1 /* probdist.h must be included before the include goard since we require
2 * proper including order. */
19 /* Maximum supported board size. (Without the S_OFFBOARD edges.) */
20 #define BOARD_MAX_SIZE 19
23 /* The board implementation has bunch of optional features.
24 * Turn them on below: */
26 #define WANT_BOARD_C // capturable groups queue
28 //#define BOARD_SIZE 9 // constant board size, allows better optimization
30 //#define BOARD_SPATHASH // incremental patternsp.h hashes
31 #define BOARD_SPATHASH_MAXD 3 // maximal diameter
33 #define BOARD_PAT3 // incremental 3x3 pattern codes
35 //#define BOARD_TRAITS 1 // incremental point traits (see struct btraits)
36 //#define BOARD_TRAIT_SAFE 1 // include btraits.safe (rather expensive, unused)
37 //#define BOARD_TRAIT_SAFE 2 // include btraits.safe based on full is_bad_selfatari()
39 //#define BOARD_UNDO_CHECKS 1 // Guard against invalid quick_play() / quick_undo() uses
41 #define BOARD_MAX_COORDS ((BOARD_MAX_SIZE+2) * (BOARD_MAX_SIZE+2) )
42 #define BOARD_MAX_MOVES (BOARD_MAX_SIZE * BOARD_MAX_SIZE)
43 #define BOARD_MAX_GROUPS (BOARD_MAX_SIZE * BOARD_MAX_SIZE / 2)
55 /* Some engines might normalize their reading and skip symmetrical
56 * moves. We will tell them how can they do it. */
57 struct board_symmetry
{
58 /* Playground is in this rectangle. */
60 /* d == 0: Full rectangle
61 * d == 1: Top triangle */
63 /* General symmetry type. */
64 /* Note that the above is redundant to this, but just provided
65 * for easier usage. */
70 typedef uint64_t hash_t
;
71 #define PRIhash PRIx64
73 /* XXX: This really belongs in pattern3.h, unfortunately that would mean
74 * a dependency hell. */
75 typedef uint32_t hash3_t
; // 3x3 pattern hash
78 /* Note that "group" is only chain of stones that is solidly
79 * connected for us. */
80 typedef coord_t group_t
;
83 /* We keep track of only up to GROUP_KEEP_LIBS; over that, we
85 /* _Combination_ of these two values can make some difference
86 * in performance - fine-tune. */
87 #define GROUP_KEEP_LIBS 10
88 // refill lib[] only when we hit this; this must be at least 2!
89 // Moggy requires at least 3 - see below for semantic impact.
90 #define GROUP_REFILL_LIBS 5
91 coord_t lib
[GROUP_KEEP_LIBS
];
92 /* libs is only LOWER BOUND for the number of real liberties!!!
93 * It denotes only number of items in lib[], thus you can rely
94 * on it to store real liberties only up to <= GROUP_REFILL_LIBS. */
98 struct neighbor_colors
{
103 /* Point traits bitmap; we update this information incrementally,
104 * it can be used e.g. for fast pattern features matching. */
106 /* Number of neighbors we can capture. 0=this move is
107 * not capturing, 1..4=this many neighbors we can capture
108 * (can be multiple neighbors of same group). */
110 /* Number of 1-stone neighbors we can capture. */
112 #ifdef BOARD_TRAIT_SAFE
113 /* Whether it is SAFE to play here. This is essentially just
114 * cached result of board_safe_to_play(). (Of course the concept
115 * of "safety" is not perfect here, but it's the cheapest
116 * reasonable thing we can do.) */
119 /* Whether we need to re-compute this coordinate; used to
120 * weed out duplicates. Maintained only for S_BLACK. */
125 /* You should treat this struct as read-only. Always call functions below if
126 * you want to change it. */
129 int size
; /* Including S_OFFBOARD margin - see below. */
130 int size2
; /* size^2 */
131 int bits2
; /* ceiling(log2(size2)) */
135 /* The ruleset is currently almost never taken into account;
136 * the board implementation is basically Chinese rules (handicap
137 * stones compensation) w/ suicide (or you can look at it as
138 * New Zealand w/o handi stones compensation), while the engine
139 * enforces no-suicide, making for real Chinese rules.
140 * However, we accept suicide moves by the opponent, so we
141 * should work with rules allowing suicide, just not taking
142 * full advantage of them. */
144 RULES_CHINESE
, /* default value */
148 RULES_STONES_ONLY
, /* do not count eyes */
149 /* http://home.snafu.de/jasiek/siming.html */
150 /* Simplified ING rules - RULES_CHINESE with handicaps
151 * counting as points and pass stones. Also should
152 * allow suicide, but Pachi will never suicide
154 /* XXX: I couldn't find the point about pass stones
155 * in the rule text, but it is Robert Jasiek's
156 * interpretation of them... These rules were
157 * used e.g. at the EGC2012 13x13 tournament.
158 * They are not supported by KGS. */
165 /* Iterator offsets for foreach_neighbor*() */
166 int nei8
[8], dnei
[4];
169 struct move last_move
;
170 struct move last_move2
; /* second-to-last move */
171 struct move last_move3
; /* just before last_move2, only set if last_move is pass */
172 struct move last_move4
; /* just before last_move3, only set if last_move & last_move2 are pass */
173 /* Whether we tried to add a hash twice; board_play*() can
174 * set this, but it will still carry out the move as well! */
175 bool superko_violation
;
177 /* The following two structures are goban maps and are indexed by
178 * coord.pos. The map is surrounded by a one-point margin from
179 * S_OFFBOARD stones in order to speed up some internal loops.
180 * Some of the foreach iterators below might include these points;
181 * you need to handle them yourselves, if you need to. */
183 /* Stones played on the board */
184 enum stone
*b
; /* enum stone */
185 /* Group id the stones are part of; 0 == no group */
187 /* Positions of next stones in the stone group; 0 == last stone */
189 /* Neighboring colors; numbers of neighbors of index color */
190 struct neighbor_colors
*n
;
191 /* Zobrist hash for each position */
193 #ifdef BOARD_SPATHASH
194 /* For spatial hashes, we use only 24 bits. */
195 /* [0] is d==1, we don't keep hash for d==0. */
196 /* We keep hashes for black-to-play ([][0]) and white-to-play
197 * ([][1], reversed stone colors since we match all patterns as
199 uint32_t (*spathash
)[BOARD_SPATHASH_MAXD
][2];
202 /* 3x3 pattern code for each position; see pattern3.h for encoding
203 * specification. The information is only valid for empty points. */
207 /* Incrementally matched point traits information, black-to-play
208 * ([][0]) and white-to-play ([][1]). */
209 /* The information is only valid for empty points. */
210 struct btraits (*t
)[2];
212 /* Cached information on x-y coordinates so that we avoid division. */
215 /* Group information - indexed by gid (which is coord of base group stone) */
218 /* Positions of free positions - queue (not map) */
219 /* Note that free position here is any valid move; including single-point eyes!
220 * However, pass is not included. */
221 coord_t
*f
; int flen
;
224 /* Queue of capturable groups */
225 group_t
*c
; int clen
;
229 /* Queue of positions that need their traits updated */
230 coord_t
*tq
; int tqlen
;
233 /* Symmetry information */
234 struct board_symmetry symmetry
;
236 /* Last ko played on the board. */
243 #ifdef BOARD_UNDO_CHECKS
244 /* Guard against invalid quick_play() / quick_undo() uses */
248 /* Engine-specific state; persistent through board development,
249 * is reset only at clear_board. */
252 /* Playout-specific state; persistent through board development,
253 * but its lifetime is maintained in play_random_game(); it should
254 * not be set outside of it. */
258 /* --- PRIVATE DATA --- */
260 /* For superko check: */
262 /* Board "history" - hashes encountered. Size of the hash should be
263 * >> board_size^2. */
264 #define history_hash_bits 12
265 #define history_hash_mask ((1 << history_hash_bits) - 1)
266 #define history_hash_prev(i) ((i - 1) & history_hash_mask)
267 #define history_hash_next(i) ((i + 1) & history_hash_mask)
268 hash_t history_hash
[1 << history_hash_bits
];
269 /* Hash of current board position. */
271 /* Hash of current board position quadrants. */
284 coord_t stones
[BOARD_MAX_MOVES
]; // TODO try small array
288 struct move last_move2
;
296 struct undo_merge merged
[4];
300 struct undo_enemy enemies
[4];
302 int captures
; /* number of stones captured */
307 /* Avoid unused variable warnings */
308 #define board_size(b_) (((b_) == (b_)) ? BOARD_SIZE + 2 : 0)
309 #define board_size2(b_) (board_size(b_) * board_size(b_))
310 #define real_board_size(b_) (((b_) == (b_)) ? BOARD_SIZE : 0)
312 #define board_size(b_) ((b_)->size)
313 #define board_size2(b_) ((b_)->size2)
314 #define real_board_size(b_) ((b_)->size - 2)
317 /* This is a shortcut for taking different action on smaller
318 * and large boards (e.g. picking different variable defaults).
319 * This is of course less optimal than fine-tuning dependency
320 * function of values on board size, but that is difficult and
321 * possibly not very rewarding if you are interested just in
323 #define board_large(b_) (board_size(b_)-2 >= 15)
324 #define board_small(b_) (board_size(b_)-2 <= 9)
327 # define board_bits2(b_) 9
328 #elif BOARD_SIZE == 13
329 # define board_bits2(b_) 8
330 #elif BOARD_SIZE == 9
331 # define board_bits2(b_) 7
333 # define board_bits2(b_) ((b_)->bits2)
336 #define board_at(b_, c) ((b_)->b[c])
337 #define board_atxy(b_, x, y) ((b_)->b[(x) + board_size(b_) * (y)])
339 #define group_at(b_, c) ((b_)->g[c])
340 #define group_atxy(b_, x, y) ((b_)->g[(x) + board_size(b_) * (y)])
342 /* Warning! Neighbor count is not kept up-to-date for S_NONE! */
343 #define neighbor_count_at(b_, coord, color) ((b_)->n[coord].colors[(enum stone) color])
344 #define set_neighbor_count_at(b_, coord, color, count) (neighbor_count_at(b_, coord, color) = (count))
345 #define inc_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)++)
346 #define dec_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)--)
347 #define immediate_liberty_count(b_, coord) (4 - neighbor_count_at(b_, coord, S_BLACK) - neighbor_count_at(b_, coord, S_WHITE) - neighbor_count_at(b_, coord, S_OFFBOARD))
349 #define trait_at(b_, coord, color) (b_)->t[coord][(color) - 1]
351 #define groupnext_at(b_, c) ((b_)->p[c])
352 #define groupnext_atxy(b_, x, y) ((b_)->p[(x) + board_size(b_) * (y)])
354 #define group_base(g_) (g_)
355 #define group_is_onestone(b_, g_) (groupnext_at(b_, group_base(g_)) == 0)
356 #define board_group_info(b_, g_) ((b_)->gi[(g_)])
357 #define board_group_captured(b_, g_) (board_group_info(b_, g_).libs == 0)
358 /* board_group_other_lib() makes sense only for groups with two liberties. */
359 #define board_group_other_lib(b_, g_, l_) (board_group_info(b_, g_).lib[board_group_info(b_, g_).lib[0] != (l_) ? 0 : 1])
361 #define hash_at(b_, coord, color) ((b_)->h[((color) == S_BLACK ? board_size2(b_) : 0) + coord])
363 struct board
*board_init(char *fbookfile
);
364 struct board
*board_copy(struct board
*board2
, struct board
*board1
);
365 void board_done_noalloc(struct board
*board
);
366 void board_done(struct board
*board
);
367 /* size here is without the S_OFFBOARD margin. */
368 void board_resize(struct board
*board
, int size
);
369 void board_clear(struct board
*board
);
371 typedef char *(*board_cprint
)(struct board
*b
, coord_t c
, char *s
, char *end
, void *data
);
372 void board_print(struct board
*board
, FILE *f
);
373 void board_print_custom(struct board
*board
, FILE *f
, board_cprint cprint
, void *data
);
375 /* Debugging: Compare 2 boards byte by byte. Don't use that for sorting =) */
376 int board_cmp(struct board
*b1
, struct board
*b2
);
377 /* Same but only care about fields maintained by quick_play() / quick_undo() */
378 int board_quick_cmp(struct board
*b1
, struct board
*b2
);
380 /* Place given handicap on the board; coordinates are printed to f. */
381 void board_handicap(struct board
*board
, int stones
, FILE *f
);
383 /* Returns group id, 0 on allowed suicide, pass or resign, -1 on error */
384 int board_play(struct board
*board
, struct move
*m
);
385 /* Like above, but plays random move; the move coordinate is recorded
386 * to *coord. This method will never fill your own eye. pass is played
387 * when no move can be played. You can impose extra restrictions if you
388 * supply your own permit function; the permit function can also modify
389 * the move coordinate to redirect the move elsewhere. */
390 typedef bool (*ppr_permit
)(void *data
, struct board
*b
, struct move
*m
);
391 void board_play_random(struct board
*b
, enum stone color
, coord_t
*coord
, ppr_permit permit
, void *permit_data
);
393 /* Undo, supported only for pass moves. Returns -1 on error, 0 otherwise. */
394 int board_undo(struct board
*board
);
396 /* Returns true if given move can be played. */
397 static bool board_is_valid_play(struct board
*b
, enum stone color
, coord_t coord
);
398 static bool board_is_valid_move(struct board
*b
, struct move
*m
);
399 /* Returns true if ko was just taken. */
400 static bool board_playing_ko_threat(struct board
*b
);
401 /* Returns 0 or ID of neighboring group in atari. */
402 static group_t
board_get_atari_neighbor(struct board
*b
, coord_t coord
, enum stone group_color
);
403 /* Returns true if the move is not obvious self-atari. */
404 static bool board_safe_to_play(struct board
*b
, coord_t coord
, enum stone color
);
406 /* Determine number of stones in a group, up to @max stones. */
407 static int group_stone_count(struct board
*b
, group_t group
, int max
);
409 /* Adjust symmetry information as if given coordinate has been played. */
410 void board_symmetry_update(struct board
*b
, struct board_symmetry
*symmetry
, coord_t c
);
411 /* Check if coordinates are within symmetry base. (If false, they can
412 * be derived from the base.) */
413 static bool board_coord_in_symmetry(struct board
*b
, coord_t c
);
415 /* Returns true if given coordinate has all neighbors of given color or the edge. */
416 static bool board_is_eyelike(struct board
*board
, coord_t coord
, enum stone eye_color
);
417 /* Returns true if given coordinate could be a false eye; this check makes
418 * sense only if you already know the coordinate is_eyelike(). */
419 bool board_is_false_eyelike(struct board
*board
, coord_t coord
, enum stone eye_color
);
420 /* Returns true if given coordinate is a 1-pt eye (checks against false eyes, or
421 * at least tries to). */
422 bool board_is_one_point_eye(struct board
*board
, coord_t c
, enum stone eye_color
);
423 /* Returns color of a 1pt eye owner, S_NONE if not an eye. */
424 enum stone
board_get_one_point_eye(struct board
*board
, coord_t c
);
426 /* board_official_score() is the scoring method for yielding score suitable
427 * for external presentation. For fast scoring of entirely filled boards
428 * (e.g. playouts), use board_fast_score(). */
429 /* Positive: W wins */
430 /* Compare number of stones + 1pt eyes. */
431 floating_t
board_fast_score(struct board
*board
);
432 /* Tromp-Taylor scoring, assuming given groups are actually dead. */
434 floating_t
board_official_score(struct board
*board
, struct move_queue
*mq
);
436 /* Set board rules according to given string. Returns false in case
437 * of unknown ruleset name. */
438 bool board_set_rules(struct board
*board
, char *name
);
440 /* Quick play/undo to try out a move.
441 * WARNING Only core board structures are maintained !
442 * Code in between can't rely on anything else.
444 * Currently this means these can't be used:
445 * - incremental patterns (pat3)
446 * - hashes, superko_violation (spathash, hash, qhash, history_hash)
447 * - list of free positions (f / flen)
448 * - list of capturable groups (c / clen)
449 * - traits (btraits, t, tq, tqlen)
450 * - last_move3, last_move4, last_ko_age
451 * - symmetry information
453 * Invalid quick_play()/quick_undo() combinations (missing undo for example)
454 * are caught at next board_play() if BOARD_UNDO_CHECKS is defined.
456 int board_quick_play(struct board
*board
, struct move
*m
, struct board_undo
*u
);
457 void board_quick_undo(struct board
*b
, struct move
*m
, struct board_undo
*u
);
459 /* quick_play() + quick_undo() combo.
460 * Body is executed only if move is valid (silently ignored otherwise).
461 * Can break out in body, but definitely *NOT* return / jump around !
462 * (caught at run time if BOARD_UNDO_CHECKS defined). Can use
463 * with_move_return(val) to return value for non-nested with_move()'s
465 #define with_move(board_, coord_, color_, body_) \
467 struct board *board__ = (board_); /* For with_move_return() */ \
468 struct move m_ = { .coord = (coord_), .color = (color_) }; \
469 struct board_undo u_; \
470 if (board_quick_play(board__, &m_, &u_) >= 0) { \
471 do { body_ } while(0); \
472 board_quick_undo(board__, &m_, &u_); \
476 /* Return value from within with_move() statement.
477 * Valid for non-nested with_move() *ONLY* */
478 #define with_move_return(val_) \
479 do { typeof(val_) val__ = (val_); board_quick_undo(board__, &m_, &u_); return val__; } while (0)
481 /* Same as with_move() but assert out in case of invalid move. */
482 #define with_move_strict(board_, coord_, color_, body_) \
484 struct board *board__ = (board_); /* For with_move_return() */ \
485 struct move m_ = { .coord = (coord_), .color = (color_) }; \
486 struct board_undo u_; \
487 assert (board_quick_play(board__, &m_, &u_) >= 0); \
488 do { body_ } while(0); \
489 board_quick_undo(board__, &m_, &u_); \
495 #define foreach_point(board_) \
498 for (; c < board_size(board_) * board_size(board_); c++)
499 #define foreach_point_and_pass(board_) \
502 for (; c < board_size(board_) * board_size(board_); c++)
503 #define foreach_point_end \
506 #define foreach_free_point(board_) \
508 int fmax__ = (board_)->flen; \
509 for (int f__ = 0; f__ < fmax__; f__++) { \
510 coord_t c = (board_)->f[f__];
511 #define foreach_free_point_end \
515 #define foreach_in_group(board_, group_) \
517 struct board *board__ = board_; \
518 coord_t c = group_base(group_); \
519 coord_t c2 = c; c2 = groupnext_at(board__, c2); \
521 #define foreach_in_group_end \
522 c = c2; c2 = groupnext_at(board__, c2); \
526 /* NOT VALID inside of foreach_point() or another foreach_neighbor(), or rather
527 * on S_OFFBOARD coordinates. */
528 #define foreach_neighbor(board_, coord_, loop_body) \
530 struct board *board__ = board_; \
531 coord_t coord__ = coord_; \
533 c = coord__ - board_size(board__); do { loop_body } while (0); \
534 c = coord__ - 1; do { loop_body } while (0); \
535 c = coord__ + 1; do { loop_body } while (0); \
536 c = coord__ + board_size(board__); do { loop_body } while (0); \
539 #define foreach_8neighbor(board_, coord_) \
542 coord_t c = (coord_); \
543 for (fn__i = 0; fn__i < 8; fn__i++) { \
544 c += (board_)->nei8[fn__i];
545 #define foreach_8neighbor_end \
549 #define foreach_diag_neighbor(board_, coord_) \
552 coord_t c = (coord_); \
553 for (fn__i = 0; fn__i < 4; fn__i++) { \
554 c += (board_)->dnei[fn__i];
555 #define foreach_diag_neighbor_end \
561 board_is_eyelike(struct board
*board
, coord_t coord
, enum stone eye_color
)
563 return (neighbor_count_at(board
, coord
, eye_color
)
564 + neighbor_count_at(board
, coord
, S_OFFBOARD
)) == 4;
567 /* Group suicides allowed */
569 board_is_valid_play(struct board
*board
, enum stone color
, coord_t coord
)
571 if (board_at(board
, coord
) != S_NONE
)
573 if (!board_is_eyelike(board
, coord
, stone_other(color
)))
575 /* Play within {true,false} eye-ish formation */
576 if (board
->ko
.coord
== coord
&& board
->ko
.color
== color
)
579 /* XXX: Disallows suicide. */
580 return trait_at(board
, coord
, color
).cap
> 0;
582 int groups_in_atari
= 0;
583 foreach_neighbor(board
, coord
, {
584 group_t g
= group_at(board
, c
);
585 groups_in_atari
+= (board_group_info(board
, g
).libs
== 1);
587 return !!groups_in_atari
;
591 /* Check group suicides, slower than board_is_valid_play() */
593 board_is_valid_play_no_suicide(struct board
*board
, enum stone color
, coord_t coord
)
595 if (board_at(board
, coord
) != S_NONE
)
597 if (immediate_liberty_count(board
, coord
) >= 1)
599 if (board_is_eyelike(board
, coord
, stone_other(color
)) &&
600 board
->ko
.coord
== coord
&& board
->ko
.color
== color
)
603 // Capturing something ?
605 /* XXX: Disallows suicide. */
606 if (trait_at(board
, coord
, color
).cap
> 0)
609 foreach_neighbor(board
, coord
, {
610 if (board_at(board
, c
) == stone_other(color
) &&
611 board_group_info(board
, group_at(board
, c
)).libs
== 1)
616 // Neighbour with 2 libs ?
617 foreach_neighbor(board
, coord
, {
618 if (board_at(board
, c
) == color
&&
619 board_group_info(board
, group_at(board
, c
)).libs
> 1)
623 return false; // Suicide
628 board_is_valid_move(struct board
*board
, struct move
*m
)
630 return board_is_valid_play(board
, m
->color
, m
->coord
);
634 board_playing_ko_threat(struct board
*b
)
636 return !is_pass(b
->ko
.coord
);
639 static inline group_t
640 board_get_atari_neighbor(struct board
*b
, coord_t coord
, enum stone group_color
)
643 if (!trait_at(b
, coord
, stone_other(group_color
)).cap
) return 0;
645 foreach_neighbor(b
, coord
, {
646 group_t g
= group_at(b
, c
);
647 if (g
&& board_at(b
, c
) == group_color
&& board_group_info(b
, g
).libs
== 1)
649 /* We return first match. */
655 board_safe_to_play(struct board
*b
, coord_t coord
, enum stone color
)
657 /* number of free neighbors */
658 int libs
= immediate_liberty_count(b
, coord
);
663 /* number of capturable enemy groups */
664 if (trait_at(b
, coord
, color
).cap
> 0)
665 return true; // XXX: We don't account for snapback.
666 /* number of non-capturable friendly groups */
667 int noncap_ours
= neighbor_count_at(b
, coord
, color
) - trait_at(b
, coord
, stone_other(color
)).cap
;
673 /* ok, but we need to check if they don't have just two libs. */
675 foreach_neighbor(b
, coord
, {
677 if (board_at(b
, c
) == stone_other(color
) && board_group_info(b
, group_at(b
, c
)).libs
== 1)
678 return true; // can capture; no snapback check
680 if (board_at(b
, c
) != color
) continue;
681 group_t g
= group_at(b
, c
);
682 if (board_group_info(b
, g
).libs
== 1) continue; // in atari
683 if (board_group_info(b
, g
).libs
== 2) { // two liberties
684 if (libs
> 0) return true; // we already have one real liberty
685 /* we might be connecting two 2-lib groups, which is ok;
686 * so remember the other liberty and just make sure it's
687 * not the same one */
688 if (onelib
>= 0 && c
!= onelib
) return true;
689 onelib
= board_group_other_lib(b
, g
, c
);
695 // no good support group
700 group_stone_count(struct board
*b
, group_t group
, int max
)
703 foreach_in_group(b
, group
) {
705 if (n
>= max
) return max
;
706 } foreach_in_group_end
;
711 board_coord_in_symmetry(struct board
*b
, coord_t c
)
713 if (coord_y(c
, b
) < b
->symmetry
.y1
|| coord_y(c
, b
) > b
->symmetry
.y2
)
715 if (coord_x(c
, b
) < b
->symmetry
.x1
|| coord_x(c
, b
) > b
->symmetry
.x2
)
718 int x
= coord_x(c
, b
);
719 if (b
->symmetry
.type
== SYM_DIAG_DOWN
)
720 x
= board_size(b
) - 1 - x
;
721 if (x
> coord_y(c
, b
))