board.h

   1 #ifndef ZZGO_BOARD_H
   2 #define ZZGO_BOARD_H
   3
   4 #include <inttypes.h>
   5 #include <stdbool.h>
   6 #include <stdint.h>
   7
   8 #include "stone.h"
   9 #include "move.h"
  10 #include "util.h"
  11
  12
  13 /* The board implementation has bunch of optional features.
  14  * Turn them on below: */
  15
  16 #define WANT_BOARD_C // capturable groups queue
  17
  18 //#define BOARD_SIZE 9 // constant board size, allows better optimization
  19
  20 //#define BOARD_SPATHASH // incremental patternsp.h hashes
  21 #define BOARD_SPATHASH_MAXD 3 // maximal diameter
  22
  23 #define BOARD_PAT3 // incremental 3x3 pattern codes
  24
  25 //#define BOARD_TRAITS 1 // incremental point traits (see struct btraits)
  26
  27
  28 /* Allow board_play_random_move() to return pass even when
  29  * there are other moves available. */
  30 extern bool random_pass;
  31
  32
  33 /* Some engines might normalize their reading and skip symmetrical
  34  * moves. We will tell them how can they do it. */
  35 struct board_symmetry {
  36         /* Playground is in this rectangle. */
  37         int x1, x2, y1, y2;
  38         /* d ==  0: Full rectangle
  39          * d ==  1: Top triangle */
  40         int d;
  41         /* General symmetry type. */
  42         /* Note that the above is redundant to this, but just provided
  43          * for easier usage. */
  44         enum {
  45                 SYM_FULL,
  46                 SYM_DIAG_UP,
  47                 SYM_DIAG_DOWN,
  48                 SYM_HORIZ,
  49                 SYM_VERT,
  50                 SYM_NONE
  51         } type;
  52 };
  53
  54
  55 typedef uint64_t hash_t;
  56 #define PRIhash PRIx64
  57
  58
  59 /* Note that "group" is only chain of stones that is solidly
  60  * connected for us. */
  61 typedef coord_t group_t;
  62
  63 struct group {
  64         /* We keep track of only up to GROUP_KEEP_LIBS; over that, we
  65          * don't care. */
  66         /* _Combination_ of these two values can make some difference
  67          * in performance - fine-tune. */
  68 #define GROUP_KEEP_LIBS 10
  69         // refill lib[] only when we hit this; this must be at least 2!
  70         // Moggy requires at least 3 - see below for semantic impact.
  71 #define GROUP_REFILL_LIBS 5
  72         coord_t lib[GROUP_KEEP_LIBS];
  73         /* libs is only LOWER BOUND for the number of real liberties!!!
  74          * It denotes only number of items in lib[], thus you can rely
  75          * on it to store real liberties only up to <= GROUP_REFILL_LIBS. */
  76         int libs;
  77 };
  78
  79 struct neighbor_colors {
  80         char colors[S_MAX];
  81 };
  82
  83
  84 /* Point traits bitmap; we update this information incrementally,
  85  * it can be used e.g. for fast pattern.h features matching. */
  86 struct btraits {
  87         /* Number of neighbors we can capture. 0=this move is
  88          * not capturing, 1..4=this many neighbors we can capture
  89          * (can be multiple neighbors of same group). */
  90         unsigned cap:3;
  91         /* Whether it is SAFE to play here. This is essentially just
  92          * cached result of the macro below. (Of course the concept
  93          * of "safety" is not perfect here, but it's the cheapest
  94          * reasonable thing we can do.) */
  95         bool safe:1;
  96 #define board_safe_to_play(b_, coord_, color_) \
  97                 (( \
  98                   /* number of free neighbors, except us */ \
  99                   immediate_liberty_count(b_, coord_) - 1 \
 100                   /* number of capturable enemy groups */ \
 101                   + trait_at(b_, coord_, color_).cap \
 102                   /* number of non-capturable friendly groups */ \
 103                   + neighbor_count_at(b_, coord_, color_) - trait_at(b_, coord_, stone_other(color_)).cap \
 104                  ) > 0)
 105 };
 106
 107
 108 /* You should treat this struct as read-only. Always call functions below if
 109  * you want to change it. */
 110
 111 struct board {
 112         int size; /* Including S_OFFBOARD margin - see below. */
 113         int size2; /* size^2 */
 114         int captures[S_MAX];
 115         float komi;
 116         int handicap;
 117
 118         /* Iterator offsets for foreach_neighbor*() */
 119         int nei8[8], dnei[4];
 120
 121         int moves;
 122         struct move last_move;
 123         struct move last_move2; /* second-to-last move */
 124         /* Whether we tried to add a hash twice; board_play*() can
 125          * set this, but it will still carry out the move as well! */
 126         bool superko_violation;
 127
 128         /* The following two structures are goban maps and are indexed by
 129          * coord.pos. The map is surrounded by a one-point margin from
 130          * S_OFFBOARD stones in order to speed up some internal loops.
 131          * Some of the foreach iterators below might include these points;
 132          * you need to handle them yourselves, if you need to. */
 133
 134         /* Stones played on the board */
 135         enum stone *b; /* enum stone */
 136         /* Group id the stones are part of; 0 == no group */
 137         group_t *g;
 138         /* Positions of next stones in the stone group; 0 == last stone */
 139         coord_t *p;
 140         /* Neighboring colors; numbers of neighbors of index color */
 141         struct neighbor_colors *n;
 142         /* Zobrist hash for each position */
 143         hash_t *h;
 144 #ifdef BOARD_SPATHASH
 145         /* For spatial hashes, we use only 24 bits. */
 146         /* [0] is d==1, we don't keep hash for d==0. */
 147         /* We keep hashes for black-to-play ([][0]) and white-to-play
 148          * ([][1], reversed stone colors since we match all patterns as
 149          * black-to-play). */
 150         uint32_t (*spathash)[BOARD_SPATHASH_MAXD][2];
 151 #endif
 152 #ifdef BOARD_PAT3
 153         /* 3x3 pattern code for each position; see pattern3.h for encoding
 154          * specification. The information is only valid for empty points. */
 155         uint16_t *pat3;
 156 #endif
 157 #ifdef BOARD_TRAITS
 158         /* Incrementally matched point traits information, black-to-play
 159          * ([][0]) and white-to-play ([][1]). */
 160         /* The information is only valid for empty points. */
 161         struct btraits (*t)[2];
 162 #endif
 163
 164         /* Group information - indexed by gid (which is coord of base group stone) */
 165         struct group *gi;
 166
 167         /* Positions of free positions - queue (not map) */
 168         /* Note that free position here is any valid move; including single-point eyes! */
 169         coord_t *f; int flen;
 170
 171 #ifdef WANT_BOARD_C
 172         /* Queue of capturable groups */
 173         group_t *c; int clen;
 174 #endif
 175
 176         /* Symmetry information */
 177         struct board_symmetry symmetry;
 178
 179         /* Last ko played on the board. */
 180         struct move last_ko;
 181         int last_ko_age;
 182
 183         /* Basic ko check */
 184         struct move ko;
 185
 186         /* Engine-specific state; persistent through board development,
 187          * is reset only at clear_board. */
 188         void *es;
 189
 190         /* Playout-specific state; persistent through board development,
 191          * but its lifetime is maintained in play_random_game(); it should
 192          * not be set outside of it. */
 193         void *ps;
 194
 195
 196         /* --- PRIVATE DATA --- */
 197
 198         /* For superko check: */
 199
 200         /* Board "history" - hashes encountered. Size of the hash should be
 201          * >> board_size^2. */
 202 #define history_hash_bits 12
 203 #define history_hash_mask ((1 << history_hash_bits) - 1)
 204 #define history_hash_prev(i) ((i - 1) & history_hash_mask)
 205 #define history_hash_next(i) ((i + 1) & history_hash_mask)
 206         hash_t history_hash[1 << history_hash_bits];
 207         /* Hash of current board position. */
 208         hash_t hash;
 209 };
 210
 211 #ifdef BOARD_SIZE
 212 /* Avoid unused variable warnings */
 213 #define board_size(b_) (((b_) == (b_)) ? BOARD_SIZE + 2 : 0)
 214 #define board_size2(b_) (board_size(b_) * board_size(b_))
 215 #else
 216 #define board_size(b_) ((b_)->size)
 217 #define board_size2(b_) ((b_)->size2)
 218 #endif
 219
 220 #define board_at(b_, c) ((b_)->b[coord_raw(c)])
 221 #define board_atxy(b_, x, y) ((b_)->b[(x) + board_size(b_) * (y)])
 222
 223 #define group_at(b_, c) ((b_)->g[coord_raw(c)])
 224 #define group_atxy(b_, x, y) ((b_)->g[(x) + board_size(b_) * (y)])
 225
 226 /* Warning! Neighbor count is kept up-to-date for S_NONE! */
 227 #define neighbor_count_at(b_, coord, color) ((b_)->n[coord_raw(coord)].colors[(enum stone) color])
 228 #define set_neighbor_count_at(b_, coord, color, count) (neighbor_count_at(b_, coord, color) = (count))
 229 #define inc_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)++)
 230 #define dec_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)--)
 231 #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))
 232
 233 #define trait_at(b_, coord, color) (b_)->t[coord][(color) - 1]
 234
 235 #define groupnext_at(b_, c) ((b_)->p[coord_raw(c)])
 236 #define groupnext_atxy(b_, x, y) ((b_)->p[(x) + board_size(b_) * (y)])
 237
 238 #define group_base(g_) (g_)
 239 #define board_group_info(b_, g_) ((b_)->gi[(g_)])
 240 #define board_group_captured(b_, g_) (board_group_info(b_, g_).libs == 0)
 241 #define group_is_onestone(b_, g_) (groupnext_at(b_, group_base(g_)) == 0)
 242
 243 #define hash_at(b_, coord, color) ((b_)->h[((color) == S_BLACK ? board_size2(b_) : 0) + coord_raw(coord)])
 244
 245 struct board *board_init(void);
 246 struct board *board_copy(struct board *board2, struct board *board1);
 247 void board_done_noalloc(struct board *board);
 248 void board_done(struct board *board);
 249 /* size here is without the S_OFFBOARD margin. */
 250 void board_resize(struct board *board, int size);
 251 void board_clear(struct board *board);
 252
 253 struct FILE;
 254 typedef void (*board_cprint)(struct board *b, coord_t c, FILE *f);
 255 void board_print(struct board *board, FILE *f);
 256 void board_print_custom(struct board *board, FILE *f, board_cprint cprint);
 257
 258 /* Place given handicap on the board; coordinates are printed to f. */
 259 void board_handicap(struct board *board, int stones, FILE *f);
 260
 261 /* Returns group id, 0 on allowed suicide, pass or resign, -1 on error */
 262 int board_play(struct board *board, struct move *m);
 263 /* Like above, but plays random move; the move coordinate is recorded
 264  * to *coord. This method will never fill your own eye. pass is played
 265  * when no move can be played. You can impose extra restrictions if you
 266  * supply your own permit function. */
 267 typedef bool (*ppr_permit)(void *data, struct board *b, struct move *m);
 268 void board_play_random(struct board *b, enum stone color, coord_t *coord, ppr_permit permit, void *permit_data);
 269
 270 /* Returns true if given move can be played. */
 271 static bool board_is_valid_move(struct board *b, struct move *m);
 272 /* Returns true if ko was just taken. */
 273 static bool board_playing_ko_threat(struct board *b);
 274 /* Returns 0 or ID of neighboring group in atari. */
 275 static group_t board_get_atari_neighbor(struct board *b, coord_t coord, enum stone group_color);
 276
 277 /* Adjust symmetry information as if given coordinate has been played. */
 278 void board_symmetry_update(struct board *b, struct board_symmetry *symmetry, coord_t c);
 279
 280 /* Returns true if given coordinate has all neighbors of given color or the edge. */
 281 static bool board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color);
 282 /* Returns true if given coordinate could be a false eye; this check makes
 283  * sense only if you already know the coordinate is_eyelike(). */
 284 bool board_is_false_eyelike(struct board *board, coord_t *coord, enum stone eye_color);
 285 /* Returns true if given coordinate is a 1-pt eye (checks against false eyes, or
 286  * at least tries to). */
 287 bool board_is_one_point_eye(struct board *board, coord_t *c, enum stone eye_color);
 288 /* Returns color of a 1pt eye owner, S_NONE if not an eye. */
 289 enum stone board_get_one_point_eye(struct board *board, coord_t *c);
 290
 291 /* board_official_score() is the scoring method for yielding score suitable
 292  * for external presentation. For fast scoring of entirely filled boards
 293  * (e.g. playouts), use board_fast_score(). */
 294 /* Positive: W wins */
 295 /* Compare number of stones + 1pt eyes. */
 296 float board_fast_score(struct board *board);
 297 /* Tromp-Taylor scoring, assuming given groups are actually dead. */
 298 struct move_queue;
 299 float board_official_score(struct board *board, struct move_queue *mq);
 300
 301 /** Iterators */
 302
 303 #define foreach_point(board_) \
 304         do { \
 305                 coord_t c; coord_pos(c, 0, (board_)); \
 306                 for (; coord_raw(c) < board_size(board_) * board_size(board_); coord_raw(c)++)
 307 #define foreach_point_and_pass(board_) \
 308         do { \
 309                 coord_t c; coord_pos(c, -1, (board_)); \
 310                 for (; coord_raw(c) < board_size(board_) * board_size(board_); coord_raw(c)++)
 311 #define foreach_point_end \
 312         } while (0)
 313
 314 #define foreach_in_group(board_, group_) \
 315         do { \
 316                 struct board *board__ = board_; \
 317                 coord_t c = group_base(group_); \
 318                 coord_t c2 = c; coord_raw(c2) = groupnext_at(board__, c2); \
 319                 do {
 320 #define foreach_in_group_end \
 321                         c = c2; coord_raw(c2) = groupnext_at(board__, c2); \
 322                 } while (coord_raw(c) != 0); \
 323         } while (0)
 324
 325 /* NOT VALID inside of foreach_point() or another foreach_neighbor(), or rather
 326  * on S_OFFBOARD coordinates. */
 327 #define foreach_neighbor(board_, coord_, loop_body) \
 328         do { \
 329                 struct board *board__ = board_; \
 330                 coord_t coord__ = coord_; \
 331                 coord_t c; \
 332                 coord_pos(c, coord_raw(coord__) - 1, (board__)); do { loop_body } while (0); \
 333                 coord_pos(c, coord_raw(coord__) - board_size(board__), (board__)); do { loop_body } while (0); \
 334                 coord_pos(c, coord_raw(coord__) + 1, (board__)); do { loop_body } while (0); \
 335                 coord_pos(c, coord_raw(coord__) + board_size(board__), (board__)); do { loop_body } while (0); \
 336         } while (0)
 337
 338 #define foreach_8neighbor(board_, coord_) \
 339         do { \
 340                 int fn__i; \
 341                 coord_t c = (coord_); \
 342                 for (fn__i = 0; fn__i < 8; fn__i++) { \
 343                         c += (board_)->nei8[fn__i];
 344 #define foreach_8neighbor_end \
 345                 } \
 346         } while (0)
 347
 348 #define foreach_diag_neighbor(board_, coord_) \
 349         do { \
 350                 int fn__i; \
 351                 coord_t c = (coord_); \
 352                 for (fn__i = 0; fn__i < 4; fn__i++) { \
 353                         c += (board_)->dnei[fn__i];
 354 #define foreach_diag_neighbor_end \
 355                 } \
 356         } while (0)
 357
 358
 359 static inline bool
 360 board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color)
 361 {
 362         return (neighbor_count_at(board, *coord, eye_color)
 363                 + neighbor_count_at(board, *coord, S_OFFBOARD)) == 4;
 364 }
 365
 366 static inline bool
 367 board_is_valid_move(struct board *board, struct move *m)
 368 {
 369         if (board_at(board, m->coord) != S_NONE)
 370                 return false;
 371         if (!board_is_eyelike(board, &m->coord, stone_other(m->color)))
 372                 return true;
 373         /* Play within {true,false} eye-ish formation */
 374         if (board->ko.coord == m->coord && board->ko.color == m->color)
 375                 return false;
 376         int groups_in_atari = 0;
 377         foreach_neighbor(board, m->coord, {
 378                 group_t g = group_at(board, c);
 379                 groups_in_atari += (board_group_info(board, g).libs == 1);
 380         });
 381         return !!groups_in_atari;
 382 }
 383
 384 static inline bool
 385 board_playing_ko_threat(struct board *b)
 386 {
 387         return !is_pass(b->ko.coord);
 388 }
 389
 390 static inline group_t
 391 board_get_atari_neighbor(struct board *b, coord_t coord, enum stone group_color)
 392 {
 393 #ifdef BOARD_TRAITS
 394         if (!trait_at(b, coord, stone_other(group_color)).cap) return 0;
 395 #endif
 396         foreach_neighbor(b, coord, {
 397                 group_t g = group_at(b, c);
 398                 if (g && board_at(b, c) == group_color && board_group_info(b, g).libs == 1)
 399                         return g;
 400                 /* We return first match. */
 401         });
 402         return 0;
 403 }
 404
 405 #endif