// san.cpp
#include "common.h"
// handy definitions
#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))))))))
#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))))))))
#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"_"))))))))
#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"_"))))))))
// prototypes of local functions
static bool SAN_DisambiguateMove (boardmove_t *move, boardmove_t *new_move);
bool Move_SetupFromSAN (boardmove_t *move, boardmove_t *new_move, int move_color)
{
// helper function to translate a SAN move into numeric from and to positions on the specified board
// WARNING: THIS FUNCTION DOES NOT RETURN WITH A FULLY CONSTRUCTED MOVE!
// FIXME: accelerate this function by reducing the number of towupper()/towlower() calls
int fieldstart;
int fieldstop;
int length;
// first, get move string length
length = wcslen (new_move->pgntext);
// parse it from the beginning
fieldstart = 0;
fieldstop = 0;
// find where it stops
while ((fieldstop < length) && !iswspace (new_move->pgntext[fieldstop]))
fieldstop++; // reach the first space
fieldstop--; // ignore the space
// does it finish with a move value estimation ?
while ((fieldstop >= fieldstart) && ((new_move->pgntext[fieldstop] == L'?') || (new_move->pgntext[fieldstop] == L'!')))
fieldstop--; // ignore these signs, they are redundant
// does it finish with a check or a checkmate sign ?
if ((fieldstop >= fieldstart) && ((new_move->pgntext[fieldstop] == L'+') || (new_move->pgntext[fieldstop] == L'#')))
fieldstop--; // chop off these signs, they are redundant
// reset relevant parts of the move we're about to build
new_move->color = move_color; // save its color
new_move->part = PART_NONE;
new_move->promotion_type = PART_NONE;
new_move->source[0] = -1;
new_move->source[1] = -1;
new_move->target[0] = -1;
new_move->target[1] = -1;
// is it a long castle ?
if ((_wcsnicmp (&new_move->pgntext[fieldstart], L"O-O-O", 5) == 0) || (wcsncmp (&new_move->pgntext[fieldstart], L"0-0-0", 5) == 0))
{
new_move->source[0] = (move_color == COLOR_WHITE ? 0 : 7);
new_move->source[1] = 4;
new_move->target[0] = (move_color == COLOR_WHITE ? 0 : 7);
new_move->target[1] = 2;
new_move->part = PART_KING; // it's a king's move
}
// else is it a short castle ?
else if ((_wcsnicmp (&new_move->pgntext[fieldstart], L"O-O", 3) == 0) || (wcsncmp (&new_move->pgntext[fieldstart], L"0-0", 3) == 0))
{
new_move->source[0] = (move_color == COLOR_WHITE ? 0 : 7);
new_move->source[1] = 4;
new_move->target[0] = (move_color == COLOR_WHITE ? 0 : 7);
new_move->target[1] = 6;
new_move->part = PART_KING; // it's a king's move
}
// else it's a normal move
else
{
// does it end with the optional "en passant" prefix ?
if ((fieldstop >= fieldstart + 4) && (wcsncmp (&new_move->pgntext[fieldstop - 3], L"e.p.", 4) == 0))
fieldstop -= 4; // if so, chop it off
// is the last character a part type ? (WARNING: PART TYPES ARE MANDATORILY IN UPPERCASE)
if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'R'))
{
new_move->promotion_type = PART_ROOK; // there's a promotion to rook
fieldstop--; // proceed to previous character
}
else if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'N'))
{
new_move->promotion_type = PART_KNIGHT; // there's a promotion to knight
fieldstop--; // proceed to previous character
}
else if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'B'))
{
new_move->promotion_type = PART_BISHOP; // there's a promotion to bishop
fieldstop--; // proceed to previous character
}
else if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'Q'))
{
new_move->promotion_type = PART_QUEEN; // there's a promotion to queen
fieldstop--; // proceed to previous character
}
// is there the promotion's equal sign ?
if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'='))
fieldstop--; // skip it, it's redundant
// read the target line and column
if (fieldstop >= fieldstart)
{
new_move->target[0] = WCHAR_TO_LINE (new_move->pgntext[fieldstop]); // read the target line
fieldstop--; // proceed to previous character
}
if (fieldstop >= fieldstart)
{
new_move->target[1] = WCHAR_TO_COLUMN (new_move->pgntext[fieldstop]); // read the target column (WARNING: ONLY IF LOWERCASE)
fieldstop--; // proceed to previous character
}
if ((fieldstop >= fieldstart) && (new_move->pgntext[fieldstop] == L'x'))
fieldstop--; // if there's a taking piece indication, it's superfluous, so skip it
// read the optional source line and column
if ((fieldstop >= fieldstart) && (WCHAR_TO_LINE (new_move->pgntext[fieldstop]) != -1))
{
new_move->source[0] = WCHAR_TO_LINE (new_move->pgntext[fieldstop]); // read the source line
fieldstop--; // proceed to previous character
}
if ((fieldstop >= fieldstart) && (WCHAR_TO_COLUMN (new_move->pgntext[fieldstop]) != -1))
{
new_move->source[1] = WCHAR_TO_COLUMN (new_move->pgntext[fieldstop]); // read the source column (WARNING: ONLY IF LOWERCASE)
fieldstop--; // proceed to previous character
}
// read the part's type (WARNING: PART TYPES ARE MANDATORILY IN UPPERCASE)
if (fieldstop >= fieldstart)
{
if (new_move->pgntext[fieldstop] == L'R') new_move->part = PART_ROOK; // it's a rook
else if (new_move->pgntext[fieldstop] == L'N') new_move->part = PART_KNIGHT; // it's a knight
else if (new_move->pgntext[fieldstop] == L'B') new_move->part = PART_BISHOP; // it's a bishop
else if (new_move->pgntext[fieldstop] == L'Q') new_move->part = PART_QUEEN; // it's a queen
else if (new_move->pgntext[fieldstop] == L'K') new_move->part = PART_KING; // it's a king
else if (new_move->pgntext[fieldstop] == L'P') new_move->part = PART_PAWN; // it's a pawn (Wikipedia says "P" is a valid part type in PGN texts...)
else return (false); // on error, cancel
}
else
new_move->part = PART_PAWN; // if not specified, it's a pawn
}
// now, disambiguate.
return (SAN_DisambiguateMove (move, new_move));
}
bool Move_DescribeInSAN (boardmove_t *move)
{
// convert a board and its part placements into a SAN notation, writing in the pgntext buffer
int line;
int column;
boardslot_t *slot;
bool needs_line;
bool needs_column;
// build move string in abbreviated algebraic notation
move->pgntext[0] = 0;
// is it a king castling or a normal move ?
if ((move->part == PART_KING) && (move->source[1] == 4) && (move->target[1] == 2))
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"O-O-O"); // long castle
else if ((move->part == PART_KING) && (move->source[1] == 4) && (move->target[1] == 6))
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"O-O"); // short castle
else
{
// part identifier (omit it if pawn)
if (move->part == PART_ROOK)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"R");
else if (move->part == PART_KNIGHT)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"N");
else if (move->part == PART_BISHOP)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"B");
else if (move->part == PART_QUEEN)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"Q");
else if (move->part == PART_KING)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"K");
// is it a pawn taking ?
if ((move->part == PART_PAWN) && (move->has_captured))
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), COLUMN_TO_WSTRING (move->source[1]));
// else is there a possible ambiguity ? (not for pawns)
if ((move->part != PART_PAWN) && (Move_CountPartsByColorAndType (move, move->color, move->part) > 1))
{
// assume we don't need to disambiguate neither by column nor by line
needs_column = false;
needs_line = false;
// cycle through the board and find all this part's siblings (be sure to parse them all)
for (line = 0; line < 8; line++)
for (column = 0; column < 8; column++)
{
slot = &move->slots[line][column]; // quick access to slot
// is this slot occupied by one of our siblings that is not the one doing the move AND its movement is valid ?
if ((slot->part == move->part) && (slot->color == move->color) && ((line != move->source[0]) || (column != move->source[1]))
&& Move_IsMoveValid (move, line, column, move->target[0], move->target[1]))
{
if (column != move->source[1])
needs_column = true; // if columns differ, remember to write start column
else
needs_line = true; // else if lines differ, remember to write start line
}
}
// do we need to write start column or start line ?
if (needs_column)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), COLUMN_TO_WSTRING (move->source[1])); // if so, write start column
if (needs_line)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), LINE_TO_WSTRING (move->source[0])); // if so, write start line
}
// does it capture something ?
if (move->has_captured)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"x");
// target column, target line
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), COLUMN_TO_WSTRING (move->target[1]));
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), LINE_TO_WSTRING (move->target[0]));
// is there a promotion ?
if (move->promotion_type == PART_ROOK)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=R");
else if (move->promotion_type == PART_KNIGHT)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=N");
else if (move->promotion_type == PART_BISHOP)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=B");
else if (move->promotion_type == PART_QUEEN)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=Q");
else if (move->promotion_type == PART_KING)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"=K");
// is there a check or a checkmate ?
if (move->is_check)
{
if (move->is_stalemate)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"#"); // checkmate
else
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"+"); // normal check
}
// is it an en passant coup ?
if (move->is_enpassant)
wcscat_s (move->pgntext, WCHAR_SIZEOF (move->pgntext), L"e.p.");
}
return (true); // finished
}
static bool SAN_DisambiguateMove (boardmove_t *move, boardmove_t *new_move)
{
// handy helper to disambiguate a move literal of which we don't know the source,
// but for which we know the part type and the target slot
int index_line;
int index_column;
// are both source line and column known ?
if ((new_move->source[0] != -1) && (new_move->source[1] != -1))
return (true); // no need to disambiguate anything
// else is source line known ?
else if (new_move->source[0] != -1)
{
// cycle through all the columns and find the part of the same type that has the right to move there
for (index_column = 0; index_column < 8; index_column++)
if ((move->slots[new_move->source[0]][index_column].color == new_move->color)
&& (move->slots[new_move->source[0]][index_column].part == new_move->part)
&& Move_IsMoveValid (move, new_move->source[0], index_column, new_move->target[0], new_move->target[1]))
{
new_move->source[1] = index_column; // save column
return (true); // we've found it, stop searching
}
}
// else is source column known ?
else if (new_move->source[1] != -1)
{
// cycle through all the lines and find the part of the same type that has the right to move there
for (index_line = 0; index_line < 8; index_line++)
if ((move->slots[index_line][new_move->source[1]].color == new_move->color)
&& (move->slots[index_line][new_move->source[1]].part == new_move->part)
&& Move_IsMoveValid (move, index_line, new_move->source[1], new_move->target[0], new_move->target[1]))
{
new_move->source[0] = index_line; // save line
return (true); // we've found it, stop searching
}
}
// else neither source line nor column is known
else
{
// cycle through all the board and find the part of the same type that has the right to move there
for (index_line = 0; index_line < 8; index_line++)
for (index_column = 0; index_column < 8; index_column++)
if ((move->slots[index_line][index_column].color == new_move->color)
&& (move->slots[index_line][index_column].part == new_move->part)
&& Move_IsMoveValid (move, index_line, index_column, new_move->target[0], new_move->target[1]))
{
new_move->source[0] = index_line; // save line and column
new_move->source[1] = index_column;
return (true); // we've found it, stop searching
}
}
return (false); // no possibility found
}