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