playout.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4
   5 #include "board.h"
   6 #include "debug.h"
   7 #include "engine.h"
   8 #include "move.h"
   9 #include "playout.h"
  10
  11 int
  12 play_random_game(struct board *b, enum stone starting_color, int gamelen,
  13                  struct playout_amafmap *amafmap,
  14                  struct playout_policy *policy)
  15 {
  16         gamelen = gamelen - b->moves;
  17         if (gamelen < 10)
  18                 gamelen = 10;
  19
  20         enum stone color = starting_color;
  21         enum stone policy_color = stone_other(starting_color);
  22         coord_t urgent;
  23
  24         int passes = is_pass(b->last_move.coord);
  25
  26         while (gamelen-- && passes < 2) {
  27                 urgent = policy->choose(policy, b, policy_color);
  28
  29                 coord_t coord;
  30
  31                 if (!is_pass(urgent)) {
  32                         struct move m;
  33                         m.coord = urgent; m.color = color;
  34                         if (board_play(b, &m) < 0) {
  35                                 if (DEBUGL(8)) {
  36                                         fprintf(stderr, "Urgent move %d,%d is ILLEGAL:\n", coord_x(urgent, b), coord_y(urgent, b));
  37                                         board_print(b, stderr);
  38                                 }
  39                                 goto play_random;
  40                         }
  41                         coord = urgent;
  42                 } else {
  43 play_random:
  44                         board_play_random(b, color, &coord);
  45                 }
  46
  47 #if 0
  48                 /* For UCT, superko test here is downright harmful since
  49                  * in superko-likely situation we throw away literally
  50                  * 95% of our playouts; UCT will deal with this fine by
  51                  * itself. */
  52                 if (unlikely(b->superko_violation)) {
  53                         /* We ignore superko violations that are suicides. These
  54                          * are common only at the end of the game and are
  55                          * rather harmless. (They will not go through as a root
  56                          * move anyway.) */
  57                         if (group_at(b, coord)) {
  58                                 if (DEBUGL(3)) {
  59                                         fprintf(stderr, "Superko fun at %d,%d in\n", coord_x(coord, b), coord_y(coord, b));
  60                                         if (DEBUGL(4))
  61                                                 board_print(b, stderr);
  62                                 }
  63                                 return -1;
  64                         } else {
  65                                 if (DEBUGL(6)) {
  66                                         fprintf(stderr, "Ignoring superko at %d,%d in\n", coord_x(coord, b), coord_y(coord, b));
  67                                         board_print(b, stderr);
  68                                 }
  69                                 b->superko_violation = false;
  70                         }
  71                 }
  72 #endif
  73
  74                 if (DEBUGL(7)) {
  75                         fprintf(stderr, "%s %s\n", stone2str(color), coord2sstr(coord, b));
  76                         if (DEBUGL(8))
  77                                 board_print(b, stderr);
  78                 }
  79
  80                 if (unlikely(is_pass(coord))) {
  81                         passes++;
  82                 } else {
  83                         /* We don't care about nakade counters, since we want
  84                          * to avoid taking pre-nakade moves into account only
  85                          * if they happenned in the tree before nakade nodes;
  86                          * but this is always out of the tree. */
  87                         if (amafmap && amafmap->map[coord] == S_NONE)
  88                                 amafmap->map[coord] = color;
  89
  90                         passes = 0;
  91                 }
  92
  93                 color = stone_other(color);
  94         }
  95
  96         float score = board_fast_score(b);
  97         bool result = (starting_color == S_WHITE ? (score > 0) : (score < 0));
  98
  99         if (DEBUGL(6)) {
 100                 fprintf(stderr, "Random playout result: %d (W %f)\n", result, score);
 101                 if (DEBUGL(7))
 102                         board_print(b, stderr);
 103         }
 104
 105         return result;
 106 }