namespace {
+ enum CastlingSide {
+ KING_SIDE,
+ QUEEN_SIDE
+ };
+
// Function
+ bool castling_is_check(const Position&, CastlingSide);
+
+ // Template
+ template<CastlingSide Side>
MoveStack* generate_castle_moves(const Position&, MoveStack*);
// Template generate_pawn_captures() with specializations
Bitboard target = pos.pieces_of_color(opposite_color(us));
MoveStack* mlist_start = mlist;
+ mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
+ mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
+ mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
+
if (us == WHITE)
mlist = generate_pawn_captures<WHITE>(pos, mlist);
else
mlist = generate_pawn_captures<BLACK>(pos, mlist);
- mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
- mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
- mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
- mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<KING>(pos, mlist, us, target);
return int(mlist - mlist_start);
}
mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- mlist = generate_castle_moves(pos, mlist);
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
return int(mlist - mlist_start);
}
/// generate_checks() generates all pseudo-legal non-capturing, non-promoting
-/// checks, except castling moves (will add this later). It returns the
-/// number of generated moves.
+/// checks. It returns the number of generated moves.
int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
// Hopefully we always have a king ;-)
mlist = generate_piece_checks_king(pos, pos.king_square(us), dc, ksq, mlist);
- // TODO: Castling moves!
+ // Castling moves that give check. Very rare but nice to have!
+ if ( pos.can_castle_queenside(us)
+ && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_D)
+ && castling_is_check(pos, QUEEN_SIDE))
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
+
+ if ( pos.can_castle_kingside(us)
+ && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_F)
+ && castling_is_check(pos, KING_SIDE))
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
return int(mlist - mlist_start);
}
// Pawn moves. Because a blocking evasion can never be a capture, we
// only generate pawn pushes.
if (us == WHITE)
- generate_pawn_blocking_evasions<WHITE>(pos, not_pinned, blockSquares, mlist);
+ mlist = generate_pawn_blocking_evasions<WHITE>(pos, not_pinned, blockSquares, mlist);
else
- generate_pawn_blocking_evasions<BLACK>(pos, not_pinned, blockSquares, mlist);
+ mlist = generate_pawn_blocking_evasions<BLACK>(pos, not_pinned, blockSquares, mlist);
// Pieces moves
b1 = pos.knights(us) & not_pinned;
if (b1)
- generate_piece_blocking_evasions<KNIGHT>(pos, b1, blockSquares, mlist);
+ mlist = generate_piece_blocking_evasions<KNIGHT>(pos, b1, blockSquares, mlist);
b1 = pos.bishops(us) & not_pinned;
if (b1)
- generate_piece_blocking_evasions<BISHOP>(pos, b1, blockSquares, mlist);
+ mlist = generate_piece_blocking_evasions<BISHOP>(pos, b1, blockSquares, mlist);
b1 = pos.rooks(us) & not_pinned;
if (b1)
- generate_piece_blocking_evasions<ROOK>(pos, b1, blockSquares, mlist);
+ mlist = generate_piece_blocking_evasions<ROOK>(pos, b1, blockSquares, mlist);
b1 = pos.queens(us) & not_pinned;
if (b1)
- generate_piece_blocking_evasions<QUEEN>(pos, b1, blockSquares, mlist);
+ mlist = generate_piece_blocking_evasions<QUEEN>(pos, b1, blockSquares, mlist);
}
// Finally, the ugly special case of en passant captures. An en passant
return mlist;
}
-
+ template<CastlingSide Side>
MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) {
Color us = pos.side_to_move();
- if (pos.can_castle(us))
+ if ( (Side == KING_SIDE && pos.can_castle_kingside(us))
+ ||(Side == QUEEN_SIDE && pos.can_castle_queenside(us)))
{
Color them = opposite_color(us);
Square ksq = pos.king_square(us);
assert(pos.piece_on(ksq) == king_of_color(us));
- if (pos.can_castle_kingside(us))
- {
- Square rsq = pos.initial_kr_square(us);
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
- Square s;
- bool illegal = false;
-
- assert(pos.piece_on(rsq) == rook_of_color(us));
-
- for (s = Min(ksq, g1); s <= Max(ksq, g1); s++)
- if ( (s != ksq && s != rsq && pos.square_is_occupied(s))
- || pos.square_is_attacked(s, them))
- illegal = true;
-
- for (s = Min(rsq, f1); s <= Max(rsq, f1); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ Square rsq = (Side == KING_SIDE ? pos.initial_kr_square(us) : pos.initial_qr_square(us));
+ Square s1 = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square s2 = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
+ Square s;
+ bool illegal = false;
- if (!illegal)
- (*mlist++).move = make_castle_move(ksq, rsq);
- }
-
- if (pos.can_castle_queenside(us))
- {
- Square rsq = pos.initial_qr_square(us);
- Square c1 = relative_square(us, SQ_C1);
- Square d1 = relative_square(us, SQ_D1);
- Square s;
- bool illegal = false;
+ assert(pos.piece_on(rsq) == rook_of_color(us));
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ // It is a bit complicated to correctly handle Chess960
+ for (s = Min(ksq, s1); s <= Max(ksq, s1); s++)
+ if ( (s != ksq && s != rsq && pos.square_is_occupied(s))
+ || pos.square_is_attacked(s, them))
+ illegal = true;
- for (s = Min(ksq, c1); s <= Max(ksq, c1); s++)
- if ( (s != ksq && s != rsq && pos.square_is_occupied(s))
- || pos.square_is_attacked(s, them))
- illegal = true;
+ for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)
+ if (s != ksq && s != rsq && pos.square_is_occupied(s))
+ illegal = true;
- for (s = Min(rsq, d1); s <= Max(rsq, d1); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
-
- if ( square_file(rsq) == FILE_B
+ if ( Side == QUEEN_SIDE
+ && square_file(rsq) == FILE_B
&& ( pos.piece_on(relative_square(us, SQ_A1)) == rook_of_color(them)
|| pos.piece_on(relative_square(us, SQ_A1)) == queen_of_color(them)))
illegal = true;
if (!illegal)
(*mlist++).move = make_castle_move(ksq, rsq);
- }
}
return mlist;
}
+ bool castling_is_check(const Position& pos, CastlingSide side) {
+
+ // After castling opponent king is attacked by the castled rook?
+ File rookFile = (side == QUEEN_SIDE ? FILE_D : FILE_F);
+ Color us = pos.side_to_move();
+ Square ksq = pos.king_square(us);
+ Bitboard occ = pos.occupied_squares(), oppKingBB = EmptyBoardBB;
+
+ set_bit(&oppKingBB, pos.king_square(opposite_color(us)));
+ clear_bit(&occ, ksq); // Remove our king from the board
+ Square rsq = make_square(rookFile, square_rank(ksq));
+ return (rook_attacks_bb(rsq, occ) & oppKingBB);
+ }
}