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         if (amafmap)
  25                 amafmap->color = color;
  26
  27         int passes = is_pass(b->last_move.coord);
  28
  29         while (gamelen-- && passes < 2) {
  30                 urgent = policy->choose(policy, b, policy_color);
  31
  32                 coord_t coord;
  33
  34                 if (!is_pass(urgent)) {
  35                         struct move m;
  36                         m.coord = urgent; m.color = color;
  37                         if (board_play(b, &m) < 0) {
  38                                 if (DEBUGL(8)) {
  39                                         fprintf(stderr, "Urgent move %d,%d is ILLEGAL:\n", coord_x(urgent, b), coord_y(urgent, b));
  40                                         board_print(b, stderr);
  41                                 }
  42                                 goto play_random;
  43                         }
  44                         coord = urgent;
  45                 } else {
  46 play_random:
  47                         board_play_random(b, color, &coord);
  48                 }
  49
  50 #if 0
  51                 /* For UCT, superko test here is downright harmful since
  52                  * in superko-likely situation we throw away literarily
  53                  * 95% of our playouts; UCT will deal with this fine by
  54                  * itself. */
  55                 if (unlikely(b->superko_violation)) {
  56                         /* We ignore superko violations that are suicides. These
  57                          * are common only at the end of the game and are
  58                          * rather harmless. (They will not go through as a root
  59                          * move anyway.) */
  60                         if (group_at(b, coord)) {
  61                                 if (DEBUGL(3)) {
  62                                         fprintf(stderr, "Superko fun at %d,%d in\n", coord_x(coord, b), coord_y(coord, b));
  63                                         if (DEBUGL(4))
  64                                                 board_print(b, stderr);
  65                                 }
  66                                 return -1;
  67                         } else {
  68                                 if (DEBUGL(6)) {
  69                                         fprintf(stderr, "Ignoring superko at %d,%d in\n", coord_x(coord, b), coord_y(coord, b));
  70                                         board_print(b, stderr);
  71                                 }
  72                                 b->superko_violation = false;
  73                         }
  74                 }
  75 #endif
  76
  77                 if (DEBUGL(8)) {
  78                         char *cs = coord2str(coord, b);
  79                         fprintf(stderr, "%s %s\n", stone2str(color), cs);
  80                         free(cs);
  81                 }
  82
  83                 if (amafmap && amafmap->map[coord] == S_NONE)
  84                         amafmap->map[coord] = color;
  85
  86                 if (unlikely(is_pass(coord))) {
  87                         passes++;
  88                 } else {
  89                         passes = 0;
  90                 }
  91
  92                 color = stone_other(color);
  93         }
  94
  95         float score = board_fast_score(b);
  96         bool result = (starting_color == S_WHITE ? (score > 0) : (score < 0));
  97
  98         if (DEBUGL(6)) {
  99                 fprintf(stderr, "Random playout result: %d (W %f)\n", result, score);
 100                 if (DEBUGL(7))
 101                         board_print(b, stderr);
 102         }
 103
 104         return result;
 105 }