playout.h

   1 #ifndef ZZGO_PLAYOUT_H
   2 #define ZZGO_PLAYOUT_H
   3
   4 struct board;
   5 struct move;
   6 enum stone;
   7
   8
   9 struct playout_policy;
  10 typedef coord_t (*playoutp_choose)(struct playout_policy *playout_policy, struct board *b, enum stone to_play);
  11 /* number of won (>0) or lost (<0) games to seed the node with (usually a proportion of @games);
  12  * can return 0 if policy has no opinion */
  13 typedef int (*playoutp_assess)(struct playout_policy *playout_policy, struct board *b, struct move *m, int games);
  14 typedef bool (*playoutp_permit)(struct playout_policy *playout_policy, struct board *b, struct move *m);
  15
  16 struct playout_policy {
  17         int debug_level;
  18         /* We call choose when we ask policy about next move.
  19          * We call assess when we ask policy about how good given move is.
  20          * We call permit when we ask policy if we can make a randomly chosen move. */
  21         playoutp_choose choose;
  22         playoutp_assess assess;
  23         playoutp_permit permit;
  24         void *data;
  25 };
  26
  27
  28 struct playout_amafmap {
  29         /* Record of the random playout - for each intersection:
  30          * S_NONE: This move was never played
  31          * S_BLACK: This move was played by black first
  32          * S_WHITE: This move was played by white first
  33          */
  34         enum stone *map; // [board_size2(b)]
  35
  36         /* the lowest &0xf is the enum stone, upper bits are nakade
  37          * counter - in case of nakade, we record only color of the
  38          * first stone played inside, but count further throwins
  39          * and ignore AMAF value after these. */
  40 #define amaf_nakade(item_) (item_ >> 8)
  41 #define amaf_op(item_, op_) do { \
  42                 int mi_ = item_; \
  43                 item_ = (mi_ & 0xf) | ((amaf_nakade(mi_) op_ 1) << 8); \
  44 } while (0)
  45
  46         /* Additionally, we keep record of the game so that we can
  47          * examine nakade moves; really going out of our way to
  48          * implement nakade AMAF properly turns out to be crucial
  49          * when reading some tactical positions in depth (even if
  50          * they are just one-stone-snapback). */
  51         struct move game[512];
  52         int gamelen;
  53         /* Our current position in the game sequence; in AMAF, we search
  54          * the range [game_baselen, gamelen]. */
  55         int game_baselen;
  56
  57         /* Whether to record the nakade moves (true) or just completely
  58          * ignore them (false; just the first color on the intersection
  59          * is stored in the map, nakade counter is not incremented; game
  60          * record is still kept). */
  61         bool record_nakade;
  62 };
  63
  64
  65 /* 1: starting_color wins, 0: starting_color loses
  66  * -1: superko inside the game tree */
  67 int play_random_game(struct board *b, enum stone starting_color, int gamelen, struct playout_amafmap *amafmap, struct playout_policy *policy);
  68
  69 #endif