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game.c
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game.c
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/*
File: game.c
Created: September 20, 1997
Modified: December 31, 2002
Author: Gunnar Andersson (gunnar@radagast.se)
Contents: All the routines needed to play a game.
*/
#include "porting.h"
#if !defined( _WIN32_WCE ) && !defined( __linux__ ) && !defined( __CYGWIN__ )
#include "dir.h"
#endif
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WIN32_WCE
#include <assert.h>
#include <time.h>
#endif
#include "bitboard.h"
#include "constant.h"
#include "display.h"
#include "end.h"
#include "error.h"
#include "eval.h"
#include "game.h"
#include "getcoeff.h"
#include "globals.h"
#include "hash.h"
#include "macros.h"
#include "midgame.h"
#include "moves.h"
#include "myrandom.h"
#include "osfbook.h"
#include "patterns.h"
#include "probcut.h"
#include "search.h"
#include "stable.h"
#include "texts.h"
#include "thordb.h"
#include "timer.h"
#include "unflip.h"
/* The pre-ordering depth used when guessing the opponent's move */
#define PONDER_DEPTH 8
/* The depth to abandon the book move and try to solve the position
in time control games. */
#define FORCE_BOOK_SOLVE 30
/* The somewhat arbitrary point where endgame typically commences
when Zebra is running on today's hardware */
#define TYPICAL_SOLVE 27
/* The recommended extra depth gained by switching to the endgame searcher;
i.e., use the endgame solver with n+ENDGAME_OFFSET empty instead of the
midgame module with depth n. */
#define ENDGAME_OFFSET 7 /* WAS: 4 */
/* Same as ENDGAME_OFFSET but forces a solve to begin */
#define ENDGAME_FORCE_OFFSET 3
/* Solve earlier for lopsided positions? */
#define ADAPTIVE_SOLVE_DEPTH FALSE
/* The depth where no time is to be gained by using the fact that
there is only one move available. */
#ifdef _WIN32_WCE
#define DISABLE_FORCED_MOVES 70
#else
#define DISABLE_FORCED_MOVES 60
#endif
/* The file to which compute_move() writes its status reports */
#define LOG_FILE_NAME "zebra.log"
/* The maximum length of any system path. */
#define MAX_PATH_LENGTH 2048
static const char *forced_opening = NULL;
static char log_file_path[MAX_PATH_LENGTH];
static double last_time_used;
static int max_depth_reached;
#ifdef _WIN32_WCE
static int use_log_file = FALSE;
#else
static int use_log_file = TRUE;
#endif
static int play_human_openings = TRUE;
static int play_thor_match_openings = TRUE;
static int game_evaluated_count;
static int komi = 0;
static int prefix_move = 0;
static int endgame_performed[3];
static EvaluatedMove evaluated_list[60];
/*
TOGGLE_STATUS_LOG
Enable/disable the use of logging all the output that the
text version of Zebra would output to the screen.
*/
void
toggle_status_log( int write_log ) {
use_log_file = write_log;
}
/*
GLOBAL_SETUP
Initialize the different sub-systems.
*/
void
global_setup( int use_random, int hash_bits ) {
FILE *log_file;
time_t timer;
/* Clear the log file. No error handling done. */
#ifdef __linux__
strcpy( log_file_path, LOG_FILE_NAME );
#else
char directory_buffer[MAX_PATH_LENGTH];
getcwd( directory_buffer, MAX_PATH_LENGTH );
if ( directory_buffer[strlen( directory_buffer ) - 1] == '\\' )
sprintf( log_file_path, "%s%s", directory_buffer, LOG_FILE_NAME );
else
sprintf( log_file_path, "%s\\%s", directory_buffer, LOG_FILE_NAME );
#endif
if ( use_log_file ) {
log_file = fopen( log_file_path, "w" );
if ( log_file != NULL ) {
time( &timer );
fprintf( log_file, "%s %s\n", LOG_TEXT, ctime( &timer ) );
fprintf( log_file, "%s %s %s\n", ENGINE_TEXT, __DATE__, __TIME__ );
fclose( log_file );
}
}
if ( use_random ) {
time( &timer );
my_srandom( timer );
}
else
my_srandom( 1 );
init_hash( hash_bits );
init_bitboard();
init_moves();
init_patterns();
init_coeffs();
init_timer();
init_probcut();
init_stable();
setup_search();
}
/*
GLOBAL_TERMINATE
Free all dynamically allocated memory.
*/
void
global_terminate( void ) {
free_hash();
clear_coeffs();
clear_osf();
}
/*
SETUP_GAME
Prepares the board.
*/
static void
setup_game( const char *file_name, int *side_to_move ) {
char buffer[65];
int i, j;
int pos, token;
FILE *stream;
for ( i = 0; i < 10; i++ )
for ( j = 0; j < 10; j++ ) {
pos = 10 * i + j;
if ( (i == 0) || (i == 9) || (j == 0) || (j == 9) )
board[pos] = OUTSIDE;
else
board[pos] = EMPTY;
}
if ( file_name == NULL ) {
board[45] = board[54] = BLACKSQ;
board[44] = board[55] = WHITESQ;
*side_to_move = BLACKSQ;
}
else {
stream = fopen( file_name, "r" );
if ( stream == NULL )
fatal_error( "%s '%s'\n", GAME_LOAD_ERROR, file_name );
fgets( buffer, 70, stream );
token = 0;
for ( i = 1; i <= 8; i++ )
for ( j = 1; j <= 8; j++ ) {
pos = 10 * i + j;
switch ( buffer[token] ) {
case '*':
case 'X':
board[pos] = BLACKSQ;
break;
case 'O':
case '0':
board[pos] = WHITESQ;
break;
case '-':
case '.':
break;
default:
#if TEXT_BASED
printf( "%s '%c' %s\n", BAD_CHARACTER_ERROR, buffer[pos],
GAME_FILE_TEXT);
#endif
break;
}
token++;
}
fgets( buffer, 10, stream );
if ( buffer[0] == 'B' )
*side_to_move = BLACKSQ;
else if ( buffer[0] == 'W' )
*side_to_move = WHITESQ;
else
fatal_error( "%s '%c' %s\n", BAD_CHARACTER_ERROR, buffer[0],
GAME_FILE_TEXT);
}
disks_played = disc_count( BLACKSQ ) + disc_count( WHITESQ ) - 4;
determine_hash_values( *side_to_move, board );
/* Make the game score look right */
if ( *side_to_move == BLACKSQ )
score_sheet_row = -1;
else {
black_moves[0] = PASS;
score_sheet_row = 0;
}
}
/*
GAME_INIT
Prepare the relevant data structures so that a game
can be played. The position is read from the file
specified by FILE_NAME.
*/
void
game_init( const char *file_name, int *side_to_move ) {
setup_game( file_name, side_to_move );
setup_search();
setup_midgame();
setup_end();
init_eval();
clear_ponder_times();
reset_counter( &total_nodes );
reset_counter( &total_evaluations );
init_flip_stack();
total_time = 0.0;
max_depth_reached = 0;
last_time_used = 0.0;
endgame_performed[BLACKSQ] = endgame_performed[WHITESQ] = FALSE;
}
/*
SET_KOMI
Set the endgame komi value.
*/
void
set_komi( int in_komi ) {
komi = in_komi;
}
/*
TOGGLE_HUMAN_OPENINGS
Specifies whether the Thor statistics should be queried for
openings moves before resorting to the usual opening book.
*/
void
toggle_human_openings( int toggle ) {
play_human_openings = toggle;
}
/*
TOGGLE_THOR_MATCH_OPENINGS
Specifies whether matching Thor games are used as opening book
before resorting to the usual opening book.
*/
void
toggle_thor_match_openings( int toggle ) {
play_thor_match_openings = toggle;
}
/*
SET_FORCED_OPENING
Specifies an opening line that Zebra is forced to follow when playing.
*/
void
set_forced_opening( const char *opening_str ) {
forced_opening = opening_str;
}
/*
PONDER_MOVE
Perform searches in response to the opponent's next move.
The results are not returned, but the hash table is filled
with useful scores and moves.
*/
void
ponder_move( int side_to_move, int book, int mid, int exact, int wld ) {
EvaluationType eval_info;
HashEntry entry;
double move_start_time, move_stop_time;
int i, j;
int this_move, hash_move;
int expect_count;
int stored_echo;
int best_pv_depth;
int expect_list[64];
int best_pv[61];
/* Disable all time control mechanisms as it's the opponent's
time we're using */
toggle_abort_check( FALSE );
toggle_midgame_abort_check( FALSE );
start_move( 0, 0, disc_count( BLACKSQ ) + disc_count( WHITESQ ) );
clear_ponder_times();
determine_hash_values( side_to_move, board );
reset_counter( &nodes );
/* Find the scores for the moves available to the opponent. */
hash_move = 0;
find_hash( &entry, ENDGAME_MODE );
if ( entry.draft != NO_HASH_MOVE )
hash_move = entry.move[0];
else {
find_hash( &entry, MIDGAME_MODE );
if ( entry.draft != NO_HASH_MOVE )
hash_move = entry.move[0];
}
stored_echo = echo;
echo = FALSE;
(void) compute_move( side_to_move, FALSE, 0, 0, FALSE, FALSE,
MIN( PONDER_DEPTH, mid ), 0, 0, FALSE, &eval_info );
echo = stored_echo;
/* Sort the opponents on the score and push the table move (if any)
to the front of the list */
if ( force_return )
expect_count = 0;
else {
sort_moves( move_count[disks_played] );
(void) float_move( hash_move, move_count[disks_played] );
expect_count = move_count[disks_played];
for ( i = 0; i < expect_count; i++ )
expect_list[i] = move_list[disks_played][i];
#if TEXT_BASED
printf( "%s=%d\n", HASH_MOVE_TEXT, hash_move );
for ( i = 0; i < expect_count; i++ ) {
printf( "%c%c %-6.2f ", TO_SQUARE( move_list[disks_played][i] ),
evals[disks_played][move_list[disks_played][i]] / 128.0 );
if ( (i % 7 == 6) || (i == expect_count - 1) )
puts( "" );
}
#endif
}
/* Go through the expected moves in order and prepare responses. */
best_pv_depth = 0;
for ( i = 0; !force_return && (i < expect_count); i++ ) {
move_start_time = get_real_timer();
set_ponder_move( expect_list[i] );
this_move = expect_list[i];
prefix_move = this_move;
(void) make_move( side_to_move, this_move, TRUE );
(void) compute_move( OPP( side_to_move ), FALSE, 0, 0, TRUE, FALSE,
mid, exact, wld, FALSE, &eval_info );
unmake_move( side_to_move, this_move );
clear_ponder_move();
move_stop_time = get_real_timer();
add_ponder_time( expect_list[i], move_stop_time - move_start_time );
ponder_depth[expect_list[i]] =
MAX( ponder_depth[expect_list[i]], max_depth_reached - 1 );
if ( (i == 0) && !force_return ) { /* Store the PV for the first move */
best_pv_depth = pv_depth[0];
for ( j = 0; j < pv_depth[0]; j++ )
best_pv[j] = pv[0][j];
}
}
/* Make sure the PV looks reasonable when leaving - either by
clearing it altogether or, preferrably, using the stored PV for
the first move if it is available. */
max_depth_reached++;
prefix_move = 0;
if ( best_pv_depth == 0 )
pv_depth[0] = 0;
else {
pv_depth[0] = best_pv_depth + 1;
pv[0][0] = expect_list[0];
for ( i = 0; i < best_pv_depth; i++ )
pv[0][i + 1] = best_pv[i];
}
/* Don't forget to enable the time control mechanisms when leaving */
toggle_abort_check( TRUE );
toggle_midgame_abort_check( TRUE );
}
/*
COMPARE_EVAL
Comparison function for two evals. Same return value conventions
as QuickSort.
*/
static int
compare_eval( EvaluationType e1, EvaluationType e2 ) {
if ( (e1.type == WLD_EVAL) || (e1.type == EXACT_EVAL) )
if ( e1.score > 0 )
e1.score += 100000;
if ( (e2.type == WLD_EVAL) || (e2.type == EXACT_EVAL) )
if ( e2.score > 0 )
e2.score += 100000;
return e1.score - e2.score;
}
/*
EXTENDED_COMPUTE_MOVE
This wrapper on top of compute_move() calculates the evaluation
of all moves available as opposed to upper bounds for all moves
except for the best.
*/
int
extended_compute_move( int side_to_move, int book_only,
int book, int mid, int exact, int wld ) {
int i, j;
int index;
int changed;
int this_move;
int disc_diff, corrected_diff;
int best_move, temp_move;
int best_score;
int best_pv_depth;
int stored_echo;
int shallow_eval;
int empties;
int current_mid, current_exact, current_wld;
int first_iteration;
int unsearched;
int unsearched_count;
int unsearched_move[61];
int best_pv[60];
unsigned int transform1[60], transform2[60];
CandidateMove book_move;
EvaluatedMove temp;
EvaluationType book_eval_info;
EvalResult res;
/* Disable all time control mechanisms and randomization */
toggle_abort_check( FALSE );
toggle_midgame_abort_check( FALSE );
toggle_perturbation_usage( FALSE );
start_move( 0, 0, disc_count( BLACKSQ ) + disc_count( WHITESQ ) );
clear_ponder_times();
determine_hash_values( side_to_move, board );
empties = 60 - disks_played;
best_move = 0;
game_evaluated_count = 0;
reset_counter( &nodes );
generate_all( side_to_move );
if ( book_only || book ) { /* Evaluations for database moves */
int flags = 0;
if ( empties <= exact )
flags = FULL_SOLVED;
else if ( empties <= wld )
flags = WLD_SOLVED;
fill_move_alternatives( side_to_move, flags );
game_evaluated_count = get_candidate_count();
for ( i = 0; i < game_evaluated_count; i++ ) {
int child_flags;
book_move = get_candidate( i );
evaluated_list[i].side_to_move = side_to_move;
evaluated_list[i].move = book_move.move;
evaluated_list[i].pv_depth = 1;
evaluated_list[i].pv[0] = book_move.move;
evaluated_list[i].eval =
create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
book_move.score, 0.0, 0, TRUE );
child_flags = book_move.flags & book_move.parent_flags;
if ( child_flags & (FULL_SOLVED | WLD_SOLVED) ) {
if ( child_flags & FULL_SOLVED )
evaluated_list[i].eval.type = EXACT_EVAL;
else
evaluated_list[i].eval.type = WLD_EVAL;
if ( book_move.score > 0 ) {
evaluated_list[i].eval.res = WON_POSITION;
/* Normalize the scores so that e.g. 33-31 becomes +256 */
evaluated_list[i].eval.score -= CONFIRMED_WIN;
evaluated_list[i].eval.score *= 128;
}
else if ( book_move.score == 0 )
evaluated_list[i].eval.res = DRAWN_POSITION;
else { /* score < 0 */
evaluated_list[i].eval.res = LOST_POSITION;
/* Normalize the scores so that e.g. 30-34 becomes -512 */
evaluated_list[i].eval.score += CONFIRMED_WIN;
evaluated_list[i].eval.score *= 128;
}
}
else
evaluated_list[i].eval.type = MIDGAME_EVAL;
}
}
if ( book_only ) { /* Only book moves are to be considered */
if ( game_evaluated_count > 0 ) {
best_move = get_book_move( side_to_move, FALSE, &book_eval_info );
set_current_eval( book_eval_info );
}
else {
pv_depth[0] = 0;
best_move = PASS;
book_eval_info = create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
0, 0.0, 0, FALSE );
set_current_eval( book_eval_info );
}
}
else { /* Make searches for moves not in the database */
int shallow_depth;
int empties = 60 - disks_played;
book = FALSE;
best_score = -INFINITE_EVAL;
if ( game_evaluated_count > 0 ) { /* Book PV available */
best_score = evaluated_list[0].eval.score;
best_move = evaluated_list[0].move;
}
negate_current_eval( TRUE );
/* Store the available moves, clear their evaluations and sort
them on shallow evaluation. */
if ( empties < 12 )
shallow_depth = 1;
else {
int max_depth = MAX( mid, MAX( exact, wld ) );
if ( max_depth >= 16 )
shallow_depth = 6;
else
shallow_depth = 4;
}
unsearched_count = 0;
for ( i = 0; i < move_count[disks_played]; i++ ) {
this_move = move_list[disks_played][i];
unsearched = TRUE;
for ( j = 0; j < game_evaluated_count; j++ )
if ( evaluated_list[j].move == this_move )
unsearched = FALSE;
if ( !unsearched )
continue;
unsearched_move[unsearched_count] = this_move;
unsearched_count++;
(void) make_move( side_to_move, this_move, TRUE );
if ( shallow_depth == 1 ) /* Compute move doesn't allow depth 0 */
shallow_eval = -static_evaluation( OPP( side_to_move ) );
else {
EvaluationType shallow_info;
(void) compute_move( OPP( side_to_move ), FALSE, 0, 0, FALSE, book,
shallow_depth - 1, 0, 0, TRUE, &shallow_info );
if ( shallow_info.type == PASS_EVAL ) {
/* Don't allow pass */
(void) compute_move( side_to_move, FALSE, 0, 0, FALSE, book,
shallow_depth - 1, 0, 0, TRUE, &shallow_info );
if ( shallow_info.type == PASS_EVAL ) { /* Game over */
disc_diff =
disc_count( side_to_move ) - disc_count( OPP( side_to_move ) );
if ( disc_diff > 0 )
corrected_diff = 64 - 2 * disc_count( OPP( side_to_move) );
else if ( disc_diff == 0 )
corrected_diff = 0;
else
corrected_diff = 2 * disc_count( side_to_move ) - 64;
shallow_eval = 128 * corrected_diff;
}
else
shallow_eval = shallow_info.score;
}
else /* Sign-correct the score produced */
shallow_eval = -shallow_info.score;
}
unmake_move( side_to_move, this_move );
evals[disks_played][this_move] = shallow_eval;
}
do {
changed = FALSE;
for ( i = 0; i < unsearched_count - 1; i++ )
if ( evals[disks_played][unsearched_move[i]] <
evals[disks_played][unsearched_move[i + 1]] ) {
temp_move = unsearched_move[i];
unsearched_move[i] = unsearched_move[i + 1];
unsearched_move[i + 1] = temp_move;
changed = TRUE;
}
} while ( changed );
/* Initialize the entire list as being empty */
for ( i = 0, index = game_evaluated_count; i < unsearched_count;
i++, index++ ) {
evaluated_list[index].side_to_move = side_to_move;
evaluated_list[index].move = unsearched_move[i];
evaluated_list[index].eval =
create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
0, 0.0, 0, FALSE );
evaluated_list[index].pv_depth = 1;
evaluated_list[index].pv[0] = unsearched_move[i];
if ( empties > MAX( wld, exact ) ) {
transform1[i] = abs( my_random() );
transform2[i] = abs( my_random() );
}
else {
transform1[i] = 0;
transform2[i] = 0;
}
}
stored_echo = echo;
echo = FALSE;
best_pv_depth = 0;
if ( mid == 1 ) { /* compute_move won't be called */
pv_depth[0] = 0;
piece_count[BLACKSQ][disks_played] = disc_count( BLACKSQ );
piece_count[WHITESQ][disks_played] = disc_count( WHITESQ );
}
/* Perform iterative deepening if the search depth is large enough */
#define ID_STEP 2
if ( exact > empties )
exact = empties;
if ( (exact < 12) || (empties > exact) )
current_exact = exact;
else
current_exact = (8 + (exact % 2)) - ID_STEP;
if ( wld > empties )
wld = empties;
if ( (wld < 14) || (empties > wld) )
current_wld = wld;
else
current_wld = (10 + (wld % 2)) - ID_STEP;
if ( ((empties == exact) || (empties == wld)) &&
(empties > 16) && (mid < empties - 12) )
mid = empties - 12;
if ( mid < 10 )
current_mid = mid;
else
current_mid = (6 + (mid % 2)) - ID_STEP;
first_iteration = TRUE;
do {
if ( current_mid < mid ) {
current_mid += ID_STEP;
/* Avoid performing deep midgame searches if the endgame
is reached anyway. */
if ( (empties <= wld) && (current_mid + 7 >= empties) ) {
current_wld = wld;
current_mid = mid;
}
if ( (empties <= exact) && (current_mid + 7 >= empties) ) {
current_exact = exact;
current_mid = mid;
}
}
else if ( current_wld < wld )
current_wld = wld;
else
current_exact = exact;
for ( i = 0; (i < unsearched_count) && !force_return; i++ ) {
EvaluationType this_eval;
this_move = unsearched_move[i];
/* Locate the current move in the list. This has to be done
because the moves might have been reordered during the
iterative deepening. */
index = 0;
while ( evaluated_list[index].move != this_move )
index++;
/* To avoid strange effects when browsing back and forth through
a game during the midgame, rehash the hash transformation masks
for each move unless the endgame is reached */
set_hash_transformation( transform1[i], transform2[i] );
/* Determine the score for the ith move */
prefix_move = this_move;
(void) make_move( side_to_move, this_move, TRUE );
if ( current_mid == 1 ) {
/* compute_move doesn't like 0-ply searches */
shallow_eval = static_evaluation( OPP( side_to_move ) );
this_eval =
create_eval_info( MIDGAME_EVAL, UNSOLVED_POSITION,
shallow_eval, 0.0, 0, FALSE );
}
else
(void) compute_move( OPP( side_to_move ), FALSE, 0, 0, FALSE, book,
current_mid - 1, current_exact - 1,
current_wld - 1, TRUE,
&this_eval );
if ( force_return ) { /* Clear eval and exit search immediately */
this_eval =
create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
0, 0.0, 0, FALSE );
unmake_move( side_to_move, this_move );
break;
}
if ( this_eval.type == PASS_EVAL ) {
/* Don't allow pass */
if ( current_mid == 1 ) {
/* compute_move doesn't like 0-ply searches */
shallow_eval = static_evaluation( side_to_move );
this_eval =
create_eval_info( MIDGAME_EVAL, UNSOLVED_POSITION,
shallow_eval, 0.0, 0, FALSE );
}
else
(void) compute_move( side_to_move, FALSE, 0, 0, FALSE, book,
current_mid - 1, current_exact - 1,
current_wld - 1, TRUE,
&this_eval );
if ( this_eval.type == PASS_EVAL ) { /* Game over */
disc_diff =
disc_count( side_to_move ) - disc_count( OPP( side_to_move ) );
if ( disc_diff > 0 ) {
corrected_diff = 64 - 2 * disc_count( OPP( side_to_move) );
res = WON_POSITION;
}
else if ( disc_diff == 0 ) {
corrected_diff = 0;
res = DRAWN_POSITION;
}
else {
corrected_diff = 2 * disc_count( side_to_move ) - 64;
res = LOST_POSITION;
}
this_eval =
create_eval_info( EXACT_EVAL, res, 128 * corrected_diff,
0.0, 60 - disks_played, FALSE );
}
}
else { /* Sign-correct the score produced */
this_eval.score =
-this_eval.score;
if ( this_eval.res == WON_POSITION )
this_eval.res = LOST_POSITION;
else if ( this_eval.res == LOST_POSITION )
this_eval.res = WON_POSITION;
}
if ( force_return )
break;
else
evaluated_list[index].eval = this_eval;
/* Store the PV corresponding to the move */
evaluated_list[index].pv_depth = pv_depth[0] + 1;
evaluated_list[index].pv[0] = this_move;
for ( j = 0; j < pv_depth[0]; j++ )
evaluated_list[index].pv[j + 1] = pv[0][j];
/* Store the PV corresponding to the best move */
if ( evaluated_list[index].eval.score > best_score ) {
best_score = evaluated_list[index].eval.score;
best_move = this_move;
best_pv_depth = pv_depth[0];
for ( j = 0; j < best_pv_depth; j++ )
best_pv[j] = pv[0][j];
}
unmake_move( side_to_move, this_move );
/* Sort the moves evaluated */
if ( first_iteration )
game_evaluated_count++;
if ( !force_return )
do {
changed = FALSE;
for ( j = 0; j < game_evaluated_count - 1; j++ )
if ( compare_eval( evaluated_list[j].eval,
evaluated_list[j + 1].eval ) < 0 ) {
changed = TRUE;
temp = evaluated_list[j];
evaluated_list[j] = evaluated_list[j + 1];
evaluated_list[j + 1] = temp;
}
} while ( changed );
}
first_iteration = FALSE;
/* Reorder the moves after each iteration. Each move is moved to
the front of the list, starting with the bad moves and ending
with the best move. This ensures that unsearched_move will be
sorted w.r.t. the order in evaluated_list. */
for ( i = game_evaluated_count - 1; i >= 0; i-- ) {
int this_move = evaluated_list[i].move;
j = 0;
while ( (j != unsearched_count) && (unsearched_move[j] != this_move) )
j++;
if ( j == unsearched_count ) /* Must be book move, skip */
continue;
/* Move the move to the front of the list. */
while ( j >= 1 ) {
unsearched_move[j] = unsearched_move[j - 1];
j--;
}
unsearched_move[0] = this_move;
}
} while ( !force_return &&
((current_mid != mid) ||
(current_exact != exact) || (current_wld != wld)) );
echo = stored_echo;
game_evaluated_count = move_count[disks_played];
/* Make sure that the PV and the score correspond to the best move */
pv_depth[0] = best_pv_depth + 1;
pv[0][0] = best_move;
for ( i = 0; i < best_pv_depth; i++ )
pv[0][i + 1] = best_pv[i];
negate_current_eval( FALSE );
if ( move_count[disks_played] > 0 )
set_current_eval( evaluated_list[0].eval );
}
/* Reset the hash transformation masks prior to leaving */
set_hash_transformation( 0, 0 );
/* Don't forget to enable the time control mechanisms when leaving */
toggle_abort_check( TRUE );
toggle_midgame_abort_check( TRUE );
toggle_perturbation_usage( TRUE );
max_depth_reached++;
prefix_move = 0;
return best_move;
}
/*
PERFORM_EXTENDED_SOLVE
Calculates exact score or WLD status for the move ACTUAL_MOVE as
well as for the best move in the position (if it is any other move).
*/
void
perform_extended_solve( int side_to_move, int actual_move,
int book, int exact_solve ) {
int i;
int mid, wld, exact;
int best_move;
int disc_diff, corrected_diff;
EvaluatedMove temp;
EvalResult res;
/* Disable all time control mechanisms */
toggle_abort_check( FALSE );
toggle_midgame_abort_check( FALSE );
toggle_perturbation_usage( FALSE );
start_move( 0, 0, disc_count( BLACKSQ ) + disc_count( WHITESQ ) );
clear_ponder_times();
determine_hash_values( side_to_move, board );
reset_counter( &nodes );
/* Set search depths that result in Zebra solving after a brief
midgame analysis */
mid = 60;
wld = 60;
if ( exact_solve )
exact = 60;
else
exact = 0;