}
-/// Position::backup() is called when making a move. All information
+/// Position::backup() is called when making a move. All information
/// necessary to restore the position when the move is later unmade
-/// is saved to an UndoInfo object. The function Position::restore
+/// is saved to an UndoInfo object. The function Position::restore
/// does the reverse operation: When one does a backup followed by
/// a restore with the same UndoInfo object, the position is restored
/// to the state before backup was called.
-void Position::backup(UndoInfo &u) const {
+void Position::backup(UndoInfo& u) const {
+
u.castleRights = castleRights;
u.epSquare = epSquare;
u.checkersBB = checkersBB;
/// Position::restore() is called when unmaking a move. It copies back
/// the information backed up during a previous call to Position::backup.
-void Position::restore(const UndoInfo &u) {
+void Position::restore(const UndoInfo& u) {
+
castleRights = u.castleRights;
epSquare = u.epSquare;
checkersBB = u.checkersBB;
materialKey = u.materialKey;
rule50 = u.rule50;
lastMove = u.lastMove;
+ // u.capture is restored in undo_move()
mgValue = u.mgValue;
egValue = u.egValue;
}
/// the discovered check candidates makes it easier to update the checkersBB
/// member variable in the position object.
-void Position::do_move(Move m, UndoInfo &u) {
+void Position::do_move(Move m, UndoInfo& u) {
+
do_move(m, u, discovered_check_candidates(side_to_move()));
}
-void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) {
+void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) {
+
assert(is_ok());
assert(move_is_ok(m));
// Back up the necessary information to our UndoInfo object (except the
- // captured piece, which is taken care of later:
+ // captured piece, which is taken care of later.
backup(u);
// Save the current key to the history[] array, in order to be able to
- // detect repetition draws:
+ // detect repetition draws.
history[gamePly] = key;
- // Increment the 50 moves rule draw counter. Resetting it to zero in the
+ // Increment the 50 moves rule draw counter. Resetting it to zero in the
// case of non-reversible moves is taken care of later.
rule50++;
- if(move_is_castle(m))
- do_castle_move(m);
- else if(move_promotion(m))
- do_promotion_move(m, u);
- else if(move_is_ep(m))
- do_ep_move(m);
- else {
- Color us, them;
- Square from, to;
- PieceType piece, capture;
-
- us = side_to_move();
- them = opposite_color(us);
-
- from = move_from(m);
- to = move_to(m);
+ if (move_is_castle(m))
+ do_castle_move(m);
+ else if (move_promotion(m))
+ do_promotion_move(m, u);
+ else if (move_is_ep(m))
+ do_ep_move(m);
+ else
+ {
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
assert(color_of_piece_on(from) == us);
assert(color_of_piece_on(to) == them || piece_on(to) == EMPTY);
- piece = type_of_piece_on(from);
- capture = type_of_piece_on(to);
+ PieceType piece = type_of_piece_on(from);
+ PieceType capture = type_of_piece_on(to);
- if(capture) {
- assert(capture != KING);
+ if (capture)
+ {
+ assert(capture != KING);
- // Remove captured piece:
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
+ // Remove captured piece
+ clear_bit(&(byColorBB[them]), to);
+ clear_bit(&(byTypeBB[capture]), to);
- // Update hash key:
- key ^= zobrist[them][capture][to];
+ // Update hash key
+ key ^= zobrist[them][capture][to];
- // If the captured piece was a pawn, update pawn hash key:
- if(capture == PAWN)
- pawnKey ^= zobrist[them][PAWN][to];
+ // If the captured piece was a pawn, update pawn hash key
+ if (capture == PAWN)
+ pawnKey ^= zobrist[them][PAWN][to];
- // Update incremental scores:
- mgValue -= mg_pst(them, capture, to);
- egValue -= eg_pst(them, capture, to);
+ // Update incremental scores
+ mgValue -= mg_pst(them, capture, to);
+ egValue -= eg_pst(them, capture, to);
- // Update material:
- if(capture != PAWN)
- npMaterial[them] -= piece_value_midgame(capture);
+ // Update material
+ if (capture != PAWN)
+ npMaterial[them] -= piece_value_midgame(capture);
- // Update material hash key:
- materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
+ // Update material hash key
+ materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
- // Update piece count:
- pieceCount[them][capture]--;
+ // Update piece count
+ pieceCount[them][capture]--;
- // Update piece list:
- pieceList[them][capture][index[to]] =
- pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
+ // Update piece list
+ pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
+ index[pieceList[them][capture][index[to]]] = index[to];
- // Remember the captured piece, in order to be able to undo the move
- // correctly:
- u.capture = capture;
+ // Remember the captured piece, in order to be able to undo the move correctly
+ u.capture = capture;
- // Reset rule 50 counter:
- rule50 = 0;
+ // Reset rule 50 counter
+ rule50 = 0;
}
- // Move the piece:
+ // Move the piece
clear_bit(&(byColorBB[us]), from);
clear_bit(&(byTypeBB[piece]), from);
clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
board[to] = board[from];
board[from] = EMPTY;
- // Update hash key:
+ // Update hash key
key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to];
- // Update incremental scores:
+ // Update incremental scores
mgValue -= mg_pst(us, piece, from);
mgValue += mg_pst(us, piece, to);
egValue -= eg_pst(us, piece, from);
egValue += eg_pst(us, piece, to);
- // If the moving piece was a king, update the king square:
- if(piece == KING)
- kingSquare[us] = to;
+ // If the moving piece was a king, update the king square
+ if (piece == KING)
+ kingSquare[us] = to;
// If the move was a double pawn push, set the en passant square.
// This code is a bit ugly right now, and should be cleaned up later.
// FIXME
- if(epSquare != SQ_NONE) {
- key ^= zobEp[epSquare];
- epSquare = SQ_NONE;
+ if (epSquare != SQ_NONE)
+ {
+ key ^= zobEp[epSquare];
+ epSquare = SQ_NONE;
}
- if(piece == PAWN) {
- if(abs(int(to) - int(from)) == 16) {
- if((us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) &
- pawns(BLACK))) ||
- (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) &
- pawns(WHITE)))) {
- epSquare = Square((int(from) + int(to)) / 2);
- key ^= zobEp[epSquare];
+ if (piece == PAWN)
+ {
+ if (abs(int(to) - int(from)) == 16)
+ {
+ if( ( us == WHITE
+ && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
+ || ( us == BLACK
+ && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
+ {
+ epSquare = Square((int(from) + int(to)) / 2);
+ key ^= zobEp[epSquare];
+ }
}
- }
- // Reset rule 50 draw counter.
- rule50 = 0;
- // Update pawn hash key:
- pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- }
+ // Reset rule 50 draw counter
+ rule50 = 0;
- // Update piece lists:
+ // Update pawn hash key
+ pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
+ }
+ // Update piece lists
pieceList[us][piece][index[from]] = to;
index[to] = index[from];
- // Update castle rights:
+ // Update castle rights
key ^= zobCastle[castleRights];
castleRights &= castleRightsMask[from];
castleRights &= castleRightsMask[to];
key ^= zobCastle[castleRights];
- // Update checkers bitboard:
+ // Update checkers bitboard
checkersBB = EmptyBoardBB;
Square ksq = king_square(them);
-
- switch(piece) {
-
+ switch (piece)
+ {
case PAWN:
- if(bit_is_set(pawn_attacks(them, ksq), to))
- set_bit(&checkersBB, to);
- if(bit_is_set(dcCandidates, from))
- checkersBB |=
- ((piece_attacks<ROOK>(ksq) & rooks_and_queens(us)) |
- (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
- break;
+ if (bit_is_set(pawn_attacks(them, ksq), to))
+ set_bit(&checkersBB, to);
+
+ if (bit_is_set(dcCandidates, from))
+ checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
+ |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
+ break;
case KNIGHT:
- if(bit_is_set(piece_attacks<KNIGHT>(ksq), to))
- set_bit(&checkersBB, to);
- if(bit_is_set(dcCandidates, from))
- checkersBB |=
- ((piece_attacks<ROOK>(ksq) & rooks_and_queens(us)) |
- (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
- break;
+ if (bit_is_set(piece_attacks<KNIGHT>(ksq), to))
+ set_bit(&checkersBB, to);
+
+ if (bit_is_set(dcCandidates, from))
+ checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
+ |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
+ break;
case BISHOP:
- if(bit_is_set(piece_attacks<BISHOP>(ksq), to))
- set_bit(&checkersBB, to);
- if(bit_is_set(dcCandidates, from))
- checkersBB |=
- (piece_attacks<ROOK>(ksq) & rooks_and_queens(us));
- break;
+ if (bit_is_set(piece_attacks<BISHOP>(ksq), to))
+ set_bit(&checkersBB, to);
+
+ if (bit_is_set(dcCandidates, from))
+ checkersBB |= (piece_attacks<ROOK>(ksq) & rooks_and_queens(us));
+ break;
case ROOK:
- if(bit_is_set(piece_attacks<ROOK>(ksq), to))
- set_bit(&checkersBB, to);
- if(bit_is_set(dcCandidates, from))
- checkersBB |=
- (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us));
- break;
+ if (bit_is_set(piece_attacks<ROOK>(ksq), to))
+ set_bit(&checkersBB, to);
+
+ if (bit_is_set(dcCandidates, from))
+ checkersBB |= (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us));
+ break;
case QUEEN:
- if(bit_is_set(piece_attacks<QUEEN>(ksq), to))
- set_bit(&checkersBB, to);
- break;
+ if (bit_is_set(piece_attacks<QUEEN>(ksq), to))
+ set_bit(&checkersBB, to);
+ break;
case KING:
- if(bit_is_set(dcCandidates, from))
- checkersBB |=
- ((piece_attacks<ROOK>(ksq) & rooks_and_queens(us)) |
- (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
- break;
+ if (bit_is_set(dcCandidates, from))
+ checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
+ |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
+ break;
default:
assert(false);
/// instance white short castling in a non-Chess960 game is encoded as e1h1.
void Position::do_castle_move(Move m) {
- Color us, them;
- Square kfrom, kto, rfrom, rto;
assert(is_ok());
assert(move_is_ok(m));
assert(move_is_castle(m));
- us = side_to_move();
- them = opposite_color(us);
+ Color us = side_to_move();
+ Color them = opposite_color(us);
- // Find source squares for king and rook:
- kfrom = move_from(m);
- rfrom = move_to(m); // HACK: See comment at beginning of function.
+ // Find source squares for king and rook
+ Square kfrom = move_from(m);
+ Square rfrom = move_to(m); // HACK: See comment at beginning of function
+ Square kto, rto;
assert(piece_on(kfrom) == king_of_color(us));
assert(piece_on(rfrom) == rook_of_color(us));
- // Find destination squares for king and rook:
- if(rfrom > kfrom) { // O-O
- kto = relative_square(us, SQ_G1);
- rto = relative_square(us, SQ_F1);
- }
- else { // O-O-O
- kto = relative_square(us, SQ_C1);
- rto = relative_square(us, SQ_D1);
+ // Find destination squares for king and rook
+ if (rfrom > kfrom) // O-O
+ {
+ kto = relative_square(us, SQ_G1);
+ rto = relative_square(us, SQ_F1);
+ } else { // O-O-O
+ kto = relative_square(us, SQ_C1);
+ rto = relative_square(us, SQ_D1);
}
- // Remove pieces from source squares:
+ // Remove pieces from source squares
clear_bit(&(byColorBB[us]), kfrom);
clear_bit(&(byTypeBB[KING]), kfrom);
clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
clear_bit(&(byTypeBB[ROOK]), rfrom);
clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
- // Put pieces on destination squares:
+ // Put pieces on destination squares
set_bit(&(byColorBB[us]), kto);
set_bit(&(byTypeBB[KING]), kto);
set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
set_bit(&(byTypeBB[ROOK]), rto);
set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
- // Update board array:
+ // Update board array
board[kfrom] = board[rfrom] = EMPTY;
board[kto] = king_of_color(us);
board[rto] = rook_of_color(us);
- // Update king square:
+ // Update king square
kingSquare[us] = kto;
- // Update piece lists:
+ // Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
int tmp = index[rfrom];
index[kto] = index[kfrom];
index[rto] = tmp;
- // Update incremental scores:
+ // Update incremental scores
mgValue -= mg_pst(us, KING, kfrom);
mgValue += mg_pst(us, KING, kto);
egValue -= eg_pst(us, KING, kfrom);
egValue -= eg_pst(us, ROOK, rfrom);
egValue += eg_pst(us, ROOK, rto);
- // Update hash key:
+ // Update hash key
key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto];
key ^= zobrist[us][ROOK][rfrom] ^ zobrist[us][ROOK][rto];
- // Clear en passant square:
- if(epSquare != SQ_NONE) {
- key ^= zobEp[epSquare];
- epSquare = SQ_NONE;
+ // Clear en passant square
+ if(epSquare != SQ_NONE)
+ {
+ key ^= zobEp[epSquare];
+ epSquare = SQ_NONE;
}
- // Update castling rights:
+ // Update castling rights
key ^= zobCastle[castleRights];
castleRights &= castleRightsMask[kfrom];
key ^= zobCastle[castleRights];
- // Reset rule 50 counter:
+ // Reset rule 50 counter
rule50 = 0;
- // Update checkers BB:
+ // Update checkers BB
checkersBB = attacks_to(king_square(them), us);
}
projects / stockfish / blobdiff