- // chessengine.cpp 
-   
- #include "common.h" 
-   
-   
- // global variables used in this module only 
- static wchar_t chessengine_path[MAX_PATH]; 
- static wchar_t chessengine_shellcommand[MAX_PATH]; 
- static wchar_t chessengineinitfile_pathname[MAX_PATH]; 
- static int current_obstinacy; 
- static int max_cores; 
- static bool is_hint_pending; 
- static bool should_initialize; 
- FILE *fpipe; 
-   
- // prototypes of local functions 
- static void PlayerEngine_Recv (player_t *player); 
- static void PlayerEngine_Send (player_t *player); 
- static wchar_t *Move_BuildString (boardmove_t *move); 
-   
-   
- bool PlayerEngine_Init (player_t *player) 
- { 
-    // this function starts a chess engine as a child process. This process's stdin and 
-    // stdout are redirected to the handles we give it, so that we may read/write to it. 
-   
-    engineprogram_t *program; 
-    wchar_t current_path[MAX_PATH]; 
-    wchar_t widechar_buffer[1024]; 
-    SYSTEM_INFO sysinfo; 
-    int attempt_index; 
-    int64_t exit_code; 
-    FILE *fp; 
-   
-    // reset stuff first 
-    player->wants_hint = false; 
-   
-    // quick access to engine program 
-    program = &options.engine.programs[options.engine.selected_program]; 
-   
-    // build the chess engine module path and pathname 
-    swprintf_s (chessengine_path, WCHAR_SIZEOF (chessengine_path), L"%s/engines/%s", app_path, program->folder); 
-    swprintf_s (chessengine_shellcommand, WCHAR_SIZEOF (chessengine_shellcommand), L"\"%s/%s\" %s", chessengine_path, program->executable_name, program->executable_arguments); 
-   
-    // start the engine behind a bidirectional I/O pipe 
-    GetCurrentDirectory (WCHAR_SIZEOF (current_path), current_path); // save current directory 
-    SetCurrentDirectory (chessengine_path); // temporarily set chess engine's startup directory as current directory 
-    fpipe = pipe_open (chessengine_shellcommand, L"r+"); 
-    SetCurrentDirectory (current_path); // restore current directory 
-    for (attempt_index = 0; attempt_index < 10; attempt_index++) 
-       if (!pipe_isalive (fpipe, &exit_code)) 
-          Sleep (100); // wait for the pipe to come to life, stop as soon as it's alive 
-       else 
-          break; // wait for the pipe to come to life 
-    if ((fpipe == NULL) || (attempt_index == 10)) 
-    { 
-       dont_nag = true; // remember NOT to nag the user if he experienced any bug 
-   
-       messagebox.hWndParent = hMainWnd; 
-       wcscpy_s (messagebox.title, WCHAR_SIZEOF (messagebox.title), LOCALIZE (L"ImportantMessage")); 
-       wcscpy_s (messagebox.text, WCHAR_SIZEOF (messagebox.text), LOCALIZE (L"Error_ChessEngineInitializationFailed")); 
-       messagebox.flags = MB_ICONWARNING | MB_OK; 
-       DialogBox_Message (&messagebox); // display a modeless error message box 
-   
-       PlayerEngine_Shutdown (player); // on error, shutdown the engine 
-       return (false); 
-    } 
-   
-    // SMP HACK -- save the max CPUs to use to core max - 1 (the computer will look like hung if all CPU is taken) 
-    GetSystemInfo (&sysinfo); // get the number of cores 
-    max_cores = max (1, sysinfo.dwNumberOfProcessors - 1); 
-   
-    // optionally initialize the debug log file 
-    Debug_Init (L"Chess engine output.txt"); 
-    Debug_Log (L"===Using engine: %s [%s]===\n", program->friendly_name, chessengine_shellcommand); 
-   
-    // build the init file full qualified path name and try to open it 
-    swprintf_s (chessengineinitfile_pathname, WCHAR_SIZEOF (chessengineinitfile_pathname), L"%s/engines/%s/init.txt", app_path, program->folder); 
-    _wfopen_s (&fp, chessengineinitfile_pathname, L"r"); 
-   
-    // could the init file be opened ? 
-    if (fp != NULL) 
-    { 
-       Debug_Log (L"===Found initialization file, parsing...===\n", chessengineinitfile_pathname); 
-   
-       // read line per line 
-       while (fgetws (widechar_buffer, WCHAR_SIZEOF (widechar_buffer), fp) != NULL) 
-       { 
-          if ((widechar_buffer[0] == L'#') || (widechar_buffer[0] == L'\n')) 
-             continue; // skip comments and empty lines 
-   
-          // new command line found, append it to the send buffer 
-          Player_SendBuffer_Add (player, 1000, widechar_buffer); 
-       } 
-   
-       fclose (fp); // finished, close the file 
-    } 
-   
-    // everything's okay, set engine name as the player's name 
-    wcscpy_s (player->name, WCHAR_SIZEOF (player->name), program->friendly_name); 
-   
-    should_initialize = true; // remember the engine should be initialized 
-    return (true); // finished 
- } 
-   
-   
- void PlayerEngine_Shutdown (player_t *player) 
- { 
-    // this function terminates the chess engine process and releases all handles attached to it 
-   
-    int attempt_index; 
-    int64_t exit_code; 
-   
-    // send the engine a quit command 
-    Player_SendBuffer_Add (player, 1000, options.engine.programs[options.engine.selected_program].command_quit); 
-    Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-    PlayerEngine_Send (player); 
-   
-    // check 10 times if the engine process has ended cleanly 
-    for (attempt_index = 0; attempt_index < 10; attempt_index++) 
-    { 
-       if (!pipe_isalive (fpipe, &exit_code)) 
-          break; // break as soon as we've told the process exited cleanly 
-   
-       Sleep (100); // else wait one tenth second 
-    } 
-   
-    // close the pipe (this will terminate the child process if it hasn't terminated yet) 
-    pipe_close (fpipe); 
-   
-    Debug_Log (L"===Engine closed===\n"); 
-    return; // finished 
- } 
-   
-   
- bool PlayerEngine_Think (player_t *player) 
- { 
-    // this function reads and writes any necessary data from and to the chess engine. Returns TRUE if scene needs to be updated. 
-   
-    engineprogram_t *program; 
-    wchar_t line_buffer[1024]; 
-    wchar_t *line_pointer; 
-    wchar_t *move_string; 
-    int64_t exit_code; 
-    int char_index; 
-    int length; 
-    boardmove_t move; 
-    player_t *current_player; 
-    player_t *opposite_player; 
-    bool do_update; 
-   
-    // quick access to chess engine program 
-    program = &options.engine.programs[options.engine.selected_program]; 
-   
-    // don't update the scene until told otherwise 
-    do_update = false; 
-   
-    // get current and opposite players 
-    current_player = Player_GetCurrent (); 
-    opposite_player = Player_GetOpposite (); 
-   
-    // is the game still alive AND has the engine just died ? 
-    if ((the_board.game_state == STATE_PLAYING) && !pipe_isalive (fpipe, &exit_code)) 
-    { 
-       Debug_Log (L"===Unrecoverable engine error (engine disappeared unexpectedly with exit code %lld [0x%08x]): opponent wins!===\n", exit_code, exit_code); 
-       dont_nag = true; // remember NOT to nag the user if he experienced any bug 
-   
-       // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board 
-       Audio_PlaySoundAtCenter (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT); 
-   
-       // display a crash notification dialog box 
-       if (MessageBox (hMainWnd, LOCALIZE (L"Error_EngineCrashed"), LOCALIZE (L"ImportantMessage"), MB_ICONWARNING | MB_YESNO) == IDYES) 
-       { 
-          sprintf_s ((char *) line_buffer, sizeof (line_buffer), "engine disappeared unexpectedly (exit code %lld)", exit_code); 
-          if (Debug_SendLogToAuthor ((char *) line_buffer, true)) 
-             MessageBox (hMainWnd, LOCALIZE (L"MessageSent"), PROGRAM_NAME, MB_ICONINFORMATION | MB_OK); // send the game engine history to the author 
-          else 
-             MessageBox (hMainWnd, LOCALIZE (L"NoInternetConnection"), LOCALIZE (L"FatalError"), MB_ICONWARNING | MB_OK); // and display an error message if failed 
-       } 
-   
-       // and display the game over dialog box 
-       the_board.game_state = (opposite_player->color == COLOR_BLACK ? STATE_WHITEWIN_RESIGNORFORFEIT : STATE_BLACKWIN_RESIGNORFORFEIT); 
-       DialogBox_EndGame (); 
-   
-       do_update = true; // remember to update the 3D scene 
-    } 
-   
-    // read from pipe (non-blocking) 
-    PlayerEngine_Recv (player); 
-   
-    //////////////// 
-    // START PARSING 
-   
-    // read line per line... 
-    line_pointer = player->recvbuffer; // start at the first character 
-    while ((line_pointer = ReadACompleteLine (line_buffer, WCHAR_SIZEOF (line_buffer), line_pointer)) != NULL) 
-    { 
-       // is it an empty line or engine noise ? 
-       if ((line_buffer[0] == 0) || iswspace (line_buffer[0])) 
-          continue; // skip empty lines and engine noise 
-   
-       // is the engine offering us a draw ? 
-       if (wcsncmp (line_buffer, L"offer draw", 10) == 0) 
-          continue; // if so, discard its offer (engine draws are unsupported) and proceed to the next line 
-   
-       // else is it an *irrevocable* draw ? (at this point there's nothing we can do but accept it) 
-       else if (wcsstr (line_buffer, L"1/2-1/2") != NULL) 
-       { 
-          Debug_Log (L"===Engine tells us that it's a draw: nobody wins!===\n"); 
-   
-          // play defeat sound (a draw is always a sort of defeat...) at the center of the board 
-          Audio_PlaySoundAtCenter (SOUNDTYPE_DEFEAT); 
-   
-          // display the game over dialog box 
-          the_board.game_state = STATE_DRAW_OTHER; 
-          DialogBox_EndGame (); 
-   
-          do_update = true; // remember to update the 3D scene 
-          continue; // we processed that line 
-       } 
-   
-       // else is the engine *irrevocably* resigning ? (at this point there's nothing we can do but accept it) 
-       else if (wcsncmp (line_buffer, L"resign", 6) == 0) 
-       { 
-          Debug_Log (L"===Engine tells us that %s resigns: %s wins!===\n", (current_player->color == COLOR_BLACK ? "black" : "white"), (current_player->color == COLOR_BLACK ? "white" : "black")); 
-   
-          // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board 
-          Audio_PlaySoundAtCenter (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT); 
-   
-          // display the game over dialog box 
-          the_board.game_state = (current_player->color == COLOR_BLACK ? STATE_WHITEWIN_RESIGNORFORFEIT : STATE_BLACKWIN_RESIGNORFORFEIT); 
-          DialogBox_EndGame (); 
-   
-          do_update = true; // remember to update the 3D scene 
-          continue; // we processed that line 
-       } 
-   
-       // is engine allowed to resign ? if so, check if it's a game results 
-       if (options.engine.obstinacy_level >= 0) 
-       { 
-          // is it a game result AND are we still in play ? 
-          if ((wcsstr (line_buffer, L"1-0") != NULL) && (the_board.game_state == STATE_PLAYING)) 
-          { 
-             // have we NOT been obstinate enough ? 
-             if (current_obstinacy < options.engine.obstinacy_level) 
-                current_obstinacy++; // if so, discard this resign and go on 
-             else 
-             { 
-                Debug_Log (L"===Engine tells us that black resigns: white wins!===\n"); 
-   
-                // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board 
-                Audio_PlaySoundAtCenter (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT); 
-   
-                // display the game over dialog box 
-                the_board.game_state = STATE_WHITEWIN_RESIGNORFORFEIT; 
-                DialogBox_EndGame (); 
-   
-                do_update = true; // remember to update the 3D scene 
-             } 
-   
-             continue; // we processed that line 
-          } 
-          else if ((wcsstr (line_buffer, L"0-1") != NULL) && (the_board.game_state == STATE_PLAYING)) 
-          { 
-             // have we NOT been obstinate enough ? 
-             if (current_obstinacy < options.engine.obstinacy_level) 
-                current_obstinacy++; // if so, discard this resign and go on 
-             else 
-             { 
-                Debug_Log (L"===Engine tells us that white resigns: black wins!===\n"); 
-   
-                // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board 
-                Audio_PlaySoundAtCenter (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT); 
-   
-                // display the game over dialog box 
-                the_board.game_state = STATE_BLACKWIN_RESIGNORFORFEIT; 
-                DialogBox_EndGame (); 
-   
-                do_update = true; // remember to update the 3D scene 
-             } 
-   
-             continue; // we processed that line 
-          } 
-       } 
-   
-       // has the game ended already ? 
-       if (the_board.game_state > STATE_PLAYING) 
-          continue; // ignore all that the engine tells us. Game is over already. 
-   
-       // else is it an unrecoverable engine error ? 
-       else if ((wcsstr (line_buffer, L"illegal") != NULL) || (wcsstr (line_buffer, L"invalid") != NULL)) 
-       { 
-          Debug_Log (L"===Unrecoverable engine error: opponent wins!===\n"); 
-          dont_nag = true; // remember NOT to nag the user if he experienced any bug 
-   
-          // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board 
-          Audio_PlaySoundAtCenter (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT); 
-   
-          // display a crash notification dialog box 
-          if (MessageBox (hMainWnd, LOCALIZE (L"Error_EngineCrashed"), LOCALIZE (L"ImportantMessage"), MB_ICONWARNING | MB_YESNO) == IDYES) 
-             if (Debug_SendLogToAuthor ("engine refused our command", true)) 
-                MessageBox (hMainWnd, LOCALIZE (L"MessageSent"), PROGRAM_NAME, MB_ICONINFORMATION | MB_OK); // send the game engine history to the author 
-             else 
-                MessageBox (hMainWnd, LOCALIZE (L"NoInternetConnection"), LOCALIZE (L"FatalError"), MB_ICONWARNING | MB_OK); // and display an error message if failed 
-   
-          // and display the game over dialog box 
-          the_board.game_state = (opposite_player->color == COLOR_BLACK ? STATE_WHITEWIN_RESIGNORFORFEIT : STATE_BLACKWIN_RESIGNORFORFEIT); 
-          DialogBox_EndGame (); 
-   
-          do_update = true; // remember to update the 3D scene 
-       } 
-   
-       // else is it a normal move ? 
-       else if ((move_string = wcsstr (line_buffer, program->replystring_move)) != NULL) 
-          move_string += wcslen (program->replystring_move); // go to the parsable data 
-   
-       // else it's any other sort of line 
-       else 
-          continue; // skip lines that don't contain any valid move data 
-   
-       // now we are sure it's either a hint or a move (or some pondering) 
-   
-       length = wcslen (move_string); 
-       if (length < 2) 
-          continue; // if string is too short to be a move, skip it 
-   
-       // there must be valid move data on that line. 
-   
-       // evaluate the engine move string 
-       memcpy (move.slots, the_board.moves[the_board.move_count - 1].slots, sizeof (move.slots)); 
-       char_index = 0; 
-       while ((move_string[char_index] != 0) && !iswspace (move_string[char_index])) 
-       { 
-          move.pgntext[char_index] = move_string[char_index]; 
-          char_index++; 
-       } 
-       move.pgntext[char_index] = 0; 
-       if (!Move_SetupFromSAN (&the_board.moves[the_board.move_count - 1], &move, Board_ColorToMove (&the_board))) 
-       { 
-          Debug_Log (L"===Skipping line (invalid move syntax)===\n%s", move_string); 
-          continue; // so now, if there are NOT two digits AND it's not a kind of castle, it can't be a move so skip that line 
-       } 
-   
-       // is it NOT a hint, are blunders allowed, should we do one now AND can we do one now ? 
-       if (!is_hint_pending && (options.engine.blunder_chances > 0) && (rand () % 100 < options.engine.blunder_chances) 
-           && Move_FindRandomMove (&the_board.moves[the_board.move_count - 1], player->color, &move)) 
-       { 
-          if (program->command_force[0] != 0) // "force" commands are only used with CECP engines such as Crafty. Others are sent the game history, so no need to force anything 
-          { 
-             Player_SendBuffer_Add (player, 1000, program->command_force, Move_BuildString (&move)); // send the blunderous move to the engine 
-             Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-          } 
-          Debug_LogMove (&move, L"===Overriding engine choice with blunderous move: [%s]===\n", Move_BuildString (&move)); // blunder 
-       } 
-   
-       // mark the engine's selected and hovered squares 
-       Board_SetSelectedAndHovered (&the_board, move.source[0], move.source[1], move.target[0], move.target[1]); 
-   
-       // was it NOT a hint ? 
-       if (!is_hint_pending) 
-       { 
-          the_scene.gui.central_text.disappear_time = current_time + 1.0f; // fade the "thinking" phrase out now (FIXME: ugly) 
-          the_scene.gui.want_spinwheel = false; // stop spinning wheel 
-   
-          Board_AppendMove (&the_board, the_board.selected_position[0], the_board.selected_position[1], the_board.hovered_position[0], the_board.hovered_position[1], move.promotion_type, NULL); 
-          Player_GetOpposite ()->should_wakeup = true; // do the movement and switch players 
-   
-          // forget the hovered and selected positions 
-          Board_SetSelectedAndHovered (&the_board, -1, -1, -1, -1); 
-          animation_endtime = current_time + ANIMATION_DURATION; // wait for animation time seconds 
-       } 
-   
-       // else it was a hint 
-       else 
-       { 
-          the_scene.gui.central_text.disappear_time = current_time + 0.1f; // fade the "thinking" phrase out now quickly (FIXME: ugly) 
-          the_scene.gui.want_spinwheel = false; // stop spinning wheel 
-   
-          highlight_endtime = current_time + 2.0f; // just highlight this part for a little more than one second 
-          is_hint_pending = false; // remember no hint is pending any longer 
-   
-          // we must now restore the board to its last state. Just set up the board again from its current Forsyth-Edwards notation 
-          Debug_Log (L"===Hint received, rebuilding board and telling engine to backup 1 move===\n"); 
-          Debug_LogMove (&the_board.moves[the_board.move_count - 1], L"===setting up board using FEN string: [%s]===\n", the_board.moves[the_board.move_count - 1].fen_string); 
-   
-          // get the current game state in FEN format and feed it to the engine 
-          Player_SendBuffer_Add (player, 1000, program->command_setboard, the_board.moves[the_board.move_count - 1].fen_string); 
-          Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-       } 
-   
-       do_update = true; // remember to update the 3D scene 
-    } 
-   
-    // now clean the input buffer of all the lines we parsed 
-    line_pointer = wcsrchr (player->recvbuffer, L'\n'); // reach the last carriage return 
-    if (line_pointer != NULL) 
-    { 
-       line_pointer++; // skip the carriage return 
-       length = wcslen (line_pointer); // get the remaining string length 
-       for (char_index = 0; char_index < length; char_index++) 
-          player->recvbuffer[char_index] = line_pointer[char_index]; // and recopy the remaining string at the beginning of the buffer 
-       player->recvbuffer[char_index] = 0; // finish the string ourselves 
-    } 
-   
-    // END PARSING 
-    ////////////// 
-   
-    ///////////////////////////////// 
-    // START NOTIFICATIONS PROCESSING 
-   
-    // have we been notified that the board was just set up ? 
-    if (the_board.was_setup) 
-    { 
-       Debug_Log (L"===Got board setup notification from interface===\n"); 
-   
-       // send a new game command to the chess engine 
-       Player_SendBuffer_Add (player, 1000, program->command_new); 
-       Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-   
-       // just set up the board from its Forsyth-Edwards notation 
-       Debug_LogMove (&the_board.moves[the_board.move_count - 1], L"===setting up board using FEN string: [%s]===\n", the_board.moves[the_board.move_count - 1].fen_string); 
-   
-       // get the current game state in FEN format and feed it to the engine 
-       Player_SendBuffer_Add (player, 1000, program->command_setboard, the_board.moves[the_board.move_count - 1].fen_string); 
-       Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-   
-       current_obstinacy = 0; // reset current obstinacy 
-       is_hint_pending = false; // no hint was requested so far 
-    } 
-   
-    // have we been notified that players are swapping colors ? (N.B. when this happens in human vs. computer mode, it's always that the human player is *GIVING* his turn) 
-    if (the_board.want_playerswap) 
-    { 
-       Debug_Log (L"===Got player SWAP notification from interface===\n"); 
-       Player_SendBuffer_Add (player, 1000, program->command_go); // tell engine it's now the current player 
-       Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-    } 
-   
-    // have we been notified that the current player just changed AND is the animation finished ? 
-    if (player->should_wakeup && (animation_endtime < current_time)) 
-    { 
-       Debug_Log (L"===Got player change notification from interface===\n"); 
-   
-       // is the current player our color ? (meaning is it engine's turn to play) ? 
-       if (Board_ColorToMove (&the_board) == player->color) 
-       { 
-          // is it NOT a board setup AND has at least one move been played (meaning it was just the other's turn before) ? 
-          if (!the_board.was_setup && (the_board.move_count > 1)) 
-          { 
-             Debug_LogMove (&the_board.moves[the_board.move_count - 1], L"===Player just played, sending the chosen move to engine: [%s]===\n", Move_BuildString (&the_board.moves[the_board.move_count - 1])); 
-   
-             // build the move string, and send the move string to the engine 
-             Player_SendBuffer_Add (player, 1000, program->command_move, Move_BuildString (&the_board.moves[the_board.move_count - 1])); 
-             Player_SendBuffer_Add (player, 1000, L"\n"); // end the send buffer with a carriage return 
-          } 
-   
-          // else game has not started yet, but it's our turn 
-          else 
-          { 
-             Player_SendBuffer_Add (player, 1000, program->command_go); // so let's start the game 
-             Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-          } 
-       } 
-   
-       player->should_wakeup = false; // remember we taken this notification in account 
-    } 
-   
-    // END NOTIFICATIONS PROCESSING 
-    /////////////////////////////// 
-   
-    // is it NOT our turn ? 
-    if (current_player != player) 
-    { 
-       // does our opponent want a hint ? 
-       if (current_player->wants_hint) 
-       { 
-          current_player->wants_hint = false; // don't ask twice 
-          Debug_Log (L"===Hint requested, asking engine for it===\n"); 
-          Player_SendBuffer_Add (player, 1000, program->command_go); // tell the computer to analyze this position 
-          Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-          is_hint_pending = true; // remember a hint is pending 
-   
-          // FIXME: move to scene.cpp 
-          Scene_UpdateText (&the_scene.gui.central_text, RGBA_TO_RGBACOLOR (255, 255, 255, 191), DURATION_INFINITE, true, LOCALIZE (L"Thinking")); // display the "thinking" phrase in the middle of the screen 
-          the_scene.gui.want_spinwheel = true; // start spinning wheel 
-          do_update = true; // remember to update the 3D scene 
-       } 
-   
-       // does our opponent want to cancel a move ? 
-       if (current_player->wants_cancel) 
-       { 
-          current_player->wants_cancel = false; // don't ask twice (remember now before we switch players) 
-          Debug_Log (L"===Move cancellation requested, rebuilding board and telling engine to backup 2 moves===\n"); 
-   
-          // rewind game 2 moves back 
-          the_board.moves = (boardmove_t *) SAFE_realloc (the_board.moves, the_board.move_count, max (1, the_board.move_count - 2), sizeof (boardmove_t), false); 
-          the_board.move_count = max (1, the_board.move_count - 2); // figure out how many moves we have now 
-          the_board.viewed_move = the_board.move_count - 1; // take us back to the last move 
-          the_board.game_state = STATE_PLAYING; // remember the game is now playing (in case we wanted to cancel the closing move of a finished game, this opens the game again) 
-   
-          // just set up the board from its Forsyth-Edwards notation 
-          Debug_LogMove (&the_board.moves[the_board.move_count - 1], L"===setting up board using FEN string: [%s]===\n", the_board.moves[the_board.move_count - 1].fen_string); 
-   
-          // get the current game state in FEN format and feed it to the engine 
-          Player_SendBuffer_Add (player, 1000, program->command_setboard, the_board.moves[the_board.move_count - 1].fen_string); 
-          Player_SendBuffer_Add (player, 1000, L"\n"); // since the format string was read from the options, don't forget to end it with a carriage return 
-   
-          do_update = true; // remember to update the 3D scene 
-       } 
-    } 
-   
-    // write to pipe (when we're allowed to) 
-    if (!player->sendbuffer_locked && (animation_endtime + 1.0f < current_time)) 
-       PlayerEngine_Send (player); 
-   
-    return (do_update); // finished, return whether we should update the scene or not 
- } 
-   
-   
- static void PlayerEngine_Recv (player_t *player) 
- { 
-    // helper function to read data from the pipe communicating with the game engine process 
-   
-    //unsigned long amount_to_read; 
-    unsigned long read_count; 
-    int length; 
-    unsigned int initial_pos; 
-   
-    // get reception buffer's initial end position 
-    initial_pos = wcslen (player->recvbuffer); 
-    length = initial_pos; 
-   
-    // as long as the pipe reports us there is data to read, read one byte at a time 
-    while (pipe_hasdata (fpipe)) 
-    { 
-       read_count = pipe_read (fpipe, player->ascii_recvbuffer, 1); 
-       if (read_count == 0) 
-          break; // read the pipe; if it fails, stop trying 
-       if ((player->ascii_recvbuffer[0] == '\r') || (player->ascii_recvbuffer[0] == '%')) 
-          continue; // ignore carriage returns and percent signs 
-   
-       // convert the received character to wide char and append it to recvbuffer 
-       player->ascii_recvbuffer[1] = 0; // terminate the received string ourselves 
-       player->recvbuffer[length] = (wchar_t) player->ascii_recvbuffer[0]; 
-       //ConvertToWideChar (&player->recvbuffer[length], player->recvbuffer_size - length, player->ascii_recvbuffer); 
-       length++; // there's one more character in the player's recv buffer 
-       player->recvbuffer[length] = 0; // terminate the string ourselves 
-    } 
-   
-    // write what we received (if we received anything) 
-    if (wcslen (player->recvbuffer) > initial_pos) 
-       Debug_Log (L"===================================RECEIVED:===================================\n%s\n", &player->recvbuffer[initial_pos]); 
-   
-    return; // finished 
- } 
-   
-   
- int wcs_replace (wchar_t *haystack, wchar_t *needle, wchar_t *replacement) 
- { 
-    size_t replacement_length; 
-    size_t replacement_count; 
-    size_t pattern_length; 
-    wchar_t *line_pointer; 
-   
-    replacement_count = 0; 
-    while ((line_pointer = wcsstr (haystack, needle)) != NULL) 
-    { 
-       pattern_length = wcslen (needle); 
-       replacement_length = wcslen (replacement); 
-       memmove (&line_pointer[replacement_length], &line_pointer[pattern_length], (wcslen (&line_pointer[pattern_length]) + 1) * sizeof (wchar_t)); 
-       memcpy (line_pointer, replacement, replacement_length * sizeof (wchar_t)); 
-       replacement_count++; 
-    } 
-   
-    return (replacement_count); 
- } 
-   
-   
- static void PlayerEngine_Send (player_t *player) 
- { 
-    // helper function to send data through the pipe communicating with the game engine process 
-   
-    static wchar_t replacement_string[65536]; 
-    static wchar_t widechar_buffer[65536]; // needs to be big enough to hold game history 
-    static char ascii_buffer[65536]; // needs to be big enough to hold game history 
-    wchar_t *line_pointer; 
-    unsigned long amount_written; 
-    int move_index; 
-    int try_index; 
-   
-    player->sendbuffer_locked = true; // lock the buffer 
-   
-    // perform variable replacements on sendbuffer 
-    if (the_board.move_count > 0) 
-    { 
-       wcs_replace (player->sendbuffer, L"${START_POS}", the_board.moves[0].fen_string); 
-       wcs_replace (player->sendbuffer, L"${CURRENT_POS}", (/*the_board.move_count == 2 ? L"startpos" : */the_board.moves[the_board.move_count - 1].fen_string)); 
-       wcs_replace (player->sendbuffer, L"${LAST_MOVE}", Move_BuildString (&the_board.moves[the_board.move_count - 1])); 
-       while (wcsstr (player->sendbuffer, L"${MAX_CORES}") != NULL) 
-       { 
-          swprintf_s (replacement_string, WCHAR_SIZEOF (replacement_string), L"%d", max_cores); 
-          wcs_replace (player->sendbuffer, L"${MAX_CORES}", replacement_string); 
-       } 
-       while (wcsstr (player->sendbuffer, L"${SEARCH_DEPTH}") != NULL) 
-       { 
-          swprintf_s (replacement_string, WCHAR_SIZEOF (replacement_string), L"%d", options.engine.depth); 
-          wcs_replace (player->sendbuffer, L"${SEARCH_DEPTH}", replacement_string); 
-       } 
-       while (wcsstr (player->sendbuffer, L"${GAME_HISTORY}") != NULL) 
-       { 
-          replacement_string[0] = 0; 
-          for (move_index = 1; move_index < the_board.move_count; move_index++) 
-          { 
-             if (move_index > 1) 
-                wcscat_s (replacement_string, WCHAR_SIZEOF (replacement_string), L" "); 
-             wcscat_s (replacement_string, WCHAR_SIZEOF (replacement_string), Move_BuildString (&the_board.moves[move_index])); 
-          } 
-          wcs_replace (player->sendbuffer, L"${GAME_HISTORY}", replacement_string); 
-       } 
-    } 
-   
-    // write what we're sending (if we're sending anything) 
-    if (player->sendbuffer[0] != 0) 
-       Debug_Log (L"====================================SENDING:===================================\n%s\n", player->sendbuffer); 
-   
-    // now read line per line... 
-    line_pointer = player->sendbuffer; // start at the first character 
-    while ((line_pointer = wcsgets (widechar_buffer, WCHAR_SIZEOF (widechar_buffer), line_pointer)) != NULL) 
-    { 
-       wcscat_s (widechar_buffer, WCHAR_SIZEOF (widechar_buffer), L"\n"); // put the carriage return back 
-       ConvertTo7BitASCII (ascii_buffer, sizeof (ascii_buffer), widechar_buffer); // convert to ASCII 
-       amount_written = pipe_write (fpipe, ascii_buffer, strlen (ascii_buffer)); // send data 
-    } 
-   
-    player->sendbuffer[0] = 0; // what we had to send has been sent, reset the send buffer 
-    player->sendbuffer_locked = false; // and unlock it 
-   
-    // should the engine be initialized ? 
-    if (should_initialize) 
-    { 
-       // wait for the engine process to display something (which will mean it's ready). Try for 5 seconds. 
-       for (try_index = 0; try_index < 50; try_index++) 
-       { 
-          // read from pipe (non-blocking) 
-          PlayerEngine_Recv (player); 
-          if (player->recvbuffer[0] != 0) 
-             break; // break as soon as we get something 
-          Sleep (100); // next try in 100 milliseconds 
-       } 
-   
-       // has the engine process not spoken yet ? 
-       if (player->recvbuffer[0] == 0) 
-       { 
-          messagebox.hWndParent = hMainWnd; 
-          wcscpy_s (messagebox.title, WCHAR_SIZEOF (messagebox.title), LOCALIZE (L"ImportantMessage")); 
-          swprintf_s (messagebox.text, WCHAR_SIZEOF (messagebox.text), LOCALIZE (L"Error_ChessEngineInitializationFailed"), options.engine.programs[options.engine.selected_program].folder); 
-          messagebox.flags = MB_ICONWARNING | MB_OK; 
-          DialogBox_Message (&messagebox); // display a modeless error message box 
-   
-          PlayerEngine_Shutdown (player); // on error, shutdown the engine 
-       } 
-   
-       should_initialize = false; // remember this is no longer to be done (until the next call to PlayerEngine_Init()) 
-    } 
-   
-    return; // finished 
- } 
-   
-   
- static wchar_t *Move_BuildString (boardmove_t *move) 
- { 
-    // helper function to build a move string to send to the engine from a particular board move. NOT THREAD SAFE. 
-   
-    static wchar_t output_string[8]; 
-   
-    // construct the four first characters 
-    swprintf_s (output_string, WCHAR_SIZEOF (output_string), L"%c%c%c%c", 
-                L'a' + move->source[1], L'1' + move->source[0], 
-                L'a' + move->target[1], L'1' + move->target[0]); 
-   
-    // append any eventual promotion 
-    if (move->promotion_type == PART_ROOK) 
-       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"r"); 
-    else if (move->promotion_type == PART_KNIGHT) 
-       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"n"); 
-    else if (move->promotion_type == PART_BISHOP) 
-       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"b"); 
-    else if (move->promotion_type == PART_QUEEN) 
-       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"q"); 
-   
-    return (output_string); // finished, return the move string 
- } 
-