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