bool is_attacked(const board_t * board, int to, int colour) {
const uint8 * ptr;
int from, piece;
ASSERT(board_is_ok(board));
ASSERT(square_is_ok(to));
ASSERT(colour_is_ok(colour));
for (ptr = board->list[colour]; (from=*ptr) != SquareNone; ptr++) {
piece = board->square[from];
ASSERT(colour_equal(piece,colour));
if (piece_attack(board,piece,from,to)) return true;
}
return false;
}
static int move_from_lan(const char string[], const board_t * board) {
int len;
int move;
int promote;
char s[256];
int from, to;
int colour;
int inc;
int piece_char;
int n;
const uint8 * ptr;
int piece;
int side;
ASSERT(string!=NULL);
ASSERT(board_is_ok(board));
// init
len = strlen(string);
if (len != 7) return MoveNone;
move = MoveNone;
colour = board->turn;
// promote
promote = 0;
switch (string[6]) {
case '?': // not a promotion
break;
case 'N':
promote = MovePromoteKnight;
break;
case 'B':
promote = MovePromoteBishop;
break;
case 'R':
promote = MovePromoteRook;
break;
case 'Q':
promote = MovePromoteQueen;
break;
default:
return MoveNone;
break;
}
// to square
s[0] = string[4];
s[1] = string[5];
s[2] = '\0';
to = square_from_string(s);
if (to == SquareNone) return MoveNone;
// known from square?
if (string[1] != '?' && string[2] != '?') {
// from square
s[0] = string[1];
s[1] = string[2];
s[2] = '\0';
from = square_from_string(s);
if (from == SquareNone) return MoveNone;
// convert "king slide" castling to KxR
if (piece_is_king(board->square[from])
&& square_rank(to) == square_rank(from)
&& abs(to-from) > 1) {
side = (to > from) ? SideH : SideA;
to = board->castle[colour][side];
if (to == SquareNone) return MoveNone;
}
// move
move = move_make(from,to) | promote;
return move;
}
// pawn non-capture?
if (string[0] == '?' && string[1] == '?') {
if (board->square[to] != Empty) return MoveNone; // useful?
inc = (colour_is_white(colour)) ? +16 : -16;
from = to - inc;
if (board->square[from] == Empty && square_side_rank(to,colour) == Rank4) {
from -= inc;
}
if (board->square[from] != piece_make_pawn(colour)) { // useful?
return MoveNone;
}
// move
move = move_make(from,to) | promote;
return move;
}
// pawn capture?
piece_char = string[0];
if (piece_char == '?' && string[1] != '?') {
piece_char = 'P';
}
// attack loop
n = 0;
for (ptr = board->list[colour]; (from=*ptr) != SquareNone; ptr++) {
piece = board->square[from];
if (toupper(piece_to_char(piece)) == piece_char) {
if (piece_attack(board,piece,from,to)) {
if (true
&& (string[1] == '?' || file_to_char(square_file(from)) == string[1])
&& (string[2] == '?' || rank_to_char(square_rank(from)) == string[2])) {
if (!is_pinned(board,from,to,colour)) {
move = move_make(from,to) | promote;
n++;
}
}
}
}
}
if (n != 1) move = MoveNone;
return move;
}