2 * map.c: Game involving four-colouring a map.
9 * - better four-colouring algorithm?
10 * - ability to drag a set of pencil marks?
23 * In standalone solver mode, `verbose' is a variable which can be
24 * set by command-line option; in debugging mode it's simply always
27 #if defined STANDALONE_SOLVER
28 #define SOLVER_DIAGNOSTICS
30 #elif defined SOLVER_DIAGNOSTICS
35 * I don't seriously anticipate wanting to change the number of
36 * colours used in this game, but it doesn't cost much to use a
37 * #define just in case :-)
40 #define THREE (FOUR-1)
45 * Ghastly run-time configuration option, just for Gareth (again).
47 static int flash_type
= -1;
48 static float flash_length
;
51 * Difficulty levels. I do some macro ickery here to ensure that my
52 * enum and the various forms of my name list always match up.
58 A(RECURSE,Unreasonable,u)
59 #define ENUM(upper,title,lower) DIFF_ ## upper,
60 #define TITLE(upper,title,lower) #title,
61 #define ENCODE(upper,title,lower) #lower
62 #define CONFIG(upper,title,lower) ":" #title
63 enum { DIFFLIST(ENUM
) DIFFCOUNT
};
64 static char const *const map_diffnames
[] = { DIFFLIST(TITLE
) };
65 static char const map_diffchars
[] = DIFFLIST(ENCODE
);
66 #define DIFFCONFIG DIFFLIST(CONFIG)
68 enum { TE
, BE
, LE
, RE
}; /* top/bottom/left/right edges */
73 COL_0
, COL_1
, COL_2
, COL_3
,
74 COL_ERROR
, COL_ERRTEXT
,
89 int *edgex
, *edgey
; /* position of a point on each edge */
90 int *regionx
, *regiony
; /* position of a point in each region */
96 int *colouring
, *pencil
;
97 int completed
, cheated
;
100 static game_params
*default_params(void)
102 game_params
*ret
= snew(game_params
);
107 ret
->diff
= DIFF_NORMAL
;
112 static const struct game_params map_presets
[] = {
113 {20, 15, 30, DIFF_EASY
},
114 {20, 15, 30, DIFF_NORMAL
},
115 {20, 15, 30, DIFF_HARD
},
116 {20, 15, 30, DIFF_RECURSE
},
117 {30, 25, 75, DIFF_NORMAL
},
118 {30, 25, 75, DIFF_HARD
},
121 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
126 if (i
< 0 || i
>= lenof(map_presets
))
129 ret
= snew(game_params
);
130 *ret
= map_presets
[i
];
132 sprintf(str
, "%dx%d, %d regions, %s", ret
->w
, ret
->h
, ret
->n
,
133 map_diffnames
[ret
->diff
]);
140 static void free_params(game_params
*params
)
145 static game_params
*dup_params(game_params
*params
)
147 game_params
*ret
= snew(game_params
);
148 *ret
= *params
; /* structure copy */
152 static void decode_params(game_params
*params
, char const *string
)
154 char const *p
= string
;
157 while (*p
&& isdigit((unsigned char)*p
)) p
++;
161 while (*p
&& isdigit((unsigned char)*p
)) p
++;
163 params
->h
= params
->w
;
168 while (*p
&& (*p
== '.' || isdigit((unsigned char)*p
))) p
++;
170 params
->n
= params
->w
* params
->h
/ 8;
175 for (i
= 0; i
< DIFFCOUNT
; i
++)
176 if (*p
== map_diffchars
[i
])
182 static char *encode_params(game_params
*params
, int full
)
186 sprintf(ret
, "%dx%dn%d", params
->w
, params
->h
, params
->n
);
188 sprintf(ret
+ strlen(ret
), "d%c", map_diffchars
[params
->diff
]);
193 static config_item
*game_configure(game_params
*params
)
198 ret
= snewn(5, config_item
);
200 ret
[0].name
= "Width";
201 ret
[0].type
= C_STRING
;
202 sprintf(buf
, "%d", params
->w
);
203 ret
[0].sval
= dupstr(buf
);
206 ret
[1].name
= "Height";
207 ret
[1].type
= C_STRING
;
208 sprintf(buf
, "%d", params
->h
);
209 ret
[1].sval
= dupstr(buf
);
212 ret
[2].name
= "Regions";
213 ret
[2].type
= C_STRING
;
214 sprintf(buf
, "%d", params
->n
);
215 ret
[2].sval
= dupstr(buf
);
218 ret
[3].name
= "Difficulty";
219 ret
[3].type
= C_CHOICES
;
220 ret
[3].sval
= DIFFCONFIG
;
221 ret
[3].ival
= params
->diff
;
231 static game_params
*custom_params(config_item
*cfg
)
233 game_params
*ret
= snew(game_params
);
235 ret
->w
= atoi(cfg
[0].sval
);
236 ret
->h
= atoi(cfg
[1].sval
);
237 ret
->n
= atoi(cfg
[2].sval
);
238 ret
->diff
= cfg
[3].ival
;
243 static char *validate_params(game_params
*params
, int full
)
245 if (params
->w
< 2 || params
->h
< 2)
246 return "Width and height must be at least two";
248 return "Must have at least five regions";
249 if (params
->n
> params
->w
* params
->h
)
250 return "Too many regions to fit in grid";
254 /* ----------------------------------------------------------------------
255 * Cumulative frequency table functions.
259 * Initialise a cumulative frequency table. (Hardly worth writing
260 * this function; all it does is to initialise everything in the
263 static void cf_init(int *table
, int n
)
267 for (i
= 0; i
< n
; i
++)
272 * Increment the count of symbol `sym' by `count'.
274 static void cf_add(int *table
, int n
, int sym
, int count
)
291 * Cumulative frequency lookup: return the total count of symbols
292 * with value less than `sym'.
294 static int cf_clookup(int *table
, int n
, int sym
)
296 int bit
, index
, limit
, count
;
301 assert(0 < sym
&& sym
<= n
);
303 count
= table
[0]; /* start with the whole table size */
313 * Find the least number with its lowest set bit in this
314 * position which is greater than or equal to sym.
316 index
= ((sym
+ bit
- 1) &~ (bit
* 2 - 1)) + bit
;
319 count
-= table
[index
];
330 * Single frequency lookup: return the count of symbol `sym'.
332 static int cf_slookup(int *table
, int n
, int sym
)
336 assert(0 <= sym
&& sym
< n
);
340 for (bit
= 1; sym
+bit
< n
&& !(sym
& bit
); bit
<<= 1)
341 count
-= table
[sym
+bit
];
347 * Return the largest symbol index such that the cumulative
348 * frequency up to that symbol is less than _or equal to_ count.
350 static int cf_whichsym(int *table
, int n
, int count
) {
353 assert(count
>= 0 && count
< table
[0]);
364 if (count
>= top
- table
[sym
+bit
])
367 top
-= table
[sym
+bit
];
376 /* ----------------------------------------------------------------------
379 * FIXME: this isn't entirely optimal at present, because it
380 * inherently prioritises growing the largest region since there
381 * are more squares adjacent to it. This acts as a destabilising
382 * influence leading to a few large regions and mostly small ones.
383 * It might be better to do it some other way.
386 #define WEIGHT_INCREASED 2 /* for increased perimeter */
387 #define WEIGHT_DECREASED 4 /* for decreased perimeter */
388 #define WEIGHT_UNCHANGED 3 /* for unchanged perimeter */
391 * Look at a square and decide which colours can be extended into
394 * If called with index < 0, it adds together one of
395 * WEIGHT_INCREASED, WEIGHT_DECREASED or WEIGHT_UNCHANGED for each
396 * colour that has a valid extension (according to the effect that
397 * it would have on the perimeter of the region being extended) and
398 * returns the overall total.
400 * If called with index >= 0, it returns one of the possible
401 * colours depending on the value of index, in such a way that the
402 * number of possible inputs which would give rise to a given
403 * return value correspond to the weight of that value.
405 static int extend_options(int w
, int h
, int n
, int *map
,
406 int x
, int y
, int index
)
412 if (map
[y
*w
+x
] >= 0) {
414 return 0; /* can't do this square at all */
418 * Fetch the eight neighbours of this square, in order around
421 for (dy
= -1; dy
<= +1; dy
++)
422 for (dx
= -1; dx
<= +1; dx
++) {
423 int index
= (dy
< 0 ?
6-dx
: dy
> 0 ?
2+dx
: 2*(1+dx
));
424 if (x
+dx
>= 0 && x
+dx
< w
&& y
+dy
>= 0 && y
+dy
< h
)
425 col
[index
] = map
[(y
+dy
)*w
+(x
+dx
)];
431 * Iterate over each colour that might be feasible.
433 * FIXME: this routine currently has O(n) running time. We
434 * could turn it into O(FOUR) by only bothering to iterate over
435 * the colours mentioned in the four neighbouring squares.
438 for (c
= 0; c
< n
; c
++) {
439 int count
, neighbours
, runs
;
442 * One of the even indices of col (representing the
443 * orthogonal neighbours of this square) must be equal to
444 * c, or else this square is not adjacent to region c and
445 * obviously cannot become an extension of it at this time.
448 for (i
= 0; i
< 8; i
+= 2)
455 * Now we know this square is adjacent to region c. The
456 * next question is, would extending it cause the region to
457 * become non-simply-connected? If so, we mustn't do it.
459 * We determine this by looking around col to see if we can
460 * find more than one separate run of colour c.
463 for (i
= 0; i
< 8; i
++)
464 if (col
[i
] == c
&& col
[(i
+1) & 7] != c
)
472 * This square is a possibility. Determine its effect on
473 * the region's perimeter (computed from the number of
474 * orthogonal neighbours - 1 means a perimeter increase, 3
475 * a decrease, 2 no change; 4 is impossible because the
476 * region would already not be simply connected) and we're
479 assert(neighbours
> 0 && neighbours
< 4);
480 count
= (neighbours
== 1 ? WEIGHT_INCREASED
:
481 neighbours
== 2 ? WEIGHT_UNCHANGED
: WEIGHT_DECREASED
);
484 if (index
>= 0 && index
< count
)
495 static void genmap(int w
, int h
, int n
, int *map
, random_state
*rs
)
502 tmp
= snewn(wh
, int);
505 * Clear the map, and set up `tmp' as a list of grid indices.
507 for (i
= 0; i
< wh
; i
++) {
513 * Place the region seeds by selecting n members from `tmp'.
516 for (i
= 0; i
< n
; i
++) {
517 int j
= random_upto(rs
, k
);
523 * Re-initialise `tmp' as a cumulative frequency table. This
524 * will store the number of possible region colours we can
525 * extend into each square.
530 * Go through the grid and set up the initial cumulative
533 for (y
= 0; y
< h
; y
++)
534 for (x
= 0; x
< w
; x
++)
535 cf_add(tmp
, wh
, y
*w
+x
,
536 extend_options(w
, h
, n
, map
, x
, y
, -1));
539 * Now repeatedly choose a square we can extend a region into,
543 int k
= random_upto(rs
, tmp
[0]);
548 sq
= cf_whichsym(tmp
, wh
, k
);
549 k
-= cf_clookup(tmp
, wh
, sq
);
552 colour
= extend_options(w
, h
, n
, map
, x
, y
, k
);
557 * Re-scan the nine cells around the one we've just
560 for (yy
= max(y
-1, 0); yy
< min(y
+2, h
); yy
++)
561 for (xx
= max(x
-1, 0); xx
< min(x
+2, w
); xx
++) {
562 cf_add(tmp
, wh
, yy
*w
+xx
,
563 -cf_slookup(tmp
, wh
, yy
*w
+xx
) +
564 extend_options(w
, h
, n
, map
, xx
, yy
, -1));
569 * Finally, go through and normalise the region labels into
570 * order, meaning that indistinguishable maps are actually
573 for (i
= 0; i
< n
; i
++)
576 for (i
= 0; i
< wh
; i
++) {
580 map
[i
] = tmp
[map
[i
]];
586 /* ----------------------------------------------------------------------
587 * Functions to handle graphs.
591 * Having got a map in a square grid, convert it into a graph
594 static int gengraph(int w
, int h
, int n
, int *map
, int *graph
)
599 * Start by setting the graph up as an adjacency matrix. We'll
600 * turn it into a list later.
602 for (i
= 0; i
< n
*n
; i
++)
606 * Iterate over the map looking for all adjacencies.
608 for (y
= 0; y
< h
; y
++)
609 for (x
= 0; x
< w
; x
++) {
612 if (x
+1 < w
&& (vx
= map
[y
*w
+(x
+1)]) != v
)
613 graph
[v
*n
+vx
] = graph
[vx
*n
+v
] = 1;
614 if (y
+1 < h
&& (vy
= map
[(y
+1)*w
+x
]) != v
)
615 graph
[v
*n
+vy
] = graph
[vy
*n
+v
] = 1;
619 * Turn the matrix into a list.
621 for (i
= j
= 0; i
< n
*n
; i
++)
628 static int graph_edge_index(int *graph
, int n
, int ngraph
, int i
, int j
)
635 while (top
- bot
> 1) {
636 mid
= (top
+ bot
) / 2;
639 else if (graph
[mid
] < v
)
647 #define graph_adjacent(graph, n, ngraph, i, j) \
648 (graph_edge_index((graph), (n), (ngraph), (i), (j)) >= 0)
650 static int graph_vertex_start(int *graph
, int n
, int ngraph
, int i
)
657 while (top
- bot
> 1) {
658 mid
= (top
+ bot
) / 2;
667 /* ----------------------------------------------------------------------
668 * Generate a four-colouring of a graph.
670 * FIXME: it would be nice if we could convert this recursion into
671 * pseudo-recursion using some sort of explicit stack array, for
672 * the sake of the Palm port and its limited stack.
675 static int fourcolour_recurse(int *graph
, int n
, int ngraph
,
676 int *colouring
, int *scratch
, random_state
*rs
)
678 int nfree
, nvert
, start
, i
, j
, k
, c
, ci
;
682 * Find the smallest number of free colours in any uncoloured
683 * vertex, and count the number of such vertices.
686 nfree
= FIVE
; /* start off bigger than FOUR! */
688 for (i
= 0; i
< n
; i
++)
689 if (colouring
[i
] < 0 && scratch
[i
*FIVE
+FOUR
] <= nfree
) {
690 if (nfree
> scratch
[i
*FIVE
+FOUR
]) {
691 nfree
= scratch
[i
*FIVE
+FOUR
];
698 * If there aren't any uncoloured vertices at all, we're done.
701 return TRUE
; /* we've got a colouring! */
704 * Pick a random vertex in that set.
706 j
= random_upto(rs
, nvert
);
707 for (i
= 0; i
< n
; i
++)
708 if (colouring
[i
] < 0 && scratch
[i
*FIVE
+FOUR
] == nfree
)
712 start
= graph_vertex_start(graph
, n
, ngraph
, i
);
715 * Loop over the possible colours for i, and recurse for each
719 for (c
= 0; c
< FOUR
; c
++)
720 if (scratch
[i
*FIVE
+c
] == 0)
722 shuffle(cs
, ci
, sizeof(*cs
), rs
);
728 * Fill in this colour.
733 * Update the scratch space to reflect a new neighbour
734 * of this colour for each neighbour of vertex i.
736 for (j
= start
; j
< ngraph
&& graph
[j
] < n
*(i
+1); j
++) {
738 if (scratch
[k
*FIVE
+c
] == 0)
739 scratch
[k
*FIVE
+FOUR
]--;
746 if (fourcolour_recurse(graph
, n
, ngraph
, colouring
, scratch
, rs
))
747 return TRUE
; /* got one! */
750 * If that didn't work, clean up and try again with a
753 for (j
= start
; j
< ngraph
&& graph
[j
] < n
*(i
+1); j
++) {
756 if (scratch
[k
*FIVE
+c
] == 0)
757 scratch
[k
*FIVE
+FOUR
]++;
763 * If we reach here, we were unable to find a colouring at all.
764 * (This doesn't necessarily mean the Four Colour Theorem is
765 * violated; it might just mean we've gone down a dead end and
766 * need to back up and look somewhere else. It's only an FCT
767 * violation if we get all the way back up to the top level and
773 static void fourcolour(int *graph
, int n
, int ngraph
, int *colouring
,
780 * For each vertex and each colour, we store the number of
781 * neighbours that have that colour. Also, we store the number
782 * of free colours for the vertex.
784 scratch
= snewn(n
* FIVE
, int);
785 for (i
= 0; i
< n
* FIVE
; i
++)
786 scratch
[i
] = (i
% FIVE
== FOUR ? FOUR
: 0);
789 * Clear the colouring to start with.
791 for (i
= 0; i
< n
; i
++)
794 i
= fourcolour_recurse(graph
, n
, ngraph
, colouring
, scratch
, rs
);
795 assert(i
); /* by the Four Colour Theorem :-) */
800 /* ----------------------------------------------------------------------
801 * Non-recursive solver.
804 struct solver_scratch
{
805 unsigned char *possible
; /* bitmap of colours for each region */
813 #ifdef SOLVER_DIAGNOSTICS
820 static struct solver_scratch
*new_scratch(int *graph
, int n
, int ngraph
)
822 struct solver_scratch
*sc
;
824 sc
= snew(struct solver_scratch
);
828 sc
->possible
= snewn(n
, unsigned char);
830 sc
->bfsqueue
= snewn(n
, int);
831 sc
->bfscolour
= snewn(n
, int);
832 #ifdef SOLVER_DIAGNOSTICS
833 sc
->bfsprev
= snewn(n
, int);
839 static void free_scratch(struct solver_scratch
*sc
)
843 sfree(sc
->bfscolour
);
844 #ifdef SOLVER_DIAGNOSTICS
851 * Count the bits in a word. Only needs to cope with FOUR bits.
853 static int bitcount(int word
)
855 assert(FOUR
<= 4); /* or this needs changing */
856 word
= ((word
& 0xA) >> 1) + (word
& 0x5);
857 word
= ((word
& 0xC) >> 2) + (word
& 0x3);
861 #ifdef SOLVER_DIAGNOSTICS
862 static const char colnames
[FOUR
] = { 'R', 'Y', 'G', 'B' };
865 static int place_colour(struct solver_scratch
*sc
,
866 int *colouring
, int index
, int colour
867 #ifdef SOLVER_DIAGNOSTICS
872 int *graph
= sc
->graph
, n
= sc
->n
, ngraph
= sc
->ngraph
;
875 if (!(sc
->possible
[index
] & (1 << colour
))) {
876 #ifdef SOLVER_DIAGNOSTICS
878 printf("%*scannot place %c in region %d\n", 2*sc
->depth
, "",
879 colnames
[colour
], index
);
881 return FALSE
; /* can't do it */
884 sc
->possible
[index
] = 1 << colour
;
885 colouring
[index
] = colour
;
887 #ifdef SOLVER_DIAGNOSTICS
889 printf("%*s%s %c in region %d\n", 2*sc
->depth
, "",
890 verb
, colnames
[colour
], index
);
894 * Rule out this colour from all the region's neighbours.
896 for (j
= graph_vertex_start(graph
, n
, ngraph
, index
);
897 j
< ngraph
&& graph
[j
] < n
*(index
+1); j
++) {
898 k
= graph
[j
] - index
*n
;
899 #ifdef SOLVER_DIAGNOSTICS
900 if (verbose
&& (sc
->possible
[k
] & (1 << colour
)))
901 printf("%*s ruling out %c in region %d\n", 2*sc
->depth
, "",
902 colnames
[colour
], k
);
904 sc
->possible
[k
] &= ~(1 << colour
);
910 #ifdef SOLVER_DIAGNOSTICS
911 static char *colourset(char *buf
, int set
)
917 for (i
= 0; i
< FOUR
; i
++)
918 if (set
& (1 << i
)) {
919 p
+= sprintf(p
, "%s%c", sep
, colnames
[i
]);
928 * Returns 0 for impossible, 1 for success, 2 for failure to
929 * converge (i.e. puzzle is either ambiguous or just too
932 static int map_solver(struct solver_scratch
*sc
,
933 int *graph
, int n
, int ngraph
, int *colouring
,
938 if (sc
->depth
== 0) {
940 * Initialise scratch space.
942 for (i
= 0; i
< n
; i
++)
943 sc
->possible
[i
] = (1 << FOUR
) - 1;
948 for (i
= 0; i
< n
; i
++)
949 if (colouring
[i
] >= 0) {
950 if (!place_colour(sc
, colouring
, i
, colouring
[i
]
951 #ifdef SOLVER_DIAGNOSTICS
955 #ifdef SOLVER_DIAGNOSTICS
957 printf("%*sinitial clue set is inconsistent\n",
960 return 0; /* the clues aren't even consistent! */
966 * Now repeatedly loop until we find nothing further to do.
969 int done_something
= FALSE
;
971 if (difficulty
< DIFF_EASY
)
972 break; /* can't do anything at all! */
975 * Simplest possible deduction: find a region with only one
978 for (i
= 0; i
< n
; i
++) if (colouring
[i
] < 0) {
979 int p
= sc
->possible
[i
];
982 #ifdef SOLVER_DIAGNOSTICS
984 printf("%*sregion %d has no possible colours left\n",
987 return 0; /* puzzle is inconsistent */
990 if ((p
& (p
-1)) == 0) { /* p is a power of two */
992 for (c
= 0; c
< FOUR
; c
++)
996 ret
= place_colour(sc
, colouring
, i
, c
997 #ifdef SOLVER_DIAGNOSTICS
1002 * place_colour() can only fail if colour c was not
1003 * even a _possibility_ for region i, and we're
1004 * pretty sure it was because we checked before
1005 * calling place_colour(). So we can safely assert
1006 * here rather than having to return a nice
1007 * friendly error code.
1010 done_something
= TRUE
;
1017 if (difficulty
< DIFF_NORMAL
)
1018 break; /* can't do anything harder */
1021 * Failing that, go up one level. Look for pairs of regions
1022 * which (a) both have the same pair of possible colours,
1023 * (b) are adjacent to one another, (c) are adjacent to the
1024 * same region, and (d) that region still thinks it has one
1025 * or both of those possible colours.
1027 * Simplest way to do this is by going through the graph
1028 * edge by edge, so that we start with property (b) and
1029 * then look for (a) and finally (c) and (d).
1031 for (i
= 0; i
< ngraph
; i
++) {
1032 int j1
= graph
[i
] / n
, j2
= graph
[i
] % n
;
1034 #ifdef SOLVER_DIAGNOSTICS
1035 int started
= FALSE
;
1039 continue; /* done it already, other way round */
1041 if (colouring
[j1
] >= 0 || colouring
[j2
] >= 0)
1042 continue; /* they're not undecided */
1044 if (sc
->possible
[j1
] != sc
->possible
[j2
])
1045 continue; /* they don't have the same possibles */
1047 v
= sc
->possible
[j1
];
1049 * See if v contains exactly two set bits.
1051 v2
= v
& -v
; /* find lowest set bit */
1052 v2
= v
& ~v2
; /* clear it */
1053 if (v2
== 0 || (v2
& (v2
-1)) != 0) /* not power of 2 */
1057 * We've found regions j1 and j2 satisfying properties
1058 * (a) and (b): they have two possible colours between
1059 * them, and since they're adjacent to one another they
1060 * must use _both_ those colours between them.
1061 * Therefore, if they are both adjacent to any other
1062 * region then that region cannot be either colour.
1064 * Go through the neighbours of j1 and see if any are
1067 for (j
= graph_vertex_start(graph
, n
, ngraph
, j1
);
1068 j
< ngraph
&& graph
[j
] < n
*(j1
+1); j
++) {
1069 k
= graph
[j
] - j1
*n
;
1070 if (graph_adjacent(graph
, n
, ngraph
, k
, j2
) &&
1071 (sc
->possible
[k
] & v
)) {
1072 #ifdef SOLVER_DIAGNOSTICS
1076 printf("%*sadjacent regions %d,%d share colours"
1077 " %s\n", 2*sc
->depth
, "", j1
, j2
,
1080 printf("%*s ruling out %s in region %d\n",2*sc
->depth
,
1081 "", colourset(buf
, sc
->possible
[k
] & v
), k
);
1084 sc
->possible
[k
] &= ~v
;
1085 done_something
= TRUE
;
1093 if (difficulty
< DIFF_HARD
)
1094 break; /* can't do anything harder */
1097 * Right; now we get creative. Now we're going to look for
1098 * `forcing chains'. A forcing chain is a path through the
1099 * graph with the following properties:
1101 * (a) Each vertex on the path has precisely two possible
1104 * (b) Each pair of vertices which are adjacent on the
1105 * path share at least one possible colour in common.
1107 * (c) Each vertex in the middle of the path shares _both_
1108 * of its colours with at least one of its neighbours
1109 * (not the same one with both neighbours).
1111 * These together imply that at least one of the possible
1112 * colour choices at one end of the path forces _all_ the
1113 * rest of the colours along the path. In order to make
1114 * real use of this, we need further properties:
1116 * (c) Ruling out some colour C from the vertex at one end
1117 * of the path forces the vertex at the other end to
1120 * (d) The two end vertices are mutually adjacent to some
1123 * (e) That third vertex currently has C as a possibility.
1125 * If we can find all of that lot, we can deduce that at
1126 * least one of the two ends of the forcing chain has
1127 * colour C, and that therefore the mutually adjacent third
1130 * To find forcing chains, we're going to start a bfs at
1131 * each suitable vertex of the graph, once for each of its
1132 * two possible colours.
1134 for (i
= 0; i
< n
; i
++) {
1137 if (colouring
[i
] >= 0 || bitcount(sc
->possible
[i
]) != 2)
1140 for (c
= 0; c
< FOUR
; c
++)
1141 if (sc
->possible
[i
] & (1 << c
)) {
1142 int j
, k
, gi
, origc
, currc
, head
, tail
;
1144 * Try a bfs from this vertex, ruling out
1147 * Within this loop, we work in colour bitmaps
1148 * rather than actual colours, because
1149 * converting back and forth is a needless
1150 * computational expense.
1155 for (j
= 0; j
< n
; j
++) {
1156 sc
->bfscolour
[j
] = -1;
1157 #ifdef SOLVER_DIAGNOSTICS
1158 sc
->bfsprev
[j
] = -1;
1162 sc
->bfsqueue
[tail
++] = i
;
1163 sc
->bfscolour
[i
] = sc
->possible
[i
] &~ origc
;
1165 while (head
< tail
) {
1166 j
= sc
->bfsqueue
[head
++];
1167 currc
= sc
->bfscolour
[j
];
1170 * Try neighbours of j.
1172 for (gi
= graph_vertex_start(graph
, n
, ngraph
, j
);
1173 gi
< ngraph
&& graph
[gi
] < n
*(j
+1); gi
++) {
1174 k
= graph
[gi
] - j
*n
;
1177 * To continue with the bfs in vertex
1178 * k, we need k to be
1179 * (a) not already visited
1180 * (b) have two possible colours
1181 * (c) those colours include currc.
1184 if (sc
->bfscolour
[k
] < 0 &&
1186 bitcount(sc
->possible
[k
]) == 2 &&
1187 (sc
->possible
[k
] & currc
)) {
1188 sc
->bfsqueue
[tail
++] = k
;
1190 sc
->possible
[k
] &~ currc
;
1191 #ifdef SOLVER_DIAGNOSTICS
1197 * One other possibility is that k
1198 * might be the region in which we can
1199 * make a real deduction: if it's
1200 * adjacent to i, contains currc as a
1201 * possibility, and currc is equal to
1202 * the original colour we ruled out.
1204 if (currc
== origc
&&
1205 graph_adjacent(graph
, n
, ngraph
, k
, i
) &&
1206 (sc
->possible
[k
] & currc
)) {
1207 #ifdef SOLVER_DIAGNOSTICS
1209 char buf
[80], *sep
= "";
1212 printf("%*sforcing chain, colour %s, ",
1214 colourset(buf
, origc
));
1215 for (r
= j
; r
!= -1; r
= sc
->bfsprev
[r
]) {
1216 printf("%s%d", sep
, r
);
1219 printf("\n%*s ruling out %s in region"
1220 " %d\n", 2*sc
->depth
, "",
1221 colourset(buf
, origc
), k
);
1224 sc
->possible
[k
] &= ~origc
;
1225 done_something
= TRUE
;
1234 if (!done_something
)
1239 * See if we've got a complete solution, and return if so.
1241 for (i
= 0; i
< n
; i
++)
1242 if (colouring
[i
] < 0)
1245 #ifdef SOLVER_DIAGNOSTICS
1247 printf("%*sone solution found\n", 2*sc
->depth
, "");
1249 return 1; /* success! */
1253 * If recursion is not permissible, we now give up.
1255 if (difficulty
< DIFF_RECURSE
) {
1256 #ifdef SOLVER_DIAGNOSTICS
1258 printf("%*sunable to proceed further without recursion\n",
1261 return 2; /* unable to complete */
1265 * Now we've got to do something recursive. So first hunt for a
1266 * currently-most-constrained region.
1270 struct solver_scratch
*rsc
;
1271 int *subcolouring
, *origcolouring
;
1273 int we_already_got_one
;
1278 for (i
= 0; i
< n
; i
++) if (colouring
[i
] < 0) {
1279 int p
= sc
->possible
[i
];
1280 enum { compile_time_assertion
= 1 / (FOUR
<= 4) };
1283 /* Count the set bits. */
1284 c
= (p
& 5) + ((p
>> 1) & 5);
1285 c
= (c
& 3) + ((c
>> 2) & 3);
1286 assert(c
> 1); /* or colouring[i] would be >= 0 */
1294 assert(best
>= 0); /* or we'd be solved already */
1296 #ifdef SOLVER_DIAGNOSTICS
1298 printf("%*srecursing on region %d\n", 2*sc
->depth
, "", best
);
1302 * Now iterate over the possible colours for this region.
1304 rsc
= new_scratch(graph
, n
, ngraph
);
1305 rsc
->depth
= sc
->depth
+ 1;
1306 origcolouring
= snewn(n
, int);
1307 memcpy(origcolouring
, colouring
, n
* sizeof(int));
1308 subcolouring
= snewn(n
, int);
1309 we_already_got_one
= FALSE
;
1312 for (i
= 0; i
< FOUR
; i
++) {
1313 if (!(sc
->possible
[best
] & (1 << i
)))
1316 memcpy(rsc
->possible
, sc
->possible
, n
);
1317 memcpy(subcolouring
, origcolouring
, n
* sizeof(int));
1319 place_colour(rsc
, subcolouring
, best
, i
1320 #ifdef SOLVER_DIAGNOSTICS
1325 subret
= map_solver(rsc
, graph
, n
, ngraph
,
1326 subcolouring
, difficulty
);
1328 #ifdef SOLVER_DIAGNOSTICS
1330 printf("%*sretracting %c in region %d; found %s\n",
1331 2*sc
->depth
, "", colnames
[i
], best
,
1332 subret
== 0 ?
"no solutions" :
1333 subret
== 1 ?
"one solution" : "multiple solutions");
1338 * If this possibility turned up more than one valid
1339 * solution, or if it turned up one and we already had
1340 * one, we're definitely ambiguous.
1342 if (subret
== 2 || (subret
== 1 && we_already_got_one
)) {
1348 * If this possibility turned up one valid solution and
1349 * it's the first we've seen, copy it into the output.
1352 memcpy(colouring
, subcolouring
, n
* sizeof(int));
1353 we_already_got_one
= TRUE
;
1358 * Otherwise, this guess led to a contradiction, so we
1363 sfree(subcolouring
);
1366 #ifdef SOLVER_DIAGNOSTICS
1367 if (verbose
&& sc
->depth
== 0) {
1368 printf("%*s%s found\n",
1370 ret
== 0 ?
"no solutions" :
1371 ret
== 1 ?
"one solution" : "multiple solutions");
1378 /* ----------------------------------------------------------------------
1379 * Game generation main function.
1382 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1383 char **aux
, int interactive
)
1385 struct solver_scratch
*sc
= NULL
;
1386 int *map
, *graph
, ngraph
, *colouring
, *colouring2
, *regions
;
1387 int i
, j
, w
, h
, n
, solveret
, cfreq
[FOUR
];
1390 #ifdef GENERATION_DIAGNOSTICS
1394 int retlen
, retsize
;
1403 map
= snewn(wh
, int);
1404 graph
= snewn(n
*n
, int);
1405 colouring
= snewn(n
, int);
1406 colouring2
= snewn(n
, int);
1407 regions
= snewn(n
, int);
1410 * This is the minimum difficulty below which we'll completely
1411 * reject a map design. Normally we set this to one below the
1412 * requested difficulty, ensuring that we have the right
1413 * result. However, for particularly dense maps or maps with
1414 * particularly few regions it might not be possible to get the
1415 * desired difficulty, so we will eventually drop this down to
1416 * -1 to indicate that any old map will do.
1418 mindiff
= params
->diff
;
1426 genmap(w
, h
, n
, map
, rs
);
1428 #ifdef GENERATION_DIAGNOSTICS
1429 for (y
= 0; y
< h
; y
++) {
1430 for (x
= 0; x
< w
; x
++) {
1435 putchar('a' + v
-36);
1437 putchar('A' + v
-10);
1446 * Convert the map into a graph.
1448 ngraph
= gengraph(w
, h
, n
, map
, graph
);
1450 #ifdef GENERATION_DIAGNOSTICS
1451 for (i
= 0; i
< ngraph
; i
++)
1452 printf("%d-%d\n", graph
[i
]/n
, graph
[i
]%n
);
1458 fourcolour(graph
, n
, ngraph
, colouring
, rs
);
1460 #ifdef GENERATION_DIAGNOSTICS
1461 for (i
= 0; i
< n
; i
++)
1462 printf("%d: %d\n", i
, colouring
[i
]);
1464 for (y
= 0; y
< h
; y
++) {
1465 for (x
= 0; x
< w
; x
++) {
1466 int v
= colouring
[map
[y
*w
+x
]];
1468 putchar('a' + v
-36);
1470 putchar('A' + v
-10);
1479 * Encode the solution as an aux string.
1481 if (*aux
) /* in case we've come round again */
1483 retlen
= retsize
= 0;
1485 for (i
= 0; i
< n
; i
++) {
1488 if (colouring
[i
] < 0)
1491 len
= sprintf(buf
, "%s%d:%d", i ?
";" : "S;", colouring
[i
], i
);
1492 if (retlen
+ len
>= retsize
) {
1493 retsize
= retlen
+ len
+ 256;
1494 ret
= sresize(ret
, retsize
, char);
1496 strcpy(ret
+ retlen
, buf
);
1502 * Remove the region colours one by one, keeping
1503 * solubility. Also ensure that there always remains at
1504 * least one region of every colour, so that the user can
1505 * drag from somewhere.
1507 for (i
= 0; i
< FOUR
; i
++)
1509 for (i
= 0; i
< n
; i
++) {
1511 cfreq
[colouring
[i
]]++;
1513 for (i
= 0; i
< FOUR
; i
++)
1517 shuffle(regions
, n
, sizeof(*regions
), rs
);
1519 if (sc
) free_scratch(sc
);
1520 sc
= new_scratch(graph
, n
, ngraph
);
1522 for (i
= 0; i
< n
; i
++) {
1525 if (cfreq
[colouring
[j
]] == 1)
1526 continue; /* can't remove last region of colour */
1528 memcpy(colouring2
, colouring
, n
*sizeof(int));
1530 solveret
= map_solver(sc
, graph
, n
, ngraph
, colouring2
,
1532 assert(solveret
>= 0); /* mustn't be impossible! */
1533 if (solveret
== 1) {
1534 cfreq
[colouring
[j
]]--;
1539 #ifdef GENERATION_DIAGNOSTICS
1540 for (i
= 0; i
< n
; i
++)
1541 if (colouring
[i
] >= 0) {
1545 putchar('a' + i
-36);
1547 putchar('A' + i
-10);
1550 printf(": %d\n", colouring
[i
]);
1555 * Finally, check that the puzzle is _at least_ as hard as
1556 * required, and indeed that it isn't already solved.
1557 * (Calling map_solver with negative difficulty ensures the
1558 * latter - if a solver which _does nothing_ can solve it,
1561 memcpy(colouring2
, colouring
, n
*sizeof(int));
1562 if (map_solver(sc
, graph
, n
, ngraph
, colouring2
,
1563 mindiff
- 1) == 1) {
1565 * Drop minimum difficulty if necessary.
1567 if (mindiff
> 0 && (n
< 9 || n
> 2*wh
/3)) {
1569 mindiff
= 0; /* give up and go for Easy */
1578 * Encode as a game ID. We do this by:
1580 * - first going along the horizontal edges row by row, and
1581 * then the vertical edges column by column
1582 * - encoding the lengths of runs of edges and runs of
1584 * - the decoder will reconstitute the region boundaries from
1585 * this and automatically number them the same way we did
1586 * - then we encode the initial region colours in a Slant-like
1587 * fashion (digits 0-3 interspersed with letters giving
1588 * lengths of runs of empty spaces).
1590 retlen
= retsize
= 0;
1597 * Start with a notional non-edge, so that there'll be an
1598 * explicit `a' to distinguish the case where we start with
1604 for (i
= 0; i
< w
*(h
-1) + (w
-1)*h
; i
++) {
1605 int x
, y
, dx
, dy
, v
;
1608 /* Horizontal edge. */
1614 /* Vertical edge. */
1615 x
= (i
- w
*(h
-1)) / h
;
1616 y
= (i
- w
*(h
-1)) % h
;
1621 if (retlen
+ 10 >= retsize
) {
1622 retsize
= retlen
+ 256;
1623 ret
= sresize(ret
, retsize
, char);
1626 v
= (map
[y
*w
+x
] != map
[(y
+dy
)*w
+(x
+dx
)]);
1629 ret
[retlen
++] = 'a'-1 + run
;
1634 * 'z' is a special case in this encoding. Rather
1635 * than meaning a run of 26 and a state switch, it
1636 * means a run of 25 and _no_ state switch, because
1637 * otherwise there'd be no way to encode runs of
1641 ret
[retlen
++] = 'z';
1648 ret
[retlen
++] = 'a'-1 + run
;
1649 ret
[retlen
++] = ',';
1652 for (i
= 0; i
< n
; i
++) {
1653 if (retlen
+ 10 >= retsize
) {
1654 retsize
= retlen
+ 256;
1655 ret
= sresize(ret
, retsize
, char);
1658 if (colouring
[i
] < 0) {
1660 * In _this_ encoding, 'z' is a run of 26, since
1661 * there's no implicit state switch after each run.
1662 * Confusingly different, but more compact.
1665 ret
[retlen
++] = 'z';
1671 ret
[retlen
++] = 'a'-1 + run
;
1672 ret
[retlen
++] = '0' + colouring
[i
];
1677 ret
[retlen
++] = 'a'-1 + run
;
1680 assert(retlen
< retsize
);
1693 static char *parse_edge_list(game_params
*params
, char **desc
, int *map
)
1695 int w
= params
->w
, h
= params
->h
, wh
= w
*h
, n
= params
->n
;
1696 int i
, k
, pos
, state
;
1699 for (i
= 0; i
< wh
; i
++)
1706 * Parse the game description to get the list of edges, and
1707 * build up a disjoint set forest as we go (by identifying
1708 * pairs of squares whenever the edge list shows a non-edge).
1710 while (*p
&& *p
!= ',') {
1711 if (*p
< 'a' || *p
> 'z')
1712 return "Unexpected character in edge list";
1723 } else if (pos
< w
*(h
-1)) {
1724 /* Horizontal edge. */
1729 } else if (pos
< 2*wh
-w
-h
) {
1730 /* Vertical edge. */
1731 x
= (pos
- w
*(h
-1)) / h
;
1732 y
= (pos
- w
*(h
-1)) % h
;
1736 return "Too much data in edge list";
1738 dsf_merge(map
+wh
, y
*w
+x
, (y
+dy
)*w
+(x
+dx
));
1746 assert(pos
<= 2*wh
-w
-h
);
1748 return "Too little data in edge list";
1751 * Now go through again and allocate region numbers.
1754 for (i
= 0; i
< wh
; i
++)
1756 for (i
= 0; i
< wh
; i
++) {
1757 k
= dsf_canonify(map
+wh
, i
);
1763 return "Edge list defines the wrong number of regions";
1770 static char *validate_desc(game_params
*params
, char *desc
)
1772 int w
= params
->w
, h
= params
->h
, wh
= w
*h
, n
= params
->n
;
1777 map
= snewn(2*wh
, int);
1778 ret
= parse_edge_list(params
, &desc
, map
);
1784 return "Expected comma before clue list";
1785 desc
++; /* eat comma */
1789 if (*desc
>= '0' && *desc
< '0'+FOUR
)
1791 else if (*desc
>= 'a' && *desc
<= 'z')
1792 area
+= *desc
- 'a' + 1;
1794 return "Unexpected character in clue list";
1798 return "Too little data in clue list";
1800 return "Too much data in clue list";
1805 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1807 int w
= params
->w
, h
= params
->h
, wh
= w
*h
, n
= params
->n
;
1810 game_state
*state
= snew(game_state
);
1813 state
->colouring
= snewn(n
, int);
1814 for (i
= 0; i
< n
; i
++)
1815 state
->colouring
[i
] = -1;
1816 state
->pencil
= snewn(n
, int);
1817 for (i
= 0; i
< n
; i
++)
1818 state
->pencil
[i
] = 0;
1820 state
->completed
= state
->cheated
= FALSE
;
1822 state
->map
= snew(struct map
);
1823 state
->map
->refcount
= 1;
1824 state
->map
->map
= snewn(wh
*4, int);
1825 state
->map
->graph
= snewn(n
*n
, int);
1827 state
->map
->immutable
= snewn(n
, int);
1828 for (i
= 0; i
< n
; i
++)
1829 state
->map
->immutable
[i
] = FALSE
;
1835 ret
= parse_edge_list(params
, &p
, state
->map
->map
);
1840 * Set up the other three quadrants in `map'.
1842 for (i
= wh
; i
< 4*wh
; i
++)
1843 state
->map
->map
[i
] = state
->map
->map
[i
% wh
];
1849 * Now process the clue list.
1853 if (*p
>= '0' && *p
< '0'+FOUR
) {
1854 state
->colouring
[pos
] = *p
- '0';
1855 state
->map
->immutable
[pos
] = TRUE
;
1858 assert(*p
>= 'a' && *p
<= 'z');
1859 pos
+= *p
- 'a' + 1;
1865 state
->map
->ngraph
= gengraph(w
, h
, n
, state
->map
->map
, state
->map
->graph
);
1868 * Attempt to smooth out some of the more jagged region
1869 * outlines by the judicious use of diagonally divided squares.
1872 random_state
*rs
= random_init(desc
, strlen(desc
));
1873 int *squares
= snewn(wh
, int);
1876 for (i
= 0; i
< wh
; i
++)
1878 shuffle(squares
, wh
, sizeof(*squares
), rs
);
1881 done_something
= FALSE
;
1882 for (i
= 0; i
< wh
; i
++) {
1883 int y
= squares
[i
] / w
, x
= squares
[i
] % w
;
1884 int c
= state
->map
->map
[y
*w
+x
];
1887 if (x
== 0 || x
== w
-1 || y
== 0 || y
== h
-1)
1890 if (state
->map
->map
[TE
* wh
+ y
*w
+x
] !=
1891 state
->map
->map
[BE
* wh
+ y
*w
+x
])
1894 tc
= state
->map
->map
[BE
* wh
+ (y
-1)*w
+x
];
1895 bc
= state
->map
->map
[TE
* wh
+ (y
+1)*w
+x
];
1896 lc
= state
->map
->map
[RE
* wh
+ y
*w
+(x
-1)];
1897 rc
= state
->map
->map
[LE
* wh
+ y
*w
+(x
+1)];
1900 * If this square is adjacent on two sides to one
1901 * region and on the other two sides to the other
1902 * region, and is itself one of the two regions, we can
1903 * adjust it so that it's a diagonal.
1905 if (tc
!= bc
&& (tc
== c
|| bc
== c
)) {
1906 if ((lc
== tc
&& rc
== bc
) ||
1907 (lc
== bc
&& rc
== tc
)) {
1908 state
->map
->map
[TE
* wh
+ y
*w
+x
] = tc
;
1909 state
->map
->map
[BE
* wh
+ y
*w
+x
] = bc
;
1910 state
->map
->map
[LE
* wh
+ y
*w
+x
] = lc
;
1911 state
->map
->map
[RE
* wh
+ y
*w
+x
] = rc
;
1912 done_something
= TRUE
;
1916 } while (done_something
);
1922 * Analyse the map to find a canonical line segment
1923 * corresponding to each edge, and a canonical point
1924 * corresponding to each region. The former are where we'll
1925 * eventually put error markers; the latter are where we'll put
1926 * per-region flags such as numbers (when in diagnostic mode).
1929 int *bestx
, *besty
, *an
, pass
;
1930 float *ax
, *ay
, *best
;
1932 ax
= snewn(state
->map
->ngraph
+ n
, float);
1933 ay
= snewn(state
->map
->ngraph
+ n
, float);
1934 an
= snewn(state
->map
->ngraph
+ n
, int);
1935 bestx
= snewn(state
->map
->ngraph
+ n
, int);
1936 besty
= snewn(state
->map
->ngraph
+ n
, int);
1937 best
= snewn(state
->map
->ngraph
+ n
, float);
1939 for (i
= 0; i
< state
->map
->ngraph
+ n
; i
++) {
1940 bestx
[i
] = besty
[i
] = -1;
1941 best
[i
] = 2*(w
+h
)+1;
1942 ax
[i
] = ay
[i
] = 0.0F
;
1947 * We make two passes over the map, finding all the line
1948 * segments separating regions and all the suitable points
1949 * within regions. In the first pass, we compute the
1950 * _average_ x and y coordinate of all the points in a
1951 * given class; in the second pass, for each such average
1952 * point, we find the candidate closest to it and call that
1955 * Line segments are considered to have coordinates in
1956 * their centre. Thus, at least one coordinate for any line
1957 * segment is always something-and-a-half; so we store our
1958 * coordinates as twice their normal value.
1960 for (pass
= 0; pass
< 2; pass
++) {
1963 for (y
= 0; y
< h
; y
++)
1964 for (x
= 0; x
< w
; x
++) {
1965 int ex
[4], ey
[4], ea
[4], eb
[4], en
= 0;
1968 * Look for an edge to the right of this
1969 * square, an edge below it, and an edge in the
1970 * middle of it. Also look to see if the point
1971 * at the bottom right of this square is on an
1972 * edge (and isn't a place where more than two
1977 ea
[en
] = state
->map
->map
[RE
* wh
+ y
*w
+x
];
1978 eb
[en
] = state
->map
->map
[LE
* wh
+ y
*w
+(x
+1)];
1985 ea
[en
] = state
->map
->map
[BE
* wh
+ y
*w
+x
];
1986 eb
[en
] = state
->map
->map
[TE
* wh
+ (y
+1)*w
+x
];
1992 ea
[en
] = state
->map
->map
[TE
* wh
+ y
*w
+x
];
1993 eb
[en
] = state
->map
->map
[BE
* wh
+ y
*w
+x
];
1998 if (x
+1 < w
&& y
+1 < h
) {
1999 /* bottom right corner */
2000 int oct
[8], othercol
, nchanges
;
2001 oct
[0] = state
->map
->map
[RE
* wh
+ y
*w
+x
];
2002 oct
[1] = state
->map
->map
[LE
* wh
+ y
*w
+(x
+1)];
2003 oct
[2] = state
->map
->map
[BE
* wh
+ y
*w
+(x
+1)];
2004 oct
[3] = state
->map
->map
[TE
* wh
+ (y
+1)*w
+(x
+1)];
2005 oct
[4] = state
->map
->map
[LE
* wh
+ (y
+1)*w
+(x
+1)];
2006 oct
[5] = state
->map
->map
[RE
* wh
+ (y
+1)*w
+x
];
2007 oct
[6] = state
->map
->map
[TE
* wh
+ (y
+1)*w
+x
];
2008 oct
[7] = state
->map
->map
[BE
* wh
+ y
*w
+x
];
2012 for (i
= 0; i
< 8; i
++) {
2013 if (oct
[i
] != oct
[0]) {
2016 else if (othercol
!= oct
[i
])
2017 break; /* three colours at this point */
2019 if (oct
[i
] != oct
[(i
+1) & 7])
2024 * Now if there are exactly two regions at
2025 * this point (not one, and not three or
2026 * more), and only two changes around the
2027 * loop, then this is a valid place to put
2030 if (i
== 8 && othercol
>= 0 && nchanges
== 2) {
2039 * If there's exactly _one_ region at this
2040 * point, on the other hand, it's a valid
2041 * place to put a region centre.
2044 ea
[en
] = eb
[en
] = oct
[0];
2052 * Now process the points we've found, one by
2055 for (i
= 0; i
< en
; i
++) {
2056 int emin
= min(ea
[i
], eb
[i
]);
2057 int emax
= max(ea
[i
], eb
[i
]);
2063 graph_edge_index(state
->map
->graph
, n
,
2064 state
->map
->ngraph
, emin
,
2068 gindex
= state
->map
->ngraph
+ emin
;
2071 assert(gindex
>= 0);
2075 * In pass 0, accumulate the values
2076 * we'll use to compute the average
2079 ax
[gindex
] += ex
[i
];
2080 ay
[gindex
] += ey
[i
];
2084 * In pass 1, work out whether this
2085 * point is closer to the average than
2086 * the last one we've seen.
2090 assert(an
[gindex
] > 0);
2091 dx
= ex
[i
] - ax
[gindex
];
2092 dy
= ey
[i
] - ay
[gindex
];
2093 d
= sqrt(dx
*dx
+ dy
*dy
);
2094 if (d
< best
[gindex
]) {
2096 bestx
[gindex
] = ex
[i
];
2097 besty
[gindex
] = ey
[i
];
2104 for (i
= 0; i
< state
->map
->ngraph
+ n
; i
++)
2112 state
->map
->edgex
= snewn(state
->map
->ngraph
, int);
2113 state
->map
->edgey
= snewn(state
->map
->ngraph
, int);
2114 memcpy(state
->map
->edgex
, bestx
, state
->map
->ngraph
* sizeof(int));
2115 memcpy(state
->map
->edgey
, besty
, state
->map
->ngraph
* sizeof(int));
2117 state
->map
->regionx
= snewn(n
, int);
2118 state
->map
->regiony
= snewn(n
, int);
2119 memcpy(state
->map
->regionx
, bestx
+ state
->map
->ngraph
, n
*sizeof(int));
2120 memcpy(state
->map
->regiony
, besty
+ state
->map
->ngraph
, n
*sizeof(int));
2122 for (i
= 0; i
< state
->map
->ngraph
; i
++)
2123 if (state
->map
->edgex
[i
] < 0) {
2124 /* Find the other representation of this edge. */
2125 int e
= state
->map
->graph
[i
];
2126 int iprime
= graph_edge_index(state
->map
->graph
, n
,
2127 state
->map
->ngraph
, e
%n
, e
/n
);
2128 assert(state
->map
->edgex
[iprime
] >= 0);
2129 state
->map
->edgex
[i
] = state
->map
->edgex
[iprime
];
2130 state
->map
->edgey
[i
] = state
->map
->edgey
[iprime
];
2144 static game_state
*dup_game(game_state
*state
)
2146 game_state
*ret
= snew(game_state
);
2149 ret
->colouring
= snewn(state
->p
.n
, int);
2150 memcpy(ret
->colouring
, state
->colouring
, state
->p
.n
* sizeof(int));
2151 ret
->pencil
= snewn(state
->p
.n
, int);
2152 memcpy(ret
->pencil
, state
->pencil
, state
->p
.n
* sizeof(int));
2153 ret
->map
= state
->map
;
2154 ret
->map
->refcount
++;
2155 ret
->completed
= state
->completed
;
2156 ret
->cheated
= state
->cheated
;
2161 static void free_game(game_state
*state
)
2163 if (--state
->map
->refcount
<= 0) {
2164 sfree(state
->map
->map
);
2165 sfree(state
->map
->graph
);
2166 sfree(state
->map
->immutable
);
2167 sfree(state
->map
->edgex
);
2168 sfree(state
->map
->edgey
);
2169 sfree(state
->map
->regionx
);
2170 sfree(state
->map
->regiony
);
2173 sfree(state
->colouring
);
2177 static char *solve_game(game_state
*state
, game_state
*currstate
,
2178 char *aux
, char **error
)
2185 struct solver_scratch
*sc
;
2189 int retlen
, retsize
;
2191 colouring
= snewn(state
->map
->n
, int);
2192 memcpy(colouring
, state
->colouring
, state
->map
->n
* sizeof(int));
2194 sc
= new_scratch(state
->map
->graph
, state
->map
->n
, state
->map
->ngraph
);
2195 sret
= map_solver(sc
, state
->map
->graph
, state
->map
->n
,
2196 state
->map
->ngraph
, colouring
, DIFFCOUNT
-1);
2202 *error
= "Puzzle is inconsistent";
2204 *error
= "Unable to find a unique solution for this puzzle";
2209 ret
= snewn(retsize
, char);
2213 for (i
= 0; i
< state
->map
->n
; i
++) {
2216 assert(colouring
[i
] >= 0);
2217 if (colouring
[i
] == currstate
->colouring
[i
])
2219 assert(!state
->map
->immutable
[i
]);
2221 len
= sprintf(buf
, ";%d:%d", colouring
[i
], i
);
2222 if (retlen
+ len
>= retsize
) {
2223 retsize
= retlen
+ len
+ 256;
2224 ret
= sresize(ret
, retsize
, char);
2226 strcpy(ret
+ retlen
, buf
);
2237 static char *game_text_format(game_state
*state
)
2243 int drag_colour
; /* -1 means no drag active */
2248 static game_ui
*new_ui(game_state
*state
)
2250 game_ui
*ui
= snew(game_ui
);
2251 ui
->dragx
= ui
->dragy
= -1;
2252 ui
->drag_colour
= -2;
2253 ui
->show_numbers
= FALSE
;
2257 static void free_ui(game_ui
*ui
)
2262 static char *encode_ui(game_ui
*ui
)
2267 static void decode_ui(game_ui
*ui
, char *encoding
)
2271 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
2272 game_state
*newstate
)
2276 struct game_drawstate
{
2278 unsigned long *drawn
, *todraw
;
2280 int dragx
, dragy
, drag_visible
;
2284 /* Flags in `drawn'. */
2285 #define ERR_BASE 0x00800000L
2286 #define ERR_MASK 0xFF800000L
2287 #define PENCIL_T_BASE 0x00080000L
2288 #define PENCIL_T_MASK 0x00780000L
2289 #define PENCIL_B_BASE 0x00008000L
2290 #define PENCIL_B_MASK 0x00078000L
2291 #define PENCIL_MASK 0x007F8000L
2292 #define SHOW_NUMBERS 0x00004000L
2294 #define TILESIZE (ds->tilesize)
2295 #define BORDER (TILESIZE)
2296 #define COORD(x) ( (x) * TILESIZE + BORDER )
2297 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
2299 static int region_from_coords(game_state
*state
, game_drawstate
*ds
,
2302 int w
= state
->p
.w
, h
= state
->p
.h
, wh
= w
*h
/*, n = state->p.n */;
2303 int tx
= FROMCOORD(x
), ty
= FROMCOORD(y
);
2304 int dx
= x
- COORD(tx
), dy
= y
- COORD(ty
);
2307 if (tx
< 0 || tx
>= w
|| ty
< 0 || ty
>= h
)
2308 return -1; /* border */
2310 quadrant
= 2 * (dx
> dy
) + (TILESIZE
- dx
> dy
);
2311 quadrant
= (quadrant
== 0 ? BE
:
2312 quadrant
== 1 ? LE
:
2313 quadrant
== 2 ? RE
: TE
);
2315 return state
->map
->map
[quadrant
* wh
+ ty
*w
+tx
];
2318 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
2319 int x
, int y
, int button
)
2324 * Enable or disable numeric labels on regions.
2326 if (button
== 'l' || button
== 'L') {
2327 ui
->show_numbers
= !ui
->show_numbers
;
2331 if (button
== LEFT_BUTTON
|| button
== RIGHT_BUTTON
) {
2332 int r
= region_from_coords(state
, ds
, x
, y
);
2335 ui
->drag_colour
= state
->colouring
[r
];
2337 ui
->drag_colour
= -1;
2343 if ((button
== LEFT_DRAG
|| button
== RIGHT_DRAG
) &&
2344 ui
->drag_colour
> -2) {
2350 if ((button
== LEFT_RELEASE
|| button
== RIGHT_RELEASE
) &&
2351 ui
->drag_colour
> -2) {
2352 int r
= region_from_coords(state
, ds
, x
, y
);
2353 int c
= ui
->drag_colour
;
2356 * Cancel the drag, whatever happens.
2358 ui
->drag_colour
= -2;
2359 ui
->dragx
= ui
->dragy
= -1;
2362 return ""; /* drag into border; do nothing else */
2364 if (state
->map
->immutable
[r
])
2365 return ""; /* can't change this region */
2367 if (state
->colouring
[r
] == c
)
2368 return ""; /* don't _need_ to change this region */
2370 if (button
== RIGHT_RELEASE
&& state
->colouring
[r
] >= 0)
2371 return ""; /* can't pencil on a coloured region */
2373 sprintf(buf
, "%s%c:%d", (button
== RIGHT_RELEASE ?
"p" : ""),
2374 (int)(c
< 0 ?
'C' : '0' + c
), r
);
2381 static game_state
*execute_move(game_state
*state
, char *move
)
2384 game_state
*ret
= dup_game(state
);
2395 if ((c
== 'C' || (c
>= '0' && c
< '0'+FOUR
)) &&
2396 sscanf(move
+1, ":%d%n", &k
, &adv
) == 1 &&
2397 k
>= 0 && k
< state
->p
.n
) {
2400 if (ret
->colouring
[k
] >= 0) {
2407 ret
->pencil
[k
] ^= 1 << (c
- '0');
2409 ret
->colouring
[k
] = (c
== 'C' ?
-1 : c
- '0');
2412 } else if (*move
== 'S') {
2414 ret
->cheated
= TRUE
;
2420 if (*move
&& *move
!= ';') {
2429 * Check for completion.
2431 if (!ret
->completed
) {
2434 for (i
= 0; i
< n
; i
++)
2435 if (ret
->colouring
[i
] < 0) {
2441 for (i
= 0; i
< ret
->map
->ngraph
; i
++) {
2442 int j
= ret
->map
->graph
[i
] / n
;
2443 int k
= ret
->map
->graph
[i
] % n
;
2444 if (ret
->colouring
[j
] == ret
->colouring
[k
]) {
2452 ret
->completed
= TRUE
;
2458 /* ----------------------------------------------------------------------
2462 static void game_compute_size(game_params
*params
, int tilesize
,
2465 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2466 struct { int tilesize
; } ads
, *ds
= &ads
;
2467 ads
.tilesize
= tilesize
;
2469 *x
= params
->w
* TILESIZE
+ 2 * BORDER
+ 1;
2470 *y
= params
->h
* TILESIZE
+ 2 * BORDER
+ 1;
2473 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
2474 game_params
*params
, int tilesize
)
2476 ds
->tilesize
= tilesize
;
2479 blitter_free(dr
, ds
->bl
);
2480 ds
->bl
= blitter_new(dr
, TILESIZE
+3, TILESIZE
+3);
2483 const float map_colours
[FOUR
][3] = {
2487 {0.55F
, 0.45F
, 0.35F
},
2489 const int map_hatching
[FOUR
] = {
2490 HATCH_VERT
, HATCH_SLASH
, HATCH_HORIZ
, HATCH_BACKSLASH
2493 static float *game_colours(frontend
*fe
, game_state
*state
, int *ncolours
)
2495 float *ret
= snewn(3 * NCOLOURS
, float);
2497 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
2499 ret
[COL_GRID
* 3 + 0] = 0.0F
;
2500 ret
[COL_GRID
* 3 + 1] = 0.0F
;
2501 ret
[COL_GRID
* 3 + 2] = 0.0F
;
2503 memcpy(ret
+ COL_0
* 3, map_colours
[0], 3 * sizeof(float));
2504 memcpy(ret
+ COL_1
* 3, map_colours
[1], 3 * sizeof(float));
2505 memcpy(ret
+ COL_2
* 3, map_colours
[2], 3 * sizeof(float));
2506 memcpy(ret
+ COL_3
* 3, map_colours
[3], 3 * sizeof(float));
2508 ret
[COL_ERROR
* 3 + 0] = 1.0F
;
2509 ret
[COL_ERROR
* 3 + 1] = 0.0F
;
2510 ret
[COL_ERROR
* 3 + 2] = 0.0F
;
2512 ret
[COL_ERRTEXT
* 3 + 0] = 1.0F
;
2513 ret
[COL_ERRTEXT
* 3 + 1] = 1.0F
;
2514 ret
[COL_ERRTEXT
* 3 + 2] = 1.0F
;
2516 *ncolours
= NCOLOURS
;
2520 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
2522 struct game_drawstate
*ds
= snew(struct game_drawstate
);
2526 ds
->drawn
= snewn(state
->p
.w
* state
->p
.h
, unsigned long);
2527 for (i
= 0; i
< state
->p
.w
* state
->p
.h
; i
++)
2528 ds
->drawn
[i
] = 0xFFFFL
;
2529 ds
->todraw
= snewn(state
->p
.w
* state
->p
.h
, unsigned long);
2530 ds
->started
= FALSE
;
2532 ds
->drag_visible
= FALSE
;
2533 ds
->dragx
= ds
->dragy
= -1;
2538 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
2543 blitter_free(dr
, ds
->bl
);
2547 static void draw_error(drawing
*dr
, game_drawstate
*ds
, int x
, int y
)
2555 coords
[0] = x
- TILESIZE
*2/5;
2558 coords
[3] = y
- TILESIZE
*2/5;
2559 coords
[4] = x
+ TILESIZE
*2/5;
2562 coords
[7] = y
+ TILESIZE
*2/5;
2563 draw_polygon(dr
, coords
, 4, COL_ERROR
, COL_GRID
);
2566 * Draw an exclamation mark in the diamond. This turns out to
2567 * look unpleasantly off-centre if done via draw_text, so I do
2568 * it by hand on the basis that exclamation marks aren't that
2569 * difficult to draw...
2572 yext
= TILESIZE
*2/5 - (xext
*2+2);
2573 draw_rect(dr
, x
-xext
, y
-yext
, xext
*2+1, yext
*2+1 - (xext
*3),
2575 draw_rect(dr
, x
-xext
, y
+yext
-xext
*2+1, xext
*2+1, xext
*2, COL_ERRTEXT
);
2578 static void draw_square(drawing
*dr
, game_drawstate
*ds
,
2579 game_params
*params
, struct map
*map
,
2580 int x
, int y
, int v
)
2582 int w
= params
->w
, h
= params
->h
, wh
= w
*h
;
2583 int tv
, bv
, xo
, yo
, errs
, pencil
, i
, j
, oldj
;
2586 errs
= v
& ERR_MASK
;
2588 pencil
= v
& PENCIL_MASK
;
2590 show_numbers
= v
& SHOW_NUMBERS
;
2595 clip(dr
, COORD(x
), COORD(y
), TILESIZE
, TILESIZE
);
2598 * Draw the region colour.
2600 draw_rect(dr
, COORD(x
), COORD(y
), TILESIZE
, TILESIZE
,
2601 (tv
== FOUR ? COL_BACKGROUND
: COL_0
+ tv
));
2603 * Draw the second region colour, if this is a diagonally
2606 if (map
->map
[TE
* wh
+ y
*w
+x
] != map
->map
[BE
* wh
+ y
*w
+x
]) {
2608 coords
[0] = COORD(x
)-1;
2609 coords
[1] = COORD(y
+1)+1;
2610 if (map
->map
[LE
* wh
+ y
*w
+x
] == map
->map
[TE
* wh
+ y
*w
+x
])
2611 coords
[2] = COORD(x
+1)+1;
2613 coords
[2] = COORD(x
)-1;
2614 coords
[3] = COORD(y
)-1;
2615 coords
[4] = COORD(x
+1)+1;
2616 coords
[5] = COORD(y
+1)+1;
2617 draw_polygon(dr
, coords
, 3,
2618 (bv
== FOUR ? COL_BACKGROUND
: COL_0
+ bv
), COL_GRID
);
2622 * Draw `pencil marks'. Currently we arrange these in a square
2623 * formation, which means we may be in trouble if the value of
2624 * FOUR changes later...
2627 for (yo
= 0; yo
< 4; yo
++)
2628 for (xo
= 0; xo
< 4; xo
++) {
2629 int te
= map
->map
[TE
* wh
+ y
*w
+x
];
2632 e
= (yo
< xo
&& yo
< 3-xo ? TE
:
2633 yo
> xo
&& yo
> 3-xo ? BE
:
2635 ee
= map
->map
[e
* wh
+ y
*w
+x
];
2637 if (xo
!= (yo
* 2 + 1) % 5)
2641 if (!(pencil
& ((ee
== te ? PENCIL_T_BASE
: PENCIL_B_BASE
) << c
)))
2645 (map
->map
[TE
* wh
+ y
*w
+x
] != map
->map
[LE
* wh
+ y
*w
+x
]))
2646 continue; /* avoid TL-BR diagonal line */
2648 (map
->map
[TE
* wh
+ y
*w
+x
] != map
->map
[RE
* wh
+ y
*w
+x
]))
2649 continue; /* avoid BL-TR diagonal line */
2651 draw_circle(dr
, COORD(x
) + (xo
+1)*TILESIZE
/5,
2652 COORD(y
) + (yo
+1)*TILESIZE
/5,
2653 TILESIZE
/8, COL_0
+ c
, COL_0
+ c
);
2657 * Draw the grid lines, if required.
2659 if (x
<= 0 || map
->map
[RE
*wh
+y
*w
+(x
-1)] != map
->map
[LE
*wh
+y
*w
+x
])
2660 draw_rect(dr
, COORD(x
), COORD(y
), 1, TILESIZE
, COL_GRID
);
2661 if (y
<= 0 || map
->map
[BE
*wh
+(y
-1)*w
+x
] != map
->map
[TE
*wh
+y
*w
+x
])
2662 draw_rect(dr
, COORD(x
), COORD(y
), TILESIZE
, 1, COL_GRID
);
2663 if (x
<= 0 || y
<= 0 ||
2664 map
->map
[RE
*wh
+(y
-1)*w
+(x
-1)] != map
->map
[TE
*wh
+y
*w
+x
] ||
2665 map
->map
[BE
*wh
+(y
-1)*w
+(x
-1)] != map
->map
[LE
*wh
+y
*w
+x
])
2666 draw_rect(dr
, COORD(x
), COORD(y
), 1, 1, COL_GRID
);
2669 * Draw error markers.
2671 for (yo
= 0; yo
< 3; yo
++)
2672 for (xo
= 0; xo
< 3; xo
++)
2673 if (errs
& (ERR_BASE
<< (yo
*3+xo
)))
2675 (COORD(x
)*2+TILESIZE
*xo
)/2,
2676 (COORD(y
)*2+TILESIZE
*yo
)/2);
2679 * Draw region numbers, if desired.
2683 for (i
= 0; i
< 2; i
++) {
2684 j
= map
->map
[(i?BE
:TE
)*wh
+y
*w
+x
];
2689 xo
= map
->regionx
[j
] - 2*x
;
2690 yo
= map
->regiony
[j
] - 2*y
;
2691 if (xo
>= 0 && xo
<= 2 && yo
>= 0 && yo
<= 2) {
2693 sprintf(buf
, "%d", j
);
2694 draw_text(dr
, (COORD(x
)*2+TILESIZE
*xo
)/2,
2695 (COORD(y
)*2+TILESIZE
*yo
)/2,
2696 FONT_VARIABLE
, 3*TILESIZE
/5,
2697 ALIGN_HCENTRE
|ALIGN_VCENTRE
,
2705 draw_update(dr
, COORD(x
), COORD(y
), TILESIZE
, TILESIZE
);
2708 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
2709 game_state
*state
, int dir
, game_ui
*ui
,
2710 float animtime
, float flashtime
)
2712 int w
= state
->p
.w
, h
= state
->p
.h
, wh
= w
*h
, n
= state
->p
.n
;
2716 if (ds
->drag_visible
) {
2717 blitter_load(dr
, ds
->bl
, ds
->dragx
, ds
->dragy
);
2718 draw_update(dr
, ds
->dragx
, ds
->dragy
, TILESIZE
+ 3, TILESIZE
+ 3);
2719 ds
->drag_visible
= FALSE
;
2723 * The initial contents of the window are not guaranteed and
2724 * can vary with front ends. To be on the safe side, all games
2725 * should start by drawing a big background-colour rectangle
2726 * covering the whole window.
2731 game_compute_size(&state
->p
, TILESIZE
, &ww
, &wh
);
2732 draw_rect(dr
, 0, 0, ww
, wh
, COL_BACKGROUND
);
2733 draw_rect(dr
, COORD(0), COORD(0), w
*TILESIZE
+1, h
*TILESIZE
+1,
2736 draw_update(dr
, 0, 0, ww
, wh
);
2741 if (flash_type
== 1)
2742 flash
= (int)(flashtime
* FOUR
/ flash_length
);
2744 flash
= 1 + (int)(flashtime
* THREE
/ flash_length
);
2749 * Set up the `todraw' array.
2751 for (y
= 0; y
< h
; y
++)
2752 for (x
= 0; x
< w
; x
++) {
2753 int tv
= state
->colouring
[state
->map
->map
[TE
* wh
+ y
*w
+x
]];
2754 int bv
= state
->colouring
[state
->map
->map
[BE
* wh
+ y
*w
+x
]];
2763 if (flash_type
== 1) {
2768 } else if (flash_type
== 2) {
2773 tv
= (tv
+ flash
) % FOUR
;
2775 bv
= (bv
+ flash
) % FOUR
;
2784 for (i
= 0; i
< FOUR
; i
++) {
2785 if (state
->colouring
[state
->map
->map
[TE
* wh
+ y
*w
+x
]] < 0 &&
2786 (state
->pencil
[state
->map
->map
[TE
* wh
+ y
*w
+x
]] & (1<<i
)))
2787 v
|= PENCIL_T_BASE
<< i
;
2788 if (state
->colouring
[state
->map
->map
[BE
* wh
+ y
*w
+x
]] < 0 &&
2789 (state
->pencil
[state
->map
->map
[BE
* wh
+ y
*w
+x
]] & (1<<i
)))
2790 v
|= PENCIL_B_BASE
<< i
;
2793 if (ui
->show_numbers
)
2796 ds
->todraw
[y
*w
+x
] = v
;
2800 * Add error markers to the `todraw' array.
2802 for (i
= 0; i
< state
->map
->ngraph
; i
++) {
2803 int v1
= state
->map
->graph
[i
] / n
;
2804 int v2
= state
->map
->graph
[i
] % n
;
2807 if (state
->colouring
[v1
] < 0 || state
->colouring
[v2
] < 0)
2809 if (state
->colouring
[v1
] != state
->colouring
[v2
])
2812 x
= state
->map
->edgex
[i
];
2813 y
= state
->map
->edgey
[i
];
2818 ds
->todraw
[y
*w
+x
] |= ERR_BASE
<< (yo
*3+xo
);
2821 ds
->todraw
[y
*w
+(x
-1)] |= ERR_BASE
<< (yo
*3+2);
2825 ds
->todraw
[(y
-1)*w
+x
] |= ERR_BASE
<< (2*3+xo
);
2827 if (xo
== 0 && yo
== 0) {
2828 assert(x
> 0 && y
> 0);
2829 ds
->todraw
[(y
-1)*w
+(x
-1)] |= ERR_BASE
<< (2*3+2);
2834 * Now actually draw everything.
2836 for (y
= 0; y
< h
; y
++)
2837 for (x
= 0; x
< w
; x
++) {
2838 int v
= ds
->todraw
[y
*w
+x
];
2839 if (ds
->drawn
[y
*w
+x
] != v
) {
2840 draw_square(dr
, ds
, &state
->p
, state
->map
, x
, y
, v
);
2841 ds
->drawn
[y
*w
+x
] = v
;
2846 * Draw the dragged colour blob if any.
2848 if (ui
->drag_colour
> -2) {
2849 ds
->dragx
= ui
->dragx
- TILESIZE
/2 - 2;
2850 ds
->dragy
= ui
->dragy
- TILESIZE
/2 - 2;
2851 blitter_save(dr
, ds
->bl
, ds
->dragx
, ds
->dragy
);
2852 draw_circle(dr
, ui
->dragx
, ui
->dragy
, TILESIZE
/2,
2853 (ui
->drag_colour
< 0 ? COL_BACKGROUND
:
2854 COL_0
+ ui
->drag_colour
), COL_GRID
);
2855 draw_update(dr
, ds
->dragx
, ds
->dragy
, TILESIZE
+ 3, TILESIZE
+ 3);
2856 ds
->drag_visible
= TRUE
;
2860 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
2861 int dir
, game_ui
*ui
)
2866 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
2867 int dir
, game_ui
*ui
)
2869 if (!oldstate
->completed
&& newstate
->completed
&&
2870 !oldstate
->cheated
&& !newstate
->cheated
) {
2871 if (flash_type
< 0) {
2872 char *env
= getenv("MAP_ALTERNATIVE_FLASH");
2874 flash_type
= atoi(env
);
2877 flash_length
= (flash_type
== 1 ?
0.50 : 0.30);
2879 return flash_length
;
2884 static int game_wants_statusbar(void)
2889 static int game_timing_state(game_state
*state
, game_ui
*ui
)
2894 static void game_print_size(game_params
*params
, float *x
, float *y
)
2899 * I'll use 4mm squares by default, I think. Simplest way to
2900 * compute this size is to compute the pixel puzzle size at a
2901 * given tile size and then scale.
2903 game_compute_size(params
, 400, &pw
, &ph
);
2908 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
2910 int w
= state
->p
.w
, h
= state
->p
.h
, wh
= w
*h
, n
= state
->p
.n
;
2911 int ink
, c
[FOUR
], i
;
2913 int *coords
, ncoords
, coordsize
;
2915 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2916 struct { int tilesize
; } ads
, *ds
= &ads
;
2917 ads
.tilesize
= tilesize
;
2919 ink
= print_mono_colour(dr
, 0);
2920 for (i
= 0; i
< FOUR
; i
++)
2921 c
[i
] = print_rgb_colour(dr
, map_hatching
[i
], map_colours
[i
][0],
2922 map_colours
[i
][1], map_colours
[i
][2]);
2927 print_line_width(dr
, TILESIZE
/ 16);
2930 * Draw a single filled polygon around each region.
2932 for (r
= 0; r
< n
; r
++) {
2933 int octants
[8], lastdir
, d1
, d2
, ox
, oy
;
2936 * Start by finding a point on the region boundary. Any
2937 * point will do. To do this, we'll search for a square
2938 * containing the region and then decide which corner of it
2942 for (y
= 0; y
< h
; y
++) {
2943 for (x
= 0; x
< w
; x
++) {
2944 if (state
->map
->map
[wh
*0+y
*w
+x
] == r
||
2945 state
->map
->map
[wh
*1+y
*w
+x
] == r
||
2946 state
->map
->map
[wh
*2+y
*w
+x
] == r
||
2947 state
->map
->map
[wh
*3+y
*w
+x
] == r
)
2953 assert(y
< h
&& x
< w
); /* we must have found one somewhere */
2955 * This is the first square in lexicographic order which
2956 * contains part of this region. Therefore, one of the top
2957 * two corners of the square must be what we're after. The
2958 * only case in which it isn't the top left one is if the
2959 * square is diagonally divided and the region is in the
2960 * bottom right half.
2962 if (state
->map
->map
[wh
*TE
+y
*w
+x
] != r
&&
2963 state
->map
->map
[wh
*LE
+y
*w
+x
] != r
)
2964 x
++; /* could just as well have done y++ */
2967 * Now we have a point on the region boundary. Trace around
2968 * the region until we come back to this point,
2969 * accumulating coordinates for a polygon draw operation as
2979 * There are eight possible directions we could head in
2980 * from here. We identify them by octant numbers, and
2981 * we also use octant numbers to identify the spaces
2994 octants
[0] = x
<w
&& y
>0 ? state
->map
->map
[wh
*LE
+(y
-1)*w
+x
] : -1;
2995 octants
[1] = x
<w
&& y
>0 ? state
->map
->map
[wh
*BE
+(y
-1)*w
+x
] : -1;
2996 octants
[2] = x
<w
&& y
<h ? state
->map
->map
[wh
*TE
+y
*w
+x
] : -1;
2997 octants
[3] = x
<w
&& y
<h ? state
->map
->map
[wh
*LE
+y
*w
+x
] : -1;
2998 octants
[4] = x
>0 && y
<h ? state
->map
->map
[wh
*RE
+y
*w
+(x
-1)] : -1;
2999 octants
[5] = x
>0 && y
<h ? state
->map
->map
[wh
*TE
+y
*w
+(x
-1)] : -1;
3000 octants
[6] = x
>0 && y
>0 ? state
->map
->map
[wh
*BE
+(y
-1)*w
+(x
-1)] :-1;
3001 octants
[7] = x
>0 && y
>0 ? state
->map
->map
[wh
*RE
+(y
-1)*w
+(x
-1)] :-1;
3004 for (i
= 0; i
< 8; i
++)
3005 if ((octants
[i
] == r
) ^ (octants
[(i
+1)%8] == r
)) {
3013 assert(d1
!= -1 && d2
!= -1);
3018 * Now we're heading in direction d1. Save the current
3021 if (ncoords
+ 2 > coordsize
) {
3023 coords
= sresize(coords
, coordsize
, int);
3025 coords
[ncoords
++] = COORD(x
);
3026 coords
[ncoords
++] = COORD(y
);
3029 * Compute the new coordinates.
3031 x
+= (d1
% 4 == 3 ?
0 : d1
< 4 ?
+1 : -1);
3032 y
+= (d1
% 4 == 1 ?
0 : d1
> 1 && d1
< 5 ?
+1 : -1);
3033 assert(x
>= 0 && x
<= w
&& y
>= 0 && y
<= h
);
3036 } while (x
!= ox
|| y
!= oy
);
3038 draw_polygon(dr
, coords
, ncoords
/2,
3039 state
->colouring
[r
] >= 0 ?
3040 c
[state
->colouring
[r
]] : -1, ink
);
3049 const struct game thegame
= {
3057 TRUE
, game_configure
, custom_params
,
3065 FALSE
, game_text_format
,
3073 20, game_compute_size
, game_set_size
,
3076 game_free_drawstate
,
3080 TRUE
, TRUE
, game_print_size
, game_print
,
3081 game_wants_statusbar
,
3082 FALSE
, game_timing_state
,
3083 0, /* mouse_priorities */
3086 #ifdef STANDALONE_SOLVER
3090 void frontend_default_colour(frontend
*fe
, float *output
) {}
3091 void draw_text(drawing
*dr
, int x
, int y
, int fonttype
, int fontsize
,
3092 int align
, int colour
, char *text
) {}
3093 void draw_rect(drawing
*dr
, int x
, int y
, int w
, int h
, int colour
) {}
3094 void draw_line(drawing
*dr
, int x1
, int y1
, int x2
, int y2
, int colour
) {}
3095 void draw_polygon(drawing
*dr
, int *coords
, int npoints
,
3096 int fillcolour
, int outlinecolour
) {}
3097 void draw_circle(drawing
*dr
, int cx
, int cy
, int radius
,
3098 int fillcolour
, int outlinecolour
) {}
3099 void clip(drawing
*dr
, int x
, int y
, int w
, int h
) {}
3100 void unclip(drawing
*dr
) {}
3101 void start_draw(drawing
*dr
) {}
3102 void draw_update(drawing
*dr
, int x
, int y
, int w
, int h
) {}
3103 void end_draw(drawing
*dr
) {}
3104 blitter
*blitter_new(drawing
*dr
, int w
, int h
) {return NULL
;}
3105 void blitter_free(drawing
*dr
, blitter
*bl
) {}
3106 void blitter_save(drawing
*dr
, blitter
*bl
, int x
, int y
) {}
3107 void blitter_load(drawing
*dr
, blitter
*bl
, int x
, int y
) {}
3108 int print_mono_colour(drawing
*dr
, int grey
) { return 0; }
3109 int print_rgb_colour(drawing
*dr
, int hatch
, float r
, float g
, float b
)
3111 void print_line_width(drawing
*dr
, int width
) {}
3113 void fatal(char *fmt
, ...)
3117 fprintf(stderr
, "fatal error: ");
3120 vfprintf(stderr
, fmt
, ap
);
3123 fprintf(stderr
, "\n");
3127 int main(int argc
, char **argv
)
3131 char *id
= NULL
, *desc
, *err
;
3133 int ret
, diff
, really_verbose
= FALSE
;
3134 struct solver_scratch
*sc
;
3137 while (--argc
> 0) {
3139 if (!strcmp(p
, "-v")) {
3140 really_verbose
= TRUE
;
3141 } else if (!strcmp(p
, "-g")) {
3143 } else if (*p
== '-') {
3144 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
3152 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
3156 desc
= strchr(id
, ':');
3158 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
3163 p
= default_params();
3164 decode_params(p
, id
);
3165 err
= validate_desc(p
, desc
);
3167 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
3170 s
= new_game(NULL
, p
, desc
);
3172 sc
= new_scratch(s
->map
->graph
, s
->map
->n
, s
->map
->ngraph
);
3175 * When solving an Easy puzzle, we don't want to bother the
3176 * user with Hard-level deductions. For this reason, we grade
3177 * the puzzle internally before doing anything else.
3179 ret
= -1; /* placate optimiser */
3180 for (diff
= 0; diff
< DIFFCOUNT
; diff
++) {
3181 for (i
= 0; i
< s
->map
->n
; i
++)
3182 if (!s
->map
->immutable
[i
])
3183 s
->colouring
[i
] = -1;
3184 ret
= map_solver(sc
, s
->map
->graph
, s
->map
->n
, s
->map
->ngraph
,
3185 s
->colouring
, diff
);
3190 if (diff
== DIFFCOUNT
) {
3192 printf("Difficulty rating: harder than Hard, or ambiguous\n");
3194 printf("Unable to find a unique solution\n");
3198 printf("Difficulty rating: impossible (no solution exists)\n");
3200 printf("Difficulty rating: %s\n", map_diffnames
[diff
]);
3202 verbose
= really_verbose
;
3203 for (i
= 0; i
< s
->map
->n
; i
++)
3204 if (!s
->map
->immutable
[i
])
3205 s
->colouring
[i
] = -1;
3206 ret
= map_solver(sc
, s
->map
->graph
, s
->map
->n
, s
->map
->ngraph
,
3207 s
->colouring
, diff
);
3209 printf("Puzzle is inconsistent\n");
3213 for (i
= 0; i
< s
->map
->n
; i
++) {
3214 printf("%5d <- %c%c", i
, colnames
[s
->colouring
[i
]],
3215 (col
< 6 && i
+1 < s
->map
->n ?
' ' : '\n'));