/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008 Marco Costalba
- Glaurung is free software: you can redistribute it and/or modify
+ Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
- Glaurung is distributed in the hope that it will be useful,
+
+ Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#if defined(_MSC_VER)
// Forcing value to bool 'true' or 'false' (performance warning)
-#pragma warning(disable: 4800) \r
-\r
+#pragma warning(disable: 4800)
+
#endif
////
////
/// FEN string for the initial position:
-const std::string StartPosition =
+const std::string StartPosition =
"rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
/// Maximum number of plies per game (220 should be enough, because the
/// Castle rights, encoded as bit fields:
enum CastleRights {
- NO_CASTLES = 0,
+ NO_CASTLES = 0,
WHITE_OO = 1,
- BLACK_OO = 2,
+ BLACK_OO = 2,
WHITE_OOO = 4,
BLACK_OOO = 8,
ALL_CASTLES = 15
};
-/// The UndoInfo struct stores information we need to restore a Position
-/// object to its previous state when we retract a move. Whenever a move
-/// is made on the board (by calling Position::do_move), an UndoInfo object
-/// must be passed as a parameter. When the move is unmade (by calling
-/// Position::undo_move), the same UndoInfo object must be passed again.
+/// The StateInfo struct stores information we need to restore a Position
+/// object to its previous state when we retract a move. Whenever a move
+/// is made on the board (by calling Position::do_move), an StateInfo object
+/// must be passed as a parameter.
-struct UndoInfo {
- int castleRights;
- Square epSquare;
- Bitboard checkersBB;
+struct StateInfo {
+ Bitboard pinners[2], pinned[2], dcCandidates[2], checkersBB;
Key key, pawnKey, materialKey;
- int rule50;
+ int castleRights, rule50;
+ Square epSquare;
Move lastMove;
- PieceType capture;
Value mgValue, egValue;
+ PieceType capture;
+ StateInfo* previous;
};
/// The position data structure. A position consists of the following data:
-///
+///
/// * For each piece type, a bitboard representing the squares occupied
/// by pieces of that type.
/// * For each color, a bitboard representing the squares occupiecd by
class Position {
friend class MaterialInfo;
+ friend class EndgameFunctions;
public:
// Constructors
Position() {};
- Position(const Position &pos);
- Position(const std::string &fen);
+ Position(const Position& pos);
+ Position(const std::string& fen);
// Text input/output
- void from_fen(const std::string &fen);
+ void from_fen(const std::string& fen);
const std::string to_fen() const;
- void print() const;
+ void print(Move m = MOVE_NONE) const;
// Copying
void copy(const Position &pos);
// Number of pieces of each color and type
int piece_count(Color c, PieceType pt) const;
- int pawn_count(Color c) const;
- int knight_count(Color c) const;
- int bishop_count(Color c) const;
- int rook_count(Color c) const;
- int queen_count(Color c) const;
- // The en passant square:
+ // The en passant square
Square ep_square() const;
// Current king position for each color
Square king_square(Color c) const;
- // Castling rights.
+ // Castling rights
bool can_castle_kingside(Color c) const;
bool can_castle_queenside(Color c) const;
bool can_castle(Color c) const;
Bitboard sliding_attacks(Square s, Direction d) const;
Bitboard ray_attacks(Square s, SignedDirection d) const;
Bitboard pawn_attacks(Color c, Square s) const;
- Bitboard white_pawn_attacks(Square s) const;
- Bitboard black_pawn_attacks(Square s) const;
template<PieceType>
Bitboard piece_attacks(Square s) const;
// Bitboards for pinned pieces and discovered check candidates
Bitboard discovered_check_candidates(Color c) const;
+ Bitboard pinned_pieces(Color c, Bitboard& p) const;
Bitboard pinned_pieces(Color c) const;
// Checking pieces
Bitboard checkers() const;
- // Piece lists:
+ // Piece lists
Square piece_list(Color c, PieceType pt, int index) const;
- Square pawn_list(Color c, int index) const;
- Square knight_list(Color c, int index) const;
- Square bishop_list(Color c, int index) const;
- Square rook_list(Color c, int index) const;
- Square queen_list(Color c, int index) const;
// Attack information for a given square
bool square_is_attacked(Square s, Color c) const;
Bitboard attacks_to(Square s) const;
Bitboard attacks_to(Square s, Color c) const;
bool is_check() const;
- bool piece_attacks_square(Square f, Square t) const;
- bool white_pawn_attacks_square(Square f, Square t) const;
- bool black_pawn_attacks_square(Square f, Square t) const;
- bool knight_attacks_square(Square f, Square t) const;
- bool bishop_attacks_square(Square f, Square t) const;
- bool rook_attacks_square(Square f, Square t) const;
- bool queen_attacks_square(Square f, Square t) const;
- bool king_attacks_square(Square f, Square t) const;
+ bool pawn_attacks_square(Color c, Square f, Square t) const;
+
+ template<PieceType>
+ Bitboard piece_attacks_square(Square f, Square t) const; // Dispatch at compile-time
+
+ bool piece_attacks_square(Piece p, Square f, Square t) const; // Dispatch at run-time
// Properties of moves
- bool move_is_legal(Move m) const;
- bool move_is_legal(Move m, Bitboard pinned) const;
+ bool pl_move_is_legal(Move m) const;
bool move_is_check(Move m) const;
- bool move_is_check(Move m, Bitboard dcCandidates) const;
bool move_is_capture(Move m) const;
bool move_is_deep_pawn_push(Move m) const;
bool move_is_pawn_push_to_7th(Move m) const;
bool square_is_weak(Square s, Color c) const;
// Doing and undoing moves
- void backup(UndoInfo &u) const;
- void restore(const UndoInfo &u);
- void do_move(Move m, UndoInfo &u);
- void do_move(Move m, UndoInfo &u, Bitboard dcCandidates);
- void undo_move(Move m, const UndoInfo &u);
- void do_null_move(UndoInfo &u);
- void undo_null_move(const UndoInfo &u);
+ void do_move(Move m, StateInfo& st);
+ void undo_move(Move m);
+ void do_null_move(StateInfo& st);
+ void undo_null_move();
// Static exchange evaluation
int see(Square from, Square to) const;
int see(Move m) const;
+ int see(Square to) const;
// Accessing hash keys
Key get_key() const;
Value mg_pst_delta(Move m) const;
// Game termination checks
- bool is_mate();
+ bool is_mate() const;
bool is_draw() const;
// Check if one side threatens a mate in one
// Reset the gamePly variable to 0
void reset_game_ply();
-
+
// Position consistency check, for debugging
bool is_ok(int* failedStep = NULL) const;
void allow_ooo(Color c);
// Helper functions for doing and undoing moves
+ void do_capture_move(Move m, PieceType capture, Color them, Square to);
void do_castle_move(Move m);
- void do_promotion_move(Move m, UndoInfo &u);
+ void do_promotion_move(Move m);
void do_ep_move(Move m);
void undo_castle_move(Move m);
- void undo_promotion_move(Move m, const UndoInfo &u);
+ void undo_promotion_move(Move m);
void undo_ep_move(Move m);
void find_checkers();
+ void find_pinned();
+
+ template<PieceType Piece>
+ void update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates);
+
+ template<PieceType Piece, bool FindPinned>
+ Bitboard hidden_checks(Color c, Square ksq, Bitboard& pinners) const;
// Computing hash keys from scratch (for initialization and debugging)
Key compute_key() const;
Key compute_material_key() const;
// Computing incremental evaluation scores and material counts
- Value mg_pst(Color c, PieceType pt, Square s) const;
- Value eg_pst(Color c, PieceType pt, Square s) const;
- Value compute_mg_value() const;
- Value compute_eg_value() const;
+ enum GamePhase {
+ MidGame,
+ EndGame
+ };
+ template<GamePhase> Value pst(Color c, PieceType pt, Square s) const;
+ template<GamePhase> Value compute_value() const;
Value compute_non_pawn_material(Color c) const;
// Bitboards
Bitboard byColorBB[2], byTypeBB[8];
- Bitboard checkersBB;
// Board
Piece board[64];
// Piece counts
int pieceCount[2][8]; // [color][pieceType]
-
+
// Piece lists
Square pieceList[2][8][16]; // [color][pieceType][index]
int index[64];
// Other info
- Color sideToMove;
- int castleRights;
- File initialKFile, initialKRFile, initialQRFile;
- Square epSquare;
Square kingSquare[2];
- Move lastMove;
- Key key, pawnKey, materialKey, history[MaxGameLength];
- int rule50, gamePly;
- Value mgValue, egValue;
+ Color sideToMove;
+ int gamePly;
+ Key history[MaxGameLength];
Value npMaterial[2];
+ File initialKFile, initialKRFile, initialQRFile;
+ StateInfo startState;
+ StateInfo* st;
// Static variables
static int castleRightsMask[64];
return pieceCount[c][pt];
}
-inline int Position::pawn_count(Color c) const {
- return piece_count(c, PAWN);
-}
-
-inline int Position::knight_count(Color c) const {
- return piece_count(c, KNIGHT);
-}
-
-inline int Position::bishop_count(Color c) const {
- return piece_count(c, BISHOP);
-}
-
-inline int Position::rook_count(Color c) const {
- return piece_count(c, ROOK);
-}
-
-inline int Position::queen_count(Color c) const {
- return piece_count(c, QUEEN);
-}
-
inline Square Position::piece_list(Color c, PieceType pt, int index) const {
return pieceList[c][pt][index];
}
-inline Square Position::pawn_list(Color c, int index) const {
- return piece_list(c, PAWN, index);
-}
-
-inline Square Position::knight_list(Color c, int index) const {
- return piece_list(c, KNIGHT, index);
-}
-
-inline Square Position::bishop_list(Color c, int index) const {
- return piece_list(c, BISHOP, index);
-}
-
-inline Square Position::rook_list(Color c, int index) const {
- return piece_list(c, ROOK, index);
-}
-
-inline Square Position::queen_list(Color c, int index) const {
- return piece_list(c, QUEEN, index);
-}
-
inline Square Position::ep_square() const {
- return epSquare;
+ return st->epSquare;
}
inline Square Position::king_square(Color c) const {
}
inline bool Position::can_castle_kingside(Color side) const {
- return castleRights & (1+int(side));
+ return st->castleRights & (1+int(side));
}
inline bool Position::can_castle_queenside(Color side) const {
- return castleRights & (4+4*int(side));
+ return st->castleRights & (4+4*int(side));
}
inline bool Position::can_castle(Color side) const {
}
inline Bitboard Position::pawn_attacks(Color c, Square s) const {
- return StepAttackBB[pawn_of_color(c)][s];
+ return StepAttackBB[piece_of_color_and_type(c, PAWN)][s];
}
-inline Bitboard Position::white_pawn_attacks(Square s) const {
- return pawn_attacks(WHITE, s);
-}
-
-inline Bitboard Position::black_pawn_attacks(Square s) const {
- return pawn_attacks(BLACK, s);
+template<>
+inline Bitboard Position::piece_attacks<PAWN>(Square s) const {
+ return StepAttackBB[piece_of_color_and_type(opposite_color(sideToMove), PAWN)][s];
}
template<>
return StepAttackBB[KING][s];
}
-inline Bitboard Position::checkers() const {
- return checkersBB;
+inline Bitboard Position::pinned_pieces(Color c) const {
+ return st->pinned[c];
}
-inline bool Position::is_check() const {
- return checkers() != EmptyBoardBB;
+inline Bitboard Position::pinned_pieces(Color c, Bitboard& p) const {
+ p = st->pinners[c];
+ return st->pinned[c];
}
-inline bool Position::white_pawn_attacks_square(Square f, Square t) const {
- return bit_is_set(white_pawn_attacks(f), t);
+inline Bitboard Position::discovered_check_candidates(Color c) const {
+ return st->dcCandidates[c];
}
-inline bool Position::black_pawn_attacks_square(Square f, Square t) const {
- return bit_is_set(black_pawn_attacks(f), t);
+inline Bitboard Position::checkers() const {
+ return st->checkersBB;
}
-inline bool Position::knight_attacks_square(Square f, Square t) const {
- return bit_is_set(piece_attacks<KNIGHT>(f), t);
+inline bool Position::is_check() const {
+ return st->checkersBB != EmptyBoardBB;
}
-inline bool Position::bishop_attacks_square(Square f, Square t) const {
- return bit_is_set(piece_attacks<BISHOP>(f), t);
+inline bool Position::pawn_attacks_square(Color c, Square f, Square t) const {
+ return bit_is_set(pawn_attacks(c, f), t);
}
-inline bool Position::rook_attacks_square(Square f, Square t) const {
- return bit_is_set(piece_attacks<ROOK>(f), t);
+template<PieceType Piece>
+Bitboard Position::piece_attacks_square(Square f, Square t) const {
+ return bit_is_set(piece_attacks<Piece>(f), t);
}
-inline bool Position::queen_attacks_square(Square f, Square t) const {
- return bit_is_set(piece_attacks<QUEEN>(f), t);
+inline Bitboard Position::attacks_to(Square s, Color c) const {
+
+ return attacks_to(s) & pieces_of_color(c);
}
-inline bool Position::king_attacks_square(Square f, Square t) const {
- return bit_is_set(piece_attacks<KING>(f), t);
+inline bool Position::square_is_attacked(Square s, Color c) const {
+
+ return attacks_to(s, c) != EmptyBoardBB;
}
inline bool Position::pawn_is_passed(Color c, Square s) const {
inline bool Position::square_is_weak(Square s, Color c) const {
return !(pawns(c) & outpost_mask(opposite_color(c), s));
}
-
+
inline Key Position::get_key() const {
- return key;
+ return st->key;
}
inline Key Position::get_pawn_key() const {
- return pawnKey;
+ return st->pawnKey;
}
inline Key Position::get_material_key() const {
- return materialKey;
+ return st->materialKey;
}
-inline Value Position::mg_pst(Color c, PieceType pt, Square s) const {
- return MgPieceSquareTable[piece_of_color_and_type(c, pt)][s];
+template<Position::GamePhase Phase>
+inline Value Position::pst(Color c, PieceType pt, Square s) const {
+ return (Phase == MidGame ? MgPieceSquareTable[piece_of_color_and_type(c, pt)][s]
+ : EgPieceSquareTable[piece_of_color_and_type(c, pt)][s]);
}
inline Value Position::mg_pst_delta(Move m) const {
-MgPieceSquareTable[piece_on(move_from(m))][move_from(m)];
}
-inline Value Position::eg_pst(Color c, PieceType pt, Square s) const {
- return EgPieceSquareTable[piece_of_color_and_type(c, pt)][s];
-}
-
inline Value Position::mg_value() const {
- return mgValue;
+ return st->mgValue;
}
inline Value Position::eg_value() const {
- return egValue;
+ return st->egValue;
}
inline Value Position::non_pawn_material(Color c) const {
static const Value EndgameLimit = 4 * RookValueMidgame - Value(325);
Value npm = non_pawn_material(WHITE) + non_pawn_material(BLACK);
-
+
if (npm >= MidgameLimit)
return PHASE_MIDGAME;
else if(npm <= EndgameLimit)
inline bool Position::move_is_deep_pawn_push(Move m) const {
Color c = side_to_move();
- return piece_on(move_from(m)) == pawn_of_color(c)
+ return piece_on(move_from(m)) == piece_of_color_and_type(c, PAWN)
&& relative_rank(c, move_to(m)) > RANK_4;
}
inline bool Position::move_is_pawn_push_to_7th(Move m) const {
Color c = side_to_move();
- return piece_on(move_from(m)) == pawn_of_color(c)
+ return piece_on(move_from(m)) == piece_of_color_and_type(c, PAWN)
&& relative_rank(c, move_to(m)) == RANK_7;
}
inline bool Position::move_is_passed_pawn_push(Move m) const {
Color c = side_to_move();
- return piece_on(move_from(m)) == pawn_of_color(c)
+ return piece_on(move_from(m)) == piece_of_color_and_type(c, PAWN)
&& pawn_is_passed(c, move_to(m));
}
inline bool Position::move_was_passed_pawn_push(Move m) const {
Color c = opposite_color(side_to_move());
- return piece_on(move_to(m)) == pawn_of_color(c)
+ return piece_on(move_to(m)) == piece_of_color_and_type(c, PAWN)
&& pawn_is_passed(c, move_to(m));
}
inline int Position::rule_50_counter() const {
- return rule50;
+ return st->rule50;
}
inline bool Position::opposite_colored_bishops() const {
- return bishop_count(WHITE) == 1
- && bishop_count(BLACK) == 1
- && square_color(bishop_list(WHITE, 0)) != square_color(bishop_list(BLACK, 0));
+ return piece_count(WHITE, BISHOP) == 1
+ && piece_count(BLACK, BISHOP) == 1
+ && square_color(piece_list(WHITE, BISHOP, 0)) != square_color(piece_list(BLACK, BISHOP, 0));
}
inline bool Position::has_pawn_on_7th(Color c) const {
return pawns(c) & relative_rank_bb(c, RANK_7);
}
-
+
#endif // !defined(POSITION_H_INCLUDED)
projects / stockfish / blobdiff