2 * slant.c: Puzzle from nikoli.co.jp involving drawing a diagonal
3 * line through each square of a grid.
7 * In this puzzle you have a grid of squares, each of which must
8 * contain a diagonal line; you also have clue numbers placed at
9 * _points_ of that grid, which means there's a (w+1) x (h+1) array
10 * of possible clue positions.
12 * I'm therefore going to adopt a rigid convention throughout this
13 * source file of using w and h for the dimensions of the grid of
14 * squares, and W and H for the dimensions of the grid of points.
15 * Thus, W == w+1 and H == h+1 always.
17 * Clue arrays will be W*H `signed char's, and the clue at each
18 * point will be a number from 0 to 4, or -1 if there's no clue.
20 * Solution arrays will be W*H `signed char's, and the number at
21 * each point will be +1 for a forward slash (/), -1 for a
22 * backslash (\), and 0 for unknown.
44 * In standalone solver mode, `verbose' is a variable which can be
45 * set by command-line option; in debugging mode it's simply always
48 #if defined STANDALONE_SOLVER
49 #define SOLVER_DIAGNOSTICS
51 #elif defined SOLVER_DIAGNOSTICS
56 * Difficulty levels. I do some macro ickery here to ensure that my
57 * enum and the various forms of my name list always match up.
62 #define ENUM(upper,title,lower) DIFF_ ## upper,
63 #define TITLE(upper,title,lower) #title,
64 #define ENCODE(upper,title,lower) #lower
65 #define CONFIG(upper,title,lower) ":" #title
66 enum { DIFFLIST(ENUM
) DIFFCOUNT
};
67 static char const *const slant_diffnames
[] = { DIFFLIST(TITLE
) };
68 static char const slant_diffchars
[] = DIFFLIST(ENCODE
);
69 #define DIFFCONFIG DIFFLIST(CONFIG)
75 typedef struct game_clues
{
78 int *dsf
; /* scratch space for completion check */
87 int used_solve
; /* used to suppress completion flash */
90 static game_params
*default_params(void)
92 game_params
*ret
= snew(game_params
);
95 ret
->diff
= DIFF_EASY
;
100 static const struct game_params slant_presets
[] = {
109 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
114 if (i
< 0 || i
>= lenof(slant_presets
))
117 ret
= snew(game_params
);
118 *ret
= slant_presets
[i
];
120 sprintf(str
, "%dx%d %s", ret
->w
, ret
->h
, slant_diffnames
[ret
->diff
]);
127 static void free_params(game_params
*params
)
132 static game_params
*dup_params(game_params
*params
)
134 game_params
*ret
= snew(game_params
);
135 *ret
= *params
; /* structure copy */
139 static void decode_params(game_params
*ret
, char const *string
)
141 ret
->w
= ret
->h
= atoi(string
);
142 while (*string
&& isdigit((unsigned char)*string
)) string
++;
143 if (*string
== 'x') {
145 ret
->h
= atoi(string
);
146 while (*string
&& isdigit((unsigned char)*string
)) string
++;
148 if (*string
== 'd') {
151 for (i
= 0; i
< DIFFCOUNT
; i
++)
152 if (*string
== slant_diffchars
[i
])
154 if (*string
) string
++;
158 static char *encode_params(game_params
*params
, int full
)
162 sprintf(data
, "%dx%d", params
->w
, params
->h
);
164 sprintf(data
+ strlen(data
), "d%c", slant_diffchars
[params
->diff
]);
169 static config_item
*game_configure(game_params
*params
)
174 ret
= snewn(4, config_item
);
176 ret
[0].name
= "Width";
177 ret
[0].type
= C_STRING
;
178 sprintf(buf
, "%d", params
->w
);
179 ret
[0].sval
= dupstr(buf
);
182 ret
[1].name
= "Height";
183 ret
[1].type
= C_STRING
;
184 sprintf(buf
, "%d", params
->h
);
185 ret
[1].sval
= dupstr(buf
);
188 ret
[2].name
= "Difficulty";
189 ret
[2].type
= C_CHOICES
;
190 ret
[2].sval
= DIFFCONFIG
;
191 ret
[2].ival
= params
->diff
;
201 static game_params
*custom_params(config_item
*cfg
)
203 game_params
*ret
= snew(game_params
);
205 ret
->w
= atoi(cfg
[0].sval
);
206 ret
->h
= atoi(cfg
[1].sval
);
207 ret
->diff
= cfg
[2].ival
;
212 static char *validate_params(game_params
*params
, int full
)
215 * (At least at the time of writing this comment) The grid
216 * generator is actually capable of handling even zero grid
217 * dimensions without crashing. Puzzles with a zero-area grid
218 * are a bit boring, though, because they're already solved :-)
219 * And puzzles with a dimension of 1 can't be made Hard, which
220 * means the simplest thing is to forbid them altogether.
223 if (params
->w
< 2 || params
->h
< 2)
224 return "Width and height must both be at least two";
230 * Scratch space for solver.
232 struct solver_scratch
{
234 * Disjoint set forest which tracks the connected sets of
240 * Counts the number of possible exits from each connected set
241 * of points. (That is, the number of possible _simultaneous_
242 * exits: an unconnected point labelled 2 has an exit count of
243 * 2 even if all four possible edges are still under
249 * Tracks whether each connected set of points includes a
252 unsigned char *border
;
255 * Another disjoint set forest. This one tracks _squares_ which
256 * are known to slant in the same direction.
261 * Stores slash values which we know for an equivalence class.
262 * When we fill in a square, we set slashval[canonify(x)] to
263 * the same value as soln[x], so that we can then spot other
264 * squares equivalent to it and fill them in immediately via
265 * their known equivalence.
267 signed char *slashval
;
270 * Useful to have this information automatically passed to
271 * solver subroutines. (This pointer is not dynamically
272 * allocated by new_scratch and free_scratch.)
274 const signed char *clues
;
277 static struct solver_scratch
*new_scratch(int w
, int h
)
279 int W
= w
+1, H
= h
+1;
280 struct solver_scratch
*ret
= snew(struct solver_scratch
);
281 ret
->connected
= snewn(W
*H
, int);
282 ret
->exits
= snewn(W
*H
, int);
283 ret
->border
= snewn(W
*H
, unsigned char);
284 ret
->equiv
= snewn(w
*h
, int);
285 ret
->slashval
= snewn(w
*h
, signed char);
289 static void free_scratch(struct solver_scratch
*sc
)
295 sfree(sc
->connected
);
300 * Wrapper on dsf_merge() which updates the `exits' and `border'
303 static void merge_vertices(int *connected
,
304 struct solver_scratch
*sc
, int i
, int j
)
306 int exits
= -1, border
= FALSE
; /* initialise to placate optimiser */
309 i
= dsf_canonify(connected
, i
);
310 j
= dsf_canonify(connected
, j
);
313 * We have used one possible exit from each of the two
314 * classes. Thus, the viable exit count of the new class is
315 * the sum of the old exit counts minus two.
317 exits
= sc
->exits
[i
] + sc
->exits
[j
] - 2;
319 border
= sc
->border
[i
] || sc
->border
[j
];
322 dsf_merge(connected
, i
, j
);
325 i
= dsf_canonify(connected
, i
);
326 sc
->exits
[i
] = exits
;
327 sc
->border
[i
] = border
;
332 * Called when we have just blocked one way out of a particular
333 * point. If that point is a non-clue point (thus has a variable
334 * number of exits), we have therefore decreased its potential exit
335 * count, so we must decrement the exit count for the group as a
338 static void decr_exits(struct solver_scratch
*sc
, int i
)
340 if (sc
->clues
[i
] < 0) {
341 i
= dsf_canonify(sc
->connected
, i
);
346 static void fill_square(int w
, int h
, int x
, int y
, int v
,
348 int *connected
, struct solver_scratch
*sc
)
350 int W
= w
+1 /*, H = h+1 */;
352 assert(x
>= 0 && x
< w
&& y
>= 0 && y
< h
);
354 if (soln
[y
*w
+x
] != 0) {
355 return; /* do nothing */
358 #ifdef SOLVER_DIAGNOSTICS
360 printf(" placing %c in %d,%d\n", v
== -1 ?
'\\' : '/', x
, y
);
366 int c
= dsf_canonify(sc
->equiv
, y
*w
+x
);
371 merge_vertices(connected
, sc
, y
*W
+x
, (y
+1)*W
+(x
+1));
373 decr_exits(sc
, y
*W
+(x
+1));
374 decr_exits(sc
, (y
+1)*W
+x
);
377 merge_vertices(connected
, sc
, y
*W
+(x
+1), (y
+1)*W
+x
);
379 decr_exits(sc
, y
*W
+x
);
380 decr_exits(sc
, (y
+1)*W
+(x
+1));
386 * Solver. Returns 0 for impossibility, 1 for success, 2 for
387 * ambiguity or failure to converge.
389 static int slant_solve(int w
, int h
, const signed char *clues
,
390 signed char *soln
, struct solver_scratch
*sc
,
393 int W
= w
+1, H
= h
+1;
400 memset(soln
, 0, w
*h
);
405 * Establish a disjoint set forest for tracking connectedness
406 * between grid points.
408 for (i
= 0; i
< W
*H
; i
++)
409 sc
->connected
[i
] = i
; /* initially all distinct */
412 * Establish a disjoint set forest for tracking which squares
413 * are known to slant in the same direction.
415 for (i
= 0; i
< w
*h
; i
++)
416 sc
->equiv
[i
] = i
; /* initially all distinct */
419 * Clear the slashval array.
421 memset(sc
->slashval
, 0, w
*h
);
424 * Initialise the `exits' and `border' arrays. Theses is used
425 * to do second-order loop avoidance: the dual of the no loops
426 * constraint is that every point must be somehow connected to
427 * the border of the grid (otherwise there would be a solid
428 * loop around it which prevented this).
430 * I define a `dead end' to be a connected group of points
431 * which contains no border point, and which can form at most
432 * one new connection outside itself. Then I forbid placing an
433 * edge so that it connects together two dead-end groups, since
434 * this would yield a non-border-connected isolated subgraph
435 * with no further scope to extend it.
437 for (y
= 0; y
< H
; y
++)
438 for (x
= 0; x
< W
; x
++) {
439 if (y
== 0 || y
== H
-1 || x
== 0 || x
== W
-1)
440 sc
->border
[y
*W
+x
] = TRUE
;
442 sc
->border
[y
*W
+x
] = FALSE
;
444 if (clues
[y
*W
+x
] < 0)
445 sc
->exits
[y
*W
+x
] = 4;
447 sc
->exits
[y
*W
+x
] = clues
[y
*W
+x
];
451 * Make a one-off preliminary pass over the grid looking for
452 * starting-point arrangements. The ones we need to spot are:
454 * - two adjacent 1s in the centre of the grid imply that each
455 * one's single line points towards the other. (If either 1
456 * were connected on the far side, the two squares shared
457 * between the 1s would both link to the other 1 as a
458 * consequence of neither linking to the first.) Thus, we
459 * can fill in the four squares around them.
461 * - dually, two adjacent 3s imply that each one's _non_-line
462 * points towards the other.
464 * - if the pair of 1s and 3s is not _adjacent_ but is
465 * separated by one or more 2s, the reasoning still applies.
467 * This is more advanced than just spotting obvious starting
468 * squares such as central 4s and edge 2s, so we disable it on
471 * (I don't like this loop; it feels grubby to me. My
472 * mathematical intuition feels there ought to be some more
473 * general deductive form which contains this loop as a special
474 * case, but I can't bring it to mind right now.)
476 if (difficulty
> DIFF_EASY
) {
477 for (y
= 1; y
+1 < H
; y
++)
478 for (x
= 1; x
+1 < W
; x
++) {
479 int v
= clues
[y
*W
+x
], s
, x2
, y2
, dx
, dy
;
480 if (v
!= 1 && v
!= 3)
482 /* Slash value of the square up and left of (x,y). */
483 s
= (v
== 1 ?
+1 : -1);
485 /* Look in each direction once. */
486 for (dy
= 0; dy
< 2; dy
++) {
490 if (x2
+1 >= W
|| y2
+1 >= H
)
491 continue; /* too close to the border */
492 while (x2
+dx
+1 < W
&& y2
+dy
+1 < H
&& clues
[y2
*W
+x2
] == 2)
494 if (clues
[y2
*W
+x2
] == v
) {
495 #ifdef SOLVER_DIAGNOSTICS
497 printf("found adjacent %ds at %d,%d and %d,%d\n",
500 fill_square(w
, h
, x
-1, y
-1, s
, soln
,
502 fill_square(w
, h
, x
-1+dy
, y
-1+dx
, -s
, soln
,
504 fill_square(w
, h
, x2
, y2
, s
, soln
,
506 fill_square(w
, h
, x2
-dy
, y2
-dx
, -s
, soln
,
514 * Repeatedly try to deduce something until we can't.
517 done_something
= FALSE
;
520 * Any clue point with the number of remaining lines equal
521 * to zero or to the number of remaining undecided
522 * neighbouring squares can be filled in completely.
524 for (y
= 0; y
< H
; y
++)
525 for (x
= 0; x
< W
; x
++) {
530 int nu
, nl
, c
, s
, eq
, eq2
, last
, meq
, mj1
, mj2
;
532 if ((c
= clues
[y
*W
+x
]) < 0)
536 * We have a clue point. Start by listing its
537 * neighbouring squares, in order around the point,
538 * together with the type of slash that would be
539 * required in that square to connect to the point.
542 if (x
> 0 && y
> 0) {
543 neighbours
[nneighbours
].pos
= (y
-1)*w
+(x
-1);
544 neighbours
[nneighbours
].slash
= -1;
547 if (x
> 0 && y
< h
) {
548 neighbours
[nneighbours
].pos
= y
*w
+(x
-1);
549 neighbours
[nneighbours
].slash
= +1;
552 if (x
< w
&& y
< h
) {
553 neighbours
[nneighbours
].pos
= y
*w
+x
;
554 neighbours
[nneighbours
].slash
= -1;
557 if (x
< w
&& y
> 0) {
558 neighbours
[nneighbours
].pos
= (y
-1)*w
+x
;
559 neighbours
[nneighbours
].slash
= +1;
564 * Count up the number of undecided neighbours, and
565 * also the number of lines already present.
567 * If we're not on DIFF_EASY, then in this loop we
568 * also track whether we've seen two adjacent empty
569 * squares belonging to the same equivalence class
570 * (meaning they have the same type of slash). If
571 * so, we count them jointly as one line.
575 last
= neighbours
[nneighbours
-1].pos
;
577 eq
= dsf_canonify(sc
->equiv
, last
);
580 meq
= mj1
= mj2
= -1;
581 for (i
= 0; i
< nneighbours
; i
++) {
582 j
= neighbours
[i
].pos
;
583 s
= neighbours
[i
].slash
;
585 nu
++; /* undecided */
586 if (meq
< 0 && difficulty
> DIFF_EASY
) {
587 eq2
= dsf_canonify(sc
->equiv
, j
);
588 if (eq
== eq2
&& last
!= j
) {
590 * We've found an equivalent pair.
591 * Mark it. This also inhibits any
592 * further equivalence tracking
593 * around this square, since we can
594 * only handle one pair (and in
595 * particular we want to avoid
596 * being misled by two overlapping
597 * equivalence pairs).
602 nl
--; /* count one line */
603 nu
-= 2; /* and lose two undecideds */
610 nl
--; /* here's a line */
618 if (nl
< 0 || nl
> nu
) {
620 * No consistent value for this at all!
622 #ifdef SOLVER_DIAGNOSTICS
624 printf("need %d / %d lines around clue point at %d,%d!\n",
627 return 0; /* impossible */
630 if (nu
> 0 && (nl
== 0 || nl
== nu
)) {
631 #ifdef SOLVER_DIAGNOSTICS
634 printf("partially (since %d,%d == %d,%d) ",
635 mj1
%w
, mj1
/w
, mj2
%w
, mj2
/w
);
636 printf("%s around clue point at %d,%d\n",
637 nl ?
"filling" : "emptying", x
, y
);
640 for (i
= 0; i
< nneighbours
; i
++) {
641 j
= neighbours
[i
].pos
;
642 s
= neighbours
[i
].slash
;
643 if (soln
[j
] == 0 && j
!= mj1
&& j
!= mj2
)
644 fill_square(w
, h
, j
%w
, j
/w
, (nl ? s
: -s
), soln
,
648 done_something
= TRUE
;
649 } else if (nu
== 2 && nl
== 1 && difficulty
> DIFF_EASY
) {
651 * If we have precisely two undecided squares
652 * and precisely one line to place between
653 * them, _and_ those squares are adjacent, then
654 * we can mark them as equivalent to one
657 * This even applies if meq >= 0: if we have a
658 * 2 clue point and two of its neighbours are
659 * already marked equivalent, we can indeed
660 * mark the other two as equivalent.
662 * We don't bother with this on DIFF_EASY,
663 * since we wouldn't have used the results
667 for (i
= 0; i
< nneighbours
; i
++) {
668 j
= neighbours
[i
].pos
;
669 if (soln
[j
] == 0 && j
!= mj1
&& j
!= mj2
) {
672 else if (last
== i
-1 || (last
== 0 && i
== 3))
673 break; /* found a pair */
676 if (i
< nneighbours
) {
681 * neighbours[last] and neighbours[i] are
682 * the pair. Mark them equivalent.
684 #ifdef SOLVER_DIAGNOSTICS
687 printf("since %d,%d == %d,%d, ",
688 mj1
%w
, mj1
/w
, mj2
%w
, mj2
/w
);
691 mj1
= neighbours
[last
].pos
;
692 mj2
= neighbours
[i
].pos
;
693 #ifdef SOLVER_DIAGNOSTICS
695 printf("clue point at %d,%d implies %d,%d == %d,"
696 "%d\n", x
, y
, mj1
%w
, mj1
/w
, mj2
%w
, mj2
/w
);
698 mj1
= dsf_canonify(sc
->equiv
, mj1
);
699 sv1
= sc
->slashval
[mj1
];
700 mj2
= dsf_canonify(sc
->equiv
, mj2
);
701 sv2
= sc
->slashval
[mj2
];
702 if (sv1
!= 0 && sv2
!= 0 && sv1
!= sv2
) {
703 #ifdef SOLVER_DIAGNOSTICS
705 printf("merged two equivalence classes with"
706 " different slash values!\n");
710 sv1
= sv1 ? sv1
: sv2
;
711 dsf_merge(sc
->equiv
, mj1
, mj2
);
712 mj1
= dsf_canonify(sc
->equiv
, mj1
);
713 sc
->slashval
[mj1
] = sv1
;
722 * Failing that, we now apply the second condition, which
723 * is that no square may be filled in such a way as to form
724 * a loop. Also in this loop (since it's over squares
725 * rather than points), we check slashval to see if we've
726 * already filled in another square in the same equivalence
729 * The slashval check is disabled on DIFF_EASY, as is dead
730 * end avoidance. Only _immediate_ loop avoidance remains.
732 for (y
= 0; y
< h
; y
++)
733 for (x
= 0; x
< w
; x
++) {
736 #ifdef SOLVER_DIAGNOSTICS
737 char *reason
= "<internal error>";
741 continue; /* got this one already */
746 if (difficulty
> DIFF_EASY
)
747 v
= sc
->slashval
[dsf_canonify(sc
->equiv
, y
*w
+x
)];
752 * Try to rule out connectivity between (x,y) and
753 * (x+1,y+1); if successful, we will deduce that we
754 * must have a forward slash.
756 c1
= dsf_canonify(sc
->connected
, y
*W
+x
);
757 c2
= dsf_canonify(sc
->connected
, (y
+1)*W
+(x
+1));
760 #ifdef SOLVER_DIAGNOSTICS
761 reason
= "simple loop avoidance";
764 if (difficulty
> DIFF_EASY
&&
765 !sc
->border
[c1
] && !sc
->border
[c2
] &&
766 sc
->exits
[c1
] <= 1 && sc
->exits
[c2
] <= 1) {
768 #ifdef SOLVER_DIAGNOSTICS
769 reason
= "dead end avoidance";
774 #ifdef SOLVER_DIAGNOSTICS
775 reason
= "equivalence to an already filled square";
780 * Now do the same between (x+1,y) and (x,y+1), to
781 * see if we are required to have a backslash.
783 c1
= dsf_canonify(sc
->connected
, y
*W
+(x
+1));
784 c2
= dsf_canonify(sc
->connected
, (y
+1)*W
+x
);
787 #ifdef SOLVER_DIAGNOSTICS
788 reason
= "simple loop avoidance";
791 if (difficulty
> DIFF_EASY
&&
792 !sc
->border
[c1
] && !sc
->border
[c2
] &&
793 sc
->exits
[c1
] <= 1 && sc
->exits
[c2
] <= 1) {
795 #ifdef SOLVER_DIAGNOSTICS
796 reason
= "dead end avoidance";
801 #ifdef SOLVER_DIAGNOSTICS
802 reason
= "equivalence to an already filled square";
808 * No consistent value for this at all!
810 #ifdef SOLVER_DIAGNOSTICS
812 printf("%d,%d has no consistent slash!\n", x
, y
);
814 return 0; /* impossible */
818 #ifdef SOLVER_DIAGNOSTICS
820 printf("employing %s\n", reason
);
822 fill_square(w
, h
, x
, y
, +1, soln
, sc
->connected
, sc
);
823 done_something
= TRUE
;
825 #ifdef SOLVER_DIAGNOSTICS
827 printf("employing %s\n", reason
);
829 fill_square(w
, h
, x
, y
, -1, soln
, sc
->connected
, sc
);
830 done_something
= TRUE
;
834 } while (done_something
);
837 * Solver can make no more progress. See if the grid is full.
839 for (i
= 0; i
< w
*h
; i
++)
841 return 2; /* failed to converge */
842 return 1; /* success */
846 * Filled-grid generator.
848 static void slant_generate(int w
, int h
, signed char *soln
, random_state
*rs
)
850 int W
= w
+1, H
= h
+1;
852 int *connected
, *indices
;
857 memset(soln
, 0, w
*h
);
860 * Establish a disjoint set forest for tracking connectedness
861 * between grid points.
863 connected
= snewn(W
*H
, int);
864 for (i
= 0; i
< W
*H
; i
++)
865 connected
[i
] = i
; /* initially all distinct */
868 * Prepare a list of the squares in the grid, and fill them in
871 indices
= snewn(w
*h
, int);
872 for (i
= 0; i
< w
*h
; i
++)
874 shuffle(indices
, w
*h
, sizeof(*indices
), rs
);
877 * Fill in each one in turn.
879 for (i
= 0; i
< w
*h
; i
++) {
885 fs
= (dsf_canonify(connected
, y
*W
+x
) ==
886 dsf_canonify(connected
, (y
+1)*W
+(x
+1)));
887 bs
= (dsf_canonify(connected
, (y
+1)*W
+x
) ==
888 dsf_canonify(connected
, y
*W
+(x
+1)));
891 * It isn't possible to get into a situation where we
892 * aren't allowed to place _either_ type of slash in a
893 * square. Thus, filled-grid generation never has to
896 * Proof (thanks to Gareth Taylor):
898 * If it were possible, it would have to be because there
899 * was an existing path (not using this square) between the
900 * top-left and bottom-right corners of this square, and
901 * another between the other two. These two paths would
902 * have to cross at some point.
904 * Obviously they can't cross in the middle of a square, so
905 * they must cross by sharing a point in common. But this
906 * isn't possible either: if you chessboard-colour all the
907 * points on the grid, you find that any continuous
908 * diagonal path is entirely composed of points of the same
909 * colour. And one of our two hypothetical paths is between
910 * two black points, and the other is between two white
911 * points - therefore they can have no point in common. []
915 v
= fs ?
+1 : bs ?
-1 : 2 * random_upto(rs
, 2) - 1;
916 fill_square(w
, h
, x
, y
, v
, soln
, connected
, NULL
);
923 static char *new_game_desc(game_params
*params
, random_state
*rs
,
924 char **aux
, int interactive
)
926 int w
= params
->w
, h
= params
->h
, W
= w
+1, H
= h
+1;
927 signed char *soln
, *tmpsoln
, *clues
;
929 struct solver_scratch
*sc
;
933 soln
= snewn(w
*h
, signed char);
934 tmpsoln
= snewn(w
*h
, signed char);
935 clues
= snewn(W
*H
, signed char);
936 clueindices
= snewn(W
*H
, int);
937 sc
= new_scratch(w
, h
);
941 * Create the filled grid.
943 slant_generate(w
, h
, soln
, rs
);
946 * Fill in the complete set of clues.
948 for (y
= 0; y
< H
; y
++)
949 for (x
= 0; x
< W
; x
++) {
952 if (x
> 0 && y
> 0 && soln
[(y
-1)*w
+(x
-1)] == -1) v
++;
953 if (x
> 0 && y
< h
&& soln
[y
*w
+(x
-1)] == +1) v
++;
954 if (x
< w
&& y
> 0 && soln
[(y
-1)*w
+x
] == +1) v
++;
955 if (x
< w
&& y
< h
&& soln
[y
*w
+x
] == -1) v
++;
961 * With all clue points filled in, all puzzles are easy: we can
962 * simply process the clue points in lexicographic order, and
963 * at each clue point we will always have at most one square
964 * undecided, which we can then fill in uniquely.
966 assert(slant_solve(w
, h
, clues
, tmpsoln
, sc
, DIFF_EASY
) == 1);
969 * Remove as many clues as possible while retaining solubility.
971 * In DIFF_HARD mode, we prioritise the removal of obvious
972 * starting points (4s, 0s, border 2s and corner 1s), on
973 * the grounds that having as few of these as possible
974 * seems like a good thing. In particular, we can often get
975 * away without _any_ completely obvious starting points,
976 * which is even better.
978 for (i
= 0; i
< W
*H
; i
++)
980 shuffle(clueindices
, W
*H
, sizeof(*clueindices
), rs
);
981 for (j
= 0; j
< 2; j
++) {
982 for (i
= 0; i
< W
*H
; i
++) {
985 y
= clueindices
[i
] / W
;
986 x
= clueindices
[i
] % W
;
990 * Identify which pass we should process this point
991 * in. If it's an obvious start point, _or_ we're
992 * in DIFF_EASY, then it goes in pass 0; otherwise
995 xb
= (x
== 0 || x
== W
-1);
996 yb
= (y
== 0 || y
== H
-1);
997 if (params
->diff
== DIFF_EASY
|| v
== 4 || v
== 0 ||
998 (v
== 2 && (xb
||yb
)) || (v
== 1 && xb
&& yb
))
1005 if (slant_solve(w
, h
, clues
, tmpsoln
, sc
,
1007 clues
[y
*W
+x
] = v
; /* put it back */
1013 * And finally, verify that the grid is of _at least_ the
1014 * requested difficulty, by running the solver one level
1015 * down and verifying that it can't manage it.
1017 } while (params
->diff
> 0 &&
1018 slant_solve(w
, h
, clues
, tmpsoln
, sc
, params
->diff
- 1) <= 1);
1021 * Now we have the clue set as it will be presented to the
1022 * user. Encode it in a game desc.
1028 desc
= snewn(W
*H
+1, char);
1031 for (i
= 0; i
<= W
*H
; i
++) {
1032 int n
= (i
< W
*H ? clues
[i
] : -2);
1039 int c
= 'a' - 1 + run
;
1043 run
-= c
- ('a' - 1);
1051 assert(p
- desc
<= W
*H
);
1053 desc
= sresize(desc
, p
- desc
, char);
1057 * Encode the solution as an aux_info.
1061 *aux
= auxbuf
= snewn(w
*h
+1, char);
1062 for (i
= 0; i
< w
*h
; i
++)
1063 auxbuf
[i
] = soln
[i
] < 0 ?
'\\' : '/';
1076 static char *validate_desc(game_params
*params
, char *desc
)
1078 int w
= params
->w
, h
= params
->h
, W
= w
+1, H
= h
+1;
1084 if (n
>= 'a' && n
<= 'z') {
1085 squares
+= n
- 'a' + 1;
1086 } else if (n
>= '0' && n
<= '4') {
1089 return "Invalid character in game description";
1093 return "Not enough data to fill grid";
1096 return "Too much data to fit in grid";
1101 static game_state
*new_game(midend_data
*me
, game_params
*params
, char *desc
)
1103 int w
= params
->w
, h
= params
->h
, W
= w
+1, H
= h
+1;
1104 game_state
*state
= snew(game_state
);
1109 state
->soln
= snewn(w
*h
, signed char);
1110 memset(state
->soln
, 0, w
*h
);
1111 state
->completed
= state
->used_solve
= FALSE
;
1113 state
->clues
= snew(game_clues
);
1114 state
->clues
->w
= w
;
1115 state
->clues
->h
= h
;
1116 state
->clues
->clues
= snewn(W
*H
, signed char);
1117 state
->clues
->refcount
= 1;
1118 state
->clues
->dsf
= snewn(W
*H
, int);
1119 memset(state
->clues
->clues
, -1, W
*H
);
1122 if (n
>= 'a' && n
<= 'z') {
1123 squares
+= n
- 'a' + 1;
1124 } else if (n
>= '0' && n
<= '4') {
1125 state
->clues
->clues
[squares
++] = n
- '0';
1127 assert(!"can't get here");
1129 assert(squares
== area
);
1134 static game_state
*dup_game(game_state
*state
)
1136 int w
= state
->p
.w
, h
= state
->p
.h
;
1137 game_state
*ret
= snew(game_state
);
1140 ret
->clues
= state
->clues
;
1141 ret
->clues
->refcount
++;
1142 ret
->completed
= state
->completed
;
1143 ret
->used_solve
= state
->used_solve
;
1145 ret
->soln
= snewn(w
*h
, signed char);
1146 memcpy(ret
->soln
, state
->soln
, w
*h
);
1151 static void free_game(game_state
*state
)
1154 assert(state
->clues
);
1155 if (--state
->clues
->refcount
<= 0) {
1156 sfree(state
->clues
->clues
);
1157 sfree(state
->clues
->dsf
);
1158 sfree(state
->clues
);
1163 static int check_completion(game_state
*state
)
1165 int w
= state
->p
.w
, h
= state
->p
.h
, W
= w
+1, H
= h
+1;
1169 * Establish a disjoint set forest for tracking connectedness
1170 * between grid points. Use the dsf scratch space in the shared
1171 * clues structure, to avoid mallocing too often.
1173 for (i
= 0; i
< W
*H
; i
++)
1174 state
->clues
->dsf
[i
] = i
; /* initially all distinct */
1177 * Now go through the grid checking connectedness. While we're
1178 * here, also check that everything is filled in.
1180 for (y
= 0; y
< h
; y
++)
1181 for (x
= 0; x
< w
; x
++) {
1184 if (state
->soln
[y
*w
+x
] == 0)
1186 if (state
->soln
[y
*w
+x
] < 0) {
1195 * Our edge connects i1 with i2. If they're already
1196 * connected, return failure. Otherwise, link them.
1198 if (dsf_canonify(state
->clues
->dsf
, i1
) ==
1199 dsf_canonify(state
->clues
->dsf
, i2
))
1202 dsf_merge(state
->clues
->dsf
, i1
, i2
);
1206 * The grid is _a_ valid grid; let's see if it matches the
1209 for (y
= 0; y
< H
; y
++)
1210 for (x
= 0; x
< W
; x
++) {
1213 if ((c
= state
->clues
->clues
[y
*W
+x
]) < 0)
1218 if (x
> 0 && y
> 0 && state
->soln
[(y
-1)*w
+(x
-1)] == -1) v
++;
1219 if (x
> 0 && y
< h
&& state
->soln
[y
*w
+(x
-1)] == +1) v
++;
1220 if (x
< w
&& y
> 0 && state
->soln
[(y
-1)*w
+x
] == +1) v
++;
1221 if (x
< w
&& y
< h
&& state
->soln
[y
*w
+x
] == -1) v
++;
1230 static char *solve_game(game_state
*state
, game_state
*currstate
,
1231 char *aux
, char **error
)
1233 int w
= state
->p
.w
, h
= state
->p
.h
;
1236 int free_soln
= FALSE
;
1237 char *move
, buf
[80];
1238 int movelen
, movesize
;
1243 * If we already have the solution, save ourselves some
1246 soln
= (signed char *)aux
;
1247 bs
= (signed char)'\\';
1250 struct solver_scratch
*sc
= new_scratch(w
, h
);
1251 soln
= snewn(w
*h
, signed char);
1253 ret
= slant_solve(w
, h
, state
->clues
->clues
, soln
, sc
, DIFF_HARD
);
1258 *error
= "This puzzle is not self-consistent";
1260 *error
= "Unable to find a unique solution for this puzzle";
1267 * Construct a move string which turns the current state into
1271 move
= snewn(movesize
, char);
1273 move
[movelen
++] = 'S';
1274 move
[movelen
] = '\0';
1275 for (y
= 0; y
< h
; y
++)
1276 for (x
= 0; x
< w
; x
++) {
1277 int v
= (soln
[y
*w
+x
] == bs ?
-1 : +1);
1278 if (state
->soln
[y
*w
+x
] != v
) {
1279 int len
= sprintf(buf
, ";%c%d,%d", (int)(v
< 0 ?
'\\' : '/'), x
, y
);
1280 if (movelen
+ len
>= movesize
) {
1281 movesize
= movelen
+ len
+ 256;
1282 move
= sresize(move
, movesize
, char);
1284 strcpy(move
+ movelen
, buf
);
1295 static char *game_text_format(game_state
*state
)
1297 int w
= state
->p
.w
, h
= state
->p
.h
, W
= w
+1, H
= h
+1;
1302 * There are h+H rows of w+W columns.
1304 len
= (h
+H
) * (w
+W
+1) + 1;
1305 ret
= snewn(len
, char);
1308 for (y
= 0; y
< H
; y
++) {
1309 for (x
= 0; x
< W
; x
++) {
1310 if (state
->clues
->clues
[y
*W
+x
] >= 0)
1311 *p
++ = state
->clues
->clues
[y
*W
+x
] + '0';
1319 for (x
= 0; x
< W
; x
++) {
1322 if (state
->soln
[y
*w
+x
] != 0)
1323 *p
++ = (state
->soln
[y
*w
+x
] < 0 ?
'\\' : '/');
1333 assert(p
- ret
== len
);
1337 static game_ui
*new_ui(game_state
*state
)
1342 static void free_ui(game_ui
*ui
)
1346 static char *encode_ui(game_ui
*ui
)
1351 static void decode_ui(game_ui
*ui
, char *encoding
)
1355 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
1356 game_state
*newstate
)
1360 #define PREFERRED_TILESIZE 32
1361 #define TILESIZE (ds->tilesize)
1362 #define BORDER TILESIZE
1363 #define CLUE_RADIUS (TILESIZE / 3)
1364 #define CLUE_TEXTSIZE (TILESIZE / 2)
1365 #define COORD(x) ( (x) * TILESIZE + BORDER )
1366 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
1368 #define FLASH_TIME 0.30F
1371 * Bit fields in the `grid' and `todraw' elements of the drawstate.
1373 #define BACKSLASH 0x0001
1374 #define FORWSLASH 0x0002
1387 #define FLASH 0x4000
1389 struct game_drawstate
{
1396 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
1397 int x
, int y
, int button
)
1399 int w
= state
->p
.w
, h
= state
->p
.h
;
1401 if (button
== LEFT_BUTTON
|| button
== RIGHT_BUTTON
) {
1406 * This is an utterly awful hack which I should really sort out
1407 * by means of a proper configuration mechanism. One Slant
1408 * player has observed that they prefer the mouse buttons to
1409 * function exactly the opposite way round, so here's a
1410 * mechanism for environment-based configuration. I cache the
1411 * result in a global variable - yuck! - to avoid repeated
1415 static int swap_buttons
= -1;
1416 if (swap_buttons
< 0) {
1417 char *env
= getenv("SLANT_SWAP_BUTTONS");
1418 swap_buttons
= (env
&& (env
[0] == 'y' || env
[0] == 'Y'));
1421 if (button
== LEFT_BUTTON
)
1422 button
= RIGHT_BUTTON
;
1424 button
= LEFT_BUTTON
;
1430 if (x
< 0 || y
< 0 || x
>= w
|| y
>= h
)
1433 if (button
== LEFT_BUTTON
) {
1435 * Left-clicking cycles blank -> \ -> / -> blank.
1437 v
= state
->soln
[y
*w
+x
] - 1;
1442 * Right-clicking cycles blank -> / -> \ -> blank.
1444 v
= state
->soln
[y
*w
+x
] + 1;
1449 sprintf(buf
, "%c%d,%d", (int)(v
==-1 ?
'\\' : v
==+1 ?
'/' : 'C'), x
, y
);
1456 static game_state
*execute_move(game_state
*state
, char *move
)
1458 int w
= state
->p
.w
, h
= state
->p
.h
;
1461 game_state
*ret
= dup_game(state
);
1466 ret
->used_solve
= TRUE
;
1468 } else if (c
== '\\' || c
== '/' || c
== 'C') {
1470 if (sscanf(move
, "%d,%d%n", &x
, &y
, &n
) != 2 ||
1471 x
< 0 || y
< 0 || x
>= w
|| y
>= h
) {
1475 ret
->soln
[y
*w
+x
] = (c
== '\\' ?
-1 : c
== '/' ?
+1 : 0);
1489 if (!ret
->completed
)
1490 ret
->completed
= check_completion(ret
);
1495 /* ----------------------------------------------------------------------
1499 static void game_compute_size(game_params
*params
, int tilesize
,
1502 /* fool the macros */
1503 struct dummy
{ int tilesize
; } dummy
= { tilesize
}, *ds
= &dummy
;
1505 *x
= 2 * BORDER
+ params
->w
* TILESIZE
+ 1;
1506 *y
= 2 * BORDER
+ params
->h
* TILESIZE
+ 1;
1509 static void game_set_size(game_drawstate
*ds
, game_params
*params
,
1512 ds
->tilesize
= tilesize
;
1515 static float *game_colours(frontend
*fe
, game_state
*state
, int *ncolours
)
1517 float *ret
= snewn(3 * NCOLOURS
, float);
1519 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
1521 ret
[COL_GRID
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.7F
;
1522 ret
[COL_GRID
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.7F
;
1523 ret
[COL_GRID
* 3 + 2] = ret
[COL_BACKGROUND
* 3 + 2] * 0.7F
;
1525 ret
[COL_INK
* 3 + 0] = 0.0F
;
1526 ret
[COL_INK
* 3 + 1] = 0.0F
;
1527 ret
[COL_INK
* 3 + 2] = 0.0F
;
1529 ret
[COL_SLANT1
* 3 + 0] = 0.0F
;
1530 ret
[COL_SLANT1
* 3 + 1] = 0.0F
;
1531 ret
[COL_SLANT1
* 3 + 2] = 0.0F
;
1533 ret
[COL_SLANT2
* 3 + 0] = 0.0F
;
1534 ret
[COL_SLANT2
* 3 + 1] = 0.0F
;
1535 ret
[COL_SLANT2
* 3 + 2] = 0.0F
;
1537 *ncolours
= NCOLOURS
;
1541 static game_drawstate
*game_new_drawstate(game_state
*state
)
1543 int w
= state
->p
.w
, h
= state
->p
.h
;
1545 struct game_drawstate
*ds
= snew(struct game_drawstate
);
1548 ds
->started
= FALSE
;
1549 ds
->grid
= snewn(w
*h
, int);
1550 ds
->todraw
= snewn(w
*h
, int);
1551 for (i
= 0; i
< w
*h
; i
++)
1552 ds
->grid
[i
] = ds
->todraw
[i
] = -1;
1557 static void game_free_drawstate(game_drawstate
*ds
)
1564 static void draw_clue(frontend
*fe
, game_drawstate
*ds
,
1565 int x
, int y
, int v
)
1568 int col
= ((x
^ y
) & 1) ? COL_SLANT1
: COL_SLANT2
;
1575 draw_circle(fe
, COORD(x
), COORD(y
), CLUE_RADIUS
, COL_BACKGROUND
, col
);
1576 draw_text(fe
, COORD(x
), COORD(y
), FONT_VARIABLE
,
1577 CLUE_TEXTSIZE
, ALIGN_VCENTRE
|ALIGN_HCENTRE
,
1581 static void draw_tile(frontend
*fe
, game_drawstate
*ds
, game_clues
*clues
,
1582 int x
, int y
, int v
)
1584 int w
= clues
->w
/*, h = clues->h*/, W
= w
+1 /*, H = h+1 */;
1586 int chesscolour
= (x
^ y
) & 1;
1587 int fscol
= chesscolour ? COL_SLANT2
: COL_SLANT1
;
1588 int bscol
= chesscolour ? COL_SLANT1
: COL_SLANT2
;
1590 clip(fe
, COORD(x
), COORD(y
), TILESIZE
+1, TILESIZE
+1);
1592 draw_rect(fe
, COORD(x
), COORD(y
), TILESIZE
, TILESIZE
,
1593 (v
& FLASH
) ? COL_GRID
: COL_BACKGROUND
);
1596 * Draw the grid lines.
1598 draw_line(fe
, COORD(x
), COORD(y
), COORD(x
+1), COORD(y
), COL_GRID
);
1599 draw_line(fe
, COORD(x
), COORD(y
+1), COORD(x
+1), COORD(y
+1), COL_GRID
);
1600 draw_line(fe
, COORD(x
), COORD(y
), COORD(x
), COORD(y
+1), COL_GRID
);
1601 draw_line(fe
, COORD(x
+1), COORD(y
), COORD(x
+1), COORD(y
+1), COL_GRID
);
1606 if (v
& BACKSLASH
) {
1607 draw_line(fe
, COORD(x
), COORD(y
), COORD(x
+1), COORD(y
+1), bscol
);
1608 draw_line(fe
, COORD(x
)+1, COORD(y
), COORD(x
+1), COORD(y
+1)-1,
1610 draw_line(fe
, COORD(x
), COORD(y
)+1, COORD(x
+1)-1, COORD(y
+1),
1612 } else if (v
& FORWSLASH
) {
1613 draw_line(fe
, COORD(x
+1), COORD(y
), COORD(x
), COORD(y
+1), fscol
);
1614 draw_line(fe
, COORD(x
+1)-1, COORD(y
), COORD(x
), COORD(y
+1)-1,
1616 draw_line(fe
, COORD(x
+1), COORD(y
)+1, COORD(x
)+1, COORD(y
+1),
1621 * Draw dots on the grid corners that appear if a slash is in a
1622 * neighbouring cell.
1625 draw_rect(fe
, COORD(x
), COORD(y
)+1, 1, 1, bscol
);
1627 draw_rect(fe
, COORD(x
), COORD(y
+1)-1, 1, 1, fscol
);
1629 draw_rect(fe
, COORD(x
+1), COORD(y
)+1, 1, 1, fscol
);
1631 draw_rect(fe
, COORD(x
+1), COORD(y
+1)-1, 1, 1, bscol
);
1633 draw_rect(fe
, COORD(x
)+1, COORD(y
), 1, 1, bscol
);
1635 draw_rect(fe
, COORD(x
+1)-1, COORD(y
), 1, 1, fscol
);
1637 draw_rect(fe
, COORD(x
)+1, COORD(y
+1), 1, 1, fscol
);
1639 draw_rect(fe
, COORD(x
+1)-1, COORD(y
+1), 1, 1, bscol
);
1641 draw_rect(fe
, COORD(x
), COORD(y
), 1, 1, bscol
);
1643 draw_rect(fe
, COORD(x
+1), COORD(y
), 1, 1, fscol
);
1645 draw_rect(fe
, COORD(x
), COORD(y
+1), 1, 1, fscol
);
1647 draw_rect(fe
, COORD(x
+1), COORD(y
+1), 1, 1, bscol
);
1650 * And finally the clues at the corners.
1652 for (xx
= x
; xx
<= x
+1; xx
++)
1653 for (yy
= y
; yy
<= y
+1; yy
++)
1654 draw_clue(fe
, ds
, xx
, yy
, clues
->clues
[yy
*W
+xx
]);
1657 draw_update(fe
, COORD(x
), COORD(y
), TILESIZE
+1, TILESIZE
+1);
1660 static void game_redraw(frontend
*fe
, game_drawstate
*ds
, game_state
*oldstate
,
1661 game_state
*state
, int dir
, game_ui
*ui
,
1662 float animtime
, float flashtime
)
1664 int w
= state
->p
.w
, h
= state
->p
.h
, W
= w
+1, H
= h
+1;
1669 flashing
= (int)(flashtime
* 3 / FLASH_TIME
) != 1;
1675 game_compute_size(&state
->p
, TILESIZE
, &ww
, &wh
);
1676 draw_rect(fe
, 0, 0, ww
, wh
, COL_BACKGROUND
);
1677 draw_update(fe
, 0, 0, ww
, wh
);
1680 * Draw any clues on the very edges (since normal tile
1681 * redraw won't draw the bits outside the grid boundary).
1683 for (y
= 0; y
< H
; y
++) {
1684 draw_clue(fe
, ds
, 0, y
, state
->clues
->clues
[y
*W
+0]);
1685 draw_clue(fe
, ds
, w
, y
, state
->clues
->clues
[y
*W
+w
]);
1687 for (x
= 0; x
< W
; x
++) {
1688 draw_clue(fe
, ds
, x
, 0, state
->clues
->clues
[0*W
+x
]);
1689 draw_clue(fe
, ds
, x
, h
, state
->clues
->clues
[h
*W
+x
]);
1696 * Loop over the grid and work out where all the slashes are.
1697 * We need to do this because a slash in one square affects the
1698 * drawing of the next one along.
1700 for (y
= 0; y
< h
; y
++)
1701 for (x
= 0; x
< w
; x
++)
1702 ds
->todraw
[y
*w
+x
] = flashing ? FLASH
: 0;
1704 for (y
= 0; y
< h
; y
++) {
1705 for (x
= 0; x
< w
; x
++) {
1706 if (state
->soln
[y
*w
+x
] < 0) {
1707 ds
->todraw
[y
*w
+x
] |= BACKSLASH
;
1709 ds
->todraw
[y
*w
+(x
-1)] |= R_T
| C_TR
;
1711 ds
->todraw
[y
*w
+(x
+1)] |= L_B
| C_BL
;
1713 ds
->todraw
[(y
-1)*w
+x
] |= B_L
| C_BL
;
1715 ds
->todraw
[(y
+1)*w
+x
] |= T_R
| C_TR
;
1717 ds
->todraw
[(y
-1)*w
+(x
-1)] |= C_BR
;
1718 if (x
+1 < w
&& y
+1 < h
)
1719 ds
->todraw
[(y
+1)*w
+(x
+1)] |= C_TL
;
1720 } else if (state
->soln
[y
*w
+x
] > 0) {
1721 ds
->todraw
[y
*w
+x
] |= FORWSLASH
;
1723 ds
->todraw
[y
*w
+(x
-1)] |= R_B
| C_BR
;
1725 ds
->todraw
[y
*w
+(x
+1)] |= L_T
| C_TL
;
1727 ds
->todraw
[(y
-1)*w
+x
] |= B_R
| C_BR
;
1729 ds
->todraw
[(y
+1)*w
+x
] |= T_L
| C_TL
;
1730 if (x
> 0 && y
+1 < h
)
1731 ds
->todraw
[(y
+1)*w
+(x
-1)] |= C_TR
;
1732 if (x
+1 < w
&& y
> 0)
1733 ds
->todraw
[(y
-1)*w
+(x
+1)] |= C_BL
;
1739 * Now go through and draw the grid squares.
1741 for (y
= 0; y
< h
; y
++) {
1742 for (x
= 0; x
< w
; x
++) {
1743 if (ds
->todraw
[y
*w
+x
] != ds
->grid
[y
*w
+x
]) {
1744 draw_tile(fe
, ds
, state
->clues
, x
, y
, ds
->todraw
[y
*w
+x
]);
1745 ds
->grid
[y
*w
+x
] = ds
->todraw
[y
*w
+x
];
1751 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
1752 int dir
, game_ui
*ui
)
1757 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
1758 int dir
, game_ui
*ui
)
1760 if (!oldstate
->completed
&& newstate
->completed
&&
1761 !oldstate
->used_solve
&& !newstate
->used_solve
)
1767 static int game_wants_statusbar(void)
1772 static int game_timing_state(game_state
*state
, game_ui
*ui
)
1778 #define thegame slant
1781 const struct game thegame
= {
1782 "Slant", "games.slant",
1789 TRUE
, game_configure
, custom_params
,
1797 TRUE
, game_text_format
,
1805 PREFERRED_TILESIZE
, game_compute_size
, game_set_size
,
1808 game_free_drawstate
,
1812 game_wants_statusbar
,
1813 FALSE
, game_timing_state
,
1814 0, /* mouse_priorities */
1817 #ifdef STANDALONE_SOLVER
1822 * gcc -DSTANDALONE_SOLVER -o slantsolver slant.c malloc.c
1825 void frontend_default_colour(frontend
*fe
, float *output
) {}
1826 void draw_text(frontend
*fe
, int x
, int y
, int fonttype
, int fontsize
,
1827 int align
, int colour
, char *text
) {}
1828 void draw_rect(frontend
*fe
, int x
, int y
, int w
, int h
, int colour
) {}
1829 void draw_line(frontend
*fe
, int x1
, int y1
, int x2
, int y2
, int colour
) {}
1830 void draw_polygon(frontend
*fe
, int *coords
, int npoints
,
1831 int fillcolour
, int outlinecolour
) {}
1832 void draw_circle(frontend
*fe
, int cx
, int cy
, int radius
,
1833 int fillcolour
, int outlinecolour
) {}
1834 void clip(frontend
*fe
, int x
, int y
, int w
, int h
) {}
1835 void unclip(frontend
*fe
) {}
1836 void start_draw(frontend
*fe
) {}
1837 void draw_update(frontend
*fe
, int x
, int y
, int w
, int h
) {}
1838 void end_draw(frontend
*fe
) {}
1839 unsigned long random_bits(random_state
*state
, int bits
)
1840 { assert(!"Shouldn't get randomness"); return 0; }
1841 unsigned long random_upto(random_state
*state
, unsigned long limit
)
1842 { assert(!"Shouldn't get randomness"); return 0; }
1843 void shuffle(void *array
, int nelts
, int eltsize
, random_state
*rs
)
1844 { assert(!"Shouldn't get randomness"); }
1846 void fatal(char *fmt
, ...)
1850 fprintf(stderr
, "fatal error: ");
1853 vfprintf(stderr
, fmt
, ap
);
1856 fprintf(stderr
, "\n");
1860 int main(int argc
, char **argv
)
1864 char *id
= NULL
, *desc
, *err
;
1866 int ret
, diff
, really_verbose
= FALSE
;
1867 struct solver_scratch
*sc
;
1869 while (--argc
> 0) {
1871 if (!strcmp(p
, "-v")) {
1872 really_verbose
= TRUE
;
1873 } else if (!strcmp(p
, "-g")) {
1875 } else if (*p
== '-') {
1876 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
1884 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
1888 desc
= strchr(id
, ':');
1890 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
1895 p
= default_params();
1896 decode_params(p
, id
);
1897 err
= validate_desc(p
, desc
);
1899 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
1902 s
= new_game(NULL
, p
, desc
);
1904 sc
= new_scratch(p
->w
, p
->h
);
1907 * When solving an Easy puzzle, we don't want to bother the
1908 * user with Hard-level deductions. For this reason, we grade
1909 * the puzzle internally before doing anything else.
1911 for (diff
= 0; diff
< DIFFCOUNT
; diff
++) {
1912 ret
= slant_solve(p
->w
, p
->h
, s
->clues
->clues
,
1918 if (diff
== DIFFCOUNT
) {
1920 printf("Difficulty rating: harder than Hard, or ambiguous\n");
1922 printf("Unable to find a unique solution\n");
1926 printf("Difficulty rating: impossible (no solution exists)\n");
1928 printf("Difficulty rating: %s\n", slant_diffnames
[diff
]);
1930 verbose
= really_verbose
;
1931 ret
= slant_solve(p
->w
, p
->h
, s
->clues
->clues
,
1934 printf("Puzzle is inconsistent\n");
1936 fputs(game_text_format(s
), stdout
);