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