playout.c

   1 #define DEBUG
   2 #include <assert.h>
   3 #include <math.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "board.h"
   9 #include "debug.h"
  10 #include "engine.h"
  11 #include "move.h"
  12 #include "ownermap.h"
  13 #include "playout.h"
  14
  15
  16 int
  17 play_random_game(struct playout_setup *setup,
  18                  struct board *b, enum stone starting_color,
  19                  struct playout_amafmap *amafmap,
  20                  struct board_ownermap *ownermap,
  21                  struct playout_policy *policy)
  22 {
  23         assert(setup && policy);
  24
  25         int gamelen = setup->gamelen - b->moves;
  26         if (gamelen < 10)
  27                 gamelen = 10;
  28
  29         if (policy->setboard)
  30                 policy->setboard(policy, b);
  31
  32         enum stone color = starting_color;
  33
  34         int passes = is_pass(b->last_move.coord) && b->moves > 0;
  35
  36         while (gamelen-- && passes < 2) {
  37                 coord_t coord;
  38                 coord = policy->choose(policy, b, color);
  39
  40                 if (is_pass(coord)) {
  41 play_random:
  42                         /* Defer to uniformly random move choice. */
  43                         /* This must never happen if the policy is tracking
  44                          * internal board state, obviously. */
  45                         assert(!policy->setboard);
  46                         board_play_random(b, color, &coord, (ppr_permit) policy->permit, policy);
  47
  48                 } else {
  49                         struct move m;
  50                         m.coord = coord; m.color = color;
  51                         if (board_play(b, &m) < 0) {
  52                                 if (DEBUGL(4)) {
  53                                         fprintf(stderr, "Pre-picked move %d,%d is ILLEGAL:\n",
  54                                                 coord_x(coord, b), coord_y(coord, b));
  55                                         board_print(b, stderr);
  56                                 }
  57                                 goto play_random;
  58                         }
  59                 }
  60
  61 #if 0
  62                 /* For UCT, superko test here is downright harmful since
  63                  * in superko-likely situation we throw away literally
  64                  * 95% of our playouts; UCT will deal with this fine by
  65                  * itself. */
  66                 if (unlikely(b->superko_violation)) {
  67                         /* We ignore superko violations that are suicides. These
  68                          * are common only at the end of the game and are
  69                          * rather harmless. (They will not go through as a root
  70                          * move anyway.) */
  71                         if (group_at(b, coord)) {
  72                                 if (DEBUGL(3)) {
  73                                         fprintf(stderr, "Superko fun at %d,%d in\n", coord_x(coord, b), coord_y(coord, b));
  74                                         if (DEBUGL(4))
  75                                                 board_print(b, stderr);
  76                                 }
  77                                 return 0;
  78                         } else {
  79                                 if (DEBUGL(6)) {
  80                                         fprintf(stderr, "Ignoring superko at %d,%d in\n", coord_x(coord, b), coord_y(coord, b));
  81                                         board_print(b, stderr);
  82                                 }
  83                                 b->superko_violation = false;
  84                         }
  85                 }
  86 #endif
  87
  88                 if (DEBUGL(7)) {
  89                         fprintf(stderr, "%s %s\n", stone2str(color), coord2sstr(coord, b));
  90                         if (DEBUGL(8))
  91                                 board_print(b, stderr);
  92                 }
  93
  94                 if (unlikely(is_pass(coord))) {
  95                         passes++;
  96                 } else {
  97                         /* We don't care about nakade counters, since we want
  98                          * to avoid taking pre-nakade moves into account only
  99                          * if they happenned in the tree before nakade nodes;
 100                          * but this is always out of the tree. */
 101                         if (amafmap) {
 102                                 if (amafmap->map[coord] == S_NONE || amafmap->map[coord] == color)
 103                                         amafmap->map[coord] = color;
 104                                 else if (amafmap->record_nakade)
 105                                         amaf_op(amafmap->map[coord], +);
 106                                 amafmap->game[amafmap->gamelen].coord = coord;
 107                                 amafmap->game[amafmap->gamelen].color = color;
 108                                 amafmap->gamelen++;
 109                                 assert(amafmap->gamelen < sizeof(amafmap->game) / sizeof(amafmap->game[0]));
 110                         }
 111
 112                         passes = 0;
 113                 }
 114
 115                 if (setup->mercymin && abs(b->captures[S_BLACK] - b->captures[S_WHITE]) > setup->mercymin)
 116                         break;
 117
 118                 color = stone_other(color);
 119         }
 120
 121         float score = board_fast_score(b);
 122         int result = (starting_color == S_WHITE ? score * 2 : - (score * 2));
 123
 124         if (DEBUGL(6)) {
 125                 fprintf(stderr, "Random playout result: %d (W %f)\n", result, score);
 126                 if (DEBUGL(7))
 127                         board_print(b, stderr);
 128         }
 129
 130         if (ownermap)
 131                 board_ownermap_fill(ownermap, b);
 132
 133         if (b->ps)
 134                 free(b->ps);
 135
 136         return result;
 137 }