Subversion Repositories Games.Chess Giants

Rev

Rev 140 | Rev 150 | Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  1. // chessengine.cpp
  2.  
  3. #include "common.h"
  4.  
  5. #include <fcntl.h>
  6.  
  7. // definitions used in this module only
  8. #define RD 0
  9. #define WR 1
  10. #define CLOSE_PIPE(pipe) if (pipe[RD] != -1) _close (pipe[RD]); pipe[RD] = -1; if (pipe[WR] != -1) _close (pipe[WR]); pipe[WR] = -1
  11.  
  12.  
  13. // global variables used in this module only
  14. static wchar_t chessenginemodule_path[MAX_PATH];
  15. static wchar_t chessenginemodule_pathname[MAX_PATH];
  16. static wchar_t chessengineinitfile_pathname[MAX_PATH];
  17. static PROCESS_INFORMATION PlayerEngine_pi;
  18. static int chessgiants_to_engine[2]; // RD and WR
  19. static int engine_to_chessgiants[2]; // RD and WR
  20. static int current_obstinacy;
  21. static bool is_hint_pending;
  22.  
  23. // prototypes of local functions
  24. static void PlayerEngine_Recv (player_t *player);
  25. static void PlayerEngine_Send (player_t *player);
  26. static wchar_t *Move_BuildString (boardmove_t *move);
  27.  
  28.  
  29. bool PlayerEngine_Init (player_t *player)
  30. {
  31.    // this function starts a chess engine as a child process. This process's stdin and
  32.    // stdout are redirected to the handles we give it, so that we may read/write to it.
  33.  
  34.    engineprogram_t *program;
  35.    wchar_t widechar_buffer[256];
  36.    SYSTEM_INFO sysinfo;
  37.    HANDLE hStdOut[2] = { NULL, NULL };
  38.    HANDLE hStdIn[2] = { NULL, NULL };
  39.    SECURITY_ATTRIBUTES saAttr;
  40.    STARTUPINFO si;
  41.    int try_index;
  42.    FILE *fp;
  43.  
  44.    // reset stuff first
  45.    player->wants_hint = false;
  46.  
  47.    // quick access to engine program
  48.    program = &options.engine.programs[options.engine.selected_program];
  49.  
  50.    // build the chess engine module path and pathname
  51.    swprintf_s (chessenginemodule_path, WCHAR_SIZEOF (chessenginemodule_path), L"%s/engines/%s", app_path, program->folder);
  52.    swprintf_s (chessenginemodule_pathname, WCHAR_SIZEOF (chessenginemodule_pathname), L"%s/engines/%s/%s", app_path, program->folder, program->cmdline);
  53.  
  54.    // build the I/O pipes
  55.    memset (&saAttr, 0, sizeof (saAttr)); // prepare the pipes' security attributes
  56.    saAttr.nLength = sizeof (SECURITY_ATTRIBUTES);
  57.    saAttr.bInheritHandle = true; // set the bInheritHandle flag so pipe handles are inherited
  58.    CreatePipe (&hStdIn[RD], &hStdIn[WR], &saAttr, 0); // create a pipe for the child process's stdin
  59.    CreatePipe (&hStdOut[RD], &hStdOut[WR], &saAttr, 0); // create a pipe for the child process's stdout
  60.    SetHandleInformation (hStdIn[WR], HANDLE_FLAG_INHERIT, 0); // ensure the write handle to the pipe for STDIN is not inherited
  61.    SetHandleInformation (hStdOut[RD], HANDLE_FLAG_INHERIT, 0); // ensure the read handle to the pipe for STDOUT is not inherited
  62.    engine_to_chessgiants[RD] = _open_osfhandle ((intptr_t) hStdOut[RD], _O_BINARY);
  63.    engine_to_chessgiants[WR] = _open_osfhandle ((intptr_t) hStdOut[WR], _O_BINARY | _O_APPEND);
  64.    chessgiants_to_engine[RD] = _open_osfhandle ((intptr_t) hStdIn[RD], _O_BINARY);
  65.    chessgiants_to_engine[WR] = _open_osfhandle ((intptr_t) hStdIn[WR], _O_BINARY | _O_APPEND);
  66.  
  67.    // spawn the chess engine process with redirected input and output
  68.    memset (&si, 0, sizeof (si));
  69.    si.cb = sizeof (STARTUPINFOA);
  70.    si.dwFlags = STARTF_USESTDHANDLES;
  71.    si.hStdInput = hStdIn[RD];
  72.    si.hStdOutput = hStdOut[WR];
  73.    si.hStdError = hStdOut[WR];
  74.    if (!CreateProcess (chessenginemodule_pathname, // module pathname
  75.                        program->cmdline, // command line
  76.                        NULL, NULL,
  77.                        true, // handles are inherited
  78.                        CREATE_NO_WINDOW | DETACHED_PROCESS | CREATE_NEW_PROCESS_GROUP,
  79.                        NULL,
  80.                        chessenginemodule_path, // process path
  81.                        &si, // STARTUPINFO pointer
  82.                        &PlayerEngine_pi)) // receives PROCESS_INFORMATION
  83.    {
  84.       messagebox.hWndParent = hMainWnd;
  85.       wcscpy_s (messagebox.title, WCHAR_SIZEOF (messagebox.title), LOCALIZE (L"ImportantMessage"));
  86.       wcscpy_s (messagebox.text, WCHAR_SIZEOF (messagebox.text), LOCALIZE (L"Error_ChessEngineInitializationFailed"));
  87.       messagebox.flags = MB_ICONWARNING | MB_OK;
  88.       DialogBox_Message (&messagebox); // display a modeless error message box
  89.  
  90.       PlayerEngine_Shutdown (player); // on error, shutdown the engine
  91.       return (false);
  92.    }
  93.  
  94.    // wait for the engine process to display something (which will mean it's ready). Try for 5 seconds.
  95.    for (try_index = 0; try_index < 50; try_index++)
  96.    {
  97.       // read from pipe (non-blocking)
  98.       PlayerEngine_Recv (player);
  99.       if (player->recvbuffer[0] != 0)
  100.          break; // break as soon as we get something
  101.       Sleep (100); // next try in 100 milliseconds
  102.    }
  103.  
  104.    // has the engine process not spoken yet ?
  105.    if (player->recvbuffer[0] == 0)
  106.    {
  107.       messagebox.hWndParent = hMainWnd;
  108.       wcscpy_s (messagebox.title, WCHAR_SIZEOF (messagebox.title), LOCALIZE (L"ImportantMessage"));
  109.       swprintf_s (messagebox.text, WCHAR_SIZEOF (messagebox.text), LOCALIZE (L"Error_ChessEngineInitializationFailed"), program->folder);
  110.       messagebox.flags = MB_ICONWARNING | MB_OK;
  111.       DialogBox_Message (&messagebox); // display a modeless error message box
  112.  
  113.       PlayerEngine_Shutdown (player); // on error, shutdown the engine
  114.       return (false);
  115.    }
  116.  
  117.    // eventually initialize the debug log file
  118.    Debug_Init (L"Chess engine output.txt");
  119.  
  120.    // build the init file full qualified path name and try to open it
  121.    swprintf_s (chessengineinitfile_pathname, WCHAR_SIZEOF (chessengineinitfile_pathname), L"%s/engines/%s/init.txt", app_path, program->folder);
  122.    _wfopen_s (&fp, chessengineinitfile_pathname, L"r");
  123.  
  124.    // could the init file be opened ?
  125.    if (fp != NULL)
  126.    {
  127.       Debug_Log (L"===Found initialization file, parsing...===\n");
  128.  
  129.       // SMP HACK -- assume our engine is CECP compatible and set the max CPUs to use to core max - 1
  130.       // (the computer will look like hung if all CPU is taken)
  131.       GetSystemInfo (&sysinfo); // get the number of cores and build the corresponding engine initialization order
  132.       Player_SendBuffer_Add (player, 1000, L"mt %d\n", max (1, sysinfo.dwNumberOfProcessors - 1));
  133.  
  134.       // read line per line
  135.       while (fgetws (widechar_buffer, WCHAR_SIZEOF (widechar_buffer), fp) != NULL)
  136.       {
  137.          if ((widechar_buffer[0] == L'#') || (widechar_buffer[0] == L'\n'))
  138.             continue; // skip comments and empty lines
  139.  
  140.          // new command line found, append it to the send buffer
  141.          Player_SendBuffer_Add (player, 1000, widechar_buffer);
  142.       }
  143.  
  144.       fclose (fp); // finished, close the file
  145.    }
  146.  
  147.    // everything's okay, set engine name as the player's name
  148.    wcscpy_s (player->name, WCHAR_SIZEOF (player->name), program->name);
  149.  
  150.    return (true); // finished
  151. }
  152.  
  153.  
  154. void PlayerEngine_Shutdown (player_t *player)
  155. {
  156.    // this function terminates the chess engine process and releases all handles attached to it
  157.  
  158.    unsigned long exit_code;
  159.    unsigned long handle_flags;
  160.    int attempt_index;
  161.  
  162.    // send the engine a quit command
  163.    Player_SendBuffer_Add (player, 1000, options.engine.programs[options.engine.selected_program].command_quit);
  164.    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
  165.    PlayerEngine_Send (player);
  166.  
  167.    // close the pipes
  168.    CLOSE_PIPE (chessgiants_to_engine);
  169.    CLOSE_PIPE (engine_to_chessgiants);
  170.  
  171.    // check 10 times if the engine process has ended cleanly
  172.    for (attempt_index = 0; attempt_index < 10; attempt_index++)
  173.    {
  174.       if (GetExitCodeProcess (PlayerEngine_pi.hProcess, &exit_code) && (exit_code != STILL_ACTIVE))
  175.          break; // break as soon as we've told the process exited cleanly
  176.  
  177.       Sleep (100); // else wait one tenth second
  178.    }
  179.  
  180.    // has the engine NOT closen by itself yet ?
  181.    if ((attempt_index == 10) && GetExitCodeProcess (PlayerEngine_pi.hProcess, &exit_code) && (exit_code == STILL_ACTIVE))
  182.    {
  183.       Debug_Log (L"===Engine not closen, terminating process manually===\n");
  184.  
  185.       // terminate the chess engine process using our smart technique ^^
  186.       if (!SafeTerminateProcess (PlayerEngine_pi.hProcess, 0))
  187.          TerminateProcess (PlayerEngine_pi.hProcess, 0); // if process doesn't want to shutdown, kill it
  188.    }
  189.    else
  190.       Debug_Log (L"===Engine closed cleanly===\n");
  191.  
  192.    if (PlayerEngine_pi.hProcess)
  193.       CloseHandle (PlayerEngine_pi.hProcess);
  194.    PlayerEngine_pi.hProcess = NULL;
  195.    if (GetHandleInformation (PlayerEngine_pi.hThread, &handle_flags))
  196.       CloseHandle (PlayerEngine_pi.hThread);
  197.    PlayerEngine_pi.hThread = NULL;
  198.  
  199.    // and finally reset the process information structure
  200.    memset (&PlayerEngine_pi, 0, sizeof (PlayerEngine_pi));
  201.  
  202.    return; // finished
  203. }
  204.  
  205.  
  206. bool PlayerEngine_Think (player_t *player)
  207. {
  208.    // this function reads and writes any necessary data from and to the chess engine. Returns TRUE if scene needs to be updated.
  209.  
  210.    engineprogram_t *program;
  211.    wchar_t line_buffer[256];
  212.    wchar_t *line_pointer;
  213.    wchar_t *move_string;
  214.    int char_index;
  215.    int length;
  216.    boardmove_t move;
  217.    player_t *current_player;
  218.    player_t *opposite_player;
  219.    bool do_update;
  220.  
  221.    // quick access to chess engine program
  222.    program = &options.engine.programs[options.engine.selected_program];
  223.  
  224.    // don't update the scene until told otherwise
  225.    do_update = false;
  226.  
  227.    // get current and opposite players
  228.    current_player = Player_GetCurrent ();
  229.    opposite_player = Player_GetOpposite ();
  230.  
  231.    // read from pipe (non-blocking)
  232.    PlayerEngine_Recv (player);
  233.  
  234.    ////////////////
  235.    // START PARSING
  236.  
  237.    // read line per line...
  238.    line_pointer = player->recvbuffer; // start at the first character
  239.    while ((line_pointer = ReadACompleteLine (line_buffer, WCHAR_SIZEOF (line_buffer), line_pointer)) != NULL)
  240.    {
  241.       // is it an empty line or engine noise ?
  242.       if ((line_buffer[0] == 0) || iswspace (line_buffer[0]))
  243.          continue; // skip empty lines and engine noise
  244.  
  245.       // is the engine offering us a draw ?
  246.       if (wcsncmp (line_buffer, L"offer draw", 10) == 0)
  247.          continue; // if so, discard its offer (engine draws are unsupported) and proceed to the next line
  248.  
  249.       // else is it an *irrevocable* draw ? (at this point there's nothing we can do but accept it)
  250.       else if (wcsstr (line_buffer, L"1/2-1/2") != NULL)
  251.       {
  252.          Debug_Log (L"===Engine tells us that it's a draw: nobody wins!===\n");
  253.  
  254.          // play defeat sound (a draw is always a sort of defeat...) at the center of the board
  255.          Audio_PlaySound (SOUNDTYPE_DEFEAT, 0.0f, 0.0f, 0.04f);
  256.  
  257.          // display the game over dialog box
  258.          the_board.game_state = STATE_DRAW_OTHER;
  259.          DialogBox_EndGame ();
  260.  
  261.          do_update = true; // remember to update the 3D scene
  262.          continue; // we processed that line
  263.       }
  264.  
  265.       // else is the engine *irrevocably* resigning ? (at this point there's nothing we can do but accept it)
  266.       else if (wcsncmp (line_buffer, L"resign", 6) == 0)
  267.       {
  268.          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"));
  269.  
  270.          // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board
  271.          Audio_PlaySound (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT, 0.0f, 0.0f, 0.04f);
  272.  
  273.          // display the game over dialog box
  274.          the_board.game_state = (current_player->color == COLOR_BLACK ? STATE_WHITEWIN_RESIGNORFORFEIT : STATE_BLACKWIN_RESIGNORFORFEIT);
  275.          DialogBox_EndGame ();
  276.  
  277.          do_update = true; // remember to update the 3D scene
  278.          continue; // we processed that line
  279.       }
  280.  
  281.       // is engine allowed to resign ? if so, check if it's a game results
  282.       if (options.engine.obstinacy_level >= 0)
  283.       {
  284.          // is it a game result AND are we still in play ?
  285.          if ((wcsstr (line_buffer, L"1-0") != NULL) && (the_board.game_state == STATE_PLAYING))
  286.          {
  287.             // have we NOT been obstinate enough ?
  288.             if (current_obstinacy < options.engine.obstinacy_level)
  289.                current_obstinacy++; // if so, discard this resign and go on
  290.             else
  291.             {
  292.                Debug_Log (L"===Engine tells us that black resigns: white wins!===\n");
  293.  
  294.                // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board
  295.                Audio_PlaySound (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT, 0.0f, 0.0f, 0.04f);
  296.  
  297.                // display the game over dialog box
  298.                the_board.game_state = STATE_WHITEWIN_RESIGNORFORFEIT;
  299.                DialogBox_EndGame ();
  300.  
  301.                do_update = true; // remember to update the 3D scene
  302.             }
  303.  
  304.             continue; // we processed that line
  305.          }
  306.          else if ((wcsstr (line_buffer, L"0-1") != NULL) && (the_board.game_state == STATE_PLAYING))
  307.          {
  308.             // have we NOT been obstinate enough ?
  309.             if (current_obstinacy < options.engine.obstinacy_level)
  310.                current_obstinacy++; // if so, discard this resign and go on
  311.             else
  312.             {
  313.                Debug_Log (L"===Engine tells us that white resigns: black wins!===\n");
  314.  
  315.                // if opponent player is human, play the victory sound, else, play defeat sound at the center of the board
  316.                Audio_PlaySound (opposite_player->type == PLAYER_HUMAN ? SOUNDTYPE_VICTORY : SOUNDTYPE_DEFEAT, 0.0f, 0.0f, 0.04f);
  317.  
  318.                // display the game over dialog box
  319.                the_board.game_state = STATE_BLACKWIN_RESIGNORFORFEIT;
  320.                DialogBox_EndGame ();
  321.  
  322.                do_update = true; // remember to update the 3D scene
  323.             }
  324.  
  325.             continue; // we processed that line
  326.          }
  327.       }
  328.  
  329.       // has the game ended already ?
  330.       if (the_board.game_state > STATE_PLAYING)
  331.          continue; // ignore all that the engine tells us. Game is over already.
  332.  
  333.       // else is it a normal move ?
  334.       else if ((move_string = wcsstr (line_buffer, program->replystring_move)) != NULL)
  335.          move_string += wcslen (program->replystring_move); // go to the parsable data
  336.  
  337.       // else it's any other sort of line
  338.       else
  339.          continue; // skip lines that don't contain any valid move data
  340.  
  341.       // now we are sure it's either a hint or a move (or some pondering)
  342.  
  343.       length = wcslen (move_string);
  344.       if ((length < 2) || (length > 9))
  345.          continue; // if string is too long to be a move, skip it
  346.  
  347.       // there must be valid move data on that line.
  348.  
  349.       // evaluate the engine move string
  350.       memcpy (move.slots, the_board.moves[the_board.move_count - 1].slots, sizeof (move.slots));
  351.       wcscpy_s (move.pgntext, WCHAR_SIZEOF (move.pgntext), move_string);
  352.       if (!Move_SetupFromSAN (&the_board.moves[the_board.move_count - 1], &move, Board_ColorToMove (&the_board)))
  353.       {
  354.          Debug_Log (L"===Skipping line (invalid move syntax)===\n%s", move_string);
  355.          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
  356.       }
  357.  
  358.       // is it NOT a hint, are blunders allowed, should we do one now AND can we do one now ?
  359.       if (!is_hint_pending && (options.engine.blunder_chances > 0) && (rand () % 100 < options.engine.blunder_chances)
  360.           && Move_FindRandomMove (&the_board.moves[the_board.move_count - 1], player->color, &move))
  361.       {
  362.          Player_SendBuffer_Add (player, 1000, program->command_force, Move_BuildString (&move)); // send the blunderous move to the engine
  363.          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
  364.          if (_wcsnicmp (program->name, L"Crafty", 6) == 0)
  365.             Player_SendBuffer_Add (player, 1000, L"disp\n");
  366.          Debug_Log (L"===Discarding engine move, forcing a blunderous move (%s) instead===\n", Move_BuildString (&move)); // blunder
  367.       }
  368.  
  369.       // mark the engine's selected and hovered squares
  370.       Board_SetSelectedAndHovered (&the_board, move.source[0], move.source[1], move.target[0], move.target[1]);
  371.  
  372.       // was it NOT a hint ?
  373.       if (!is_hint_pending)
  374.       {
  375.          the_scene.gui.central_text.disappear_time = current_time + 1.0f; // fade the "thinking" phrase out now (FIXME: ugly)
  376.          the_scene.gui.want_spinwheel = false; // stop spinning wheel
  377.  
  378.          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);
  379.          the_board.has_playerchanged = true; // do the movement and switch players
  380.  
  381.          // forget the hovered and selected positions
  382.          Board_SetSelectedAndHovered (&the_board, -1, -1, -1, -1);
  383.          animation_endtime = current_time + ANIMATION_DURATION; // wait for animation time seconds
  384.       }
  385.  
  386.       // else it was a hint
  387.       else
  388.       {
  389.          the_scene.gui.central_text.disappear_time = current_time + 0.1f; // fade the "thinking" phrase out now quickly (FIXME: ugly)
  390.          the_scene.gui.want_spinwheel = false; // stop spinning wheel
  391.  
  392.          highlight_endtime = current_time + 2.0f; // just highlight this part for a little more than one second
  393.          is_hint_pending = false; // remember no hint is pending any longer
  394.  
  395.          // we must now restore the board to its last state. Just set up the board again from its current Forsyth-Edwards notation
  396.          Debug_Log (L"===Hint received, rebuilding board and telling engine to backup 1 move===\n");
  397.          Debug_Log (L"===setting up board using FEN string===\n");
  398.  
  399.          // instruct it about its allowed search depth BEFORE each table set (this ensures engine will be "ready" to handle the command)
  400.          // then get the current game state in FEN format and feed it to the engine
  401.          Player_SendBuffer_Add (player, 1000, program->command_sd, options.engine.depth);
  402.          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
  403.          Player_SendBuffer_Add (player, 1000, program->command_setboard, the_board.moves[the_board.move_count - 1].fen_string);
  404.          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
  405.  
  406.          if (_wcsnicmp (program->name, L"Crafty", 6) == 0)
  407.             Player_SendBuffer_Add (player, 1000, L"disp\n");
  408.       }
  409.  
  410.       do_update = true; // remember to update the 3D scene
  411.    }
  412.  
  413.    // now clean the input buffer of all the lines we parsed
  414.    line_pointer = wcsrchr (player->recvbuffer, L'\n'); // reach the last carriage return
  415.    if (line_pointer != NULL)
  416.    {
  417.       line_pointer++; // skip the carriage return
  418.       length = wcslen (line_pointer); // get the remaining string length
  419.       for (char_index = 0; char_index < length; char_index++)
  420.          player->recvbuffer[char_index] = line_pointer[char_index]; // and recopy the remaining string at the beginning of the buffer
  421.       player->recvbuffer[char_index] = 0; // finish the string ourselves
  422.    }
  423.  
  424.    // END PARSING
  425.    //////////////
  426.  
  427.    /////////////////////////////////
  428.    // START NOTIFICATIONS PROCESSING
  429.  
  430.    // have we been notified that the board was just set up ?
  431.    if (the_board.was_setup)
  432.    {
  433.       Debug_Log (L"===Got board setup notification from interface===\n");
  434.  
  435.       // send a new game command to the chess engine
  436.       Player_SendBuffer_Add (player, 1000, program->command_new);
  437.       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
  438.  
  439.       // just set up the board from its Forsyth-Edwards notation
  440.       Debug_Log (L"===setting up board using FEN string===\n");
  441.  
  442.       // instruct it about its allowed search depth BEFORE each table set (this ensures engine will be "ready" to handle the command)
  443.       // then get the current game state in FEN format and feed it to the engine
  444.       Player_SendBuffer_Add (player, 1000, program->command_sd, options.engine.depth);
  445.       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
  446.       Player_SendBuffer_Add (player, 1000, program->command_setboard, the_board.moves[the_board.move_count - 1].fen_string);
  447.       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
  448.  
  449.       current_obstinacy = 0; // reset current obstinacy
  450.       is_hint_pending = false; // no hint was requested so far
  451.  
  452.       if (_wcsnicmp (program->name, L"Crafty", 6) == 0)
  453.          Player_SendBuffer_Add (player, 1000, L"disp\n");
  454.    }
  455.  
  456.    // 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)
  457.    if (the_board.want_playerswap)
  458.    {
  459.       Debug_Log (L"===Got player SWAP notification from interface===\n");
  460.       Player_SendBuffer_Add (player, 1000, program->command_go); // tell engine it's now the current player
  461.       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
  462.    }
  463.  
  464.    // have we been notified that the current player just changed ?
  465.    if (the_board.has_playerchanged)
  466.    {
  467.       Debug_Log (L"===Got player change notification from interface===\n");
  468.  
  469.       // is the current player our color ? (meaning is it engine's turn to play) ?
  470.       if (Board_ColorToMove (&the_board) == player->color)
  471.       {
  472.          // is it NOT a board setup AND has at least one move been played (meaning it was just the other's turn before) ?
  473.          if (!the_board.was_setup && (the_board.move_count > 1))
  474.          {
  475.             Debug_Log (L"===Player just played, sending the chosen move to engine===\n");
  476.             if (_wcsnicmp (program->name, L"Crafty", 6) == 0)
  477.                Player_SendBuffer_Add (player, 1000, L"disp\n");
  478.  
  479.             // instruct it about its allowed search depth BEFORE each move (this ensures engine will be "ready" to handle the command)
  480.             // then build the move string, and send the move string to the engine
  481.             Player_SendBuffer_Add (player, 1000, program->command_sd, options.engine.depth);
  482.             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
  483.             Player_SendBuffer_Add (player, 1000, program->command_move, Move_BuildString (&the_board.moves[the_board.move_count - 1]));
  484.             Player_SendBuffer_Add (player, 1000, L"\n"); // end the send buffer with a carriage return
  485.          }
  486.  
  487.          // else game has not started yet, but it's our turn
  488.          else
  489.          {
  490.             Player_SendBuffer_Add (player, 1000, program->command_go); // so let's start the game
  491.             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
  492.          }
  493.       }
  494.    }
  495.  
  496.    // END NOTIFICATIONS PROCESSING
  497.    ///////////////////////////////
  498.  
  499.    // is it NOT our turn ?
  500.    if (current_player != player)
  501.    {
  502.       // does our opponent want a hint ?
  503.       if (current_player->wants_hint)
  504.       {
  505.          current_player->wants_hint = false; // don't ask twice
  506.          Debug_Log (L"===Hint requested, asking engine for it===\n");
  507.          Player_SendBuffer_Add (player, 1000, program->command_go); // tell the computer to analyze this position
  508.          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
  509.          is_hint_pending = true; // remember a hint is pending
  510.  
  511.          // FIXME: move to scene.cpp
  512.          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
  513.          the_scene.gui.want_spinwheel = true; // start spinning wheel
  514.          do_update = true; // remember to update the 3D scene
  515.       }
  516.  
  517.       // does our opponent want to cancel a move ?
  518.       if (current_player->wants_cancel)
  519.       {
  520.          current_player->wants_cancel = false; // don't ask twice (remember now before we switch players)
  521.          Debug_Log (L"===Move cancellation requested, rebuilding board and telling engine to backup 2 moves===\n");
  522.  
  523.          // rewind game 2 moves back
  524.          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);
  525.          the_board.move_count = max (1, the_board.move_count - 2); // figure out how many moves we have now
  526.          the_board.viewed_move = the_board.move_count - 1; // take us back to the last move
  527.          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)
  528.  
  529.          // just set up the board from its Forsyth-Edwards notation
  530.          Debug_Log (L"===setting up board using FEN string===\n");
  531.  
  532.          // instruct it about its allowed search depth BEFORE each table set (this ensures engine will be "ready" to handle the command)
  533.          // then get the current game state in FEN format and feed it to the engine
  534.          Player_SendBuffer_Add (player, 1000, program->command_sd, options.engine.depth);
  535.          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
  536.          Player_SendBuffer_Add (player, 1000, program->command_setboard, the_board.moves[the_board.move_count - 1].fen_string);
  537.          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
  538.  
  539.          if (_wcsnicmp (program->name, L"Crafty", 6) == 0)
  540.             Player_SendBuffer_Add (player, 1000, L"disp\n");
  541.  
  542.          do_update = true; // remember to update the 3D scene
  543.       }
  544.    }
  545.  
  546.    // write to pipe (when we're allowed to)
  547.    if (!player->sendbuffer_locked && (animation_endtime + 1.0f < current_time))
  548.       PlayerEngine_Send (player);
  549.  
  550.    return (do_update); // finished, return whether we should update the scene or not
  551. }
  552.  
  553.  
  554. static void PlayerEngine_Recv (player_t *player)
  555. {
  556.    // helper function to read data from the pipe communicating with the game engine process
  557.  
  558.    //unsigned long amount_to_read;
  559.    unsigned long read_count;
  560.    int length;
  561.    unsigned int initial_pos;
  562.  
  563.    // get reception buffer's initial end position
  564.    initial_pos = wcslen (player->recvbuffer);
  565.    length = initial_pos;
  566.  
  567.    // as long as the pipe reports us there is data to read, read one byte at a time
  568.    while (!_eof (engine_to_chessgiants[RD]))
  569.    {
  570.       read_count = _read (engine_to_chessgiants[RD], player->ascii_recvbuffer, 1);
  571.       if (read_count == 0)
  572.          break; // read the pipe; if it fails, stop trying
  573.       if ((player->ascii_recvbuffer[0] == '\r') || (player->ascii_recvbuffer[0] == '%'))
  574.          continue; // ignore carriage returns and percent signs
  575.  
  576.       // convert the received character to wide char and append it to recvbuffer
  577.       player->ascii_recvbuffer[1] = 0; // terminate the received string ourselves
  578.       ConvertToWideChar (&player->recvbuffer[length], player->recvbuffer_size - length, player->ascii_recvbuffer);
  579.       length++; // there's one more character in the player's recv buffer
  580.    }
  581.  
  582.    // write what we received (if we received anything)
  583.    if (wcslen (player->recvbuffer) > initial_pos)
  584.       Debug_Log (L"===================================RECEIVED:===================================\n%s\n", &player->recvbuffer[initial_pos]);
  585.  
  586.    return; // finished
  587. }
  588.  
  589.  
  590. static void PlayerEngine_Send (player_t *player)
  591. {
  592.    // helper function to send data through the pipe communicating with the game engine process
  593.  
  594.    wchar_t widechar_buffer[256];
  595.    wchar_t *line_pointer;
  596.    char ascii_buffer[256];
  597.    unsigned long amount_written;
  598.  
  599.    player->sendbuffer_locked = true; // lock the buffer
  600.  
  601.    // write what we're sending (if we're sending anything)
  602.    if (player->sendbuffer[0] != 0)
  603.       Debug_Log (L"====================================SENDING:===================================\n%s\n", player->sendbuffer);
  604.  
  605.    // now read line per line...
  606.    line_pointer = player->sendbuffer; // start at the first character
  607.    while ((line_pointer = wcsgets (widechar_buffer, WCHAR_SIZEOF (widechar_buffer), line_pointer)) != NULL)
  608.    {
  609.       wcscat_s (widechar_buffer, WCHAR_SIZEOF (widechar_buffer), L"\n"); // put the carriage return back
  610.       ConvertTo7BitASCII (ascii_buffer, sizeof (ascii_buffer), widechar_buffer); // convert to ASCII
  611.       amount_written = _write (chessgiants_to_engine[WR], ascii_buffer, strlen (ascii_buffer)); // send data
  612.    }
  613.  
  614.    player->sendbuffer[0] = 0; // what we had to send has been sent, reset the send buffer
  615.    player->sendbuffer_locked = false; // and unlock it
  616.  
  617.    return; // finished
  618. }
  619.  
  620.  
  621. static wchar_t *Move_BuildString (boardmove_t *move)
  622. {
  623.    // helper function to build a move string to send to the engine from a particular board move. NOT THREAD SAFE.
  624.  
  625.    static wchar_t output_string[8];
  626.  
  627.    // construct the four first characters
  628.    swprintf_s (output_string, WCHAR_SIZEOF (output_string), L"%c%c%c%c",
  629.                L'a' + move->source[1], L'1' + move->source[0],
  630.                L'a' + move->target[1], L'1' + move->target[0]);
  631.  
  632.    // append any eventual promotion
  633.    if (move->promotion_type == PART_ROOK)
  634.       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"r");
  635.    else if (move->promotion_type == PART_KNIGHT)
  636.       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"n");
  637.    else if (move->promotion_type == PART_BISHOP)
  638.       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"b");
  639.    else if (move->promotion_type == PART_QUEEN)
  640.       wcscat_s  (output_string, WCHAR_SIZEOF (output_string), L"q");
  641.  
  642.    return (output_string); // finished, return the move string
  643. }
  644.