const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO,
Side ? BLACK_OOO : BLACK_OO };
- if (!pos.can_castle(CR[us]))
+ if (pos.castle_impeded(CR[us]) || !pos.can_castle(CR[us]))
return mlist;
// After castling, the rook and king final positions are the same in Chess960
Square kfrom = pos.king_square(us);
Square rfrom = pos.castle_rook_square(CR[us]);
Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
Bitboard enemies = pos.pieces(~us);
assert(!pos.in_check());
assert(pos.piece_on(kfrom) == make_piece(us, KING));
assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
- // Unimpeded rule: All the squares between the king's initial and final squares
- // (including the final square), and all the squares between the rook's initial
- // and final squares (including the final square), must be vacant except for
- // the king and castling rook.
- for (Square s = std::min(rfrom, rto), e = std::max(rfrom, rto); s <= e; s++)
- if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- return mlist;
-
for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
- if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- ||(pos.attackers_to(s) & enemies))
+ if ( s != kfrom // We are not in check
+ && (pos.attackers_to(s) & enemies))
return mlist;
// Because we generate only legal castling moves we need to verify that