Bitboard checkSqs, b;
Square from;
- const Square* ptr = pos.piece_list_begin(us, Pt);
+ const Square* pl = pos.piece_list(us, Pt);
- if ((from = *ptr++) == SQ_NONE)
+ if ((from = *pl++) == SQ_NONE)
return mlist;
checkSqs = pos.attacks_from<Pt>(ksq) & pos.empty_squares();
b = pos.attacks_from<Pt>(from) & checkSqs;
SERIALIZE_MOVES(b);
- } while ((from = *ptr++) != SQ_NONE);
+ } while ((from = *pl++) != SQ_NONE);
return mlist;
}
Bitboard b;
Square from;
- const Square* ptr = pos.piece_list_begin(us, Pt);
+ const Square* pl = pos.piece_list(us, Pt);
- if (*ptr != SQ_NONE)
+ if (*pl != SQ_NONE)
{
do {
- from = *ptr;
+ from = *pl;
b = pos.attacks_from<Pt>(from) & target;
SERIALIZE_MOVES(b);
- } while (*++ptr != SQ_NONE);
+ } while (*++pl != SQ_NONE);
}
return mlist;
}
MoveStack* generate(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
- assert(!pos.is_check());
+ assert(!pos.in_check());
Color us = pos.side_to_move();
Bitboard target;
if (Type == MV_CAPTURE || Type == MV_NON_EVASION)
- target = pos.pieces_of_color(opposite_color(us));
+ target = pos.pieces(opposite_color(us));
else if (Type == MV_NON_CAPTURE)
target = pos.empty_squares();
else
mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- if (Type != MV_CAPTURE)
+ if (Type != MV_CAPTURE && pos.can_castle(us))
{
- if (pos.can_castle_kingside(us))
+ if (pos.can_castle(us == WHITE ? WHITE_OO : BLACK_OO))
mlist = generate_castle_moves<KING_SIDE>(pos, mlist, us);
- if (pos.can_castle_queenside(us))
+ if (pos.can_castle(us == WHITE ? WHITE_OOO : BLACK_OOO))
mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist, us);
}
MoveStack* generate<MV_NON_CAPTURE_CHECK>(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
- assert(!pos.is_check());
+ assert(!pos.in_check());
Bitboard b, dc;
Square from;
while (b)
{
from = pop_1st_bit(&b);
- switch (pos.type_of_piece_on(from))
+ switch (piece_type(pos.piece_on(from)))
{
case PAWN: /* Will be generated togheter with pawns direct checks */ break;
case KNIGHT: mlist = generate_discovered_checks<KNIGHT>(pos, mlist, from); break;
MoveStack* generate<MV_EVASION>(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
- assert(pos.is_check());
+ assert(pos.in_check());
Bitboard b, target;
Square from, checksq;
checkersCnt++;
checksq = pop_1st_bit(&b);
- assert(pos.color_of_piece_on(checksq) == opposite_color(us));
+ assert(piece_color(pos.piece_on(checksq)) == opposite_color(us));
- switch (pos.type_of_piece_on(checksq))
+ switch (piece_type(pos.piece_on(checksq)))
{
case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break;
case QUEEN:
- // In case of a queen remove also squares attacked in the other direction to
- // avoid possible illegal moves when queen and king are on adjacent squares.
- if (RookPseudoAttacks[checksq] & (1ULL << ksq))
- sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from<BISHOP>(checksq);
+ // If queen and king are far we can safely remove all the squares attacked
+ // in the other direction becuase are not reachable by the king anyway.
+ if (squares_between(ksq, checksq) || (RookPseudoAttacks[checksq] & (1ULL << ksq)))
+ sliderAttacks |= QueenPseudoAttacks[checksq];
+
+ // Otherwise, if king and queen are adjacent and on a diagonal line, we need to
+ // use real rook attacks to check if king is safe to move in the other direction.
+ // For example: king in B2, queen in A1 a knight in B1, and we can safely move to C1.
else
sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from<ROOK>(checksq);
+
default:
break;
}
} while (b);
// Generate evasions for king, capture and non capture moves
- b = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
+ b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
from = ksq;
SERIALIZE_MOVES(b);
}
-/// generate<MV_LEGAL / MV_PSEUDO_LEGAL> computes a complete list of legal
-/// or pseudo-legal moves in the current position.
-template<>
-MoveStack* generate<MV_PSEUDO_LEGAL>(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
-
- return pos.is_check() ? generate<MV_EVASION>(pos, mlist)
- : generate<MV_NON_EVASION>(pos, mlist);
-}
+/// generate<MV_LEGAL> computes a complete list of legal moves in the current position
template<>
MoveStack* generate<MV_LEGAL>(const Position& pos, MoveStack* mlist) {
MoveStack *last, *cur = mlist;
Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- last = generate<MV_PSEUDO_LEGAL>(pos, mlist);
+ last = pos.in_check() ? generate<MV_EVASION>(pos, mlist)
+ : generate<MV_NON_EVASION>(pos, mlist);
// Remove illegal moves from the list
while (cur != last)
Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;
Bitboard pawns = pos.pieces(PAWN, Us);
Bitboard pawnsOn7 = pawns & TRank7BB;
- Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces_of_color(Them));
+ Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces(Them));
// Pre-calculate pawn pushes before changing emptySquares definition
if (Type != MV_CAPTURE)
// Single and double pawn pushes
if (Type != MV_CAPTURE)
{
- b1 = pawnPushes & emptySquares;
+ b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
b2 = move_pawns<TDELTA_N>(pawnPushes & TRank3BB) & emptySquares;
if (Type == MV_CHECK)
template<CastlingSide Side>
MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
+ CastleRight f = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us);
Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
- assert(pos.piece_on(ksq) == make_piece(us, KING));
-
- 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;
-
- assert(pos.piece_on(rsq) == make_piece(us, ROOK));
-
- // 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.attackers_to(s) & pos.pieces_of_color(them)))
- illegal = true;
+ // After castling, the rook and king's final positions are exactly the same
+ // in Chess960 as they would be in standard chess.
+ Square kfrom = pos.king_square(us);
+ Square rfrom = pos.castle_rook_square(f);
+ Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
+
+ 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 = Min(kfrom, kto); s <= Max(kfrom, kto); s++)
+ if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ ||(pos.attackers_to(s) & pos.pieces(them)))
+ return mlist;
- for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ for (Square s = Min(rfrom, rto); s <= Max(rfrom, rto); s++)
+ if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ return mlist;
- if ( Side == QUEEN_SIDE
- && square_file(rsq) == FILE_B
- && ( pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, ROOK)
- || pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, QUEEN)))
- illegal = true;
+ // Because we generate only legal castling moves we need to verify that
+ // when moving the castling rook we do not discover some hidden checker.
+ // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
+ if (pos.is_chess960())
+ {
+ Bitboard occ = pos.occupied_squares();
+ clear_bit(&occ, rfrom);
+ if (pos.attackers_to(kto, occ) & pos.pieces(them))
+ return mlist;
+ }
- if (!illegal)
- (*mlist++).move = make_castle_move(ksq, rsq);
+ (*mlist++).move = make_castle_move(kfrom, rfrom);
return mlist;
}
projects / stockfish / blobdiff