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