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  1. // san.cpp
  2.  
  3. #include "common.h"
  4.  
  5.  
  6. // handy definitions
  7. #define WCHAR_TO_COLUMN(a) ((a) == L'a' ? 0 : ((a) == L'b' ? 1 : ((a) == L'c' ? 2 : ((a) == L'd' ? 3 : ((a) == L'e' ? 4 : ((a) == L'f' ? 5 : ((a) == L'g' ? 6 : ((a) == L'h' ? 7 : -1))))))))
  8. #define WCHAR_TO_LINE(a) ((a) == L'1' ? 0 : ((a) == L'2' ? 1 : ((a) == L'3' ? 2 : ((a) == L'4' ? 3 : ((a) == L'5' ? 4 : ((a) == L'6' ? 5 : ((a) == L'7' ? 6 : ((a) == L'8' ? 7 : -1))))))))
  9. #define COLUMN_TO_WSTRING(c) ((c) == 0 ? L"a" : ((c) == 1 ? L"b" : ((c) == 2 ? L"c" : ((c) == 3 ? L"d" : ((c) == 4 ? L"e" : ((c) == 5 ? L"f" : ((c) == 6 ? L"g" : ((c) == 7 ? L"h" : L"_"))))))))
  10. #define LINE_TO_WSTRING(l) ((l) == 0 ? L"1" : ((l) == 1 ? L"2" : ((l) == 2 ? L"3" : ((l) == 3 ? L"4" : ((l) == 4 ? L"5" : ((l) == 5 ? L"6" : ((l) == 6 ? L"7" : ((l) == 7 ? L"8" : L"_"))))))))
  11.  
  12.  
  13. // prototypes of local functions
  14. static bool SAN_DisambiguateMove (boardmove_t *move, boardmove_t *new_move);
  15.  
  16.  
  17. bool Move_SetupFromSAN (boardmove_t *move, boardmove_t *new_move, int move_color)
  18. {
  19.    // helper function to translate a SAN move into numeric from and to positions on the specified board
  20.    // WARNING: THIS FUNCTION DOES NOT RETURN WITH A FULLY CONSTRUCTED MOVE!
  21.  
  22.    // FIXME: accelerate this function by reducing the number of towupper()/towlower() calls
  23.  
  24.    int fieldstart;
  25.    int fieldstop;
  26.    int length;
  27.  
  28.    // first, get string length
  29.    length = wcslen (new_move->pgntext);
  30.  
  31.    // parse it from the beginning
  32.    fieldstart = 0;
  33.    fieldstop = 0;
  34.  
  35.    // find where it stops
  36.    while ((fieldstop < length) && !iswspace (new_move->pgntext[fieldstop]))
  37.       fieldstop++; // reach the next space
  38.  
  39.    fieldstop--; // ignore the last space
  40.  
  41.    // reset relevant parts of the move we're about to build
  42.    new_move->color = move_color; // save its color
  43.    new_move->part = PART_NONE;
  44.    new_move->promotion_type = PART_NONE;
  45.    new_move->source[0] = -1;
  46.    new_move->source[1] = -1;
  47.    new_move->target[0] = -1;
  48.    new_move->target[1] = -1;
  49.  
  50.    // does it finish with a move value estimation ?
  51.    while ((fieldstop >= fieldstart) && ((new_move->pgntext[fieldstop] == L'?') || (new_move->pgntext[fieldstop] == L'!')))
  52.       fieldstop--; // chop off these signs, they are redundant
  53.  
  54.    // does it finish with a check or a checkmate sign ?
  55.    if ((fieldstop >= fieldstart) && ((new_move->pgntext[fieldstop] == L'+') || (new_move->pgntext[fieldstop] == L'#')))
  56.       fieldstop--; // chop off these signs, they are redundant
  57.  
  58.    // is it a long castle ?
  59.    if ((_wcsnicmp (&new_move->pgntext[fieldstart], L"O-O-O", 5) == 0) || (wcsncmp (&new_move->pgntext[fieldstart], L"0-0-0", 5) == 0))
  60.    {
  61.       new_move->source[0] = (move_color == COLOR_WHITE ? 0 : 7);
  62.       new_move->source[1] = 4;
  63.       new_move->target[0] = (move_color == COLOR_WHITE ? 0 : 7);
  64.       new_move->target[1] = 2;
  65.       new_move->part = PART_KING; // it's a king's move
  66.    }
  67.  
  68.    // else is it a short castle ?
  69.    else if ((_wcsnicmp (&new_move->pgntext[fieldstart], L"O-O", 3) == 0) || (wcsncmp (&new_move->pgntext[fieldstart], L"0-0", 3) == 0))
  70.    {
  71.       new_move->source[0] = (move_color == COLOR_WHITE ? 0 : 7);
  72.       new_move->source[1] = 4;
  73.       new_move->target[0] = (move_color == COLOR_WHITE ? 0 : 7);
  74.       new_move->target[1] = 6;
  75.       new_move->part = PART_KING; // it's a king's move
  76.    }
  77.  
  78.    // else it's a normal move
  79.    else
  80.    {
  81.       // is the last character a part type ?
  82.       if ((fieldstop >= fieldstart) && (towupper (new_move->pgntext[fieldstop]) == L'R'))
  83.       {
  84.          new_move->promotion_type = PART_ROOK; // there's a promotion to rook
  85.          fieldstop--; // proceed to previous character
  86.       }
  87.       else if ((fieldstop >= fieldstart) && (towupper (new_move->pgntext[fieldstop]) == L'N'))
  88.       {
  89.          new_move->promotion_type = PART_KNIGHT; // there's a promotion to knight
  90.          fieldstop--; // proceed to previous character
  91.       }
  92.       else if ((fieldstop >= fieldstart) && (towupper (new_move->pgntext[fieldstop]) == L'B'))
  93.       {
  94.          new_move->promotion_type = PART_BISHOP; // there's a promotion to bishop
  95.          fieldstop--; // proceed to previous character
  96.       }
  97.       else if ((fieldstop >= fieldstart) && (towupper (new_move->pgntext[fieldstop]) == L'Q'))
  98.       {
  99.          new_move->promotion_type = PART_QUEEN; // there's a promotion to queen
  100.          fieldstop--; // proceed to previous character
  101.       }
  102.  
  103.       // is there the promotion's equal sign ?
  104.       if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'='))
  105.          fieldstop--; // skip it, it's redundant
  106.  
  107.       // read the target line and column
  108.       if (fieldstop >= fieldstart)
  109.       {
  110.          new_move->target[0] = WCHAR_TO_LINE (new_move->pgntext[fieldstop]); // read the target line
  111.          fieldstop--; // proceed to previous character
  112.       }
  113.       if (fieldstop >= fieldstart)
  114.       {
  115.          new_move->target[1] = WCHAR_TO_COLUMN (towlower (new_move->pgntext[fieldstop])); // read the target column
  116.          fieldstop--; // proceed to previous character
  117.       }
  118.  
  119.       if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'x'))
  120.          fieldstop--; // if there's a taking piece indication, it's superfluous, so skip it
  121.  
  122.       // read the eventual source line and column
  123.       if ((fieldstop >= fieldstart) && (WCHAR_TO_LINE (new_move->pgntext[fieldstop]) != -1))
  124.       {
  125.          new_move->source[0] = WCHAR_TO_LINE (new_move->pgntext[fieldstop]); // read the source line
  126.          fieldstop--; // proceed to previous character
  127.       }
  128.       if ((fieldstop >= fieldstart) && (WCHAR_TO_COLUMN (towlower (new_move->pgntext[fieldstop])) != -1))
  129.       {
  130.          new_move->source[1] = WCHAR_TO_COLUMN (towlower (new_move->pgntext[fieldstop])); // read the source column
  131.          fieldstop--; // proceed to previous character
  132.       }
  133.  
  134.       // read the part's type
  135.       if (fieldstop >= fieldstart)
  136.       {
  137.          if (towupper (new_move->pgntext[fieldstop]) == L'R')
  138.             new_move->part = PART_ROOK; // it's a rook
  139.          else if (towupper (new_move->pgntext[fieldstop]) == L'N')
  140.             new_move->part = PART_KNIGHT; // it's a knight
  141.          else if (towupper (new_move->pgntext[fieldstop]) == L'B')
  142.             new_move->part = PART_BISHOP; // it's a bishop
  143.          else if (towupper (new_move->pgntext[fieldstop]) == L'Q')
  144.             new_move->part = PART_QUEEN; // it's a queen
  145.          else if (towupper (new_move->pgntext[fieldstop]) == L'K')
  146.             new_move->part = PART_KING; // it's a king
  147.          else
  148.             return (false); // on error, cancel
  149.       }
  150.       else
  151.          new_move->part = PART_PAWN; // if not specified, it's a pawn
  152.    }
  153.  
  154.    // now, disambiguate.
  155.    return (SAN_DisambiguateMove (move, new_move));
  156. }
  157.  
  158.  
  159. bool Move_DescribeInSAN (boardmove_t *move)
  160. {
  161.    // convert a board and its part placements into a SAN notation, writing in the pgntext buffer
  162.  
  163.    int line;
  164.    int column;
  165.    boardslot_t *slot;
  166.    bool needs_line;
  167.    bool needs_column;
  168.  
  169.    // build move string in abbreviated algebraic notation
  170.    move->pgntext[0] = 0;
  171.  
  172.    // is it a king castling or a normal move ?
  173.    if ((move->part == PART_KING) && (move->source[1] == 4) && (move->target[1] == 2))
  174.       wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"O-O-O"); // long castle
  175.    else if ((move->part == PART_KING) && (move->source[1] == 4) && (move->target[1] == 6))
  176.       wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"O-O"); // short castle
  177.    else
  178.    {
  179.       // part identifier (omit it if pawn)
  180.       if (move->part == PART_ROOK)
  181.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"R");
  182.       else if (move->part == PART_KNIGHT)
  183.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"N");
  184.       else if (move->part == PART_BISHOP)
  185.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"B");
  186.       else if (move->part == PART_QUEEN)
  187.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"Q");
  188.       else if (move->part == PART_KING)
  189.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"K");
  190.  
  191.       // is it a pawn taking ?
  192.       if ((move->part == PART_PAWN) && (move->has_captured))
  193.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), COLUMN_TO_WSTRING (move->source[1]));
  194.  
  195.       // else is there a possible ambiguity ? (not for pawns)
  196.       if ((move->part != PART_PAWN) && (Move_CountPartsByColorAndType (move, move->color, move->part) > 1))
  197.       {
  198.          // assume we don't need to disambiguate neither by column nor by line
  199.          needs_column = false;
  200.          needs_line = false;
  201.  
  202.          // cycle through the board and find all this part's siblings (be sure to parse them all)
  203.          for (line = 0; line < 8; line++)
  204.             for (column = 0; column < 8; column++)
  205.             {
  206.                slot = &move->slots[line][column]; // quick access to slot
  207.  
  208.                // is this slot occupied by one of our siblings that is not the one doing the move AND its movement is valid ?
  209.                if ((slot->part == move->part) && (slot->color == move->color) && ((line != move->source[0]) || (column != move->source[1]))
  210.                    && Move_IsMoveValid (move, line, column, move->target[0], move->target[1]))
  211.                {
  212.                   if (column != move->source[1])
  213.                      needs_column = true; // if columns differ, remember to write start column
  214.                   else
  215.                      needs_line = true; // else if lines differ, remember to write start line
  216.                }
  217.             }
  218.  
  219.          // do we need to write start column or start line ?
  220.          if (needs_column)
  221.             wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), COLUMN_TO_WSTRING (move->source[1])); // if so, write start column
  222.          if (needs_line)
  223.             wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), LINE_TO_WSTRING (move->source[0])); // if so, write start line
  224.       }
  225.  
  226.       // does it capture something ?
  227.       if (move->has_captured)
  228.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"x");
  229.  
  230.       // target column, target line
  231.       wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), COLUMN_TO_WSTRING (move->target[1]));
  232.       wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), LINE_TO_WSTRING (move->target[0]));
  233.  
  234.       // is there a promotion ?
  235.       if (move->promotion_type == PART_ROOK)
  236.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=R");
  237.       else if (move->promotion_type == PART_KNIGHT)
  238.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=N");
  239.       else if (move->promotion_type == PART_BISHOP)
  240.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=B");
  241.       else if (move->promotion_type == PART_QUEEN)
  242.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=Q");
  243.       else if (move->promotion_type == PART_KING)
  244.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=K");
  245.  
  246.       // is there a check or a checkmate ?
  247.       if (move->is_check)
  248.       {
  249.          if (move->is_stalemate)
  250.             wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"#"); // checkmate
  251.          else
  252.             wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"+"); // normal check
  253.       }
  254.  
  255.       // is it an en passant coup ?
  256.       if (move->is_enpassant)
  257.          wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"e.p.");
  258.    }
  259.  
  260.    return (true); // finished
  261. }
  262.  
  263.  
  264. static bool SAN_DisambiguateMove (boardmove_t *move, boardmove_t *new_move)
  265. {
  266.    // handy helper to disambiguate a move literal of which we don't know the source,
  267.    // but for which we know the part type and the target slot
  268.  
  269.    int index_line;
  270.    int index_column;
  271.  
  272.    // are both source line and column known ?
  273.    if ((new_move->source[0] != -1) && (new_move->source[1] != -1))
  274.       return (true); // no need to disambiguate anything
  275.  
  276.    // else is source line known ?
  277.    else if (new_move->source[0] != -1)
  278.    {
  279.       // cycle through all the columns and find the part of the same type that has the right to move there
  280.       for (index_column = 0; index_column < 8; index_column++)
  281.          if ((move->slots[new_move->source[0]][index_column].color == new_move->color)
  282.              && (move->slots[new_move->source[0]][index_column].part == new_move->part)
  283.              && Move_IsMoveValid (move, new_move->source[0], index_column, new_move->target[0], new_move->target[1]))
  284.          {
  285.             new_move->source[1] = index_column; // save column
  286.             return (true); // we've found it, stop searching
  287.          }
  288.    }
  289.  
  290.    // else is source column known ?
  291.    else if (new_move->source[1] != -1)
  292.    {
  293.       // cycle through all the lines and find the part of the same type that has the right to move there
  294.       for (index_line = 0; index_line < 8; index_line++)
  295.          if ((move->slots[index_line][new_move->source[1]].color == new_move->color)
  296.              && (move->slots[index_line][new_move->source[1]].part == new_move->part)
  297.              && Move_IsMoveValid (move, index_line, new_move->source[1], new_move->target[0], new_move->target[1]))
  298.          {
  299.             new_move->source[0] = index_line; // save line
  300.             return (true); // we've found it, stop searching
  301.          }
  302.    }
  303.  
  304.    // else neither source line nor column is known
  305.    else
  306.    {
  307.       // cycle through all the board and find the part of the same type that has the right to move there
  308.       for (index_line = 0; index_line < 8; index_line++)
  309.          for (index_column = 0; index_column < 8; index_column++)
  310.             if ((move->slots[index_line][index_column].color == new_move->color)
  311.                 && (move->slots[index_line][index_column].part == new_move->part)
  312.                 && Move_IsMoveValid (move, index_line, index_column, new_move->target[0], new_move->target[1]))
  313.             {
  314.                new_move->source[0] = index_line; // save line and column
  315.                new_move->source[1] = index_column;
  316.                return (true); // we've found it, stop searching
  317.             }
  318.    }
  319.  
  320.    return (false); // no possibility found
  321. }
  322.