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         /* _Combination_ of these two values can make some difference
  36          * in performance - fine-tune. */
  37 #define GROUP_KEEP_LIBS 10
  38         // refill lib[] only when we hit this; this must be at least 2!
  39         // Moggy requires at least 3 - see below for semantic impact.
  40 #define GROUP_REFILL_LIBS 5
  41         coord_t lib[GROUP_KEEP_LIBS];
  42         /* libs is only LOWER BOUND for the number of real liberties!!!
  43          * It denotes only number of items in lib[], thus you can rely
  44          * on it to store real liberties only up to <= GROUP_REFILL_LIBS. */
  45         int libs;
  46 };
  47
  48 struct neighbor_colors {
  49         char colors[S_MAX];
  50 };
  51
  52 /* You should treat this struct as read-only. Always call functions below if
  53  * you want to change it. */
  54
  55 struct board {
  56         int size; /* Including S_OFFBOARD margin - see below. */
  57         int size2; /* size^2 */
  58         int captures[S_MAX];
  59         float komi;
  60         int handicap;
  61
  62         int moves;
  63         struct move last_move;
  64         /* Whether we tried to add a hash twice; board_play*() can
  65          * set this, but it will still carry out the move as well! */
  66         bool superko_violation;
  67
  68         /* The following two structures are goban maps and are indexed by
  69          * coord.pos. The map is surrounded by a one-point margin from
  70          * S_OFFBOARD stones in order to speed up some internal loops.
  71          * Some of the foreach iterators below might include these points;
  72          * you need to handle them yourselves, if you need to. */
  73
  74         /* Stones played on the board */
  75         enum stone *b; /* enum stone */
  76         /* Group id the stones are part of; 0 == no group */
  77         group_t *g;
  78         /* Positions of next stones in the stone group; 0 == last stone */
  79         coord_t *p;
  80         /* Neighboring colors; numbers of neighbors of index color */
  81         struct neighbor_colors *n;
  82         /* Zobrist hash for each position */
  83         hash_t *h;
  84
  85         /* Group information - indexed by gid (which is coord of base group stone) */
  86         struct group *gi;
  87
  88         /* Positions of free positions - queue (not map) */
  89         /* Note that free position here is any valid move; including single-point eyes! */
  90         coord_t *f; int flen;
  91
  92 #ifdef WANT_BOARD_C
  93         /* Queue of capturable groups */
  94         group_t *c; int clen;
  95 #endif
  96
  97
  98         /* --- PRIVATE DATA --- */
  99
 100         /* Basic ko check */
 101         struct move ko;
 102
 103         /* For superko check: */
 104
 105         /* Board "history" - hashes encountered. Size of the hash should be
 106          * >> board_size^2. */
 107 #define history_hash_bits 12
 108 #define history_hash_mask ((1 << history_hash_bits) - 1)
 109 #define history_hash_prev(i) ((i - 1) & history_hash_mask)
 110 #define history_hash_next(i) ((i + 1) & history_hash_mask)
 111         hash_t history_hash[1 << history_hash_bits];
 112         /* Hash of current board position. */
 113         hash_t hash;
 114 };
 115
 116 #ifdef BOARD_SIZE
 117 /* Avoid unused variable warnings */
 118 #define board_size(b_) (((b_) == (b_)) ? BOARD_SIZE + 2 : 0)
 119 #define board_size2(b_) (board_size(b_) * board_size(b_))
 120 #else
 121 #define board_size(b_) ((b_)->size)
 122 #define board_size2(b_) ((b_)->size2)
 123 #endif
 124
 125 #define board_at(b_, c) ((b_)->b[coord_raw(c)])
 126 #define board_atxy(b_, x, y) ((b_)->b[(x) + board_size(b_) * (y)])
 127
 128 #define group_at(b_, c) ((b_)->g[coord_raw(c)])
 129 #define group_atxy(b_, x, y) ((b_)->g[(x) + board_size(b_) * (y)])
 130
 131 #define neighbor_count_at(b_, coord, color) ((b_)->n[coord_raw(coord)].colors[(enum stone) color])
 132 #define set_neighbor_count_at(b_, coord, color, count) (neighbor_count_at(b_, coord, color) = (count))
 133 #define inc_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)++)
 134 #define dec_neighbor_count_at(b_, coord, color) (neighbor_count_at(b_, coord, color)--)
 135 #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))
 136
 137 #define groupnext_at(b_, c) ((b_)->p[coord_raw(c)])
 138 #define groupnext_atxy(b_, x, y) ((b_)->p[(x) + board_size(b_) * (y)])
 139
 140 #define group_base(g_) (g_)
 141 #define board_group_info(b_, g_) ((b_)->gi[(g_)])
 142 #define board_group_captured(b_, g_) (board_group_info(b_, g_).libs == 0)
 143
 144 #define hash_at(b_, coord, color) (b_)->h[((color) == S_BLACK ? board_size2(b_) : 0) + coord_raw(coord)]
 145
 146 struct board *board_init(void);
 147 struct board *board_copy(struct board *board2, struct board *board1);
 148 void board_done_noalloc(struct board *board);
 149 void board_done(struct board *board);
 150 /* size here is without the S_OFFBOARD margin. */
 151 void board_resize(struct board *board, int size);
 152 void board_clear(struct board *board);
 153
 154 struct FILE;
 155 void board_print(struct board *board, FILE *f);
 156
 157 /* Place given handicap on the board; coordinates are printed to f. */
 158 void board_handicap(struct board *board, int stones, FILE *f);
 159
 160 /* Returns group id, 0 on allowed suicide, pass or resign, -1 on error */
 161 int board_play(struct board *board, struct move *m);
 162 /* Like above, but plays random move; the move coordinate is recorded
 163  * to *coord. This method will never fill your own eye. pass is played
 164  * when no move can be played. */
 165 void board_play_random(struct board *b, enum stone color, coord_t *coord);
 166
 167 /* Returns true if given coordinate has all neighbors of given color or the edge. */
 168 bool board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color);
 169 /* Returns true if given coordinate is a 1-pt eye (checks against false eyes, or
 170  * at least tries to). */
 171 bool board_is_one_point_eye(struct board *board, coord_t *c, enum stone eye_color);
 172 /* Returns color of a 1pt eye owner, S_NONE if not an eye. */
 173 enum stone board_get_one_point_eye(struct board *board, coord_t *c);
 174
 175 /* Check if group is in atari. This is very fast.
 176  * The last liberty is recorded to lastlib (content is undefined if group
 177  * is not in atari). */
 178 bool board_group_in_atari(struct board *board, group_t group, coord_t *lastlib);
 179
 180 /* Check if group can be put in atari. This is also very fast.
 181  * The last two liberties are recorded to lastlib (content is undefined if group
 182  * can't be put in atari). */
 183 bool board_group_can_atari(struct board *board, group_t group, coord_t lastlib[2]);
 184
 185 /* board_official_score() is the scoring method for yielding score suitable
 186  * for external presentation. For fast scoring of entirely filled boards
 187  * (e.g. playouts), use board_fast_score(). */
 188 /* Positive: W wins */
 189 /* Tromp-Taylor scoring. */
 190 float board_official_score(struct board *board);
 191 /* Compare number of stones + 1pt eyes. */
 192 float board_fast_score(struct board *board);
 193
 194 /* Assess if it is desirable to pull out from atari
 195  * by this move. */
 196 bool valid_escape_route(struct board *b, enum stone color, coord_t to);
 197
 198 /* Checks if there are any stones in n-vincinity of coord. */
 199 bool board_stone_radar(struct board *b, coord_t coord, int distance);
 200
 201
 202 /** Iterators */
 203
 204 #define foreach_point(board_) \
 205         do { \
 206                 coord_t c; coord_pos(c, 0, (board_)); \
 207                 for (; coord_raw(c) < board_size(board_) * board_size(board_); coord_raw(c)++)
 208 #define foreach_point_end \
 209         } while (0)
 210
 211 #define foreach_in_group(board_, group_) \
 212         do { \
 213                 struct board *board__ = board_; \
 214                 coord_t c = group_base(group_); \
 215                 coord_t c2 = c; coord_raw(c2) = groupnext_at(board__, c2); \
 216                 do {
 217 #define foreach_in_group_end \
 218                         c = c2; coord_raw(c2) = groupnext_at(board__, c2); \
 219                 } while (coord_raw(c) != 0); \
 220         } while (0)
 221
 222 /* NOT VALID inside of foreach_point() or another foreach_neighbor(), or rather
 223  * on S_OFFBOARD coordinates. */
 224 #define foreach_neighbor(board_, coord_, loop_body) \
 225         do { \
 226                 struct board *board__ = board_; \
 227                 coord_t coord__ = coord_; \
 228                 coord_t c; \
 229                 coord_pos(c, coord_raw(coord__) - 1, (board__)); do { loop_body } while (0); \
 230                 coord_pos(c, coord_raw(coord__) - board_size(board__), (board__)); do { loop_body } while (0); \
 231                 coord_pos(c, coord_raw(coord__) + 1, (board__)); do { loop_body } while (0); \
 232                 coord_pos(c, coord_raw(coord__) + board_size(board__), (board__)); do { loop_body } while (0); \
 233         } while (0)
 234
 235 #define foreach_diag_neighbor(board_, coord_) \
 236         do { \
 237                 coord_t q__[4]; int q__i = 0; \
 238                 coord_pos(q__[q__i++], coord_raw(coord_) - board_size(board_) - 1, (board_)); \
 239                 coord_pos(q__[q__i++], coord_raw(coord_) - board_size(board_) + 1, (board_)); \
 240                 coord_pos(q__[q__i++], coord_raw(coord_) + board_size(board_) - 1, (board_)); \
 241                 coord_pos(q__[q__i++], coord_raw(coord_) + board_size(board_) + 1, (board_)); \
 242                 int fn__i; \
 243                 for (fn__i = 0; fn__i < q__i; fn__i++) { \
 244                         coord_t c = q__[fn__i];
 245 #define foreach_diag_neighbor_end \
 246                 } \
 247         } while (0)
 248
 249
 250 #endif