void move_do(board_t * board, int move) {
int me, opp;
int from, to;
int piece, pos, capture;
int old_flags, new_flags;
int sq, ep_square;
int pawn;
ASSERT(board_is_ok(board));
ASSERT(move_is_ok(move));
ASSERT(move_is_pseudo(move,board));
// init
me = board->turn;
opp = colour_opp(me);
from = move_from(move);
to = move_to(move);
piece = board->square[from];
ASSERT(colour_equal(piece,me));
pos = board->pos[from];
ASSERT(pos>=0);
// update turn
board->turn = opp;
board->key ^= random_64(RandomTurn);
// update castling rights
old_flags = board_flags(board);
if (piece_is_king(piece)) {
board->castle[me][SideH] = SquareNone;
board->castle[me][SideA] = SquareNone;
}
if (board->castle[me][SideH] == from) board->castle[me][SideH] = SquareNone;
if (board->castle[me][SideA] == from) board->castle[me][SideA] = SquareNone;
if (board->castle[opp][SideH] == to) board->castle[opp][SideH] = SquareNone;
if (board->castle[opp][SideA] == to) board->castle[opp][SideA] = SquareNone;
new_flags = board_flags(board);
board->key ^= hash_castle_key(new_flags^old_flags); // HACK
// update en-passant square
ep_square = sq = board->ep_square;
if (sq != SquareNone) {
board->key ^= random_64(RandomEnPassant+square_file(sq));
board->ep_square = SquareNone;
}
if (piece_is_pawn(piece) && abs(to-from) == 32) {
pawn = piece_make_pawn(opp);
if (board->square[to-1] == pawn || board->square[to+1] == pawn) {
board->ep_square = sq = (from + to) / 2;
board->key ^= random_64(RandomEnPassant+square_file(sq));
}
}
// update ply number (captures are handled later)
board->ply_nb++;
if (piece_is_pawn(piece)) board->ply_nb = 0; // conversion
// update move number
if (me == Black) board->move_nb++;
// castle
if (colour_equal(board->square[to],me)) {
int rank;
int king_from, king_to;
int rook_from, rook_to;
int rook;
rank = colour_is_white(me) ? Rank1 : Rank8;
king_from = from;
rook_from = to;
if (to > from) { // h side
king_to = square_make(FileG,rank);
rook_to = square_make(FileF,rank);
} else { // a side
king_to = square_make(FileC,rank);
rook_to = square_make(FileD,rank);
}
// remove the rook
pos = board->pos[rook_from];
ASSERT(pos>=0);
rook = Rook64 | me; // HACK
square_clear(board,rook_from,rook);
// move the king
square_move(board,king_from,king_to,piece);
// put the rook back
square_set(board,rook_to,rook,pos);
ASSERT(board->key==hash_key(board));
return;
}
// remove the captured piece
if (piece_is_pawn(piece) && to == ep_square) {
// en-passant capture
sq = square_ep_dual(to);
capture = board->square[sq];
ASSERT(capture==piece_make_pawn(opp));
square_clear(board,sq,capture);
board->ply_nb = 0; // conversion
} else {
capture = board->square[to];
if (capture != Empty) {
// normal capture
ASSERT(colour_equal(capture,opp));
ASSERT(!piece_is_king(capture));
square_clear(board,to,capture);
board->ply_nb = 0; // conversion
}
}
// move the piece
if (move_is_promote(move)) {
// promote
square_clear(board,from,piece);
piece = move_promote_hack(move) | me; // HACK
square_set(board,to,piece,pos);
} else {
// normal move
square_move(board,from,to,piece);
}
ASSERT(board->key==hash_key(board));
}
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;
}
