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