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