// 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
// Remove illegal moves from the list
for (int i = 0; i < n; i++)
- if (!pos.move_is_legal(mlist[i].move, pinned))
+ if (!pos.pl_move_is_legal(mlist[i].move, pinned))
mlist[i--].move = mlist[--n].move;
return n;
}
-/// generate_move_if_legal() takes a position and a (not necessarily
-/// pseudo-legal) move and a pinned pieces bitboard as input, and tests
-/// whether the move is legal. If the move is legal, the move itself is
-/// returned. If not, the function returns MOVE_NONE. This function must
+/// move_is_legal() takes a position and a (not necessarily pseudo-legal)
+/// move and a pinned pieces bitboard as input, and tests whether
+/// the move is legal. If the move is legal, the move itself is
+/// returned. If not, the function returns false. This function must
/// only be used when the side to move is not in check.
-Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) {
+bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
assert(pos.is_ok());
assert(!pos.is_check());
// If the from square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
if (color_of_piece(pc) != us)
- return MOVE_NONE;
+ return false;
Square to = move_to(m);
// en passant square.
if ( type_of_piece(pc) != PAWN
|| to != pos.ep_square())
- return MOVE_NONE;
+ return false;
assert(pos.square_is_empty(to));
assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them));
- // The move is pseudo-legal. If it is legal, return it.
- return (pos.move_is_legal(m, pinned) ? m : MOVE_NONE);
+ // The move is pseudo-legal, check if it is also legal
+ return pos.pl_move_is_legal(m, pinned);
}
// Castling moves
// the right to castle kingside.
if ( type_of_piece(pc) != KING
||!pos.can_castle_kingside(us))
- return MOVE_NONE;
+ return false;
assert(from == pos.king_square(us));
assert(to == pos.initial_kr_square(us));
if (s != from && s != to && !pos.square_is_empty(s))
illegal = true;
- return (!illegal ? m : MOVE_NONE);
+ return !illegal;
}
if (move_is_long_castle(m))
// the right to castle kingside.
if ( type_of_piece(pc) != KING
||!pos.can_castle_queenside(us))
- return MOVE_NONE;
+ return false;
assert(from == pos.king_square(us));
assert(to == pos.initial_qr_square(us));
|| pos.piece_on(to + DELTA_W) == queen_of_color(them)))
illegal = true;
- return (!illegal ? m : MOVE_NONE);
+ return !illegal;
}
// Normal moves
// The destination square cannot be occupied by a friendly piece
if (pos.color_of_piece_on(to) == us)
- return MOVE_NONE;
+ return false;
// Proceed according to the type of the moving piece.
if (type_of_piece(pc) == PAWN)
if ( ( (square_rank(to) == RANK_8 && us == WHITE)
||(square_rank(to) == RANK_1 && us != WHITE))
&& !move_promotion(m))
- return MOVE_NONE;
+ return false;
// Proceed according to the square delta between the source and
// destionation squares.
// Capture. The destination square must be occupied by an enemy
// piece (en passant captures was handled earlier).
if (pos.color_of_piece_on(to) != them)
- return MOVE_NONE;
+ return false;
break;
case DELTA_N:
case DELTA_S:
// Pawn push. The destination square must be empty.
if (!pos.square_is_empty(to))
- return MOVE_NONE;
+ return false;
break;
case DELTA_NN:
if ( square_rank(to) != RANK_4
|| !pos.square_is_empty(to)
|| !pos.square_is_empty(from + DELTA_N))
- return MOVE_NONE;
+ return false;
break;
case DELTA_SS:
if ( square_rank(to) != RANK_5
|| !pos.square_is_empty(to)
|| !pos.square_is_empty(from + DELTA_S))
- return MOVE_NONE;
+ return false;
break;
default:
- return MOVE_NONE;
+ return false;
}
- // The move is pseudo-legal. Return it if it is legal.
- return (pos.move_is_legal(m, pinned) ? m : MOVE_NONE);
+ // The move is pseudo-legal, check if it is also legal
+ return pos.pl_move_is_legal(m, pinned);
}
// Luckly we can handle all the other pieces in one go
return ( pos.piece_attacks_square(from, to)
- && pos.move_is_legal(m, pinned)
- && !move_promotion(m) ? m : MOVE_NONE);
+ && pos.pl_move_is_legal(m, pinned)
+ && !move_promotion(m));
}
template<Color Us, Color Them, Bitboard TRank8BB, SquareDelta TDELTA_NE,
SquareDelta TDELTA_NW, SquareDelta TDELTA_N
>
- MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) {
+ MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) {
Square to;
Bitboard pawns = pos.pawns(Us);
template<Color Us, Color Them, Bitboard TRank8BB, Bitboard TRank3BB,
SquareDelta TDELTA_NE, SquareDelta TDELTA_NW, SquareDelta TDELTA_N
>
- MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
+ MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
Bitboard pawns = pos.pawns(Us);
Bitboard enemyPieces = pos.pieces_of_color(Them);