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) \
260 A(Octagonal (dual),GRID_DUAL_OCTAGONAL,3,3)
262 #define GRID_NAME(title,type,amin,omin) #title,
263 #define GRID_CONFIG(title,type,amin,omin) ":" #title
264 #define GRID_TYPE(title,type,amin,omin) type,
265 #define GRID_SIZES(title,type,amin,omin) \
267 "Width and height for this grid type must both be at least " #amin, \
268 "At least one of width and height for this grid type must be at least " #omin,},
269 static char const *const gridnames
[] = { GRIDLIST(GRID_NAME
) };
270 #define GRID_CONFIGS GRIDLIST(GRID_CONFIG)
271 static grid_type grid_types
[] = { GRIDLIST(GRID_TYPE
) };
272 #define NUM_GRID_TYPES (sizeof(grid_types) / sizeof(grid_types[0]))
273 static const struct {
276 } grid_size_limits
[] = { GRIDLIST(GRID_SIZES
) };
278 /* Generates a (dynamically allocated) new grid, according to the
279 * type and size requested in params. Does nothing if the grid is already
281 static grid
*loopy_generate_grid(game_params
*params
, char *grid_desc
)
283 return grid_new(grid_types
[params
->type
], params
->w
, params
->h
, grid_desc
);
286 /* ----------------------------------------------------------------------
290 /* General constants */
291 #define PREFERRED_TILE_SIZE 32
292 #define BORDER(tilesize) ((tilesize) / 2)
293 #define FLASH_TIME 0.5F
295 #define BIT_SET(field, bit) ((field) & (1<<(bit)))
297 #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
298 ((field) |= (1<<(bit)), TRUE))
300 #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
301 ((field) &= ~(1<<(bit)), TRUE) : FALSE)
303 #define CLUE2CHAR(c) \
304 ((c < 0) ? ' ' : c < 10 ? c + '0' : c - 10 + 'A')
306 /* ----------------------------------------------------------------------
307 * General struct manipulation and other straightforward code
310 static game_state
*dup_game(game_state
*state
)
312 game_state
*ret
= snew(game_state
);
314 ret
->game_grid
= state
->game_grid
;
315 ret
->game_grid
->refcount
++;
317 ret
->solved
= state
->solved
;
318 ret
->cheated
= state
->cheated
;
320 ret
->clues
= snewn(state
->game_grid
->num_faces
, signed char);
321 memcpy(ret
->clues
, state
->clues
, state
->game_grid
->num_faces
);
323 ret
->lines
= snewn(state
->game_grid
->num_edges
, char);
324 memcpy(ret
->lines
, state
->lines
, state
->game_grid
->num_edges
);
326 ret
->line_errors
= snewn(state
->game_grid
->num_edges
, unsigned char);
327 memcpy(ret
->line_errors
, state
->line_errors
, state
->game_grid
->num_edges
);
329 ret
->grid_type
= state
->grid_type
;
333 static void free_game(game_state
*state
)
336 grid_free(state
->game_grid
);
339 sfree(state
->line_errors
);
344 static solver_state
*new_solver_state(game_state
*state
, int diff
) {
346 int num_dots
= state
->game_grid
->num_dots
;
347 int num_faces
= state
->game_grid
->num_faces
;
348 int num_edges
= state
->game_grid
->num_edges
;
349 solver_state
*ret
= snew(solver_state
);
351 ret
->state
= dup_game(state
);
353 ret
->solver_status
= SOLVER_INCOMPLETE
;
356 ret
->dotdsf
= snew_dsf(num_dots
);
357 ret
->looplen
= snewn(num_dots
, int);
359 for (i
= 0; i
< num_dots
; i
++) {
363 ret
->dot_solved
= snewn(num_dots
, char);
364 ret
->face_solved
= snewn(num_faces
, char);
365 memset(ret
->dot_solved
, FALSE
, num_dots
);
366 memset(ret
->face_solved
, FALSE
, num_faces
);
368 ret
->dot_yes_count
= snewn(num_dots
, char);
369 memset(ret
->dot_yes_count
, 0, num_dots
);
370 ret
->dot_no_count
= snewn(num_dots
, char);
371 memset(ret
->dot_no_count
, 0, num_dots
);
372 ret
->face_yes_count
= snewn(num_faces
, char);
373 memset(ret
->face_yes_count
, 0, num_faces
);
374 ret
->face_no_count
= snewn(num_faces
, char);
375 memset(ret
->face_no_count
, 0, num_faces
);
377 if (diff
< DIFF_NORMAL
) {
380 ret
->dlines
= snewn(2*num_edges
, char);
381 memset(ret
->dlines
, 0, 2*num_edges
);
384 if (diff
< DIFF_HARD
) {
387 ret
->linedsf
= snew_dsf(state
->game_grid
->num_edges
);
393 static void free_solver_state(solver_state
*sstate
) {
395 free_game(sstate
->state
);
396 sfree(sstate
->dotdsf
);
397 sfree(sstate
->looplen
);
398 sfree(sstate
->dot_solved
);
399 sfree(sstate
->face_solved
);
400 sfree(sstate
->dot_yes_count
);
401 sfree(sstate
->dot_no_count
);
402 sfree(sstate
->face_yes_count
);
403 sfree(sstate
->face_no_count
);
405 /* OK, because sfree(NULL) is a no-op */
406 sfree(sstate
->dlines
);
407 sfree(sstate
->linedsf
);
413 static solver_state
*dup_solver_state(const solver_state
*sstate
) {
414 game_state
*state
= sstate
->state
;
415 int num_dots
= state
->game_grid
->num_dots
;
416 int num_faces
= state
->game_grid
->num_faces
;
417 int num_edges
= state
->game_grid
->num_edges
;
418 solver_state
*ret
= snew(solver_state
);
420 ret
->state
= state
= dup_game(sstate
->state
);
422 ret
->solver_status
= sstate
->solver_status
;
423 ret
->diff
= sstate
->diff
;
425 ret
->dotdsf
= snewn(num_dots
, int);
426 ret
->looplen
= snewn(num_dots
, int);
427 memcpy(ret
->dotdsf
, sstate
->dotdsf
,
428 num_dots
* sizeof(int));
429 memcpy(ret
->looplen
, sstate
->looplen
,
430 num_dots
* sizeof(int));
432 ret
->dot_solved
= snewn(num_dots
, char);
433 ret
->face_solved
= snewn(num_faces
, char);
434 memcpy(ret
->dot_solved
, sstate
->dot_solved
, num_dots
);
435 memcpy(ret
->face_solved
, sstate
->face_solved
, num_faces
);
437 ret
->dot_yes_count
= snewn(num_dots
, char);
438 memcpy(ret
->dot_yes_count
, sstate
->dot_yes_count
, num_dots
);
439 ret
->dot_no_count
= snewn(num_dots
, char);
440 memcpy(ret
->dot_no_count
, sstate
->dot_no_count
, num_dots
);
442 ret
->face_yes_count
= snewn(num_faces
, char);
443 memcpy(ret
->face_yes_count
, sstate
->face_yes_count
, num_faces
);
444 ret
->face_no_count
= snewn(num_faces
, char);
445 memcpy(ret
->face_no_count
, sstate
->face_no_count
, num_faces
);
447 if (sstate
->dlines
) {
448 ret
->dlines
= snewn(2*num_edges
, char);
449 memcpy(ret
->dlines
, sstate
->dlines
,
455 if (sstate
->linedsf
) {
456 ret
->linedsf
= snewn(num_edges
, int);
457 memcpy(ret
->linedsf
, sstate
->linedsf
,
458 num_edges
* sizeof(int));
466 static game_params
*default_params(void)
468 game_params
*ret
= snew(game_params
);
477 ret
->diff
= DIFF_EASY
;
483 static game_params
*dup_params(game_params
*params
)
485 game_params
*ret
= snew(game_params
);
487 *ret
= *params
; /* structure copy */
491 static const game_params presets
[] = {
493 { 7, 7, DIFF_EASY
, 0 },
494 { 7, 7, DIFF_NORMAL
, 0 },
495 { 7, 7, DIFF_HARD
, 0 },
496 { 7, 7, DIFF_HARD
, 1 },
497 { 7, 7, DIFF_HARD
, 2 },
498 { 5, 5, DIFF_HARD
, 3 },
499 { 7, 7, DIFF_HARD
, 4 },
500 { 5, 4, DIFF_HARD
, 5 },
501 { 5, 5, DIFF_HARD
, 6 },
502 { 5, 5, DIFF_HARD
, 7 },
503 { 3, 3, DIFF_HARD
, 8 },
504 { 3, 3, DIFF_HARD
, 9 },
505 { 3, 3, DIFF_HARD
, 10 },
506 { 6, 6, DIFF_HARD
, 11 },
507 { 6, 6, DIFF_HARD
, 12 },
509 { 7, 7, DIFF_EASY
, 0 },
510 { 10, 10, DIFF_EASY
, 0 },
511 { 7, 7, DIFF_NORMAL
, 0 },
512 { 10, 10, DIFF_NORMAL
, 0 },
513 { 7, 7, DIFF_HARD
, 0 },
514 { 10, 10, DIFF_HARD
, 0 },
515 { 10, 10, DIFF_HARD
, 1 },
516 { 12, 10, DIFF_HARD
, 2 },
517 { 7, 7, DIFF_HARD
, 3 },
518 { 9, 9, DIFF_HARD
, 4 },
519 { 5, 4, DIFF_HARD
, 5 },
520 { 7, 7, DIFF_HARD
, 6 },
521 { 5, 5, DIFF_HARD
, 7 },
522 { 5, 5, DIFF_HARD
, 8 },
523 { 5, 4, DIFF_HARD
, 9 },
524 { 5, 4, DIFF_HARD
, 10 },
525 { 10, 10, DIFF_HARD
, 11 },
526 { 10, 10, DIFF_HARD
, 12 }
530 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
535 if (i
< 0 || i
>= lenof(presets
))
538 tmppar
= snew(game_params
);
539 *tmppar
= presets
[i
];
541 sprintf(buf
, "%dx%d %s - %s", tmppar
->h
, tmppar
->w
,
542 gridnames
[tmppar
->type
], diffnames
[tmppar
->diff
]);
548 static void free_params(game_params
*params
)
553 static void decode_params(game_params
*params
, char const *string
)
555 params
->h
= params
->w
= atoi(string
);
556 params
->diff
= DIFF_EASY
;
557 while (*string
&& isdigit((unsigned char)*string
)) string
++;
558 if (*string
== 'x') {
560 params
->h
= atoi(string
);
561 while (*string
&& isdigit((unsigned char)*string
)) string
++;
563 if (*string
== 't') {
565 params
->type
= atoi(string
);
566 while (*string
&& isdigit((unsigned char)*string
)) string
++;
568 if (*string
== 'd') {
571 for (i
= 0; i
< DIFF_MAX
; i
++)
572 if (*string
== diffchars
[i
])
574 if (*string
) string
++;
578 static char *encode_params(game_params
*params
, int full
)
581 sprintf(str
, "%dx%dt%d", params
->w
, params
->h
, params
->type
);
583 sprintf(str
+ strlen(str
), "d%c", diffchars
[params
->diff
]);
587 static config_item
*game_configure(game_params
*params
)
592 ret
= snewn(5, config_item
);
594 ret
[0].name
= "Width";
595 ret
[0].type
= C_STRING
;
596 sprintf(buf
, "%d", params
->w
);
597 ret
[0].sval
= dupstr(buf
);
600 ret
[1].name
= "Height";
601 ret
[1].type
= C_STRING
;
602 sprintf(buf
, "%d", params
->h
);
603 ret
[1].sval
= dupstr(buf
);
606 ret
[2].name
= "Grid type";
607 ret
[2].type
= C_CHOICES
;
608 ret
[2].sval
= GRID_CONFIGS
;
609 ret
[2].ival
= params
->type
;
611 ret
[3].name
= "Difficulty";
612 ret
[3].type
= C_CHOICES
;
613 ret
[3].sval
= DIFFCONFIG
;
614 ret
[3].ival
= params
->diff
;
624 static game_params
*custom_params(config_item
*cfg
)
626 game_params
*ret
= snew(game_params
);
628 ret
->w
= atoi(cfg
[0].sval
);
629 ret
->h
= atoi(cfg
[1].sval
);
630 ret
->type
= cfg
[2].ival
;
631 ret
->diff
= cfg
[3].ival
;
636 static char *validate_params(game_params
*params
, int full
)
638 if (params
->type
< 0 || params
->type
>= NUM_GRID_TYPES
)
639 return "Illegal grid type";
640 if (params
->w
< grid_size_limits
[params
->type
].amin
||
641 params
->h
< grid_size_limits
[params
->type
].amin
)
642 return grid_size_limits
[params
->type
].aerr
;
643 if (params
->w
< grid_size_limits
[params
->type
].omin
&&
644 params
->h
< grid_size_limits
[params
->type
].omin
)
645 return grid_size_limits
[params
->type
].oerr
;
648 * This shouldn't be able to happen at all, since decode_params
649 * and custom_params will never generate anything that isn't
652 assert(params
->diff
< DIFF_MAX
);
657 /* Returns a newly allocated string describing the current puzzle */
658 static char *state_to_text(const game_state
*state
)
660 grid
*g
= state
->game_grid
;
662 int num_faces
= g
->num_faces
;
663 char *description
= snewn(num_faces
+ 1, char);
664 char *dp
= description
;
668 for (i
= 0; i
< num_faces
; i
++) {
669 if (state
->clues
[i
] < 0) {
670 if (empty_count
> 25) {
671 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
677 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
680 dp
+= sprintf(dp
, "%c", (int)CLUE2CHAR(state
->clues
[i
]));
685 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
687 retval
= dupstr(description
);
693 #define GRID_DESC_SEP '_'
695 /* Splits up a (optional) grid_desc from the game desc. Returns the
696 * grid_desc (which needs freeing) and updates the desc pointer to
697 * start of real desc, or returns NULL if no desc. */
698 static char *extract_grid_desc(char **desc
)
700 char *sep
= strchr(*desc
, GRID_DESC_SEP
), *gd
;
703 if (!sep
) return NULL
;
705 gd_len
= sep
- (*desc
);
706 gd
= snewn(gd_len
+1, char);
707 memcpy(gd
, *desc
, gd_len
);
715 /* We require that the params pass the test in validate_params and that the
716 * description fills the entire game area */
717 static char *validate_desc(game_params
*params
, char *desc
)
721 char *grid_desc
, *ret
;
723 /* It's pretty inefficient to do this just for validation. All we need to
724 * know is the precise number of faces. */
725 grid_desc
= extract_grid_desc(&desc
);
726 ret
= grid_validate_desc(grid_types
[params
->type
], params
->w
, params
->h
, grid_desc
);
729 g
= loopy_generate_grid(params
, grid_desc
);
730 if (grid_desc
) sfree(grid_desc
);
732 for (; *desc
; ++desc
) {
733 if ((*desc
>= '0' && *desc
<= '9') || (*desc
>= 'A' && *desc
<= 'Z')) {
738 count
+= *desc
- 'a' + 1;
741 return "Unknown character in description";
744 if (count
< g
->num_faces
)
745 return "Description too short for board size";
746 if (count
> g
->num_faces
)
747 return "Description too long for board size";
754 /* Sums the lengths of the numbers in range [0,n) */
755 /* See equivalent function in solo.c for justification of this. */
756 static int len_0_to_n(int n
)
758 int len
= 1; /* Counting 0 as a bit of a special case */
761 for (i
= 1; i
< n
; i
*= 10) {
762 len
+= max(n
- i
, 0);
768 static char *encode_solve_move(const game_state
*state
)
773 int num_edges
= state
->game_grid
->num_edges
;
775 /* This is going to return a string representing the moves needed to set
776 * every line in a grid to be the same as the ones in 'state'. The exact
777 * length of this string is predictable. */
779 len
= 1; /* Count the 'S' prefix */
780 /* Numbers in all lines */
781 len
+= len_0_to_n(num_edges
);
782 /* For each line we also have a letter */
785 ret
= snewn(len
+ 1, char);
788 p
+= sprintf(p
, "S");
790 for (i
= 0; i
< num_edges
; i
++) {
791 switch (state
->lines
[i
]) {
793 p
+= sprintf(p
, "%dy", i
);
796 p
+= sprintf(p
, "%dn", i
);
801 /* No point in doing sums like that if they're going to be wrong */
802 assert(strlen(ret
) <= (size_t)len
);
806 static game_ui
*new_ui(game_state
*state
)
811 static void free_ui(game_ui
*ui
)
815 static char *encode_ui(game_ui
*ui
)
820 static void decode_ui(game_ui
*ui
, char *encoding
)
824 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
825 game_state
*newstate
)
829 static void game_compute_size(game_params
*params
, int tilesize
,
832 int grid_width
, grid_height
, rendered_width
, rendered_height
;
835 grid_compute_size(grid_types
[params
->type
], params
->w
, params
->h
,
836 &g_tilesize
, &grid_width
, &grid_height
);
838 /* multiply first to minimise rounding error on integer division */
839 rendered_width
= grid_width
* tilesize
/ g_tilesize
;
840 rendered_height
= grid_height
* tilesize
/ g_tilesize
;
841 *x
= rendered_width
+ 2 * BORDER(tilesize
) + 1;
842 *y
= rendered_height
+ 2 * BORDER(tilesize
) + 1;
845 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
846 game_params
*params
, int tilesize
)
848 ds
->tilesize
= tilesize
;
851 static float *game_colours(frontend
*fe
, int *ncolours
)
853 float *ret
= snewn(4 * NCOLOURS
, float);
855 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
857 ret
[COL_FOREGROUND
* 3 + 0] = 0.0F
;
858 ret
[COL_FOREGROUND
* 3 + 1] = 0.0F
;
859 ret
[COL_FOREGROUND
* 3 + 2] = 0.0F
;
862 * We want COL_LINEUNKNOWN to be a yellow which is a bit darker
863 * than the background. (I previously set it to 0.8,0.8,0, but
864 * found that this went badly with the 0.8,0.8,0.8 favoured as a
865 * background by the Java frontend.)
867 ret
[COL_LINEUNKNOWN
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
868 ret
[COL_LINEUNKNOWN
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
869 ret
[COL_LINEUNKNOWN
* 3 + 2] = 0.0F
;
871 ret
[COL_HIGHLIGHT
* 3 + 0] = 1.0F
;
872 ret
[COL_HIGHLIGHT
* 3 + 1] = 1.0F
;
873 ret
[COL_HIGHLIGHT
* 3 + 2] = 1.0F
;
875 ret
[COL_MISTAKE
* 3 + 0] = 1.0F
;
876 ret
[COL_MISTAKE
* 3 + 1] = 0.0F
;
877 ret
[COL_MISTAKE
* 3 + 2] = 0.0F
;
879 ret
[COL_SATISFIED
* 3 + 0] = 0.0F
;
880 ret
[COL_SATISFIED
* 3 + 1] = 0.0F
;
881 ret
[COL_SATISFIED
* 3 + 2] = 0.0F
;
883 /* We want the faint lines to be a bit darker than the background.
884 * Except if the background is pretty dark already; then it ought to be a
885 * bit lighter. Oy vey.
887 ret
[COL_FAINT
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
888 ret
[COL_FAINT
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
889 ret
[COL_FAINT
* 3 + 2] = ret
[COL_BACKGROUND
* 3 + 2] * 0.9F
;
891 *ncolours
= NCOLOURS
;
895 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
897 struct game_drawstate
*ds
= snew(struct game_drawstate
);
898 int num_faces
= state
->game_grid
->num_faces
;
899 int num_edges
= state
->game_grid
->num_edges
;
904 ds
->lines
= snewn(num_edges
, char);
905 ds
->clue_error
= snewn(num_faces
, char);
906 ds
->clue_satisfied
= snewn(num_faces
, char);
907 ds
->textx
= snewn(num_faces
, int);
908 ds
->texty
= snewn(num_faces
, int);
911 memset(ds
->lines
, LINE_UNKNOWN
, num_edges
);
912 memset(ds
->clue_error
, 0, num_faces
);
913 memset(ds
->clue_satisfied
, 0, num_faces
);
914 for (i
= 0; i
< num_faces
; i
++)
915 ds
->textx
[i
] = ds
->texty
[i
] = -1;
920 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
924 sfree(ds
->clue_error
);
925 sfree(ds
->clue_satisfied
);
930 static int game_timing_state(game_state
*state
, game_ui
*ui
)
935 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
936 int dir
, game_ui
*ui
)
941 static int game_can_format_as_text_now(game_params
*params
)
943 if (params
->type
!= 0)
948 static char *game_text_format(game_state
*state
)
954 grid
*g
= state
->game_grid
;
957 assert(state
->grid_type
== 0);
959 /* Work out the basic size unit */
960 f
= g
->faces
; /* first face */
961 assert(f
->order
== 4);
962 /* The dots are ordered clockwise, so the two opposite
963 * corners are guaranteed to span the square */
964 cell_size
= abs(f
->dots
[0]->x
- f
->dots
[2]->x
);
966 w
= (g
->highest_x
- g
->lowest_x
) / cell_size
;
967 h
= (g
->highest_y
- g
->lowest_y
) / cell_size
;
969 /* Create a blank "canvas" to "draw" on */
972 ret
= snewn(W
* H
+ 1, char);
973 for (y
= 0; y
< H
; y
++) {
974 for (x
= 0; x
< W
-1; x
++) {
977 ret
[y
*W
+ W
-1] = '\n';
981 /* Fill in edge info */
982 for (i
= 0; i
< g
->num_edges
; i
++) {
983 grid_edge
*e
= g
->edges
+ i
;
984 /* Cell coordinates, from (0,0) to (w-1,h-1) */
985 int x1
= (e
->dot1
->x
- g
->lowest_x
) / cell_size
;
986 int x2
= (e
->dot2
->x
- g
->lowest_x
) / cell_size
;
987 int y1
= (e
->dot1
->y
- g
->lowest_y
) / cell_size
;
988 int y2
= (e
->dot2
->y
- g
->lowest_y
) / cell_size
;
989 /* Midpoint, in canvas coordinates (canvas coordinates are just twice
990 * cell coordinates) */
993 switch (state
->lines
[i
]) {
995 ret
[y
*W
+ x
] = (y1
== y2
) ?
'-' : '|';
1001 break; /* already a space */
1003 assert(!"Illegal line state");
1008 for (i
= 0; i
< g
->num_faces
; i
++) {
1012 assert(f
->order
== 4);
1013 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1014 x1
= (f
->dots
[0]->x
- g
->lowest_x
) / cell_size
;
1015 x2
= (f
->dots
[2]->x
- g
->lowest_x
) / cell_size
;
1016 y1
= (f
->dots
[0]->y
- g
->lowest_y
) / cell_size
;
1017 y2
= (f
->dots
[2]->y
- g
->lowest_y
) / cell_size
;
1018 /* Midpoint, in canvas coordinates */
1021 ret
[y
*W
+ x
] = CLUE2CHAR(state
->clues
[i
]);
1026 /* ----------------------------------------------------------------------
1031 static void check_caches(const solver_state
* sstate
)
1034 const game_state
*state
= sstate
->state
;
1035 const grid
*g
= state
->game_grid
;
1037 for (i
= 0; i
< g
->num_dots
; i
++) {
1038 assert(dot_order(state
, i
, LINE_YES
) == sstate
->dot_yes_count
[i
]);
1039 assert(dot_order(state
, i
, LINE_NO
) == sstate
->dot_no_count
[i
]);
1042 for (i
= 0; i
< g
->num_faces
; i
++) {
1043 assert(face_order(state
, i
, LINE_YES
) == sstate
->face_yes_count
[i
]);
1044 assert(face_order(state
, i
, LINE_NO
) == sstate
->face_no_count
[i
]);
1049 #define check_caches(s) \
1051 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
1055 #endif /* DEBUG_CACHES */
1057 /* ----------------------------------------------------------------------
1058 * Solver utility functions
1061 /* Sets the line (with index i) to the new state 'line_new', and updates
1062 * the cached counts of any affected faces and dots.
1063 * Returns TRUE if this actually changed the line's state. */
1064 static int solver_set_line(solver_state
*sstate
, int i
,
1065 enum line_state line_new
1067 , const char *reason
1071 game_state
*state
= sstate
->state
;
1075 assert(line_new
!= LINE_UNKNOWN
);
1077 check_caches(sstate
);
1079 if (state
->lines
[i
] == line_new
) {
1080 return FALSE
; /* nothing changed */
1082 state
->lines
[i
] = line_new
;
1085 fprintf(stderr
, "solver: set line [%d] to %s (%s)\n",
1086 i
, line_new
== LINE_YES ?
"YES" : "NO",
1090 g
= state
->game_grid
;
1093 /* Update the cache for both dots and both faces affected by this. */
1094 if (line_new
== LINE_YES
) {
1095 sstate
->dot_yes_count
[e
->dot1
- g
->dots
]++;
1096 sstate
->dot_yes_count
[e
->dot2
- g
->dots
]++;
1098 sstate
->face_yes_count
[e
->face1
- g
->faces
]++;
1101 sstate
->face_yes_count
[e
->face2
- g
->faces
]++;
1104 sstate
->dot_no_count
[e
->dot1
- g
->dots
]++;
1105 sstate
->dot_no_count
[e
->dot2
- g
->dots
]++;
1107 sstate
->face_no_count
[e
->face1
- g
->faces
]++;
1110 sstate
->face_no_count
[e
->face2
- g
->faces
]++;
1114 check_caches(sstate
);
1119 #define solver_set_line(a, b, c) \
1120 solver_set_line(a, b, c, __FUNCTION__)
1124 * Merge two dots due to the existence of an edge between them.
1125 * Updates the dsf tracking equivalence classes, and keeps track of
1126 * the length of path each dot is currently a part of.
1127 * Returns TRUE if the dots were already linked, ie if they are part of a
1128 * closed loop, and false otherwise.
1130 static int merge_dots(solver_state
*sstate
, int edge_index
)
1133 grid
*g
= sstate
->state
->game_grid
;
1134 grid_edge
*e
= g
->edges
+ edge_index
;
1136 i
= e
->dot1
- g
->dots
;
1137 j
= e
->dot2
- g
->dots
;
1139 i
= dsf_canonify(sstate
->dotdsf
, i
);
1140 j
= dsf_canonify(sstate
->dotdsf
, j
);
1145 len
= sstate
->looplen
[i
] + sstate
->looplen
[j
];
1146 dsf_merge(sstate
->dotdsf
, i
, j
);
1147 i
= dsf_canonify(sstate
->dotdsf
, i
);
1148 sstate
->looplen
[i
] = len
;
1153 /* Merge two lines because the solver has deduced that they must be either
1154 * identical or opposite. Returns TRUE if this is new information, otherwise
1156 static int merge_lines(solver_state
*sstate
, int i
, int j
, int inverse
1158 , const char *reason
1164 assert(i
< sstate
->state
->game_grid
->num_edges
);
1165 assert(j
< sstate
->state
->game_grid
->num_edges
);
1167 i
= edsf_canonify(sstate
->linedsf
, i
, &inv_tmp
);
1169 j
= edsf_canonify(sstate
->linedsf
, j
, &inv_tmp
);
1172 edsf_merge(sstate
->linedsf
, i
, j
, inverse
);
1176 fprintf(stderr
, "%s [%d] [%d] %s(%s)\n",
1178 inverse ?
"inverse " : "", reason
);
1185 #define merge_lines(a, b, c, d) \
1186 merge_lines(a, b, c, d, __FUNCTION__)
1189 /* Count the number of lines of a particular type currently going into the
1191 static int dot_order(const game_state
* state
, int dot
, char line_type
)
1194 grid
*g
= state
->game_grid
;
1195 grid_dot
*d
= g
->dots
+ dot
;
1198 for (i
= 0; i
< d
->order
; i
++) {
1199 grid_edge
*e
= d
->edges
[i
];
1200 if (state
->lines
[e
- g
->edges
] == line_type
)
1206 /* Count the number of lines of a particular type currently surrounding the
1208 static int face_order(const game_state
* state
, int face
, char line_type
)
1211 grid
*g
= state
->game_grid
;
1212 grid_face
*f
= g
->faces
+ face
;
1215 for (i
= 0; i
< f
->order
; i
++) {
1216 grid_edge
*e
= f
->edges
[i
];
1217 if (state
->lines
[e
- g
->edges
] == line_type
)
1223 /* Set all lines bordering a dot of type old_type to type new_type
1224 * Return value tells caller whether this function actually did anything */
1225 static int dot_setall(solver_state
*sstate
, int dot
,
1226 char old_type
, char new_type
)
1228 int retval
= FALSE
, r
;
1229 game_state
*state
= sstate
->state
;
1234 if (old_type
== new_type
)
1237 g
= state
->game_grid
;
1240 for (i
= 0; i
< d
->order
; i
++) {
1241 int line_index
= d
->edges
[i
] - g
->edges
;
1242 if (state
->lines
[line_index
] == old_type
) {
1243 r
= solver_set_line(sstate
, line_index
, new_type
);
1251 /* Set all lines bordering a face of type old_type to type new_type */
1252 static int face_setall(solver_state
*sstate
, int face
,
1253 char old_type
, char new_type
)
1255 int retval
= FALSE
, r
;
1256 game_state
*state
= sstate
->state
;
1261 if (old_type
== new_type
)
1264 g
= state
->game_grid
;
1265 f
= g
->faces
+ face
;
1267 for (i
= 0; i
< f
->order
; i
++) {
1268 int line_index
= f
->edges
[i
] - g
->edges
;
1269 if (state
->lines
[line_index
] == old_type
) {
1270 r
= solver_set_line(sstate
, line_index
, new_type
);
1278 /* ----------------------------------------------------------------------
1279 * Loop generation and clue removal
1282 static void add_full_clues(game_state
*state
, random_state
*rs
)
1284 signed char *clues
= state
->clues
;
1285 grid
*g
= state
->game_grid
;
1286 char *board
= snewn(g
->num_faces
, char);
1289 generate_loop(g
, board
, rs
, NULL
, NULL
);
1291 /* Fill out all the clues by initialising to 0, then iterating over
1292 * all edges and incrementing each clue as we find edges that border
1293 * between BLACK/WHITE faces. While we're at it, we verify that the
1294 * algorithm does work, and there aren't any GREY faces still there. */
1295 memset(clues
, 0, g
->num_faces
);
1296 for (i
= 0; i
< g
->num_edges
; i
++) {
1297 grid_edge
*e
= g
->edges
+ i
;
1298 grid_face
*f1
= e
->face1
;
1299 grid_face
*f2
= e
->face2
;
1300 enum face_colour c1
= FACE_COLOUR(f1
);
1301 enum face_colour c2
= FACE_COLOUR(f2
);
1302 assert(c1
!= FACE_GREY
);
1303 assert(c2
!= FACE_GREY
);
1305 if (f1
) clues
[f1
- g
->faces
]++;
1306 if (f2
) clues
[f2
- g
->faces
]++;
1313 static int game_has_unique_soln(const game_state
*state
, int diff
)
1316 solver_state
*sstate_new
;
1317 solver_state
*sstate
= new_solver_state((game_state
*)state
, diff
);
1319 sstate_new
= solve_game_rec(sstate
);
1321 assert(sstate_new
->solver_status
!= SOLVER_MISTAKE
);
1322 ret
= (sstate_new
->solver_status
== SOLVER_SOLVED
);
1324 free_solver_state(sstate_new
);
1325 free_solver_state(sstate
);
1331 /* Remove clues one at a time at random. */
1332 static game_state
*remove_clues(game_state
*state
, random_state
*rs
,
1336 int num_faces
= state
->game_grid
->num_faces
;
1337 game_state
*ret
= dup_game(state
), *saved_ret
;
1340 /* We need to remove some clues. We'll do this by forming a list of all
1341 * available clues, shuffling it, then going along one at a
1342 * time clearing each clue in turn for which doing so doesn't render the
1343 * board unsolvable. */
1344 face_list
= snewn(num_faces
, int);
1345 for (n
= 0; n
< num_faces
; ++n
) {
1349 shuffle(face_list
, num_faces
, sizeof(int), rs
);
1351 for (n
= 0; n
< num_faces
; ++n
) {
1352 saved_ret
= dup_game(ret
);
1353 ret
->clues
[face_list
[n
]] = -1;
1355 if (game_has_unique_soln(ret
, diff
)) {
1356 free_game(saved_ret
);
1368 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1369 char **aux
, int interactive
)
1371 /* solution and description both use run-length encoding in obvious ways */
1372 char *retval
, *game_desc
, *grid_desc
;
1374 game_state
*state
= snew(game_state
);
1375 game_state
*state_new
;
1377 grid_desc
= grid_new_desc(grid_types
[params
->type
], params
->w
, params
->h
, rs
);
1378 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1380 state
->clues
= snewn(g
->num_faces
, signed char);
1381 state
->lines
= snewn(g
->num_edges
, char);
1382 state
->line_errors
= snewn(g
->num_edges
, unsigned char);
1384 state
->grid_type
= params
->type
;
1388 memset(state
->lines
, LINE_UNKNOWN
, g
->num_edges
);
1389 memset(state
->line_errors
, 0, g
->num_edges
);
1391 state
->solved
= state
->cheated
= FALSE
;
1393 /* Get a new random solvable board with all its clues filled in. Yes, this
1394 * can loop for ever if the params are suitably unfavourable, but
1395 * preventing games smaller than 4x4 seems to stop this happening */
1397 add_full_clues(state
, rs
);
1398 } while (!game_has_unique_soln(state
, params
->diff
));
1400 state_new
= remove_clues(state
, rs
, params
->diff
);
1405 if (params
->diff
> 0 && game_has_unique_soln(state
, params
->diff
-1)) {
1407 fprintf(stderr
, "Rejecting board, it is too easy\n");
1409 goto newboard_please
;
1412 game_desc
= state_to_text(state
);
1417 retval
= snewn(strlen(grid_desc
) + 1 + strlen(game_desc
) + 1, char);
1418 sprintf(retval
, "%s%c%s", grid_desc
, (int)GRID_DESC_SEP
, game_desc
);
1425 assert(!validate_desc(params
, retval
));
1430 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1433 game_state
*state
= snew(game_state
);
1434 int empties_to_make
= 0;
1439 int num_faces
, num_edges
;
1441 grid_desc
= extract_grid_desc(&desc
);
1442 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1443 if (grid_desc
) sfree(grid_desc
);
1447 num_faces
= g
->num_faces
;
1448 num_edges
= g
->num_edges
;
1450 state
->clues
= snewn(num_faces
, signed char);
1451 state
->lines
= snewn(num_edges
, char);
1452 state
->line_errors
= snewn(num_edges
, unsigned char);
1454 state
->solved
= state
->cheated
= FALSE
;
1456 state
->grid_type
= params
->type
;
1458 for (i
= 0; i
< num_faces
; i
++) {
1459 if (empties_to_make
) {
1461 state
->clues
[i
] = -1;
1467 n2
= *dp
- 'A' + 10;
1468 if (n
>= 0 && n
< 10) {
1469 state
->clues
[i
] = n
;
1470 } else if (n2
>= 10 && n2
< 36) {
1471 state
->clues
[i
] = n2
;
1475 state
->clues
[i
] = -1;
1476 empties_to_make
= n
- 1;
1481 memset(state
->lines
, LINE_UNKNOWN
, num_edges
);
1482 memset(state
->line_errors
, 0, num_edges
);
1486 /* Calculates the line_errors data, and checks if the current state is a
1488 static int check_completion(game_state
*state
)
1490 grid
*g
= state
->game_grid
;
1492 int num_faces
= g
->num_faces
;
1494 int infinite_area
, finite_area
;
1495 int loops_found
= 0;
1496 int found_edge_not_in_loop
= FALSE
;
1498 memset(state
->line_errors
, 0, g
->num_edges
);
1500 /* LL implementation of SGT's idea:
1501 * A loop will partition the grid into an inside and an outside.
1502 * If there is more than one loop, the grid will be partitioned into
1503 * even more distinct regions. We can therefore track equivalence of
1504 * faces, by saying that two faces are equivalent when there is a non-YES
1505 * edge between them.
1506 * We could keep track of the number of connected components, by counting
1507 * the number of dsf-merges that aren't no-ops.
1508 * But we're only interested in 3 separate cases:
1509 * no loops, one loop, more than one loop.
1511 * No loops: all faces are equivalent to the infinite face.
1512 * One loop: only two equivalence classes - finite and infinite.
1513 * >= 2 loops: there are 2 distinct finite regions.
1515 * So we simply make two passes through all the edges.
1516 * In the first pass, we dsf-merge the two faces bordering each non-YES
1518 * In the second pass, we look for YES-edges bordering:
1519 * a) two non-equivalent faces.
1520 * b) two non-equivalent faces, and one of them is part of a different
1521 * finite area from the first finite area we've seen.
1523 * An occurrence of a) means there is at least one loop.
1524 * An occurrence of b) means there is more than one loop.
1525 * Edges satisfying a) are marked as errors.
1527 * While we're at it, we set a flag if we find a YES edge that is not
1529 * This information will help decide, if there's a single loop, whether it
1530 * is a candidate for being a solution (that is, all YES edges are part of
1533 * If there is a candidate loop, we then go through all clues and check
1534 * they are all satisfied. If so, we have found a solution and we can
1535 * unmark all line_errors.
1538 /* Infinite face is at the end - its index is num_faces.
1539 * This macro is just to make this obvious! */
1540 #define INF_FACE num_faces
1541 dsf
= snewn(num_faces
+ 1, int);
1542 dsf_init(dsf
, num_faces
+ 1);
1545 for (i
= 0; i
< g
->num_edges
; i
++) {
1546 grid_edge
*e
= g
->edges
+ i
;
1547 int f1
= e
->face1 ? e
->face1
- g
->faces
: INF_FACE
;
1548 int f2
= e
->face2 ? e
->face2
- g
->faces
: INF_FACE
;
1549 if (state
->lines
[i
] != LINE_YES
)
1550 dsf_merge(dsf
, f1
, f2
);
1554 infinite_area
= dsf_canonify(dsf
, INF_FACE
);
1556 for (i
= 0; i
< g
->num_edges
; i
++) {
1557 grid_edge
*e
= g
->edges
+ i
;
1558 int f1
= e
->face1 ? e
->face1
- g
->faces
: INF_FACE
;
1559 int can1
= dsf_canonify(dsf
, f1
);
1560 int f2
= e
->face2 ? e
->face2
- g
->faces
: INF_FACE
;
1561 int can2
= dsf_canonify(dsf
, f2
);
1562 if (state
->lines
[i
] != LINE_YES
) continue;
1565 /* Faces are equivalent, so this edge not part of a loop */
1566 found_edge_not_in_loop
= TRUE
;
1569 state
->line_errors
[i
] = TRUE
;
1570 if (loops_found
== 0) loops_found
= 1;
1572 /* Don't bother with further checks if we've already found 2 loops */
1573 if (loops_found
== 2) continue;
1575 if (finite_area
== -1) {
1576 /* Found our first finite area */
1577 if (can1
!= infinite_area
)
1583 /* Have we found a second area? */
1584 if (finite_area
!= -1) {
1585 if (can1
!= infinite_area
&& can1
!= finite_area
) {
1589 if (can2
!= infinite_area
&& can2
!= finite_area
) {
1596 printf("loops_found = %d\n", loops_found);
1597 printf("found_edge_not_in_loop = %s\n",
1598 found_edge_not_in_loop ? "TRUE" : "FALSE");
1601 sfree(dsf
); /* No longer need the dsf */
1603 /* Have we found a candidate loop? */
1604 if (loops_found
== 1 && !found_edge_not_in_loop
) {
1605 /* Yes, so check all clues are satisfied */
1606 int found_clue_violation
= FALSE
;
1607 for (i
= 0; i
< num_faces
; i
++) {
1608 int c
= state
->clues
[i
];
1610 if (face_order(state
, i
, LINE_YES
) != c
) {
1611 found_clue_violation
= TRUE
;
1617 if (!found_clue_violation
) {
1618 /* The loop is good */
1619 memset(state
->line_errors
, 0, g
->num_edges
);
1620 return TRUE
; /* No need to bother checking for dot violations */
1624 /* Check for dot violations */
1625 for (i
= 0; i
< g
->num_dots
; i
++) {
1626 int yes
= dot_order(state
, i
, LINE_YES
);
1627 int unknown
= dot_order(state
, i
, LINE_UNKNOWN
);
1628 if ((yes
== 1 && unknown
== 0) || (yes
>= 3)) {
1629 /* violation, so mark all YES edges as errors */
1630 grid_dot
*d
= g
->dots
+ i
;
1632 for (j
= 0; j
< d
->order
; j
++) {
1633 int e
= d
->edges
[j
] - g
->edges
;
1634 if (state
->lines
[e
] == LINE_YES
)
1635 state
->line_errors
[e
] = TRUE
;
1642 /* ----------------------------------------------------------------------
1645 * Our solver modes operate as follows. Each mode also uses the modes above it.
1648 * Just implement the rules of the game.
1650 * Normal and Tricky Modes
1651 * For each (adjacent) pair of lines through each dot we store a bit for
1652 * whether at least one of them is on and whether at most one is on. (If we
1653 * know both or neither is on that's already stored more directly.)
1656 * Use edsf data structure to make equivalence classes of lines that are
1657 * known identical to or opposite to one another.
1662 * For general grids, we consider "dlines" to be pairs of lines joined
1663 * at a dot. The lines must be adjacent around the dot, so we can think of
1664 * a dline as being a dot+face combination. Or, a dot+edge combination where
1665 * the second edge is taken to be the next clockwise edge from the dot.
1666 * Original loopy code didn't have this extra restriction of the lines being
1667 * adjacent. From my tests with square grids, this extra restriction seems to
1668 * take little, if anything, away from the quality of the puzzles.
1669 * A dline can be uniquely identified by an edge/dot combination, given that
1670 * a dline-pair always goes clockwise around its common dot. The edge/dot
1671 * combination can be represented by an edge/bool combination - if bool is
1672 * TRUE, use edge->dot1 else use edge->dot2. So the total number of dlines is
1673 * exactly twice the number of edges in the grid - although the dlines
1674 * spanning the infinite face are not all that useful to the solver.
1675 * Note that, by convention, a dline goes clockwise around its common dot,
1676 * which means the dline goes anti-clockwise around its common face.
1679 /* Helper functions for obtaining an index into an array of dlines, given
1680 * various information. We assume the grid layout conventions about how
1681 * the various lists are interleaved - see grid_make_consistent() for
1684 /* i points to the first edge of the dline pair, reading clockwise around
1686 static int dline_index_from_dot(grid
*g
, grid_dot
*d
, int i
)
1688 grid_edge
*e
= d
->edges
[i
];
1693 if (i2
== d
->order
) i2
= 0;
1696 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ?
1 : 0);
1698 printf("dline_index_from_dot: d=%d,i=%d, edges [%d,%d] - %d\n",
1699 (int)(d
- g
->dots
), i
, (int)(e
- g
->edges
),
1700 (int)(e2
- g
->edges
), ret
);
1704 /* i points to the second edge of the dline pair, reading clockwise around
1705 * the face. That is, the edges of the dline, starting at edge{i}, read
1706 * anti-clockwise around the face. By layout conventions, the common dot
1707 * of the dline will be f->dots[i] */
1708 static int dline_index_from_face(grid
*g
, grid_face
*f
, int i
)
1710 grid_edge
*e
= f
->edges
[i
];
1711 grid_dot
*d
= f
->dots
[i
];
1716 if (i2
< 0) i2
+= f
->order
;
1719 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ?
1 : 0);
1721 printf("dline_index_from_face: f=%d,i=%d, edges [%d,%d] - %d\n",
1722 (int)(f
- g
->faces
), i
, (int)(e
- g
->edges
),
1723 (int)(e2
- g
->edges
), ret
);
1727 static int is_atleastone(const char *dline_array
, int index
)
1729 return BIT_SET(dline_array
[index
], 0);
1731 static int set_atleastone(char *dline_array
, int index
)
1733 return SET_BIT(dline_array
[index
], 0);
1735 static int is_atmostone(const char *dline_array
, int index
)
1737 return BIT_SET(dline_array
[index
], 1);
1739 static int set_atmostone(char *dline_array
, int index
)
1741 return SET_BIT(dline_array
[index
], 1);
1744 static void array_setall(char *array
, char from
, char to
, int len
)
1746 char *p
= array
, *p_old
= p
;
1747 int len_remaining
= len
;
1749 while ((p
= memchr(p
, from
, len_remaining
))) {
1751 len_remaining
-= p
- p_old
;
1756 /* Helper, called when doing dline dot deductions, in the case where we
1757 * have 4 UNKNOWNs, and two of them (adjacent) have *exactly* one YES between
1758 * them (because of dline atmostone/atleastone).
1759 * On entry, edge points to the first of these two UNKNOWNs. This function
1760 * will find the opposite UNKNOWNS (if they are adjacent to one another)
1761 * and set their corresponding dline to atleastone. (Setting atmostone
1762 * already happens in earlier dline deductions) */
1763 static int dline_set_opp_atleastone(solver_state
*sstate
,
1764 grid_dot
*d
, int edge
)
1766 game_state
*state
= sstate
->state
;
1767 grid
*g
= state
->game_grid
;
1770 for (opp
= 0; opp
< N
; opp
++) {
1771 int opp_dline_index
;
1772 if (opp
== edge
|| opp
== edge
+1 || opp
== edge
-1)
1774 if (opp
== 0 && edge
== N
-1)
1776 if (opp
== N
-1 && edge
== 0)
1779 if (opp2
== N
) opp2
= 0;
1780 /* Check if opp, opp2 point to LINE_UNKNOWNs */
1781 if (state
->lines
[d
->edges
[opp
] - g
->edges
] != LINE_UNKNOWN
)
1783 if (state
->lines
[d
->edges
[opp2
] - g
->edges
] != LINE_UNKNOWN
)
1785 /* Found opposite UNKNOWNS and they're next to each other */
1786 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
1787 return set_atleastone(sstate
->dlines
, opp_dline_index
);
1793 /* Set pairs of lines around this face which are known to be identical, to
1794 * the given line_state */
1795 static int face_setall_identical(solver_state
*sstate
, int face_index
,
1796 enum line_state line_new
)
1798 /* can[dir] contains the canonical line associated with the line in
1799 * direction dir from the square in question. Similarly inv[dir] is
1800 * whether or not the line in question is inverse to its canonical
1803 game_state
*state
= sstate
->state
;
1804 grid
*g
= state
->game_grid
;
1805 grid_face
*f
= g
->faces
+ face_index
;
1808 int can1
, can2
, inv1
, inv2
;
1810 for (i
= 0; i
< N
; i
++) {
1811 int line1_index
= f
->edges
[i
] - g
->edges
;
1812 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
1814 for (j
= i
+ 1; j
< N
; j
++) {
1815 int line2_index
= f
->edges
[j
] - g
->edges
;
1816 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
1819 /* Found two UNKNOWNS */
1820 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
1821 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
1822 if (can1
== can2
&& inv1
== inv2
) {
1823 solver_set_line(sstate
, line1_index
, line_new
);
1824 solver_set_line(sstate
, line2_index
, line_new
);
1831 /* Given a dot or face, and a count of LINE_UNKNOWNs, find them and
1832 * return the edge indices into e. */
1833 static void find_unknowns(game_state
*state
,
1834 grid_edge
**edge_list
, /* Edge list to search (from a face or a dot) */
1835 int expected_count
, /* Number of UNKNOWNs (comes from solver's cache) */
1836 int *e
/* Returned edge indices */)
1839 grid
*g
= state
->game_grid
;
1840 while (c
< expected_count
) {
1841 int line_index
= *edge_list
- g
->edges
;
1842 if (state
->lines
[line_index
] == LINE_UNKNOWN
) {
1850 /* If we have a list of edges, and we know whether the number of YESs should
1851 * be odd or even, and there are only a few UNKNOWNs, we can do some simple
1852 * linedsf deductions. This can be used for both face and dot deductions.
1853 * Returns the difficulty level of the next solver that should be used,
1854 * or DIFF_MAX if no progress was made. */
1855 static int parity_deductions(solver_state
*sstate
,
1856 grid_edge
**edge_list
, /* Edge list (from a face or a dot) */
1857 int total_parity
, /* Expected number of YESs modulo 2 (either 0 or 1) */
1860 game_state
*state
= sstate
->state
;
1861 int diff
= DIFF_MAX
;
1862 int *linedsf
= sstate
->linedsf
;
1864 if (unknown_count
== 2) {
1865 /* Lines are known alike/opposite, depending on inv. */
1867 find_unknowns(state
, edge_list
, 2, e
);
1868 if (merge_lines(sstate
, e
[0], e
[1], total_parity
))
1869 diff
= min(diff
, DIFF_HARD
);
1870 } else if (unknown_count
== 3) {
1872 int can
[3]; /* canonical edges */
1873 int inv
[3]; /* whether can[x] is inverse to e[x] */
1874 find_unknowns(state
, edge_list
, 3, e
);
1875 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
1876 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
1877 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
1878 if (can
[0] == can
[1]) {
1879 if (solver_set_line(sstate
, e
[2], (total_parity
^inv
[0]^inv
[1]) ?
1880 LINE_YES
: LINE_NO
))
1881 diff
= min(diff
, DIFF_EASY
);
1883 if (can
[0] == can
[2]) {
1884 if (solver_set_line(sstate
, e
[1], (total_parity
^inv
[0]^inv
[2]) ?
1885 LINE_YES
: LINE_NO
))
1886 diff
= min(diff
, DIFF_EASY
);
1888 if (can
[1] == can
[2]) {
1889 if (solver_set_line(sstate
, e
[0], (total_parity
^inv
[1]^inv
[2]) ?
1890 LINE_YES
: LINE_NO
))
1891 diff
= min(diff
, DIFF_EASY
);
1893 } else if (unknown_count
== 4) {
1895 int can
[4]; /* canonical edges */
1896 int inv
[4]; /* whether can[x] is inverse to e[x] */
1897 find_unknowns(state
, edge_list
, 4, e
);
1898 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
1899 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
1900 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
1901 can
[3] = edsf_canonify(linedsf
, e
[3], inv
+3);
1902 if (can
[0] == can
[1]) {
1903 if (merge_lines(sstate
, e
[2], e
[3], total_parity
^inv
[0]^inv
[1]))
1904 diff
= min(diff
, DIFF_HARD
);
1905 } else if (can
[0] == can
[2]) {
1906 if (merge_lines(sstate
, e
[1], e
[3], total_parity
^inv
[0]^inv
[2]))
1907 diff
= min(diff
, DIFF_HARD
);
1908 } else if (can
[0] == can
[3]) {
1909 if (merge_lines(sstate
, e
[1], e
[2], total_parity
^inv
[0]^inv
[3]))
1910 diff
= min(diff
, DIFF_HARD
);
1911 } else if (can
[1] == can
[2]) {
1912 if (merge_lines(sstate
, e
[0], e
[3], total_parity
^inv
[1]^inv
[2]))
1913 diff
= min(diff
, DIFF_HARD
);
1914 } else if (can
[1] == can
[3]) {
1915 if (merge_lines(sstate
, e
[0], e
[2], total_parity
^inv
[1]^inv
[3]))
1916 diff
= min(diff
, DIFF_HARD
);
1917 } else if (can
[2] == can
[3]) {
1918 if (merge_lines(sstate
, e
[0], e
[1], total_parity
^inv
[2]^inv
[3]))
1919 diff
= min(diff
, DIFF_HARD
);
1927 * These are the main solver functions.
1929 * Their return values are diff values corresponding to the lowest mode solver
1930 * that would notice the work that they have done. For example if the normal
1931 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
1932 * easy mode solver might be able to make progress using that. It doesn't make
1933 * sense for one of them to return a diff value higher than that of the
1936 * Each function returns the lowest value it can, as early as possible, in
1937 * order to try and pass as much work as possible back to the lower level
1938 * solvers which progress more quickly.
1941 /* PROPOSED NEW DESIGN:
1942 * We have a work queue consisting of 'events' notifying us that something has
1943 * happened that a particular solver mode might be interested in. For example
1944 * the hard mode solver might do something that helps the normal mode solver at
1945 * dot [x,y] in which case it will enqueue an event recording this fact. Then
1946 * we pull events off the work queue, and hand each in turn to the solver that
1947 * is interested in them. If a solver reports that it failed we pass the same
1948 * event on to progressively more advanced solvers and the loop detector. Once
1949 * we've exhausted an event, or it has helped us progress, we drop it and
1950 * continue to the next one. The events are sorted first in order of solver
1951 * complexity (easy first) then order of insertion (oldest first).
1952 * Once we run out of events we loop over each permitted solver in turn
1953 * (easiest first) until either a deduction is made (and an event therefore
1954 * emerges) or no further deductions can be made (in which case we've failed).
1957 * * How do we 'loop over' a solver when both dots and squares are concerned.
1958 * Answer: first all squares then all dots.
1961 static int trivial_deductions(solver_state
*sstate
)
1963 int i
, current_yes
, current_no
;
1964 game_state
*state
= sstate
->state
;
1965 grid
*g
= state
->game_grid
;
1966 int diff
= DIFF_MAX
;
1968 /* Per-face deductions */
1969 for (i
= 0; i
< g
->num_faces
; i
++) {
1970 grid_face
*f
= g
->faces
+ i
;
1972 if (sstate
->face_solved
[i
])
1975 current_yes
= sstate
->face_yes_count
[i
];
1976 current_no
= sstate
->face_no_count
[i
];
1978 if (current_yes
+ current_no
== f
->order
) {
1979 sstate
->face_solved
[i
] = TRUE
;
1983 if (state
->clues
[i
] < 0)
1987 * This code checks whether the numeric clue on a face is so
1988 * large as to permit all its remaining LINE_UNKNOWNs to be
1989 * filled in as LINE_YES, or alternatively so small as to
1990 * permit them all to be filled in as LINE_NO.
1993 if (state
->clues
[i
] < current_yes
) {
1994 sstate
->solver_status
= SOLVER_MISTAKE
;
1997 if (state
->clues
[i
] == current_yes
) {
1998 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
))
1999 diff
= min(diff
, DIFF_EASY
);
2000 sstate
->face_solved
[i
] = TRUE
;
2004 if (f
->order
- state
->clues
[i
] < current_no
) {
2005 sstate
->solver_status
= SOLVER_MISTAKE
;
2008 if (f
->order
- state
->clues
[i
] == current_no
) {
2009 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
))
2010 diff
= min(diff
, DIFF_EASY
);
2011 sstate
->face_solved
[i
] = TRUE
;
2015 if (f
->order
- state
->clues
[i
] == current_no
+ 1 &&
2016 f
->order
- current_yes
- current_no
> 2) {
2018 * One small refinement to the above: we also look for any
2019 * adjacent pair of LINE_UNKNOWNs around the face with
2020 * some LINE_YES incident on it from elsewhere. If we find
2021 * one, then we know that pair of LINE_UNKNOWNs can't
2022 * _both_ be LINE_YES, and hence that pushes us one line
2023 * closer to being able to determine all the rest.
2025 int j
, k
, e1
, e2
, e
, d
;
2027 for (j
= 0; j
< f
->order
; j
++) {
2028 e1
= f
->edges
[j
] - g
->edges
;
2029 e2
= f
->edges
[j
+1 < f
->order ? j
+1 : 0] - g
->edges
;
2031 if (g
->edges
[e1
].dot1
== g
->edges
[e2
].dot1
||
2032 g
->edges
[e1
].dot1
== g
->edges
[e2
].dot2
) {
2033 d
= g
->edges
[e1
].dot1
- g
->dots
;
2035 assert(g
->edges
[e1
].dot2
== g
->edges
[e2
].dot1
||
2036 g
->edges
[e1
].dot2
== g
->edges
[e2
].dot2
);
2037 d
= g
->edges
[e1
].dot2
- g
->dots
;
2040 if (state
->lines
[e1
] == LINE_UNKNOWN
&&
2041 state
->lines
[e2
] == LINE_UNKNOWN
) {
2042 for (k
= 0; k
< g
->dots
[d
].order
; k
++) {
2043 int e
= g
->dots
[d
].edges
[k
] - g
->edges
;
2044 if (state
->lines
[e
] == LINE_YES
)
2045 goto found
; /* multi-level break */
2053 * If we get here, we've found such a pair of edges, and
2054 * they're e1 and e2.
2056 for (j
= 0; j
< f
->order
; j
++) {
2057 e
= f
->edges
[j
] - g
->edges
;
2058 if (state
->lines
[e
] == LINE_UNKNOWN
&& e
!= e1
&& e
!= e2
) {
2059 int r
= solver_set_line(sstate
, e
, LINE_YES
);
2061 diff
= min(diff
, DIFF_EASY
);
2067 check_caches(sstate
);
2069 /* Per-dot deductions */
2070 for (i
= 0; i
< g
->num_dots
; i
++) {
2071 grid_dot
*d
= g
->dots
+ i
;
2072 int yes
, no
, unknown
;
2074 if (sstate
->dot_solved
[i
])
2077 yes
= sstate
->dot_yes_count
[i
];
2078 no
= sstate
->dot_no_count
[i
];
2079 unknown
= d
->order
- yes
- no
;
2083 sstate
->dot_solved
[i
] = TRUE
;
2084 } else if (unknown
== 1) {
2085 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2086 diff
= min(diff
, DIFF_EASY
);
2087 sstate
->dot_solved
[i
] = TRUE
;
2089 } else if (yes
== 1) {
2091 sstate
->solver_status
= SOLVER_MISTAKE
;
2093 } else if (unknown
== 1) {
2094 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
);
2095 diff
= min(diff
, DIFF_EASY
);
2097 } else if (yes
== 2) {
2099 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2100 diff
= min(diff
, DIFF_EASY
);
2102 sstate
->dot_solved
[i
] = TRUE
;
2104 sstate
->solver_status
= SOLVER_MISTAKE
;
2109 check_caches(sstate
);
2114 static int dline_deductions(solver_state
*sstate
)
2116 game_state
*state
= sstate
->state
;
2117 grid
*g
= state
->game_grid
;
2118 char *dlines
= sstate
->dlines
;
2120 int diff
= DIFF_MAX
;
2122 /* ------ Face deductions ------ */
2124 /* Given a set of dline atmostone/atleastone constraints, need to figure
2125 * out if we can deduce any further info. For more general faces than
2126 * squares, this turns out to be a tricky problem.
2127 * The approach taken here is to define (per face) NxN matrices:
2128 * "maxs" and "mins".
2129 * The entries maxs(j,k) and mins(j,k) define the upper and lower limits
2130 * for the possible number of edges that are YES between positions j and k
2131 * going clockwise around the face. Can think of j and k as marking dots
2132 * around the face (recall the labelling scheme: edge0 joins dot0 to dot1,
2133 * edge1 joins dot1 to dot2 etc).
2134 * Trivially, mins(j,j) = maxs(j,j) = 0, and we don't even bother storing
2135 * these. mins(j,j+1) and maxs(j,j+1) are determined by whether edge{j}
2136 * is YES, NO or UNKNOWN. mins(j,j+2) and maxs(j,j+2) are related to
2137 * the dline atmostone/atleastone status for edges j and j+1.
2139 * Then we calculate the remaining entries recursively. We definitely
2141 * mins(j,k) >= { mins(j,u) + mins(u,k) } for any u between j and k.
2142 * This is because any valid placement of YESs between j and k must give
2143 * a valid placement between j and u, and also between u and k.
2144 * I believe it's sufficient to use just the two values of u:
2145 * j+1 and j+2. Seems to work well in practice - the bounds we compute
2146 * are rigorous, even if they might not be best-possible.
2148 * Once we have maxs and mins calculated, we can make inferences about
2149 * each dline{j,j+1} by looking at the possible complementary edge-counts
2150 * mins(j+2,j) and maxs(j+2,j) and comparing these with the face clue.
2151 * As well as dlines, we can make similar inferences about single edges.
2152 * For example, consider a pentagon with clue 3, and we know at most one
2153 * of (edge0, edge1) is YES, and at most one of (edge2, edge3) is YES.
2154 * We could then deduce edge4 is YES, because maxs(0,4) would be 2, so
2155 * that final edge would have to be YES to make the count up to 3.
2158 /* Much quicker to allocate arrays on the stack than the heap, so
2159 * define the largest possible face size, and base our array allocations
2160 * on that. We check this with an assertion, in case someone decides to
2161 * make a grid which has larger faces than this. Note, this algorithm
2162 * could get quite expensive if there are many large faces. */
2163 #define MAX_FACE_SIZE 12
2165 for (i
= 0; i
< g
->num_faces
; i
++) {
2166 int maxs
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2167 int mins
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2168 grid_face
*f
= g
->faces
+ i
;
2171 int clue
= state
->clues
[i
];
2172 assert(N
<= MAX_FACE_SIZE
);
2173 if (sstate
->face_solved
[i
])
2175 if (clue
< 0) continue;
2177 /* Calculate the (j,j+1) entries */
2178 for (j
= 0; j
< N
; j
++) {
2179 int edge_index
= f
->edges
[j
] - g
->edges
;
2181 enum line_state line1
= state
->lines
[edge_index
];
2182 enum line_state line2
;
2186 maxs
[j
][k
] = (line1
== LINE_NO
) ?
0 : 1;
2187 mins
[j
][k
] = (line1
== LINE_YES
) ?
1 : 0;
2188 /* Calculate the (j,j+2) entries */
2189 dline_index
= dline_index_from_face(g
, f
, k
);
2190 edge_index
= f
->edges
[k
] - g
->edges
;
2191 line2
= state
->lines
[edge_index
];
2197 if (line1
== LINE_NO
) tmp
--;
2198 if (line2
== LINE_NO
) tmp
--;
2199 if (tmp
== 2 && is_atmostone(dlines
, dline_index
))
2205 if (line1
== LINE_YES
) tmp
++;
2206 if (line2
== LINE_YES
) tmp
++;
2207 if (tmp
== 0 && is_atleastone(dlines
, dline_index
))
2212 /* Calculate the (j,j+m) entries for m between 3 and N-1 */
2213 for (m
= 3; m
< N
; m
++) {
2214 for (j
= 0; j
< N
; j
++) {
2222 maxs
[j
][k
] = maxs
[j
][u
] + maxs
[u
][k
];
2223 mins
[j
][k
] = mins
[j
][u
] + mins
[u
][k
];
2224 tmp
= maxs
[j
][v
] + maxs
[v
][k
];
2225 maxs
[j
][k
] = min(maxs
[j
][k
], tmp
);
2226 tmp
= mins
[j
][v
] + mins
[v
][k
];
2227 mins
[j
][k
] = max(mins
[j
][k
], tmp
);
2231 /* See if we can make any deductions */
2232 for (j
= 0; j
< N
; j
++) {
2234 grid_edge
*e
= f
->edges
[j
];
2235 int line_index
= e
- g
->edges
;
2238 if (state
->lines
[line_index
] != LINE_UNKNOWN
)
2243 /* minimum YESs in the complement of this edge */
2244 if (mins
[k
][j
] > clue
) {
2245 sstate
->solver_status
= SOLVER_MISTAKE
;
2248 if (mins
[k
][j
] == clue
) {
2249 /* setting this edge to YES would make at least
2250 * (clue+1) edges - contradiction */
2251 solver_set_line(sstate
, line_index
, LINE_NO
);
2252 diff
= min(diff
, DIFF_EASY
);
2254 if (maxs
[k
][j
] < clue
- 1) {
2255 sstate
->solver_status
= SOLVER_MISTAKE
;
2258 if (maxs
[k
][j
] == clue
- 1) {
2259 /* Only way to satisfy the clue is to set edge{j} as YES */
2260 solver_set_line(sstate
, line_index
, LINE_YES
);
2261 diff
= min(diff
, DIFF_EASY
);
2264 /* More advanced deduction that allows propagation along diagonal
2265 * chains of faces connected by dots, for example, 3-2-...-2-3
2266 * in square grids. */
2267 if (sstate
->diff
>= DIFF_TRICKY
) {
2268 /* Now see if we can make dline deduction for edges{j,j+1} */
2270 if (state
->lines
[e
- g
->edges
] != LINE_UNKNOWN
)
2271 /* Only worth doing this for an UNKNOWN,UNKNOWN pair.
2272 * Dlines where one of the edges is known, are handled in the
2276 dline_index
= dline_index_from_face(g
, f
, k
);
2280 /* minimum YESs in the complement of this dline */
2281 if (mins
[k
][j
] > clue
- 2) {
2282 /* Adding 2 YESs would break the clue */
2283 if (set_atmostone(dlines
, dline_index
))
2284 diff
= min(diff
, DIFF_NORMAL
);
2286 /* maximum YESs in the complement of this dline */
2287 if (maxs
[k
][j
] < clue
) {
2288 /* Adding 2 NOs would mean not enough YESs */
2289 if (set_atleastone(dlines
, dline_index
))
2290 diff
= min(diff
, DIFF_NORMAL
);
2296 if (diff
< DIFF_NORMAL
)
2299 /* ------ Dot deductions ------ */
2301 for (i
= 0; i
< g
->num_dots
; i
++) {
2302 grid_dot
*d
= g
->dots
+ i
;
2304 int yes
, no
, unknown
;
2306 if (sstate
->dot_solved
[i
])
2308 yes
= sstate
->dot_yes_count
[i
];
2309 no
= sstate
->dot_no_count
[i
];
2310 unknown
= N
- yes
- no
;
2312 for (j
= 0; j
< N
; j
++) {
2315 int line1_index
, line2_index
;
2316 enum line_state line1
, line2
;
2319 dline_index
= dline_index_from_dot(g
, d
, j
);
2320 line1_index
= d
->edges
[j
] - g
->edges
;
2321 line2_index
= d
->edges
[k
] - g
->edges
;
2322 line1
= state
->lines
[line1_index
];
2323 line2
= state
->lines
[line2_index
];
2325 /* Infer dline state from line state */
2326 if (line1
== LINE_NO
|| line2
== LINE_NO
) {
2327 if (set_atmostone(dlines
, dline_index
))
2328 diff
= min(diff
, DIFF_NORMAL
);
2330 if (line1
== LINE_YES
|| line2
== LINE_YES
) {
2331 if (set_atleastone(dlines
, dline_index
))
2332 diff
= min(diff
, DIFF_NORMAL
);
2334 /* Infer line state from dline state */
2335 if (is_atmostone(dlines
, dline_index
)) {
2336 if (line1
== LINE_YES
&& line2
== LINE_UNKNOWN
) {
2337 solver_set_line(sstate
, line2_index
, LINE_NO
);
2338 diff
= min(diff
, DIFF_EASY
);
2340 if (line2
== LINE_YES
&& line1
== LINE_UNKNOWN
) {
2341 solver_set_line(sstate
, line1_index
, LINE_NO
);
2342 diff
= min(diff
, DIFF_EASY
);
2345 if (is_atleastone(dlines
, dline_index
)) {
2346 if (line1
== LINE_NO
&& line2
== LINE_UNKNOWN
) {
2347 solver_set_line(sstate
, line2_index
, LINE_YES
);
2348 diff
= min(diff
, DIFF_EASY
);
2350 if (line2
== LINE_NO
&& line1
== LINE_UNKNOWN
) {
2351 solver_set_line(sstate
, line1_index
, LINE_YES
);
2352 diff
= min(diff
, DIFF_EASY
);
2355 /* Deductions that depend on the numbers of lines.
2356 * Only bother if both lines are UNKNOWN, otherwise the
2357 * easy-mode solver (or deductions above) would have taken
2359 if (line1
!= LINE_UNKNOWN
|| line2
!= LINE_UNKNOWN
)
2362 if (yes
== 0 && unknown
== 2) {
2363 /* Both these unknowns must be identical. If we know
2364 * atmostone or atleastone, we can make progress. */
2365 if (is_atmostone(dlines
, dline_index
)) {
2366 solver_set_line(sstate
, line1_index
, LINE_NO
);
2367 solver_set_line(sstate
, line2_index
, LINE_NO
);
2368 diff
= min(diff
, DIFF_EASY
);
2370 if (is_atleastone(dlines
, dline_index
)) {
2371 solver_set_line(sstate
, line1_index
, LINE_YES
);
2372 solver_set_line(sstate
, line2_index
, LINE_YES
);
2373 diff
= min(diff
, DIFF_EASY
);
2377 if (set_atmostone(dlines
, dline_index
))
2378 diff
= min(diff
, DIFF_NORMAL
);
2380 if (set_atleastone(dlines
, dline_index
))
2381 diff
= min(diff
, DIFF_NORMAL
);
2385 /* More advanced deduction that allows propagation along diagonal
2386 * chains of faces connected by dots, for example: 3-2-...-2-3
2387 * in square grids. */
2388 if (sstate
->diff
>= DIFF_TRICKY
) {
2389 /* If we have atleastone set for this dline, infer
2390 * atmostone for each "opposite" dline (that is, each
2391 * dline without edges in common with this one).
2392 * Again, this test is only worth doing if both these
2393 * lines are UNKNOWN. For if one of these lines were YES,
2394 * the (yes == 1) test above would kick in instead. */
2395 if (is_atleastone(dlines
, dline_index
)) {
2397 for (opp
= 0; opp
< N
; opp
++) {
2398 int opp_dline_index
;
2399 if (opp
== j
|| opp
== j
+1 || opp
== j
-1)
2401 if (j
== 0 && opp
== N
-1)
2403 if (j
== N
-1 && opp
== 0)
2405 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
2406 if (set_atmostone(dlines
, opp_dline_index
))
2407 diff
= min(diff
, DIFF_NORMAL
);
2409 if (yes
== 0 && is_atmostone(dlines
, dline_index
)) {
2410 /* This dline has *exactly* one YES and there are no
2411 * other YESs. This allows more deductions. */
2413 /* Third unknown must be YES */
2414 for (opp
= 0; opp
< N
; opp
++) {
2416 if (opp
== j
|| opp
== k
)
2418 opp_index
= d
->edges
[opp
] - g
->edges
;
2419 if (state
->lines
[opp_index
] == LINE_UNKNOWN
) {
2420 solver_set_line(sstate
, opp_index
,
2422 diff
= min(diff
, DIFF_EASY
);
2425 } else if (unknown
== 4) {
2426 /* Exactly one of opposite UNKNOWNS is YES. We've
2427 * already set atmostone, so set atleastone as
2430 if (dline_set_opp_atleastone(sstate
, d
, j
))
2431 diff
= min(diff
, DIFF_NORMAL
);
2441 static int linedsf_deductions(solver_state
*sstate
)
2443 game_state
*state
= sstate
->state
;
2444 grid
*g
= state
->game_grid
;
2445 char *dlines
= sstate
->dlines
;
2447 int diff
= DIFF_MAX
;
2450 /* ------ Face deductions ------ */
2452 /* A fully-general linedsf deduction seems overly complicated
2453 * (I suspect the problem is NP-complete, though in practice it might just
2454 * be doable because faces are limited in size).
2455 * For simplicity, we only consider *pairs* of LINE_UNKNOWNS that are
2456 * known to be identical. If setting them both to YES (or NO) would break
2457 * the clue, set them to NO (or YES). */
2459 for (i
= 0; i
< g
->num_faces
; i
++) {
2460 int N
, yes
, no
, unknown
;
2463 if (sstate
->face_solved
[i
])
2465 clue
= state
->clues
[i
];
2469 N
= g
->faces
[i
].order
;
2470 yes
= sstate
->face_yes_count
[i
];
2471 if (yes
+ 1 == clue
) {
2472 if (face_setall_identical(sstate
, i
, LINE_NO
))
2473 diff
= min(diff
, DIFF_EASY
);
2475 no
= sstate
->face_no_count
[i
];
2476 if (no
+ 1 == N
- clue
) {
2477 if (face_setall_identical(sstate
, i
, LINE_YES
))
2478 diff
= min(diff
, DIFF_EASY
);
2481 /* Reload YES count, it might have changed */
2482 yes
= sstate
->face_yes_count
[i
];
2483 unknown
= N
- no
- yes
;
2485 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2486 * parity of lines. */
2487 diff_tmp
= parity_deductions(sstate
, g
->faces
[i
].edges
,
2488 (clue
- yes
) % 2, unknown
);
2489 diff
= min(diff
, diff_tmp
);
2492 /* ------ Dot deductions ------ */
2493 for (i
= 0; i
< g
->num_dots
; i
++) {
2494 grid_dot
*d
= g
->dots
+ i
;
2497 int yes
, no
, unknown
;
2498 /* Go through dlines, and do any dline<->linedsf deductions wherever
2499 * we find two UNKNOWNS. */
2500 for (j
= 0; j
< N
; j
++) {
2501 int dline_index
= dline_index_from_dot(g
, d
, j
);
2504 int can1
, can2
, inv1
, inv2
;
2506 line1_index
= d
->edges
[j
] - g
->edges
;
2507 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
2510 if (j2
== N
) j2
= 0;
2511 line2_index
= d
->edges
[j2
] - g
->edges
;
2512 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
2514 /* Infer dline flags from linedsf */
2515 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
2516 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
2517 if (can1
== can2
&& inv1
!= inv2
) {
2518 /* These are opposites, so set dline atmostone/atleastone */
2519 if (set_atmostone(dlines
, dline_index
))
2520 diff
= min(diff
, DIFF_NORMAL
);
2521 if (set_atleastone(dlines
, dline_index
))
2522 diff
= min(diff
, DIFF_NORMAL
);
2525 /* Infer linedsf from dline flags */
2526 if (is_atmostone(dlines
, dline_index
)
2527 && is_atleastone(dlines
, dline_index
)) {
2528 if (merge_lines(sstate
, line1_index
, line2_index
, 1))
2529 diff
= min(diff
, DIFF_HARD
);
2533 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2534 * parity of lines. */
2535 yes
= sstate
->dot_yes_count
[i
];
2536 no
= sstate
->dot_no_count
[i
];
2537 unknown
= N
- yes
- no
;
2538 diff_tmp
= parity_deductions(sstate
, d
->edges
,
2540 diff
= min(diff
, diff_tmp
);
2543 /* ------ Edge dsf deductions ------ */
2545 /* If the state of a line is known, deduce the state of its canonical line
2546 * too, and vice versa. */
2547 for (i
= 0; i
< g
->num_edges
; i
++) {
2550 can
= edsf_canonify(sstate
->linedsf
, i
, &inv
);
2553 s
= sstate
->state
->lines
[can
];
2554 if (s
!= LINE_UNKNOWN
) {
2555 if (solver_set_line(sstate
, i
, inv ?
OPP(s
) : s
))
2556 diff
= min(diff
, DIFF_EASY
);
2558 s
= sstate
->state
->lines
[i
];
2559 if (s
!= LINE_UNKNOWN
) {
2560 if (solver_set_line(sstate
, can
, inv ?
OPP(s
) : s
))
2561 diff
= min(diff
, DIFF_EASY
);
2569 static int loop_deductions(solver_state
*sstate
)
2571 int edgecount
= 0, clues
= 0, satclues
= 0, sm1clues
= 0;
2572 game_state
*state
= sstate
->state
;
2573 grid
*g
= state
->game_grid
;
2574 int shortest_chainlen
= g
->num_dots
;
2575 int loop_found
= FALSE
;
2577 int progress
= FALSE
;
2581 * Go through the grid and update for all the new edges.
2582 * Since merge_dots() is idempotent, the simplest way to
2583 * do this is just to update for _all_ the edges.
2584 * Also, while we're here, we count the edges.
2586 for (i
= 0; i
< g
->num_edges
; i
++) {
2587 if (state
->lines
[i
] == LINE_YES
) {
2588 loop_found
|= merge_dots(sstate
, i
);
2594 * Count the clues, count the satisfied clues, and count the
2595 * satisfied-minus-one clues.
2597 for (i
= 0; i
< g
->num_faces
; i
++) {
2598 int c
= state
->clues
[i
];
2600 int o
= sstate
->face_yes_count
[i
];
2609 for (i
= 0; i
< g
->num_dots
; ++i
) {
2611 sstate
->looplen
[dsf_canonify(sstate
->dotdsf
, i
)];
2612 if (dots_connected
> 1)
2613 shortest_chainlen
= min(shortest_chainlen
, dots_connected
);
2616 assert(sstate
->solver_status
== SOLVER_INCOMPLETE
);
2618 if (satclues
== clues
&& shortest_chainlen
== edgecount
) {
2619 sstate
->solver_status
= SOLVER_SOLVED
;
2620 /* This discovery clearly counts as progress, even if we haven't
2621 * just added any lines or anything */
2623 goto finished_loop_deductionsing
;
2627 * Now go through looking for LINE_UNKNOWN edges which
2628 * connect two dots that are already in the same
2629 * equivalence class. If we find one, test to see if the
2630 * loop it would create is a solution.
2632 for (i
= 0; i
< g
->num_edges
; i
++) {
2633 grid_edge
*e
= g
->edges
+ i
;
2634 int d1
= e
->dot1
- g
->dots
;
2635 int d2
= e
->dot2
- g
->dots
;
2637 if (state
->lines
[i
] != LINE_UNKNOWN
)
2640 eqclass
= dsf_canonify(sstate
->dotdsf
, d1
);
2641 if (eqclass
!= dsf_canonify(sstate
->dotdsf
, d2
))
2644 val
= LINE_NO
; /* loop is bad until proven otherwise */
2647 * This edge would form a loop. Next
2648 * question: how long would the loop be?
2649 * Would it equal the total number of edges
2650 * (plus the one we'd be adding if we added
2653 if (sstate
->looplen
[eqclass
] == edgecount
+ 1) {
2657 * This edge would form a loop which
2658 * took in all the edges in the entire
2659 * grid. So now we need to work out
2660 * whether it would be a valid solution
2661 * to the puzzle, which means we have to
2662 * check if it satisfies all the clues.
2663 * This means that every clue must be
2664 * either satisfied or satisfied-minus-
2665 * 1, and also that the number of
2666 * satisfied-minus-1 clues must be at
2667 * most two and they must lie on either
2668 * side of this edge.
2672 int f
= e
->face1
- g
->faces
;
2673 int c
= state
->clues
[f
];
2674 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2678 int f
= e
->face2
- g
->faces
;
2679 int c
= state
->clues
[f
];
2680 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2683 if (sm1clues
== sm1_nearby
&&
2684 sm1clues
+ satclues
== clues
) {
2685 val
= LINE_YES
; /* loop is good! */
2690 * Right. Now we know that adding this edge
2691 * would form a loop, and we know whether
2692 * that loop would be a viable solution or
2695 * If adding this edge produces a solution,
2696 * then we know we've found _a_ solution but
2697 * we don't know that it's _the_ solution -
2698 * if it were provably the solution then
2699 * we'd have deduced this edge some time ago
2700 * without the need to do loop detection. So
2701 * in this state we return SOLVER_AMBIGUOUS,
2702 * which has the effect that hitting Solve
2703 * on a user-provided puzzle will fill in a
2704 * solution but using the solver to
2705 * construct new puzzles won't consider this
2706 * a reasonable deduction for the user to
2709 progress
= solver_set_line(sstate
, i
, val
);
2710 assert(progress
== TRUE
);
2711 if (val
== LINE_YES
) {
2712 sstate
->solver_status
= SOLVER_AMBIGUOUS
;
2713 goto finished_loop_deductionsing
;
2717 finished_loop_deductionsing
:
2718 return progress ? DIFF_EASY
: DIFF_MAX
;
2721 /* This will return a dynamically allocated solver_state containing the (more)
2723 static solver_state
*solve_game_rec(const solver_state
*sstate_start
)
2725 solver_state
*sstate
;
2727 /* Index of the solver we should call next. */
2730 /* As a speed-optimisation, we avoid re-running solvers that we know
2731 * won't make any progress. This happens when a high-difficulty
2732 * solver makes a deduction that can only help other high-difficulty
2734 * For example: if a new 'dline' flag is set by dline_deductions, the
2735 * trivial_deductions solver cannot do anything with this information.
2736 * If we've already run the trivial_deductions solver (because it's
2737 * earlier in the list), there's no point running it again.
2739 * Therefore: if a solver is earlier in the list than "threshold_index",
2740 * we don't bother running it if it's difficulty level is less than
2743 int threshold_diff
= 0;
2744 int threshold_index
= 0;
2746 sstate
= dup_solver_state(sstate_start
);
2748 check_caches(sstate
);
2750 while (i
< NUM_SOLVERS
) {
2751 if (sstate
->solver_status
== SOLVER_MISTAKE
)
2753 if (sstate
->solver_status
== SOLVER_SOLVED
||
2754 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2755 /* solver finished */
2759 if ((solver_diffs
[i
] >= threshold_diff
|| i
>= threshold_index
)
2760 && solver_diffs
[i
] <= sstate
->diff
) {
2761 /* current_solver is eligible, so use it */
2762 int next_diff
= solver_fns
[i
](sstate
);
2763 if (next_diff
!= DIFF_MAX
) {
2764 /* solver made progress, so use new thresholds and
2765 * start again at top of list. */
2766 threshold_diff
= next_diff
;
2767 threshold_index
= i
;
2772 /* current_solver is ineligible, or failed to make progress, so
2773 * go to the next solver in the list */
2777 if (sstate
->solver_status
== SOLVER_SOLVED
||
2778 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2779 /* s/LINE_UNKNOWN/LINE_NO/g */
2780 array_setall(sstate
->state
->lines
, LINE_UNKNOWN
, LINE_NO
,
2781 sstate
->state
->game_grid
->num_edges
);
2788 static char *solve_game(game_state
*state
, game_state
*currstate
,
2789 char *aux
, char **error
)
2792 solver_state
*sstate
, *new_sstate
;
2794 sstate
= new_solver_state(state
, DIFF_MAX
);
2795 new_sstate
= solve_game_rec(sstate
);
2797 if (new_sstate
->solver_status
== SOLVER_SOLVED
) {
2798 soln
= encode_solve_move(new_sstate
->state
);
2799 } else if (new_sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2800 soln
= encode_solve_move(new_sstate
->state
);
2801 /**error = "Solver found ambiguous solutions"; */
2803 soln
= encode_solve_move(new_sstate
->state
);
2804 /**error = "Solver failed"; */
2807 free_solver_state(new_sstate
);
2808 free_solver_state(sstate
);
2813 /* ----------------------------------------------------------------------
2814 * Drawing and mouse-handling
2817 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
2818 int x
, int y
, int button
)
2820 grid
*g
= state
->game_grid
;
2824 char button_char
= ' ';
2825 enum line_state old_state
;
2827 button
&= ~MOD_MASK
;
2829 /* Convert mouse-click (x,y) to grid coordinates */
2830 x
-= BORDER(ds
->tilesize
);
2831 y
-= BORDER(ds
->tilesize
);
2832 x
= x
* g
->tilesize
/ ds
->tilesize
;
2833 y
= y
* g
->tilesize
/ ds
->tilesize
;
2837 e
= grid_nearest_edge(g
, x
, y
);
2843 /* I think it's only possible to play this game with mouse clicks, sorry */
2844 /* Maybe will add mouse drag support some time */
2845 old_state
= state
->lines
[i
];
2849 switch (old_state
) {
2867 switch (old_state
) {
2886 sprintf(buf
, "%d%c", i
, (int)button_char
);
2892 static game_state
*execute_move(game_state
*state
, char *move
)
2895 game_state
*newstate
= dup_game(state
);
2897 if (move
[0] == 'S') {
2899 newstate
->cheated
= TRUE
;
2904 if (i
< 0 || i
>= newstate
->game_grid
->num_edges
)
2906 move
+= strspn(move
, "1234567890");
2907 switch (*(move
++)) {
2909 newstate
->lines
[i
] = LINE_YES
;
2912 newstate
->lines
[i
] = LINE_NO
;
2915 newstate
->lines
[i
] = LINE_UNKNOWN
;
2923 * Check for completion.
2925 if (check_completion(newstate
))
2926 newstate
->solved
= TRUE
;
2931 free_game(newstate
);
2935 /* ----------------------------------------------------------------------
2939 /* Convert from grid coordinates to screen coordinates */
2940 static void grid_to_screen(const game_drawstate
*ds
, const grid
*g
,
2941 int grid_x
, int grid_y
, int *x
, int *y
)
2943 *x
= grid_x
- g
->lowest_x
;
2944 *y
= grid_y
- g
->lowest_y
;
2945 *x
= *x
* ds
->tilesize
/ g
->tilesize
;
2946 *y
= *y
* ds
->tilesize
/ g
->tilesize
;
2947 *x
+= BORDER(ds
->tilesize
);
2948 *y
+= BORDER(ds
->tilesize
);
2951 /* Returns (into x,y) position of centre of face for rendering the text clue.
2953 static void face_text_pos(const game_drawstate
*ds
, const grid
*g
,
2954 grid_face
*f
, int *xret
, int *yret
)
2956 int faceindex
= f
- g
->faces
;
2959 * Return the cached position for this face, if we've already
2962 if (ds
->textx
[faceindex
] >= 0) {
2963 *xret
= ds
->textx
[faceindex
];
2964 *yret
= ds
->texty
[faceindex
];
2969 * Otherwise, use the incentre computed by grid.c and convert it
2970 * to screen coordinates.
2972 grid_find_incentre(f
);
2973 grid_to_screen(ds
, g
, f
->ix
, f
->iy
,
2974 &ds
->textx
[faceindex
], &ds
->texty
[faceindex
]);
2976 *xret
= ds
->textx
[faceindex
];
2977 *yret
= ds
->texty
[faceindex
];
2980 static void face_text_bbox(game_drawstate
*ds
, grid
*g
, grid_face
*f
,
2981 int *x
, int *y
, int *w
, int *h
)
2984 face_text_pos(ds
, g
, f
, &xx
, &yy
);
2986 /* There seems to be a certain amount of trial-and-error involved
2987 * in working out the correct bounding-box for the text. */
2989 *x
= xx
- ds
->tilesize
/4 - 1;
2990 *y
= yy
- ds
->tilesize
/4 - 3;
2991 *w
= ds
->tilesize
/2 + 2;
2992 *h
= ds
->tilesize
/2 + 5;
2995 static void game_redraw_clue(drawing
*dr
, game_drawstate
*ds
,
2996 game_state
*state
, int i
)
2998 grid
*g
= state
->game_grid
;
2999 grid_face
*f
= g
->faces
+ i
;
3003 if (state
->clues
[i
] < 10) {
3004 c
[0] = CLUE2CHAR(state
->clues
[i
]);
3007 sprintf(c
, "%d", state
->clues
[i
]);
3010 face_text_pos(ds
, g
, f
, &x
, &y
);
3012 FONT_VARIABLE
, ds
->tilesize
/2,
3013 ALIGN_VCENTRE
| ALIGN_HCENTRE
,
3014 ds
->clue_error
[i
] ? COL_MISTAKE
:
3015 ds
->clue_satisfied
[i
] ? COL_SATISFIED
: COL_FOREGROUND
, c
);
3018 static void edge_bbox(game_drawstate
*ds
, grid
*g
, grid_edge
*e
,
3019 int *x
, int *y
, int *w
, int *h
)
3021 int x1
= e
->dot1
->x
;
3022 int y1
= e
->dot1
->y
;
3023 int x2
= e
->dot2
->x
;
3024 int y2
= e
->dot2
->y
;
3025 int xmin
, xmax
, ymin
, ymax
;
3027 grid_to_screen(ds
, g
, x1
, y1
, &x1
, &y1
);
3028 grid_to_screen(ds
, g
, x2
, y2
, &x2
, &y2
);
3029 /* Allow extra margin for dots, and thickness of lines */
3030 xmin
= min(x1
, x2
) - 2;
3031 xmax
= max(x1
, x2
) + 2;
3032 ymin
= min(y1
, y2
) - 2;
3033 ymax
= max(y1
, y2
) + 2;
3037 *w
= xmax
- xmin
+ 1;
3038 *h
= ymax
- ymin
+ 1;
3041 static void dot_bbox(game_drawstate
*ds
, grid
*g
, grid_dot
*d
,
3042 int *x
, int *y
, int *w
, int *h
)
3046 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x1
, &y1
);
3054 static const int loopy_line_redraw_phases
[] = {
3055 COL_FAINT
, COL_LINEUNKNOWN
, COL_FOREGROUND
, COL_HIGHLIGHT
, COL_MISTAKE
3057 #define NPHASES lenof(loopy_line_redraw_phases)
3059 static void game_redraw_line(drawing
*dr
, game_drawstate
*ds
,
3060 game_state
*state
, int i
, int phase
)
3062 grid
*g
= state
->game_grid
;
3063 grid_edge
*e
= g
->edges
+ i
;
3067 if (state
->line_errors
[i
])
3068 line_colour
= COL_MISTAKE
;
3069 else if (state
->lines
[i
] == LINE_UNKNOWN
)
3070 line_colour
= COL_LINEUNKNOWN
;
3071 else if (state
->lines
[i
] == LINE_NO
)
3072 line_colour
= COL_FAINT
;
3073 else if (ds
->flashing
)
3074 line_colour
= COL_HIGHLIGHT
;
3076 line_colour
= COL_FOREGROUND
;
3077 if (line_colour
!= loopy_line_redraw_phases
[phase
])
3080 /* Convert from grid to screen coordinates */
3081 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3082 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3084 if (line_colour
== COL_FAINT
) {
3085 static int draw_faint_lines
= -1;
3086 if (draw_faint_lines
< 0) {
3087 char *env
= getenv("LOOPY_FAINT_LINES");
3088 draw_faint_lines
= (!env
|| (env
[0] == 'y' ||
3091 if (draw_faint_lines
)
3092 draw_line(dr
, x1
, y1
, x2
, y2
, line_colour
);
3094 draw_thick_line(dr
, 3.0,
3101 static void game_redraw_dot(drawing
*dr
, game_drawstate
*ds
,
3102 game_state
*state
, int i
)
3104 grid
*g
= state
->game_grid
;
3105 grid_dot
*d
= g
->dots
+ i
;
3108 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x
, &y
);
3109 draw_circle(dr
, x
, y
, 2, COL_FOREGROUND
, COL_FOREGROUND
);
3112 static int boxes_intersect(int x0
, int y0
, int w0
, int h0
,
3113 int x1
, int y1
, int w1
, int h1
)
3116 * Two intervals intersect iff neither is wholly on one side of
3117 * the other. Two boxes intersect iff their horizontal and
3118 * vertical intervals both intersect.
3120 return (x0
< x1
+w1
&& x1
< x0
+w0
&& y0
< y1
+h1
&& y1
< y0
+h0
);
3123 static void game_redraw_in_rect(drawing
*dr
, game_drawstate
*ds
,
3124 game_state
*state
, int x
, int y
, int w
, int h
)
3126 grid
*g
= state
->game_grid
;
3130 clip(dr
, x
, y
, w
, h
);
3131 draw_rect(dr
, x
, y
, w
, h
, COL_BACKGROUND
);
3133 for (i
= 0; i
< g
->num_faces
; i
++) {
3134 if (state
->clues
[i
] >= 0) {
3135 face_text_bbox(ds
, g
, &g
->faces
[i
], &bx
, &by
, &bw
, &bh
);
3136 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3137 game_redraw_clue(dr
, ds
, state
, i
);
3140 for (phase
= 0; phase
< NPHASES
; phase
++) {
3141 for (i
= 0; i
< g
->num_edges
; i
++) {
3142 edge_bbox(ds
, g
, &g
->edges
[i
], &bx
, &by
, &bw
, &bh
);
3143 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3144 game_redraw_line(dr
, ds
, state
, i
, phase
);
3147 for (i
= 0; i
< g
->num_dots
; i
++) {
3148 dot_bbox(ds
, g
, &g
->dots
[i
], &bx
, &by
, &bw
, &bh
);
3149 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3150 game_redraw_dot(dr
, ds
, state
, i
);
3154 draw_update(dr
, x
, y
, w
, h
);
3157 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
3158 game_state
*state
, int dir
, game_ui
*ui
,
3159 float animtime
, float flashtime
)
3161 #define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */
3163 grid
*g
= state
->game_grid
;
3164 int border
= BORDER(ds
->tilesize
);
3167 int redraw_everything
= FALSE
;
3169 int edges
[REDRAW_OBJECTS_LIMIT
], nedges
= 0;
3170 int faces
[REDRAW_OBJECTS_LIMIT
], nfaces
= 0;
3172 /* Redrawing is somewhat involved.
3174 * An update can theoretically affect an arbitrary number of edges
3175 * (consider, for example, completing or breaking a cycle which doesn't
3176 * satisfy all the clues -- we'll switch many edges between error and
3177 * normal states). On the other hand, redrawing the whole grid takes a
3178 * while, making the game feel sluggish, and many updates are actually
3179 * quite well localized.
3181 * This redraw algorithm attempts to cope with both situations gracefully
3182 * and correctly. For localized changes, we set a clip rectangle, fill
3183 * it with background, and then redraw (a plausible but conservative
3184 * guess at) the objects which intersect the rectangle; if several
3185 * objects need redrawing, we'll do them individually. However, if lots
3186 * of objects are affected, we'll just redraw everything.
3188 * The reason for all of this is that it's just not safe to do the redraw
3189 * piecemeal. If you try to draw an antialiased diagonal line over
3190 * itself, you get a slightly thicker antialiased diagonal line, which
3191 * looks rather ugly after a while.
3193 * So, we take two passes over the grid. The first attempts to work out
3194 * what needs doing, and the second actually does it.
3198 redraw_everything
= TRUE
;
3201 /* First, trundle through the faces. */
3202 for (i
= 0; i
< g
->num_faces
; i
++) {
3203 grid_face
*f
= g
->faces
+ i
;
3204 int sides
= f
->order
;
3207 int n
= state
->clues
[i
];
3211 clue_mistake
= (face_order(state
, i
, LINE_YES
) > n
||
3212 face_order(state
, i
, LINE_NO
) > (sides
-n
));
3213 clue_satisfied
= (face_order(state
, i
, LINE_YES
) == n
&&
3214 face_order(state
, i
, LINE_NO
) == (sides
-n
));
3216 if (clue_mistake
!= ds
->clue_error
[i
] ||
3217 clue_satisfied
!= ds
->clue_satisfied
[i
]) {
3218 ds
->clue_error
[i
] = clue_mistake
;
3219 ds
->clue_satisfied
[i
] = clue_satisfied
;
3220 if (nfaces
== REDRAW_OBJECTS_LIMIT
)
3221 redraw_everything
= TRUE
;
3223 faces
[nfaces
++] = i
;
3227 /* Work out what the flash state needs to be. */
3228 if (flashtime
> 0 &&
3229 (flashtime
<= FLASH_TIME
/3 ||
3230 flashtime
>= FLASH_TIME
*2/3)) {
3231 flash_changed
= !ds
->flashing
;
3232 ds
->flashing
= TRUE
;
3234 flash_changed
= ds
->flashing
;
3235 ds
->flashing
= FALSE
;
3238 /* Now, trundle through the edges. */
3239 for (i
= 0; i
< g
->num_edges
; i
++) {
3241 state
->line_errors
[i
] ? DS_LINE_ERROR
: state
->lines
[i
];
3242 if (new_ds
!= ds
->lines
[i
] ||
3243 (flash_changed
&& state
->lines
[i
] == LINE_YES
)) {
3244 ds
->lines
[i
] = new_ds
;
3245 if (nedges
== REDRAW_OBJECTS_LIMIT
)
3246 redraw_everything
= TRUE
;
3248 edges
[nedges
++] = i
;
3253 /* Pass one is now done. Now we do the actual drawing. */
3254 if (redraw_everything
) {
3255 int grid_width
= g
->highest_x
- g
->lowest_x
;
3256 int grid_height
= g
->highest_y
- g
->lowest_y
;
3257 int w
= grid_width
* ds
->tilesize
/ g
->tilesize
;
3258 int h
= grid_height
* ds
->tilesize
/ g
->tilesize
;
3260 game_redraw_in_rect(dr
, ds
, state
,
3261 0, 0, w
+ 2*border
+ 1, h
+ 2*border
+ 1);
3264 /* Right. Now we roll up our sleeves. */
3266 for (i
= 0; i
< nfaces
; i
++) {
3267 grid_face
*f
= g
->faces
+ faces
[i
];
3270 face_text_bbox(ds
, g
, f
, &x
, &y
, &w
, &h
);
3271 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3274 for (i
= 0; i
< nedges
; i
++) {
3275 grid_edge
*e
= g
->edges
+ edges
[i
];
3278 edge_bbox(ds
, g
, e
, &x
, &y
, &w
, &h
);
3279 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3286 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
3287 int dir
, game_ui
*ui
)
3289 if (!oldstate
->solved
&& newstate
->solved
&&
3290 !oldstate
->cheated
&& !newstate
->cheated
) {
3297 static int game_status(game_state
*state
)
3299 return state
->solved ?
+1 : 0;
3302 static void game_print_size(game_params
*params
, float *x
, float *y
)
3307 * I'll use 7mm "squares" by default.
3309 game_compute_size(params
, 700, &pw
, &ph
);
3314 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
3316 int ink
= print_mono_colour(dr
, 0);
3318 game_drawstate ads
, *ds
= &ads
;
3319 grid
*g
= state
->game_grid
;
3321 ds
->tilesize
= tilesize
;
3322 ds
->textx
= snewn(g
->num_faces
, int);
3323 ds
->texty
= snewn(g
->num_faces
, int);
3324 for (i
= 0; i
< g
->num_faces
; i
++)
3325 ds
->textx
[i
] = ds
->texty
[i
] = -1;
3327 for (i
= 0; i
< g
->num_dots
; i
++) {
3329 grid_to_screen(ds
, g
, g
->dots
[i
].x
, g
->dots
[i
].y
, &x
, &y
);
3330 draw_circle(dr
, x
, y
, ds
->tilesize
/ 15, ink
, ink
);
3336 for (i
= 0; i
< g
->num_faces
; i
++) {
3337 grid_face
*f
= g
->faces
+ i
;
3338 int clue
= state
->clues
[i
];
3342 c
[0] = CLUE2CHAR(clue
);
3344 face_text_pos(ds
, g
, f
, &x
, &y
);
3346 FONT_VARIABLE
, ds
->tilesize
/ 2,
3347 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, c
);
3354 for (i
= 0; i
< g
->num_edges
; i
++) {
3355 int thickness
= (state
->lines
[i
] == LINE_YES
) ?
30 : 150;
3356 grid_edge
*e
= g
->edges
+ i
;
3358 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3359 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3360 if (state
->lines
[i
] == LINE_YES
)
3362 /* (dx, dy) points from (x1, y1) to (x2, y2).
3363 * The line is then "fattened" in a perpendicular
3364 * direction to create a thin rectangle. */
3365 double d
= sqrt(SQ((double)x1
- x2
) + SQ((double)y1
- y2
));
3366 double dx
= (x2
- x1
) / d
;
3367 double dy
= (y2
- y1
) / d
;
3370 dx
= (dx
* ds
->tilesize
) / thickness
;
3371 dy
= (dy
* ds
->tilesize
) / thickness
;
3372 points
[0] = x1
+ (int)dy
;
3373 points
[1] = y1
- (int)dx
;
3374 points
[2] = x1
- (int)dy
;
3375 points
[3] = y1
+ (int)dx
;
3376 points
[4] = x2
- (int)dy
;
3377 points
[5] = y2
+ (int)dx
;
3378 points
[6] = x2
+ (int)dy
;
3379 points
[7] = y2
- (int)dx
;
3380 draw_polygon(dr
, points
, 4, ink
, ink
);
3384 /* Draw a dotted line */
3387 for (j
= 1; j
< divisions
; j
++) {
3388 /* Weighted average */
3389 int x
= (x1
* (divisions
-j
) + x2
* j
) / divisions
;
3390 int y
= (y1
* (divisions
-j
) + y2
* j
) / divisions
;
3391 draw_circle(dr
, x
, y
, ds
->tilesize
/ thickness
, ink
, ink
);
3401 #define thegame loopy
3404 const struct game thegame
= {
3405 "Loopy", "games.loopy", "loopy",
3412 TRUE
, game_configure
, custom_params
,
3420 TRUE
, game_can_format_as_text_now
, game_text_format
,
3428 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
3431 game_free_drawstate
,
3436 TRUE
, FALSE
, game_print_size
, game_print
,
3437 FALSE
/* wants_statusbar */,
3438 FALSE
, game_timing_state
,
3439 0, /* mouse_priorities */
3442 #ifdef STANDALONE_SOLVER
3445 * Half-hearted standalone solver. It can't output the solution to
3446 * anything but a square puzzle, and it can't log the deductions
3447 * it makes either. But it can solve square puzzles, and more
3448 * importantly it can use its solver to grade the difficulty of
3449 * any puzzle you give it.
3454 int main(int argc
, char **argv
)
3458 char *id
= NULL
, *desc
, *err
;
3461 #if 0 /* verbose solver not supported here (yet) */
3462 int really_verbose
= FALSE
;
3465 while (--argc
> 0) {
3467 #if 0 /* verbose solver not supported here (yet) */
3468 if (!strcmp(p
, "-v")) {
3469 really_verbose
= TRUE
;
3472 if (!strcmp(p
, "-g")) {
3474 } else if (*p
== '-') {
3475 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
3483 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
3487 desc
= strchr(id
, ':');
3489 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
3494 p
= default_params();
3495 decode_params(p
, id
);
3496 err
= validate_desc(p
, desc
);
3498 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
3501 s
= new_game(NULL
, p
, desc
);
3504 * When solving an Easy puzzle, we don't want to bother the
3505 * user with Hard-level deductions. For this reason, we grade
3506 * the puzzle internally before doing anything else.
3508 ret
= -1; /* placate optimiser */
3509 for (diff
= 0; diff
< DIFF_MAX
; diff
++) {
3510 solver_state
*sstate_new
;
3511 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3513 sstate_new
= solve_game_rec(sstate
);
3515 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3517 else if (sstate_new
->solver_status
== SOLVER_SOLVED
)
3522 free_solver_state(sstate_new
);
3523 free_solver_state(sstate
);
3529 if (diff
== DIFF_MAX
) {
3531 printf("Difficulty rating: harder than Hard, or ambiguous\n");
3533 printf("Unable to find a unique solution\n");
3537 printf("Difficulty rating: impossible (no solution exists)\n");
3539 printf("Difficulty rating: %s\n", diffnames
[diff
]);
3541 solver_state
*sstate_new
;
3542 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3544 /* If we supported a verbose solver, we'd set verbosity here */
3546 sstate_new
= solve_game_rec(sstate
);
3548 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3549 printf("Puzzle is inconsistent\n");
3551 assert(sstate_new
->solver_status
== SOLVER_SOLVED
);
3552 if (s
->grid_type
== 0) {
3553 fputs(game_text_format(sstate_new
->state
), stdout
);
3555 printf("Unable to output non-square grids\n");
3559 free_solver_state(sstate_new
);
3560 free_solver_state(sstate
);
3569 /* vim: set shiftwidth=4 tabstop=8: */