board.h

   1 #ifndef ZZGO_BOARD_H
   2 #define ZZGO_BOARD_H
   3
   4 #include <stdbool.h>
   5 #include <stdint.h>
   6
   7 #include "stone.h"
   8 #include "move.h"
   9
  10 #define likely(x) __builtin_expect(!!(x), 1)
  11 #define unlikely(x) __builtin_expect((x), 0)
  12
  13
  14 /* The board implementation has bunch of optional features.
  15  * Turn them on below: */
  16 #define WANT_BOARD_C // required by playout_moggy
  17 //#define BOARD_SIZE 9 // constant board size, allows better optimization
  18
  19
  20 /* Allow board_play_random_move() to return pass even when
  21  * there are other moves available. */
  22 extern bool random_pass;
  23
  24
  25 typedef uint64_t hash_t;
  26
  27
  28 /* Note that "group" is only chain of stones that is solidly
  29  * connected for us. */
  30 typedef coord_t group_t;
  31
  32 struct group {
  33         /* We keep track of only up to GROUP_KEEP_LIBS; over that, we
  34          * don't care. */
  35 #define GROUP_KEEP_LIBS 4 // +1 can make noticeable speed difference
  36 #define GROUP_REFILL_LIBS 2 // refill lib[] when we go under this; this must be at least 2!
  37         coord_t lib[GROUP_KEEP_LIBS];
  38         /* libs is only LOWER BOUND for the number of real liberties!!!
  39          * It denotes only number of items in lib[], thus you can rely
  40          * on it to store real liberties only up to <= GROUP_REFILL_LIBS. */
  41         int libs;
  42 };
  43
  44 struct neighbor_colors {
  45         char colors[S_MAX];
  46 };
  47
  48 /* You should treat this struct as read-only. Always call functions below if
  49  * you want to change it. */
  50
  51 struct board {
  52         int size; /* Including S_OFFBOARD margin - see below. */
  53         int size2; /* size^2 */
  54         int captures[S_MAX];
  55         float komi;
  56         int handicap;
  57
  58         int moves;
  59         struct move last_move;
  60         /* Whether we tried to add a hash twice; board_play*() can
  61          * set this, but it will still carry out the move as well! */
  62         bool superko_violation;
  63
  64         /* The following two structures are goban maps and are indexed by
  65          * coord.pos. The map is surrounded by a one-point margin from
  66          * S_OFFBOARD stones in order to speed up some internal loops.
  67          * Some of the foreach iterators below might include these points;
  68          * you need to handle them yourselves, if you need to. */
  69
  70         /* Stones played on the board */
  71         enum stone *b; /* enum stone */
  72         /* Group id the stones are part of; 0 == no group */
  73         group_t *g;
  74         /* Positions of next stones in the stone group; 0 == last stone */
  75         coord_t *p;
  76         /* Neighboring colors; numbers of neighbors of index color */
  77         struct neighbor_colors *n;
  78         /* Zobrist hash for each position */
  79         hash_t *h;
  80
  81         /* Group information - indexed by gid (which is coord of base group stone) */
  82         struct group *gi;
  83
  84         /* Positions of free positions - queue (not map) */
  85         /* Note that free position here is any valid move; including single-point eyes! */
  86         coord_t *f; int flen;
  87
  88 #ifdef WANT_BOARD_C
  89         /* Queue of capturable groups */
  90         group_t *c; int clen;
  91 #endif
  92
  93
  94         /* --- PRIVATE DATA --- */
  95
  96         /* Basic ko check */
  97         struct move ko;
  98
  99         /* For superko check: */
 100
 101         /* Board "history" - hashes encountered. Size of the hash should be
 102          * >> board_size^2. */
 103 #define history_hash_bits 12
 104 #define history_hash_mask ((1 << history_hash_bits) - 1)
 105 #define history_hash_prev(i) ((i - 1) & history_hash_mask)
 106 #define history_hash_next(i) ((i + 1) & history_hash_mask)
 107         hash_t history_hash[1 << history_hash_bits];
 108         /* Hash of current board position. */
 109         hash_t hash;
 110 };
 111
 112 #ifdef BOARD_SIZE
 113 /* Avoid unused variable warnings */
 114 #define board_size(b_) (((b_) == (b_)) ? BOARD_SIZE + 2 : 0)
 115 #define board_size2(b_) (board_size(b_) * board_size(b_))
 116 #else
 117 #define board_size(b_) ((b_)->size)
 118 #define board_size2(b_) ((b_)->size2)
 119 #endif
 120
 121 #define board_at(b_, c) ((b_)->b[coord_raw(c)])
 122 #define board_atxy(b_, x, y) ((b_)->b[(x) + board_size(b_) * (y)])
 123
 124 #define group_at(b_, c) ((b_)->g[coord_raw(c)])
 125 #define group_atxy(b_, x, y) ((b_)->g[(x) + board_size(b_) * (y)])
 126
 127 #define neighbor_count_at(b_, coord, color) ((b_)->n[coord_raw(coord)].colors[(enum stone) color])
 128 #define set_neighbor_count_at(b_, coord, color, count) (neighbor_count_at(b_, coord, color) = (count))
 129 #define inc_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)++)
 130 #define dec_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)--)
 131 #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))
 132
 133 #define groupnext_at(b_, c) ((b_)->p[coord_raw(c)])
 134 #define groupnext_atxy(b_, x, y) ((b_)->p[(x) + board_size(b_) * (y)])
 135
 136 #define group_base(g_) (g_)
 137 #define board_group_info(b_, g_) ((b_)->gi[(g_)])
 138 #define board_group_captured(b_, g_) (board_group_info(b_, g_).libs == 0)
 139
 140 #define hash_at(b_, coord, color) (b_)->h[((color) == S_BLACK ? board_size2(b_) : 0) + coord_raw(coord)]
 141
 142 struct board *board_init(void);
 143 struct board *board_copy(struct board *board2, struct board *board1);
 144 void board_done_noalloc(struct board *board);
 145 void board_done(struct board *board);
 146 /* size here is without the S_OFFBOARD margin. */
 147 void board_resize(struct board *board, int size);
 148 void board_clear(struct board *board);
 149
 150 struct FILE;
 151 void board_print(struct board *board, FILE *f);
 152
 153 /* Place given handicap on the board; coordinates are printed to f. */
 154 void board_handicap(struct board *board, int stones, FILE *f);
 155
 156 /* Returns group id, 0 on allowed suicide, pass or resign, -1 on error */
 157 int board_play(struct board *board, struct move *m);
 158 /* Like above, but plays random move; the move coordinate is recorded
 159  * to *coord. This method will never fill your own eye. pass is played
 160  * when no move can be played. */
 161 void board_play_random(struct board *b, enum stone color, coord_t *coord);
 162
 163 /* Returns true if given coordinate has all neighbors of given color or the edge. */
 164 bool board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color);
 165 /* Returns true if given coordinate is a 1-pt eye (checks against false eyes, or
 166  * at least tries to). */
 167 bool board_is_one_point_eye(struct board *board, coord_t *c, enum stone eye_color);
 168 /* Returns color of a 1pt eye owner, S_NONE if not an eye. */
 169 enum stone board_get_one_point_eye(struct board *board, coord_t *c);
 170
 171 /* Check if group is in atari. This is very fast.
 172  * The last liberty is recorded to lastlib (content is undefined if group
 173  * is not in atari). */
 174 bool board_group_in_atari(struct board *board, group_t group, coord_t *lastlib);
 175
 176 /* Check if group can be put in atari. This is also very fast.
 177  * The last two liberties are recorded to lastlib (content is undefined if group
 178  * can't be put in atari). */
 179 bool board_group_can_atari(struct board *board, group_t group, coord_t lastlib[2]);
 180
 181 /* board_official_score() is the scoring method for yielding score suitable
 182  * for external presentation. For fast scoring of entirely filled boards
 183  * (e.g. playouts), use board_fast_score(). */
 184 /* Positive: W wins */
 185 /* Tromp-Taylor scoring. */
 186 float board_official_score(struct board *board);
 187 /* Compare number of stones + 1pt eyes. */
 188 float board_fast_score(struct board *board);
 189
 190 /* Assess if it is desirable to pull out from atari
 191  * by this move. */
 192 bool valid_escape_route(struct board *b, enum stone color, coord_t to);
 193
 194 /* Checks if there are any stones in n-vincinity of coord. */
 195 bool board_stone_radar(struct board *b, coord_t coord, int distance);
 196
 197
 198 /** Iterators */
 199
 200 #define foreach_point(board_) \
 201         do { \
 202                 coord_t c; coord_pos(c, 0, (board_)); \
 203                 for (; coord_raw(c) < board_size(board_) * board_size(board_); coord_raw(c)++)
 204 #define foreach_point_end \
 205         } while (0)
 206
 207 #define foreach_in_group(board_, group_) \
 208         do { \
 209                 struct board *board__ = board_; \
 210                 coord_t c = group_base(group_); \
 211                 coord_t c2 = c; coord_raw(c2) = groupnext_at(board__, c2); \
 212                 do {
 213 #define foreach_in_group_end \
 214                         c = c2; coord_raw(c2) = groupnext_at(board__, c2); \
 215                 } while (coord_raw(c) != 0); \
 216         } while (0)
 217
 218 /* NOT VALID inside of foreach_point() or another foreach_neighbor(), or rather
 219  * on S_OFFBOARD coordinates. */
 220 #define foreach_neighbor(board_, coord_, loop_body) \
 221         do { \
 222                 struct board *board__ = board_; \
 223                 coord_t coord__ = coord_; \
 224                 coord_t c; \
 225                 coord_pos(c, coord_raw(coord__) - 1, (board__)); do { loop_body } while (0); \
 226                 coord_pos(c, coord_raw(coord__) - board_size(board__), (board__)); do { loop_body } while (0); \
 227                 coord_pos(c, coord_raw(coord__) + 1, (board__)); do { loop_body } while (0); \
 228                 coord_pos(c, coord_raw(coord__) + board_size(board__), (board__)); do { loop_body } while (0); \
 229         } while (0)
 230
 231 #define foreach_diag_neighbor(board_, coord_) \
 232         do { \
 233                 coord_t q__[4]; int q__i = 0; \
 234                 coord_pos(q__[q__i++], coord_raw(coord_) - board_size(board_) - 1, (board_)); \
 235                 coord_pos(q__[q__i++], coord_raw(coord_) - board_size(board_) + 1, (board_)); \
 236                 coord_pos(q__[q__i++], coord_raw(coord_) + board_size(board_) - 1, (board_)); \
 237                 coord_pos(q__[q__i++], coord_raw(coord_) + board_size(board_) + 1, (board_)); \
 238                 int fn__i; \
 239                 for (fn__i = 0; fn__i < q__i; fn__i++) { \
 240                         coord_t c = q__[fn__i];
 241 #define foreach_diag_neighbor_end \
 242                 } \
 243         } while (0)
 244
 245
 246 #endif