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