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