13 struct features_gamma
;
16 /* The board implementation has bunch of optional features.
17 * Turn them on below: */
19 #define WANT_BOARD_C // capturable groups queue
21 //#define BOARD_SIZE 9 // constant board size, allows better optimization
23 //#define BOARD_SPATHASH // incremental patternsp.h hashes
24 #define BOARD_SPATHASH_MAXD 3 // maximal diameter
26 #define BOARD_PAT3 // incremental 3x3 pattern codes
28 //#define BOARD_TRAITS 1 // incremental point traits (see struct btraits)
29 //#define BOARD_GAMMA 1 // incremental probability distribution (requires BOARD_TRAITS, BOARD_PAT3)
32 /* Some engines might normalize their reading and skip symmetrical
33 * moves. We will tell them how can they do it. */
34 struct board_symmetry
{
35 /* Playground is in this rectangle. */
37 /* d == 0: Full rectangle
38 * d == 1: Top triangle */
40 /* General symmetry type. */
41 /* Note that the above is redundant to this, but just provided
42 * for easier usage. */
54 typedef uint64_t hash_t
;
55 #define PRIhash PRIx64
58 /* Note that "group" is only chain of stones that is solidly
59 * connected for us. */
60 typedef coord_t group_t
;
63 /* We keep track of only up to GROUP_KEEP_LIBS; over that, we
65 /* _Combination_ of these two values can make some difference
66 * in performance - fine-tune. */
67 #define GROUP_KEEP_LIBS 10
68 // refill lib[] only when we hit this; this must be at least 2!
69 // Moggy requires at least 3 - see below for semantic impact.
70 #define GROUP_REFILL_LIBS 5
71 coord_t lib
[GROUP_KEEP_LIBS
];
72 /* libs is only LOWER BOUND for the number of real liberties!!!
73 * It denotes only number of items in lib[], thus you can rely
74 * on it to store real liberties only up to <= GROUP_REFILL_LIBS. */
78 struct neighbor_colors
{
83 /* Point traits bitmap; we update this information incrementally,
84 * it can be used e.g. for fast pattern.h features matching. */
86 /* Number of neighbors we can capture. 0=this move is
87 * not capturing, 1..4=this many neighbors we can capture
88 * (can be multiple neighbors of same group). */
90 /* Whether it is SAFE to play here. This is essentially just
91 * cached result of board_safe_to_play(). (Of course the concept
92 * of "safety" is not perfect here, but it's the cheapest
93 * reasonable thing we can do.) */
95 /* Whether we need to re-compute this coordinate; used to
96 * weed out duplicates. Maintained only for S_BLACK. */
101 /* You should treat this struct as read-only. Always call functions below if
102 * you want to change it. */
105 int size
; /* Including S_OFFBOARD margin - see below. */
106 int size2
; /* size^2 */
110 /* The ruleset is currently almost never taken into account;
111 * the board implementation is basically Chinese rules (handicap
112 * stones compensation) w/ suicide (or you can look at it as
113 * New Zealand w/o handi stones compensation), while the engine
114 * enforces no-suicide, making for real Chinese rules. */
116 RULES_CHINESE
, /* default value */
122 /* Iterator offsets for foreach_neighbor*() */
123 int nei8
[8], dnei
[4];
126 struct move last_move
;
127 struct move last_move2
; /* second-to-last move */
128 /* Whether we tried to add a hash twice; board_play*() can
129 * set this, but it will still carry out the move as well! */
130 bool superko_violation
;
132 /* The following two structures are goban maps and are indexed by
133 * coord.pos. The map is surrounded by a one-point margin from
134 * S_OFFBOARD stones in order to speed up some internal loops.
135 * Some of the foreach iterators below might include these points;
136 * you need to handle them yourselves, if you need to. */
138 /* Stones played on the board */
139 enum stone
*b
; /* enum stone */
140 /* Group id the stones are part of; 0 == no group */
142 /* Positions of next stones in the stone group; 0 == last stone */
144 /* Neighboring colors; numbers of neighbors of index color */
145 struct neighbor_colors
*n
;
146 /* Zobrist hash for each position */
148 #ifdef BOARD_SPATHASH
149 /* For spatial hashes, we use only 24 bits. */
150 /* [0] is d==1, we don't keep hash for d==0. */
151 /* We keep hashes for black-to-play ([][0]) and white-to-play
152 * ([][1], reversed stone colors since we match all patterns as
154 uint32_t (*spathash
)[BOARD_SPATHASH_MAXD
][2];
157 /* 3x3 pattern code for each position; see pattern3.h for encoding
158 * specification. The information is only valid for empty points. */
162 /* Incrementally matched point traits information, black-to-play
163 * ([][0]) and white-to-play ([][1]). */
164 /* The information is only valid for empty points. */
165 struct btraits (*t
)[2];
168 /* Relative probabilities of moves being played next, computed by
169 * multiplying gammas of the appropriate pattern features based on
170 * pat3 and traits (see pattern.h). The probability distribution
171 * is maintained over the full board grid. */
172 /* - Always invalid moves are guaranteed to have zero probability.
173 * - Self-eye-filling moves will always have zero probability.
174 * - Ko-prohibited moves might have non-zero probability.
175 * - FEAT_CONTIGUITY is not accounted for in the probability. */
176 struct probdist prob
[2];
179 /* Group information - indexed by gid (which is coord of base group stone) */
182 /* Positions of free positions - queue (not map) */
183 /* Note that free position here is any valid move; including single-point eyes!
184 * However, pass is not included. */
185 coord_t
*f
; int flen
;
188 /* Queue of capturable groups */
189 group_t
*c
; int clen
;
193 /* Queue of positions that need their traits updated */
194 coord_t
*tq
; int tqlen
;
197 /* Symmetry information */
198 struct board_symmetry symmetry
;
200 /* Last ko played on the board. */
207 /* Engine-specific state; persistent through board development,
208 * is reset only at clear_board. */
211 /* Playout-specific state; persistent through board development,
212 * but its lifetime is maintained in play_random_game(); it should
213 * not be set outside of it. */
217 /* Gamma values for probability distribution; user must setup
218 * this pointer before any move is played, using board_gamma_set(). */
219 struct features_gamma
*gamma
;
220 /* Whether to compute the 'safe' trait using board_safe_to_play()
221 * (false) or is_bad_selfatari() (true, much slower). */
222 bool precise_selfatari
;
226 /* --- PRIVATE DATA --- */
228 /* For superko check: */
230 /* Board "history" - hashes encountered. Size of the hash should be
231 * >> board_size^2. */
232 #define history_hash_bits 12
233 #define history_hash_mask ((1 << history_hash_bits) - 1)
234 #define history_hash_prev(i) ((i - 1) & history_hash_mask)
235 #define history_hash_next(i) ((i + 1) & history_hash_mask)
236 hash_t history_hash
[1 << history_hash_bits
];
237 /* Hash of current board position. */
242 /* Avoid unused variable warnings */
243 #define board_size(b_) (((b_) == (b_)) ? BOARD_SIZE + 2 : 0)
244 #define board_size2(b_) (board_size(b_) * board_size(b_))
246 #define board_size(b_) ((b_)->size)
247 #define board_size2(b_) ((b_)->size2)
250 #define board_at(b_, c) ((b_)->b[c])
251 #define board_atxy(b_, x, y) ((b_)->b[(x) + board_size(b_) * (y)])
253 #define group_at(b_, c) ((b_)->g[c])
254 #define group_atxy(b_, x, y) ((b_)->g[(x) + board_size(b_) * (y)])
256 /* Warning! Neighbor count is kept up-to-date for S_NONE! */
257 #define neighbor_count_at(b_, coord, color) ((b_)->n[coord].colors[(enum stone) color])
258 #define set_neighbor_count_at(b_, coord, color, count) (neighbor_count_at(b_, coord, color) = (count))
259 #define inc_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)++)
260 #define dec_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)--)
261 #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))
263 #define trait_at(b_, coord, color) (b_)->t[coord][(color) - 1]
265 #define groupnext_at(b_, c) ((b_)->p[c])
266 #define groupnext_atxy(b_, x, y) ((b_)->p[(x) + board_size(b_) * (y)])
268 #define group_base(g_) (g_)
269 #define board_group_info(b_, g_) ((b_)->gi[(g_)])
270 #define board_group_captured(b_, g_) (board_group_info(b_, g_).libs == 0)
271 #define group_is_onestone(b_, g_) (groupnext_at(b_, group_base(g_)) == 0)
273 #define hash_at(b_, coord, color) ((b_)->h[((color) == S_BLACK ? board_size2(b_) : 0) + coord])
275 struct board
*board_init(void);
276 struct board
*board_copy(struct board
*board2
, struct board
*board1
);
277 void board_done_noalloc(struct board
*board
);
278 void board_done(struct board
*board
);
279 /* size here is without the S_OFFBOARD margin. */
280 void board_resize(struct board
*board
, int size
);
281 void board_clear(struct board
*board
);
284 typedef char *(*board_cprint
)(struct board
*b
, coord_t c
, char *s
, char *end
);
285 void board_print(struct board
*board
, FILE *f
);
286 void board_print_custom(struct board
*board
, FILE *f
, board_cprint cprint
);
288 /* Place given handicap on the board; coordinates are printed to f. */
289 void board_handicap(struct board
*board
, int stones
, FILE *f
);
291 /* Returns group id, 0 on allowed suicide, pass or resign, -1 on error */
292 int board_play(struct board
*board
, struct move
*m
);
293 /* Like above, but plays random move; the move coordinate is recorded
294 * to *coord. This method will never fill your own eye. pass is played
295 * when no move can be played. You can impose extra restrictions if you
296 * supply your own permit function. */
297 typedef bool (*ppr_permit
)(void *data
, struct board
*b
, struct move
*m
);
298 void board_play_random(struct board
*b
, enum stone color
, coord_t
*coord
, ppr_permit permit
, void *permit_data
);
300 /* Returns true if given move can be played. */
301 static bool board_is_valid_play(struct board
*b
, enum stone color
, coord_t coord
);
302 static bool board_is_valid_move(struct board
*b
, struct move
*m
);
303 /* Returns true if ko was just taken. */
304 static bool board_playing_ko_threat(struct board
*b
);
305 /* Returns 0 or ID of neighboring group in atari. */
306 static group_t
board_get_atari_neighbor(struct board
*b
, coord_t coord
, enum stone group_color
);
307 /* Returns true if the move is not obvious self-atari. */
308 static bool board_safe_to_play(struct board
*b
, coord_t coord
, enum stone color
);
310 /* Adjust symmetry information as if given coordinate has been played. */
311 void board_symmetry_update(struct board
*b
, struct board_symmetry
*symmetry
, coord_t c
);
312 /* Associate a set of feature gamma values (for pd building) with the board. */
313 void board_gamma_set(struct board
*b
, struct features_gamma
*gamma
, bool precise_selfatari
);
314 /* Force re-compute of a probability distribution item. */
315 void board_gamma_update(struct board
*b
, coord_t coord
, enum stone color
);
317 /* Returns true if given coordinate has all neighbors of given color or the edge. */
318 static bool board_is_eyelike(struct board
*board
, coord_t coord
, enum stone eye_color
);
319 /* Returns true if given coordinate could be a false eye; this check makes
320 * sense only if you already know the coordinate is_eyelike(). */
321 bool board_is_false_eyelike(struct board
*board
, coord_t coord
, enum stone eye_color
);
322 /* Returns true if given coordinate is a 1-pt eye (checks against false eyes, or
323 * at least tries to). */
324 bool board_is_one_point_eye(struct board
*board
, coord_t c
, enum stone eye_color
);
325 /* Returns color of a 1pt eye owner, S_NONE if not an eye. */
326 enum stone
board_get_one_point_eye(struct board
*board
, coord_t c
);
328 /* board_official_score() is the scoring method for yielding score suitable
329 * for external presentation. For fast scoring of entirely filled boards
330 * (e.g. playouts), use board_fast_score(). */
331 /* Positive: W wins */
332 /* Compare number of stones + 1pt eyes. */
333 float board_fast_score(struct board
*board
);
334 /* Tromp-Taylor scoring, assuming given groups are actually dead. */
336 float board_official_score(struct board
*board
, struct move_queue
*mq
);
340 #define foreach_point(board_) \
343 for (; c < board_size(board_) * board_size(board_); c++)
344 #define foreach_point_and_pass(board_) \
347 for (; c < board_size(board_) * board_size(board_); c++)
348 #define foreach_point_end \
351 #define foreach_in_group(board_, group_) \
353 struct board *board__ = board_; \
354 coord_t c = group_base(group_); \
355 coord_t c2 = c; c2 = groupnext_at(board__, c2); \
357 #define foreach_in_group_end \
358 c = c2; c2 = groupnext_at(board__, c2); \
362 /* NOT VALID inside of foreach_point() or another foreach_neighbor(), or rather
363 * on S_OFFBOARD coordinates. */
364 #define foreach_neighbor(board_, coord_, loop_body) \
366 struct board *board__ = board_; \
367 coord_t coord__ = coord_; \
369 c = coord__ - 1; do { loop_body } while (0); \
370 c = coord__ - board_size(board__); do { loop_body } while (0); \
371 c = coord__ + 1; do { loop_body } while (0); \
372 c = coord__ + board_size(board__); do { loop_body } while (0); \
375 #define foreach_8neighbor(board_, coord_) \
378 coord_t c = (coord_); \
379 for (fn__i = 0; fn__i < 8; fn__i++) { \
380 c += (board_)->nei8[fn__i];
381 #define foreach_8neighbor_end \
385 #define foreach_diag_neighbor(board_, coord_) \
388 coord_t c = (coord_); \
389 for (fn__i = 0; fn__i < 4; fn__i++) { \
390 c += (board_)->dnei[fn__i];
391 #define foreach_diag_neighbor_end \
397 board_is_eyelike(struct board
*board
, coord_t coord
, enum stone eye_color
)
399 return (neighbor_count_at(board
, coord
, eye_color
)
400 + neighbor_count_at(board
, coord
, S_OFFBOARD
)) == 4;
404 board_is_valid_play(struct board
*board
, enum stone color
, coord_t coord
)
406 if (board_at(board
, coord
) != S_NONE
)
408 if (!board_is_eyelike(board
, coord
, stone_other(color
)))
410 /* Play within {true,false} eye-ish formation */
411 if (board
->ko
.coord
== coord
&& board
->ko
.color
== color
)
414 /* XXX: Disallows suicide. */
415 return trait_at(board
, coord
, color
).cap
> 0;
417 int groups_in_atari
= 0;
418 foreach_neighbor(board
, coord
, {
419 group_t g
= group_at(board
, c
);
420 groups_in_atari
+= (board_group_info(board
, g
).libs
== 1);
422 return !!groups_in_atari
;
427 board_is_valid_move(struct board
*board
, struct move
*m
)
429 return board_is_valid_play(board
, m
->color
, m
->coord
);
433 board_playing_ko_threat(struct board
*b
)
435 return !is_pass(b
->ko
.coord
);
438 static inline group_t
439 board_get_atari_neighbor(struct board
*b
, coord_t coord
, enum stone group_color
)
442 if (!trait_at(b
, coord
, stone_other(group_color
)).cap
) return 0;
444 foreach_neighbor(b
, coord
, {
445 group_t g
= group_at(b
, c
);
446 if (g
&& board_at(b
, c
) == group_color
&& board_group_info(b
, g
).libs
== 1)
448 /* We return first match. */
454 board_safe_to_play(struct board
*b
, coord_t coord
, enum stone color
)
456 /* number of free neighbors */
457 int libs
= immediate_liberty_count(b
, coord
);
462 /* number of capturable enemy groups */
463 if (trait_at(b
, coord
, color
).cap
> 0)
464 return true; // XXX: We don't account for snapback.
465 /* number of non-capturable friendly groups */
466 int noncap_ours
= neighbor_count_at(b
, coord
, color
) - trait_at(b
, coord
, stone_other(color
)).cap
;
472 /* ok, but we need to check if they don't have just two libs. */
474 foreach_neighbor(b
, coord
, {
476 if (board_at(b
, c
) == stone_other(color
) && board_group_info(b
, group_at(b
, c
)).libs
== 1)
477 return true; // can capture; no snapback check
479 if (board_at(b
, c
) != color
) continue;
480 group_t g
= group_at(b
, c
);
481 if (board_group_info(b
, g
).libs
== 1) continue; // in atari
482 if (board_group_info(b
, g
).libs
== 2) { // two liberties
483 if (libs
> 0) return true; // we already have one real liberty
484 // get the other liberty
485 coord_t lib
= board_group_info(b
, g
).lib
[0];
486 if (lib
== coord
) lib
= board_group_info(b
, g
).lib
[0];
487 /* we might be connecting two 2-lib groups, which is ok;
488 * so remember the other liberty and just make sure it's
489 * not the same one */
490 if (onelib
>= 0 && lib
!= onelib
) return true;
497 // no good support group