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 };
  92
  93
  94 /* You should treat this struct as read-only. Always call functions below if
  95  * you want to change it. */
  96
  97 struct board {
  98         int size; /* Including S_OFFBOARD margin - see below. */
  99         int size2; /* size^2 */
 100         int captures[S_MAX];
 101         float komi;
 102         int handicap;
 103
 104         /* Iterator offsets for foreach_neighbor*() */
 105         int nei8[8], dnei[4];
 106
 107         int moves;
 108         struct move last_move;
 109         struct move last_move2; /* second-to-last move */
 110         /* Whether we tried to add a hash twice; board_play*() can
 111          * set this, but it will still carry out the move as well! */
 112         bool superko_violation;
 113
 114         /* The following two structures are goban maps and are indexed by
 115          * coord.pos. The map is surrounded by a one-point margin from
 116          * S_OFFBOARD stones in order to speed up some internal loops.
 117          * Some of the foreach iterators below might include these points;
 118          * you need to handle them yourselves, if you need to. */
 119
 120         /* Stones played on the board */
 121         enum stone *b; /* enum stone */
 122         /* Group id the stones are part of; 0 == no group */
 123         group_t *g;
 124         /* Positions of next stones in the stone group; 0 == last stone */
 125         coord_t *p;
 126         /* Neighboring colors; numbers of neighbors of index color */
 127         struct neighbor_colors *n;
 128         /* Zobrist hash for each position */
 129         hash_t *h;
 130 #ifdef BOARD_SPATHASH
 131         /* For spatial hashes, we use only 24 bits. */
 132         /* [0] is d==1, we don't keep hash for d==0. */
 133         /* We keep hashes for black-to-play ([][0]) and white-to-play
 134          * ([][1], reversed stone colors since we match all patterns as
 135          * black-to-play). */
 136         uint32_t (*spathash)[BOARD_SPATHASH_MAXD][2];
 137 #endif
 138 #ifdef BOARD_PAT3
 139         /* 3x3 pattern code for each position; see pattern3.h for encoding
 140          * specification. The information is only valid for empty points. */
 141         uint16_t *pat3;
 142 #endif
 143 #ifdef BOARD_TRAITS
 144         /* Incrementally matched point traits information, black-to-play
 145          * ([][0]) and white-to-play ([][1]). */
 146         /* The information is only valid for empty points. */
 147         struct btraits (*t)[2];
 148 #endif
 149
 150         /* Group information - indexed by gid (which is coord of base group stone) */
 151         struct group *gi;
 152
 153         /* Positions of free positions - queue (not map) */
 154         /* Note that free position here is any valid move; including single-point eyes! */
 155         coord_t *f; int flen;
 156
 157 #ifdef WANT_BOARD_C
 158         /* Queue of capturable groups */
 159         group_t *c; int clen;
 160 #endif
 161
 162         /* Symmetry information */
 163         struct board_symmetry symmetry;
 164
 165         /* Last ko played on the board. */
 166         struct move last_ko;
 167         int last_ko_age;
 168
 169         /* Basic ko check */
 170         struct move ko;
 171
 172         /* Engine-specific state; persistent through board development,
 173          * is reset only at clear_board. */
 174         void *es;
 175
 176         /* Playout-specific state; persistent through board development,
 177          * but its lifetime is maintained in play_random_game(); it should
 178          * not be set outside of it. */
 179         void *ps;
 180
 181
 182         /* --- PRIVATE DATA --- */
 183
 184         /* For superko check: */
 185
 186         /* Board "history" - hashes encountered. Size of the hash should be
 187          * >> board_size^2. */
 188 #define history_hash_bits 12
 189 #define history_hash_mask ((1 << history_hash_bits) - 1)
 190 #define history_hash_prev(i) ((i - 1) & history_hash_mask)
 191 #define history_hash_next(i) ((i + 1) & history_hash_mask)
 192         hash_t history_hash[1 << history_hash_bits];
 193         /* Hash of current board position. */
 194         hash_t hash;
 195 };
 196
 197 #ifdef BOARD_SIZE
 198 /* Avoid unused variable warnings */
 199 #define board_size(b_) (((b_) == (b_)) ? BOARD_SIZE + 2 : 0)
 200 #define board_size2(b_) (board_size(b_) * board_size(b_))
 201 #else
 202 #define board_size(b_) ((b_)->size)
 203 #define board_size2(b_) ((b_)->size2)
 204 #endif
 205
 206 #define board_at(b_, c) ((b_)->b[coord_raw(c)])
 207 #define board_atxy(b_, x, y) ((b_)->b[(x) + board_size(b_) * (y)])
 208
 209 #define group_at(b_, c) ((b_)->g[coord_raw(c)])
 210 #define group_atxy(b_, x, y) ((b_)->g[(x) + board_size(b_) * (y)])
 211
 212 /* Warning! Neighbor count is kept up-to-date for S_NONE! */
 213 #define neighbor_count_at(b_, coord, color) ((b_)->n[coord_raw(coord)].colors[(enum stone) color])
 214 #define set_neighbor_count_at(b_, coord, color, count) (neighbor_count_at(b_, coord, color) = (count))
 215 #define inc_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)++)
 216 #define dec_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)--)
 217 #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))
 218
 219 #define trait_at(b_, coord, color) (b_)->t[coord][(color) - 1]
 220
 221 #define groupnext_at(b_, c) ((b_)->p[coord_raw(c)])
 222 #define groupnext_atxy(b_, x, y) ((b_)->p[(x) + board_size(b_) * (y)])
 223
 224 #define group_base(g_) (g_)
 225 #define board_group_info(b_, g_) ((b_)->gi[(g_)])
 226 #define board_group_captured(b_, g_) (board_group_info(b_, g_).libs == 0)
 227 #define group_is_onestone(b_, g_) (groupnext_at(b_, group_base(g_)) == 0)
 228
 229 #define hash_at(b_, coord, color) ((b_)->h[((color) == S_BLACK ? board_size2(b_) : 0) + coord_raw(coord)])
 230
 231 struct board *board_init(void);
 232 struct board *board_copy(struct board *board2, struct board *board1);
 233 void board_done_noalloc(struct board *board);
 234 void board_done(struct board *board);
 235 /* size here is without the S_OFFBOARD margin. */
 236 void board_resize(struct board *board, int size);
 237 void board_clear(struct board *board);
 238
 239 struct FILE;
 240 typedef void (*board_cprint)(struct board *b, coord_t c, FILE *f);
 241 void board_print(struct board *board, FILE *f);
 242 void board_print_custom(struct board *board, FILE *f, board_cprint cprint);
 243
 244 /* Place given handicap on the board; coordinates are printed to f. */
 245 void board_handicap(struct board *board, int stones, FILE *f);
 246
 247 /* Returns group id, 0 on allowed suicide, pass or resign, -1 on error */
 248 int board_play(struct board *board, struct move *m);
 249 /* Like above, but plays random move; the move coordinate is recorded
 250  * to *coord. This method will never fill your own eye. pass is played
 251  * when no move can be played. You can impose extra restrictions if you
 252  * supply your own permit function. */
 253 typedef bool (*ppr_permit)(void *data, struct board *b, struct move *m);
 254 void board_play_random(struct board *b, enum stone color, coord_t *coord, ppr_permit permit, void *permit_data);
 255
 256 /* Returns true if given move can be played. */
 257 static bool board_is_valid_move(struct board *b, struct move *m);
 258 /* Returns true if ko was just taken. */
 259 static bool board_playing_ko_threat(struct board *b);
 260 /* Returns 0 or ID of neighboring group in atari. */
 261 static group_t board_get_atari_neighbor(struct board *b, coord_t coord, enum stone group_color);
 262
 263 /* Adjust symmetry information as if given coordinate has been played. */
 264 void board_symmetry_update(struct board *b, struct board_symmetry *symmetry, coord_t c);
 265
 266 /* Returns true if given coordinate has all neighbors of given color or the edge. */
 267 static bool board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color);
 268 /* Returns true if given coordinate could be a false eye; this check makes
 269  * sense only if you already know the coordinate is_eyelike(). */
 270 bool board_is_false_eyelike(struct board *board, coord_t *coord, enum stone eye_color);
 271 /* Returns true if given coordinate is a 1-pt eye (checks against false eyes, or
 272  * at least tries to). */
 273 bool board_is_one_point_eye(struct board *board, coord_t *c, enum stone eye_color);
 274 /* Returns color of a 1pt eye owner, S_NONE if not an eye. */
 275 enum stone board_get_one_point_eye(struct board *board, coord_t *c);
 276
 277 /* board_official_score() is the scoring method for yielding score suitable
 278  * for external presentation. For fast scoring of entirely filled boards
 279  * (e.g. playouts), use board_fast_score(). */
 280 /* Positive: W wins */
 281 /* Compare number of stones + 1pt eyes. */
 282 float board_fast_score(struct board *board);
 283 /* Tromp-Taylor scoring, assuming given groups are actually dead. */
 284 struct move_queue;
 285 float board_official_score(struct board *board, struct move_queue *mq);
 286
 287 /** Iterators */
 288
 289 #define foreach_point(board_) \
 290         do { \
 291                 coord_t c; coord_pos(c, 0, (board_)); \
 292                 for (; coord_raw(c) < board_size(board_) * board_size(board_); coord_raw(c)++)
 293 #define foreach_point_and_pass(board_) \
 294         do { \
 295                 coord_t c; coord_pos(c, -1, (board_)); \
 296                 for (; coord_raw(c) < board_size(board_) * board_size(board_); coord_raw(c)++)
 297 #define foreach_point_end \
 298         } while (0)
 299
 300 #define foreach_in_group(board_, group_) \
 301         do { \
 302                 struct board *board__ = board_; \
 303                 coord_t c = group_base(group_); \
 304                 coord_t c2 = c; coord_raw(c2) = groupnext_at(board__, c2); \
 305                 do {
 306 #define foreach_in_group_end \
 307                         c = c2; coord_raw(c2) = groupnext_at(board__, c2); \
 308                 } while (coord_raw(c) != 0); \
 309         } while (0)
 310
 311 /* NOT VALID inside of foreach_point() or another foreach_neighbor(), or rather
 312  * on S_OFFBOARD coordinates. */
 313 #define foreach_neighbor(board_, coord_, loop_body) \
 314         do { \
 315                 struct board *board__ = board_; \
 316                 coord_t coord__ = coord_; \
 317                 coord_t c; \
 318                 coord_pos(c, coord_raw(coord__) - 1, (board__)); do { loop_body } while (0); \
 319                 coord_pos(c, coord_raw(coord__) - board_size(board__), (board__)); do { loop_body } while (0); \
 320                 coord_pos(c, coord_raw(coord__) + 1, (board__)); do { loop_body } while (0); \
 321                 coord_pos(c, coord_raw(coord__) + board_size(board__), (board__)); do { loop_body } while (0); \
 322         } while (0)
 323
 324 #define foreach_8neighbor(board_, coord_) \
 325         do { \
 326                 int fn__i; \
 327                 coord_t c = (coord_); \
 328                 for (fn__i = 0; fn__i < 8; fn__i++) { \
 329                         c += (board_)->nei8[fn__i];
 330 #define foreach_8neighbor_end \
 331                 } \
 332         } while (0)
 333
 334 #define foreach_diag_neighbor(board_, coord_) \
 335         do { \
 336                 int fn__i; \
 337                 coord_t c = (coord_); \
 338                 for (fn__i = 0; fn__i < 4; fn__i++) { \
 339                         c += (board_)->dnei[fn__i];
 340 #define foreach_diag_neighbor_end \
 341                 } \
 342         } while (0)
 343
 344
 345 static inline bool
 346 board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color)
 347 {
 348         return (neighbor_count_at(board, *coord, eye_color)
 349                 + neighbor_count_at(board, *coord, S_OFFBOARD)) == 4;
 350 }
 351
 352 static inline bool
 353 board_is_valid_move(struct board *board, struct move *m)
 354 {
 355         if (board_at(board, m->coord) != S_NONE)
 356                 return false;
 357         if (!board_is_eyelike(board, &m->coord, stone_other(m->color)))
 358                 return true;
 359         /* Play within {true,false} eye-ish formation */
 360         if (board->ko.coord == m->coord && board->ko.color == m->color)
 361                 return false;
 362         int groups_in_atari = 0;
 363         foreach_neighbor(board, m->coord, {
 364                 group_t g = group_at(board, c);
 365                 groups_in_atari += (board_group_info(board, g).libs == 1);
 366         });
 367         return !!groups_in_atari;
 368 }
 369
 370 static inline bool
 371 board_playing_ko_threat(struct board *b)
 372 {
 373         return !is_pass(b->ko.coord);
 374 }
 375
 376 static inline group_t
 377 board_get_atari_neighbor(struct board *b, coord_t coord, enum stone group_color)
 378 {
 379 #ifdef BOARD_TRAITS
 380         if (!trait_at(b, coord, stone_other(group_color)).cap) return 0;
 381 #endif
 382         foreach_neighbor(b, coord, {
 383                 group_t g = group_at(b, c);
 384                 if (g && board_at(b, c) == group_color && board_group_info(b, g).libs == 1)
 385                         return g;
 386                 /* We return first match. */
 387         });
 388         return 0;
 389 }
 390
 391 #endif