example: 3-2-...-2-3
2386 * in square grids. */
2387 if (sstate->diff >= DIFF_TRICKY) {
2388 /* If we have atleastone set for this dline, infer
2389 * atmostone for each "opposite" dline (that is, each
2390 * dline without edges in common with this one).
2391 * Again, this test is only worth doing if both these
2392 * lines are UNKNOWN. For if one of these lines were YES,
2393 * the (yes == 1) test above would kick in instead. */
2394 if (is_atleastone(dlines, dline_index)) {
2396 for (opp = 0; opp < N; opp++) {
2397 int opp_dline_index;
2398 if (opp == j || opp == j+1 || opp == j-1)
2400 if (j == 0 && opp == N-1)
2402 if (j == N-1 && opp == 0)
2404 opp_dline_index = dline_index_from_dot(g, d, opp);
2405 if (set_atmostone(dlines, opp_dline_index))
2406 diff = min(diff, DIFF_NORMAL);
2408 if (yes == 0 && is_atmostone(dlines, dline_index)) {
2409 /* This dline has *exactly* one YES and there are no
2410 * other YESs. This allows more deductions. */
2412 /* Third unknown must be YES */
2413 for (opp = 0; opp < N; opp++) {
2415 if (opp == j || opp == k)
2417 opp_index = d->edges[opp] - g->edges;
2418 if (state->lines[opp_index] == LINE_UNKNOWN) {
2419 solver_set_line(sstate, opp_index,
2421 diff = min(diff, DIFF_EASY);
2424 } else if (unknown == 4) {
2425 /* Exactly one of opposite UNKNOWNS is YES. We've
2426 * already set atmostone, so set atleastone as
2429 if (dline_set_opp_atleastone(sstate, d, j))
2430 diff = min(diff, DIFF_NORMAL);
2440 static int linedsf_deductions(solver_state *sstate)
2442 game_state *state = sstate->state;
2443 grid *g = state->game_grid;
2444 char *dlines = sstate->dlines;
2446 int diff = DIFF_MAX;
2449 /* ------ Face deductions ------ */
2451 /* A fully-general linedsf deduction seems overly complicated
2452 * (I suspect the problem is NP-complete, though in practice it might just
2453 * be doable because faces are limited in size).
2454 * For simplicity, we only consider *pairs* of LINE_UNKNOWNS that are
2455 * known to be identical. If setting them both to YES (or NO) would break
2456 * the clue, set them to NO (or YES). */
2458 for (i = 0; i < g->num_faces; i++) {
2459 int N, yes, no, unknown;
2462 if (sstate->face_solved[i])
2464 clue = state->clues[i];
2468 N = g->faces[i].order;
2469 yes = sstate->face_yes_count[i];
2470 if (yes + 1 == clue) {
2471 if (face_setall_identical(sstate, i, LINE_NO))
2472 diff = min(diff, DIFF_EASY);
2474 no = sstate->face_no_count[i];
2475 if (no + 1 == N - clue) {
2476 if (face_setall_identical(sstate, i, LINE_YES))
2477 diff = min(diff, DIFF_EASY);
2480 /* Reload YES count, it might have changed */
2481 yes = sstate->face_yes_count[i];
2482 unknown = N - no - yes;
2484 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2485 * parity of lines. */
2486 diff_tmp = parity_deductions(sstate, g->faces[i].edges,
2487 (clue - yes) % 2, unknown);
2488 diff = min(diff, diff_tmp);
2491 /* ------ Dot deductions ------ */
2492 for (i = 0; i < g->num_dots; i++) {
2493 grid_dot *d = g->dots + i;
2496 int yes, no, unknown;
2497 /* Go through dlines, and do any dline<->linedsf deductions wherever
2498 * we find two UNKNOWNS. */
2499 for (j = 0; j < N; j++) {
2500 int dline_index = dline_index_from_dot(g, d, j);
2503 int can1, can2, inv1, inv2;
2505 line1_index = d->edges[j] - g->edges;
2506 if (state->lines[line1_index] != LINE_UNKNOWN)
2509 if (j2 == N) j2 = 0;
2510 line2_index = d->edges[j2] - g->edges;
2511 if (state->lines[line2_index] != LINE_UNKNOWN)
2513 /* Infer dline flags from linedsf */
2514 can1 = edsf_canonify(sstate->linedsf, line1_index, &inv1);
2515 can2 = edsf_canonify(sstate->linedsf, line2_index, &inv2);
2516 if (can1 == can2 && inv1 != inv2) {
2517 /* These are opposites, so set dline atmostone/atleastone */
2518 if (set_atmostone(dlines, dline_index))
2519 diff = min(diff, DIFF_NORMAL);
2520 if (set_atleastone(dlines, dline_index))
2521 diff = min(diff, DIFF_NORMAL);
2524 /* Infer linedsf from dline flags */
2525 if (is_atmostone(dlines, dline_index)
2526 && is_atleastone(dlines, dline_index)) {
2527 if (merge_lines(sstate, line1_index, line2_index, 1))
2528 diff = min(diff, DIFF_HARD);
2532 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2533 * parity of lines. */
2534 yes = sstate->dot_yes_count[i];
2535 no = sstate->dot_no_count[i];
2536 unknown = N - yes - no;
2537 diff_tmp = parity_deductions(sstate, d->edges,
2539 diff = min(diff, diff_tmp);
2542 /* ------ Edge dsf deductions ------ */
2544 /* If the state of a line is known, deduce the state of its canonical line
2545 * too, and vice versa. */
2546 for (i = 0; i < g->num_edges; i++) {
2549 can = edsf_canonify(sstate->linedsf, i, &inv);
2552 s = sstate->state->lines[can];
2553 if (s != LINE_UNKNOWN) {
2554 if (solver_set_line(sstate, i, inv ? OPP(s) : s))
2555 diff = min(diff, DIFF_EASY);
2557 s = sstate->state->lines[i];
2558 if (s != LINE_UNKNOWN) {
2559 if (solver_set_line(sstate, can, inv ? OPP(s) : s))
2560 diff = min(diff, DIFF_EASY);
2568 static int loop_deductions(solver_state *sstate)
2570 int edgecount = 0, clues = 0, satclues = 0, sm1clues = 0;
2571 game_state *state = sstate->state;
2572 grid *g = state->game_grid;
2573 int shortest_chainlen = g->num_dots;
2574 int loop_found = FALSE;
2576 int progress = FALSE;
2580 * Go through the grid and update for all the new edges.
2581 * Since merge_dots() is idempotent, the simplest way to
2582 * do this is just to update for _all_ the edges.
2583 * Also, while we're here, we count the edges.
2585 for (i = 0; i < g->num_edges; i++) {
2586 if (state->lines[i] == LINE_YES) {
2587 loop_found |= merge_dots(sstate, i);
2593 * Count the clues, count the satisfied clues, and count the
2594 * satisfied-minus-one clues.
2596 for (i = 0; i < g->num_faces; i++) {
2597 int c = state->clues[i];
2599 int o = sstate->face_yes_count[i];
2608 for (i = 0; i < g->num_dots; ++i) {
2610 sstate->looplen[dsf_canonify(sstate->dotdsf, i)];
2611 if (dots_connected > 1)
2612 shortest_chainlen = min(shortest_chainlen, dots_connected);
2615 assert(sstate->solver_status == SOLVER_INCOMPLETE);
2617 if (satclues == clues && shortest_chainlen == edgecount) {
2618 sstate->solver_status = SOLVER_SOLVED;
2619 /* This discovery clearly counts as progress, even if we haven't
2620 * just added any lines or anything */
2622 goto finished_loop_deductionsing;
2626 * Now go through looking for LINE_UNKNOWN edges which
2627 * connect two dots that are already in the same
2628 * equivalence class. If we find one, test to see if the
2629 * loop it would create is a solution.
2631 for (i = 0; i < g->num_edges; i++) {
2632 grid_edge *e = g->edges + i;
2633 int d1 = e->dot1 - g->dots;
2634 int d2 = e->dot2 - g->dots;
2636 if (state->lines[i] != LINE_UNKNOWN)
2639 eqclass = dsf_canonify(sstate->dotdsf, d1);
2640 if (eqclass != dsf_canonify(sstate->dotdsf, d2))
2643 val = LINE_NO; /* loop is bad until proven otherwise */
2646 * This edge would form a loop. Next
2647 * question: how long would the loop be?
2648 * Would it equal the total number of edges
2649 * (plus the one we'd be adding if we added
2652 if (sstate->looplen[eqclass] == edgecount + 1) {
2656 * This edge would form a loop which
2657 * took in all the edges in the entire
2658 * grid. So now we need to work out
2659 * whether it would be a valid solution
2660 * to the puzzle, which means we have to
2661 * check if it satisfies all the clues.
2662 * This means that every clue must be
2663 * either satisfied or satisfied-minus-
2664 * 1, and also that the number of
2665 * satisfied-minus-1 clues must be at
2666 * most two and they must lie on either
2667 * side of this edge.
2671 int f = e->face1 - g->faces;
2672 int c = state->clues[f];
2673 if (c >= 0 && sstate->face_yes_count[f] == c - 1)
2677 int f = e->face2 - g->faces;
2678 int c = state->clues[f];
2679 if (c >= 0 && sstate->face_yes_count[f] == c - 1)
2682 if (sm1clues == sm1_nearby &&
2683 sm1clues + satclues == clues) {
2684 val = LINE_YES; /* loop is good! */
2689 * Right. Now we know that adding this edge
2690 * would form a loop, and we know whether
2691 * that loop would be a viable solution or
2694 * If adding this edge produces a solution,
2695 * then we know we've found _a_ solution but
2696 * we don't know that it's _the_ solution -
2697 * if it were provably the solution then
2698 * we'd have deduced this edge some time ago
2699 * without the need to do loop detection. So
2700 * in this state we return SOLVER_AMBIGUOUS,
2701 * which has the effect that hitting Solve
2702 * on a user-provided puzzle will fill in a
2703 * solution but using the solver to
2704 * construct new puzzles won't consider this
2705 * a reasonable deduction for the user to
2708 progress = solver_set_line(sstate, i, val);
2709 assert(progress == TRUE);
2710 if (val == LINE_YES) {
2711 sstate->solver_status = SOLVER_AMBIGUOUS;
2712 goto finished_loop_deductionsing;
2716 finished_loop_deductionsing:
2717 return progress ? DIFF_EASY : DIFF_MAX;
2720 /* This will return a dynamically allocated solver_state containing the (more)
2722 static solver_state *solve_game_rec(const solver_state *sstate_start)
2724 solver_state *sstate;
2726 /* Index of the solver we should call next. */
2729 /* As a speed-optimisation, we avoid re-running solvers that we know
2730 * won't make any progress. This happens when a high-difficulty
2731 * solver makes a deduction that can only help other high-difficulty
2733 * For example: if a new 'dline' flag is set by dline_deductions, the
2734 * trivial_deductions solver cannot do anything with this information.
2735 * If we've already run the trivial_deductions solver (because it's
2736 * earlier in the list), there's no point running it again.
2738 * Therefore: if a solver is earlier in the list than "threshold_index",
2739 * we don't bother running it if it's difficulty level is less than
2742 int threshold_diff = 0;
2743 int threshold_index = 0;
2745 sstate = dup_solver_state(sstate_start);
2747 check_caches(sstate);
2749 while (i < NUM_SOLVERS) {
2750 if (sstate->solver_status == SOLVER_MISTAKE)
2752 if (sstate->solver_status == SOLVER_SOLVED ||
2753 sstate->solver_status == SOLVER_AMBIGUOUS) {
2754 /* solver finished */
2758 if ((solver_diffs[i] >= threshold_diff || i >= threshold_index)
2759 && solver_diffs[i] <= sstate->diff) {
2760 /* current_solver is eligible, so use it */
2761 int next_diff = solver_fns[i](sstate);
2762 if (next_diff != DIFF_MAX) {
2763 /* solver made progress, so use new thresholds and
2764 * start again at top of list. */
2765 threshold_diff = next_diff;
2766 threshold_index = i;
2771 /* current_solver is ineligible, or failed to make progress, so
2772 * go to the next solver in the list */
2776 if (sstate->solver_status == SOLVER_SOLVED ||
2777 sstate->solver_status == SOLVER_AMBIGUOUS) {
2778 /* s/LINE_UNKNOWN/LINE_NO/g */
2779 array_setall(sstate->state->lines, LINE_UNKNOWN, LINE_NO,
2780 sstate->state->game_grid->num_edges);
2787 static char *solve_game(game_state *state, game_state *currstate,
2788 char *aux, char **error)
2791 solver_state *sstate, *new_sstate;
2793 sstate = new_solver_state(state, DIFF_MAX);
2794 new_sstate = solve_game_rec(sstate);
2796 if (new_sstate->solver_status == SOLVER_SOLVED) {
2797 soln = encode_solve_move(new_sstate->state);
2798 } else if (new_sstate->solver_status == SOLVER_AMBIGUOUS) {
2799 soln = encode_solve_move(new_sstate->state);
2800 /**error = "Solver found ambiguous solutions"; */
2802 soln = encode_solve_move(new_sstate->state);
2803 /**error = "Solver failed"; */
2806 free_solver_state(new_sstate);
2807 free_solver_state(sstate);
2812 /* ----------------------------------------------------------------------
2813 * Drawing and mouse-handling
2816 static char *interpret_move(game_state *state, game_ui *ui, const game_drawstate *ds,
2817 int x, int y, int button)
2819 grid *g = state->game_grid;
2823 char button_char = ' ';
2824 enum line_state old_state;
2826 button &= ~MOD_MASK;
2828 /* Convert mouse-click (x,y) to grid coordinates */
2829 x -= BORDER(ds->tilesize);
2830 y -= BORDER(ds->tilesize);
2831 x = x * g->tilesize / ds->tilesize;
2832 y = y * g->tilesize / ds->tilesize;
2836 e = grid_nearest_edge(g, x, y);
2842 /* I think it's only possible to play this game with mouse clicks, sorry */
2843 /* Maybe will add mouse drag support some time */
2844 old_state = state->lines[i];
2848 switch (old_state) {
2866 switch (old_state) {
2885 sprintf(buf, "%d%c", i, (int)button_char);
2891 static game_state *execute_move(game_state *state, char *move)
2894 game_state *newstate = dup_game(state);
2896 if (move[0] == 'S') {
2898 newstate->cheated = TRUE;
2903 if (i < 0 || i >= newstate->game_grid->num_edges)
2905 move += strspn(move, "1234567890");
2906 switch (*(move++)) {
2908 newstate->lines[i] = LINE_YES;
2911 newstate->lines[i] = LINE_NO;
2914 newstate->lines[i] = LINE_UNKNOWN;
2922 * Check for completion.
2924 if (check_completion(newstate))
2925 newstate->solved = TRUE;
2930 free_game(newstate);
2934 /* ----------------------------------------------------------------------
2938 /* Convert from grid coordinates to screen coordinates */
2939 static void grid_to_screen(const game_drawstate *ds, const grid *g,
2940 int grid_x, int grid_y, int *x, int *y)
2942 *x = grid_x - g->lowest_x;
2943 *y = grid_y - g->lowest_y;
2944 *x = *x * ds->tilesize / g->tilesize;
2945 *y = *y * ds->tilesize / g->tilesize;
2946 *x += BORDER(ds->tilesize);
2947 *y += BORDER(ds->tilesize);
2950 /* Returns (into x,y) position of centre of face for rendering the text clue.
2952 static void face_text_pos(const game_drawstate *ds, const grid *g,
2953 grid_face *f, int *xret, int *yret)
2955 int faceindex = f - g->faces;
2958 * Return the cached position for this face, if we've already
2961 if (ds->textx[faceindex] >= 0) {
2962 *xret = ds->textx[faceindex];
2963 *yret = ds->texty[faceindex];
2968 * Otherwise, use the incentre computed by grid.c and convert it
2969 * to screen coordinates.
2971 grid_find_incentre(f);
2972 grid_to_screen(ds, g, f->ix, f->iy,
2973 &ds->textx[faceindex], &ds->texty[faceindex]);
2975 *xret = ds->textx[faceindex];
2976 *yret = ds->texty[faceindex];
2979 static void face_text_bbox(game_drawstate *ds, grid *g, grid_face *f,
2980 int *x, int *y, int *w, int *h)
2983 face_text_pos(ds, g, f, &xx, &yy);
2985 /* There seems to be a certain amount of trial-and-error involved
2986 * in working out the correct bounding-box for the text. */
2988 *x = xx - ds->tilesize/4 - 1;
2989 *y = yy - ds->tilesize/4 - 3;
2990 *w = ds->tilesize/2 + 2;
2991 *h = ds->tilesize/2 + 5;
2994 static void game_redraw_clue(drawing *dr, game_drawstate *ds,
2995 game_state *state, int i)
2997 grid *g = state->game_grid;
2998 grid_face *f = g->faces + i;
3002 sprintf(c, "%d", state->clues[i]);
3004 face_text_pos(ds, g, f, &x, &y);
3006 FONT_VARIABLE, ds->tilesize/2,
3007 ALIGN_VCENTRE | ALIGN_HCENTRE,
3008 ds->clue_error[i] ? COL_MISTAKE :
3009 ds->clue_satisfied[i] ? COL_SATISFIED : COL_FOREGROUND, c);
3012 static void edge_bbox(game_drawstate *ds, grid *g, grid_edge *e,
3013 int *x, int *y, int *w, int *h)
3015 int x1 = e->dot1->x;
3016 int y1 = e->dot1->y;
3017 int x2 = e->dot2->x;
3018 int y2 = e->dot2->y;
3019 int xmin, xmax, ymin, ymax;
3021 grid_to_screen(ds, g, x1, y1, &x1, &y1);
3022 grid_to_screen(ds, g, x2, y2, &x2, &y2);
3023 /* Allow extra margin for dots, and thickness of lines */
3024 xmin = min(x1, x2) - 2;
3025 xmax = max(x1, x2) + 2;
3026 ymin = min(y1, y2) - 2;
3027 ymax = max(y1, y2) + 2;
3031 *w = xmax - xmin + 1;
3032 *h = ymax - ymin + 1;
3035 static void dot_bbox(game_drawstate *ds, grid *g, grid_dot *d,
3036 int *x, int *y, int *w, int *h)
3040 grid_to_screen(ds, g, d->x, d->y, &x1, &y1);
3048 static const int loopy_line_redraw_phases[] = {
3049 COL_FAINT, COL_LINEUNKNOWN, COL_FOREGROUND, COL_HIGHLIGHT, COL_MISTAKE
3051 #define NPHASES lenof(loopy_line_redraw_phases)
3053 static void game_redraw_line(drawing *dr, game_drawstate *ds,
3054 game_state *state, int i, int phase)
3056 grid *g = state->game_grid;
3057 grid_edge *e = g->edges + i;
3061 if (state->line_errors[i])
3062 line_colour = COL_MISTAKE;
3063 else if (state->lines[i] == LINE_UNKNOWN)
3064 line_colour = COL_LINEUNKNOWN;
3065 else if (state->lines[i] == LINE_NO)
3066 line_colour = COL_FAINT;
3067 else if (ds->flashing)
3068 line_colour = COL_HIGHLIGHT;
3070 line_colour = COL_FOREGROUND;
3071 if (line_colour != loopy_line_redraw_phases[phase])
3074 /* Convert from grid to screen coordinates */
3075 grid_to_screen(ds, g, e->dot1->x, e->dot1->y, &x1, &y1);
3076 grid_to_screen(ds, g, e->dot2->x, e->dot2->y, &x2, &y2);
3078 if (line_colour == COL_FAINT) {
3079 static int draw_faint_lines = -1;
3080 if (draw_faint_lines < 0) {
3081 char *env = getenv("LOOPY_FAINT_LINES");
3082 draw_faint_lines = (!env || (env[0] == 'y' ||
3085 if (draw_faint_lines)
3086 draw_line(dr, x1, y1, x2, y2, line_colour);
3088 draw_thick_line(dr, 3.0,
3095 static void game_redraw_dot(drawing *dr, game_drawstate *ds,
3096 game_state *state, int i)
3098 grid *g = state->game_grid;
3099 grid_dot *d = g->dots + i;
3102 grid_to_screen(ds, g, d->x, d->y, &x, &y);
3103 draw_circle(dr, x, y, 2, COL_FOREGROUND, COL_FOREGROUND);
3106 static int boxes_intersect(int x0, int y0, int w0, int h0,
3107 int x1, int y1, int w1, int h1)
3110 * Two intervals intersect iff neither is wholly on one side of
3111 * the other. Two boxes intersect iff their horizontal and
3112 * vertical intervals both intersect.
3114 return (x0 < x1+w1 && x1 < x0+w0 && y0 < y1+h1 && y1 < y0+h0);
3117 static void game_redraw_in_rect(drawing *dr, game_drawstate *ds,
3118 game_state *state, int x, int y, int w, int h)
3120 grid *g = state->game_grid;
3124 clip(dr, x, y, w, h);
3125 draw_rect(dr, x, y, w, h, COL_BACKGROUND);
3127 for (i = 0; i < g->num_faces; i++) {
3128 if (state->clues[i] >= 0) {
3129 face_text_bbox(ds, g, &g->faces[i], &bx, &by, &bw, &bh);
3130 if (boxes_intersect(x, y, w, h, bx, by, bw, bh))
3131 game_redraw_clue(dr, ds, state, i);
3134 for (phase = 0; phase < NPHASES; phase++) {
3135 for (i = 0; i < g->num_edges; i++) {
3136 edge_bbox(ds, g, &g->edges[i], &bx, &by, &bw, &bh);
3137 if (boxes_intersect(x, y, w, h, bx, by, bw, bh))
3138 game_redraw_line(dr, ds, state, i, phase);
3141 for (i = 0; i < g->num_dots; i++) {
3142 dot_bbox(ds, g, &g->dots[i], &bx, &by, &bw, &bh);
3143 if (boxes_intersect(x, y, w, h, bx, by, bw, bh))
3144 game_redraw_dot(dr, ds, state, i);
3148 draw_update(dr, x, y, w, h);
3151 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
3152 game_state *state, int dir, game_ui *ui,
3153 float animtime, float flashtime)
3155 #define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */
3157 grid *g = state->game_grid;
3158 int border = BORDER(ds->tilesize);
3161 int redraw_everything = FALSE;
3163 int edges[REDRAW_OBJECTS_LIMIT], nedges = 0;
3164 int faces[REDRAW_OBJECTS_LIMIT], nfaces = 0;
3166 /* Redrawing is somewhat involved.
3168 * An update can theoretically affect an arbitrary number of edges
3169 * (consider, for example, completing or breaking a cycle which doesn't
3170 * satisfy all the clues -- we'll switch many edges between error and
3171 * normal states). On the other hand, redrawing the whole grid takes a
3172 * while, making the game feel sluggish, and many updates are actually
3173 * quite well localized.
3175 * This redraw algorithm attempts to cope with both situations gracefully
3176 * and correctly. For localized changes, we set a clip rectangle, fill
3177 * it with background, and then redraw (a plausible but conservative
3178 * guess at) the objects which intersect the rectangle; if several
3179 * objects need redrawing, we'll do them individually. However, if lots
3180 * of objects are affected, we'll just redraw everything.
3182 * The reason for all of this is that it's just not safe to do the redraw
3183 * piecemeal. If you try to draw an antialiased diagonal line over
3184 * itself, you get a slightly thicker antialiased diagonal line, which
3185 * looks rather ugly after a while.
3187 * So, we take two passes over the grid. The first attempts to work out
3188 * what needs doing, and the second actually does it.
3192 redraw_everything = TRUE;
3194 * But we must still go through the upcoming loops, so that we
3195 * set up stuff in ds correctly for the initial redraw.
3199 /* First, trundle through the faces. */
3200 for (i = 0; i < g->num_faces; i++) {
3201 grid_face *f = g->faces + i;
3202 int sides = f->order;
3205 int n = state->clues[i];
3209 clue_mistake = (face_order(state, i, LINE_YES) > n ||
3210 face_order(state, i, LINE_NO ) > (sides-n));
3211 clue_satisfied = (face_order(state, i, LINE_YES) == n &&
3212 face_order(state, i, LINE_NO ) == (sides-n));
3214 if (clue_mistake != ds->clue_error[i] ||
3215 clue_satisfied != ds->clue_satisfied[i]) {
3216 ds->clue_error[i] = clue_mistake;
3217 ds->clue_satisfied[i] = clue_satisfied;
3218 if (nfaces == REDRAW_OBJECTS_LIMIT)
3219 redraw_everything = TRUE;
3221 faces[nfaces++] = i;
3225 /* Work out what the flash state needs to be. */
3226 if (flashtime > 0 &&
3227 (flashtime <= FLASH_TIME/3 ||
3228 flashtime >= FLASH_TIME*2/3)) {
3229 flash_changed = !ds->flashing;
3230 ds->flashing = TRUE;
3232 flash_changed = ds->flashing;
3233 ds->flashing = FALSE;
3236 /* Now, trundle through the edges. */
3237 for (i = 0; i < g->num_edges; i++) {
3239 state->line_errors[i] ? DS_LINE_ERROR : state->lines[i];
3240 if (new_ds != ds->lines[i] ||
3241 (flash_changed && state->lines[i] == LINE_YES)) {
3242 ds->lines[i] = new_ds;
3243 if (nedges == REDRAW_OBJECTS_LIMIT)
3244 redraw_everything = TRUE;
3246 edges[nedges++] = i;
3250 /* Pass one is now done. Now we do the actual drawing. */
3251 if (redraw_everything) {
3252 int grid_width = g->highest_x - g->lowest_x;
3253 int grid_height = g->highest_y - g->lowest_y;
3254 int w = grid_width * ds->tilesize / g->tilesize;
3255 int h = grid_height * ds->tilesize / g->tilesize;
3257 game_redraw_in_rect(dr, ds, state,
3258 0, 0, w + 2*border + 1, h + 2*border + 1);
3261 /* Right. Now we roll up our sleeves. */
3263 for (i = 0; i < nfaces; i++) {
3264 grid_face *f = g->faces + faces[i];
3267 face_text_bbox(ds, g, f, &x, &y, &w, &h);
3268 game_redraw_in_rect(dr, ds, state, x, y, w, h);
3271 for (i = 0; i < nedges; i++) {
3272 grid_edge *e = g->edges + edges[i];
3275 edge_bbox(ds, g, e, &x, &y, &w, &h);
3276 game_redraw_in_rect(dr, ds, state, x, y, w, h);
3283 static float game_flash_length(game_state *oldstate, game_state *newstate,
3284 int dir, game_ui *ui)
3286 if (!oldstate->solved && newstate->solved &&
3287 !oldstate->cheated && !newstate->cheated) {
3294 static int game_status(game_state *state)
3296 return state->solved ? +1 : 0;
3299 static void game_print_size(game_params *params, float *x, float *y)
3304 * I'll use 7mm "squares" by default.
3306 game_compute_size(params, 700, &pw, &ph);
3311 static void game_print(drawing *dr, game_state *state, int tilesize)
3313 int ink = print_mono_colour(dr, 0);
3315 game_drawstate ads, *ds = &ads;
3316 grid *g = state->game_grid;
3318 ds->tilesize = tilesize;
3319 ds->textx = snewn(g->num_faces, int);
3320 ds->texty = snewn(g->num_faces, int);
3321 for (i = 0; i < g->num_faces; i++)
3322 ds->textx[i] = ds->texty[i] = -1;
3324 for (i = 0; i < g->num_dots; i++) {
3326 grid_to_screen(ds, g, g->dots[i].x, g->dots[i].y, &x, &y);
3327 draw_circle(dr, x, y, ds->tilesize / 15, ink, ink);
3333 for (i = 0; i < g->num_faces; i++) {
3334 grid_face *f = g->faces + i;
3335 int clue = state->clues[i];
3339 sprintf(c, "%d", state->clues[i]);
3340 face_text_pos(ds, g, f, &x, &y);
3342 FONT_VARIABLE, ds->tilesize / 2,
3343 ALIGN_VCENTRE | ALIGN_HCENTRE, ink, c);
3350 for (i = 0; i < g->num_edges; i++) {
3351 int thickness = (state->lines[i] == LINE_YES) ? 30 : 150;
3352 grid_edge *e = g->edges + i;
3354 grid_to_screen(ds, g, e->dot1->x, e->dot1->y, &x1, &y1);
3355 grid_to_screen(ds, g, e->dot2->x, e->dot2->y, &x2, &y2);
3356 if (state->lines[i] == LINE_YES)
3358 /* (dx, dy) points from (x1, y1) to (x2, y2).
3359 * The line is then "fattened" in a perpendicular
3360 * direction to create a thin rectangle. */
3361 double d = sqrt(SQ((double)x1 - x2) + SQ((double)y1 - y2));
3362 double dx = (x2 - x1) / d;
3363 double dy = (y2 - y1) / d;
3366 dx = (dx * ds->tilesize) / thickness;
3367 dy = (dy * ds->tilesize) / thickness;
3368 points[0] = x1 + (int)dy;
3369 points[1] = y1 - (int)dx;
3370 points[2] = x1 - (int)dy;
3371 points[3] = y1 + (int)dx;
3372 points[4] = x2 - (int)dy;
3373 points[5] = y2 + (int)dx;
3374 points[6] = x2 + (int)dy;
3375 points[7] = y2 - (int)dx;
3376 draw_polygon(dr, points, 4, ink, ink);
3380 /* Draw a dotted line */
3383 for (j = 1; j < divisions; j++) {
3384 /* Weighted average */
3385 int x = (x1 * (divisions -j) + x2 * j) / divisions;
3386 int y = (y1 * (divisions -j) + y2 * j) / divisions;
3387 draw_circle(dr, x, y, ds->tilesize / thickness, ink, ink);
3397 #define thegame loopy
3400 const struct game thegame = {
3401 "Loopy", "games.loopy", "loopy",
3408 TRUE, game_configure, custom_params,
3416 TRUE, game_can_format_as_text_now, game_text_format,
3424 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
3427 game_free_drawstate,
3432 TRUE, FALSE, game_print_size, game_print,
3433 FALSE /* wants_statusbar */,
3434 FALSE, game_timing_state,
3435 0, /* mouse_priorities */
3438 #ifdef STANDALONE_SOLVER
3441 * Half-hearted standalone solver. It can't output the solution to
3442 * anything but a square puzzle, and it can't log the deductions
3443 * it makes either. But it can solve square puzzles, and more
3444 * importantly it can use its solver to grade the difficulty of
3445 * any puzzle you give it.
3450 int main(int argc, char **argv)
3454 char *id = NULL, *desc, *err;
3457 #if 0 /* verbose solver not supported here (yet) */
3458 int really_verbose = FALSE;
3461 while (--argc > 0) {
3463 #if 0 /* verbose solver not supported here (yet) */
3464 if (!strcmp(p, "-v")) {
3465 really_verbose = TRUE;
3468 if (!strcmp(p, "-g")) {
3470 } else if (*p == '-') {
3471 fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
3479 fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]);
3483 desc = strchr(id, ':');
3485 fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
3490 p = default_params();
3491 decode_params(p, id);
3492 err = validate_desc(p, desc);
3494 fprintf(stderr, "%s: %s\n", argv[0], err);
3497 s = new_game(NULL, p, desc);
3500 * When solving an Easy puzzle, we don't want to bother the
3501 * user with Hard-level deductions. For this reason, we grade
3502 * the puzzle internally before doing anything else.
3504 ret = -1; /* placate optimiser */
3505 for (diff = 0; diff < DIFF_MAX; diff++) {
3506 solver_state *sstate_new;
3507 solver_state *sstate = new_solver_state((game_state *)s, diff);
3509 sstate_new = solve_game_rec(sstate);
3511 if (sstate_new->solver_status == SOLVER_MISTAKE)
3513 else if (sstate_new->solver_status == SOLVER_SOLVED)
3518 free_solver_state(sstate_new);
3519 free_solver_state(sstate);
3525 if (diff == DIFF_MAX) {
3527 printf("Difficulty rating: harder than Hard, or ambiguous\n");
3529 printf("Unable to find a unique solution\n");
3533 printf("Difficulty rating: impossible (no solution exists)\n");
3535 printf("Difficulty rating: %s\n", diffnames[diff]);
3537 solver_state *sstate_new;
3538 solver_state *sstate = new_solver_state((game_state *)s, diff);
3540 /* If we supported a verbose solver, we'd set verbosity here */
3542 sstate_new = solve_game_rec(sstate);
3544 if (sstate_new->solver_status == SOLVER_MISTAKE)
3545 printf("Puzzle is inconsistent\n");
3547 assert(sstate_new->solver_status == SOLVER_SOLVED);
3548 if (s->grid_type == 0) {
3549 fputs(game_text_format(sstate_new->state), stdout);
3551 printf("Unable to output non-square grids\n");
3555 free_solver_state(sstate_new);
3556 free_solver_state(sstate);
3565 /* vim: set shiftwidth=4 tabstop=8: */