/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
//// Types
////
+/// struct checkInfo is initialized at c'tor time and keeps
+/// info used to detect if a move gives check.
+
+struct CheckInfo {
+
+ CheckInfo(const Position&);
+
+ Bitboard dcCandidates;
+ Bitboard checkSq[8];
+ Square ksq;
+};
+
/// Castle rights, encoded as bit fields
enum CastleRights {
/// must be passed as a parameter.
struct StateInfo {
- Key key, pawnKey, materialKey;
- int castleRights, rule50;
+ Key pawnKey, materialKey;
+ int castleRights, rule50, pliesFromNull;
Square epSquare;
- Value mgValue, egValue;
+ Score value;
Value npMaterial[2];
PieceType capture;
+ Key key;
Bitboard checkersBB;
StateInfo* previous;
};
};
// Constructors
- Position() {};
- Position(const Position& pos);
- Position(const std::string& fen);
+ Position();
+ explicit Position(const Position& pos);
+ explicit Position(const std::string& fen);
// Text input/output
void from_fen(const std::string& fen);
void print(Move m = MOVE_NONE) const;
// Copying
- void copy(const Position& pos);
void flipped_copy(const Position& pos);
// The piece on a given square
Bitboard empty_squares() const;
Bitboard occupied_squares() const;
Bitboard pieces_of_color(Color c) const;
- Bitboard pieces_of_type(PieceType pt) const;
- Bitboard pieces_of_color_and_type(Color c, PieceType pt) const;
- Bitboard pawns() const;
- Bitboard knights() const;
- Bitboard bishops() const;
- Bitboard rooks() const;
- Bitboard queens() const;
- Bitboard kings() const;
- Bitboard rooks_and_queens() const;
- Bitboard bishops_and_queens() const;
- Bitboard sliders() const;
- Bitboard pawns(Color c) const;
- Bitboard knights(Color c) const;
- Bitboard bishops(Color c) const;
- Bitboard rooks(Color c) const;
- Bitboard queens(Color c) const;
- Bitboard kings(Color c) const;
- Bitboard rooks_and_queens(Color c) const;
- Bitboard bishops_and_queens(Color c) const;
- Bitboard sliders_of_color(Color c) const;
+ Bitboard pieces(PieceType pt) const;
+ Bitboard pieces(PieceType pt, Color c) const;
+ Bitboard pieces(PieceType pt1, PieceType pt2) const;
+ Bitboard pieces(PieceType pt1, PieceType pt2, Color c) const;
// Number of pieces of each color and type
int piece_count(Color c, PieceType pt) const;
Square initial_kr_square(Color c) const;
Square initial_qr_square(Color c) const;
- // Attack bitboards
- Bitboard sliding_attacks(Square s, Direction d) const;
- Bitboard ray_attacks(Square s, SignedDirection d) const;
- Bitboard pawn_attacks(Color c, 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
+ // Checking pieces and under check information
Bitboard checkers() const;
+ bool is_check() const;
// Piece lists
Square piece_list(Color c, PieceType pt, int index) const;
+ const Square* piece_list_begin(Color c, PieceType pt) 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 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
+ // Information about attacks to or from a given square
+ Bitboard attackers_to(Square s) const;
+ Bitboard attacks_from(Piece p, Square s) const;
+ template<PieceType> Bitboard attacks_from(Square s) const;
+ template<PieceType> Bitboard attacks_from(Square s, Color c) const;
// Properties of moves
- bool pl_move_is_legal(Move m) const;
bool pl_move_is_legal(Move m, Bitboard pinned) const;
+ bool pl_move_is_evasion(Move m, Bitboard pinned) const;
bool move_is_check(Move m) const;
- bool move_is_check(Move m, Bitboard dcCandidates) const;
+ bool move_is_check(Move m, const CheckInfo& ci) 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 move_is_capture_or_promotion(Move m) const;
bool move_is_passed_pawn_push(Move m) const;
- bool move_was_passed_pawn_push(Move m) const;
bool move_attacks_square(Move m, Square s) const;
+ // Piece captured with previous moves
+ PieceType captured_piece() const;
+
// Information about pawns
bool pawn_is_passed(Color c, Square s) const;
- static bool pawn_is_passed(Bitboard theirPawns, Color c, Square s);
- static bool pawn_is_isolated(Bitboard ourPawns, Square s);
- static bool pawn_is_doubled(Bitboard ourPawns, Color c, Square s);
// Weak squares
bool square_is_weak(Square s, Color c) const;
// Doing and undoing moves
- void saveState();
+ void detach();
void do_move(Move m, StateInfo& st);
- void do_move(Move m, StateInfo& st, Bitboard dcCandidates);
+ void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
void undo_move(Move m);
void do_null_move(StateInfo& st);
void undo_null_move();
// Accessing hash keys
Key get_key() const;
+ Key get_exclusion_key() const;
Key get_pawn_key() const;
Key get_material_key() const;
// Incremental evaluation
- Value mg_value() const;
- Value eg_value() const;
+ Score value() const;
Value non_pawn_material(Color c) const;
- Phase game_phase() const;
- template<GamePhase> Value pst_delta(Piece piece, Square from, Square to) const;
+ Score pst_delta(Piece piece, Square from, Square to) const;
// Game termination checks
bool is_mate() const;
// Position consistency check, for debugging
bool is_ok(int* failedStep = NULL) const;
- // Static member functions:
+ // Static member functions
static void init_zobrist();
static void init_piece_square_tables();
void allow_ooo(Color c);
// Helper functions for doing and undoing moves
- void do_capture_move(PieceType capture, Color them, Square to);
+ void do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep);
void do_castle_move(Move m);
- void do_promotion_move(Move m);
- void do_ep_move(Move m);
void undo_castle_move(Move m);
- void undo_promotion_move(Move m);
- void undo_ep_move(Move m);
void find_checkers();
- template<PieceType Piece>
- void update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates);
-
template<bool FindPinned>
Bitboard hidden_checkers(Color c) const;
Key compute_material_key() const;
// Computing incremental evaluation scores and material counts
- template<GamePhase> Value pst(Color c, PieceType pt, Square s) const;
- template<GamePhase> Value compute_value() const;
+ Score pst(Color c, PieceType pt, Square s) const;
+ Score compute_value() const;
Value compute_non_pawn_material(Color c) const;
- // Bitboards
- Bitboard byColorBB[2], byTypeBB[8];
-
// Board
Piece board[64];
+ // Bitboards
+ Bitboard byTypeBB[8], byColorBB[2];
+
// Piece counts
int pieceCount[2][8]; // [color][pieceType]
// Piece lists
Square pieceList[2][8][16]; // [color][pieceType][index]
- int index[64];
+ int index[64]; // [square]
// Other info
- Square kingSquare[2];
Color sideToMove;
int gamePly;
Key history[MaxGameLength];
- File initialKFile, initialKRFile, initialQRFile;
+ int castleRightsMask[64];
StateInfo startState;
+ File initialKFile, initialKRFile, initialQRFile;
StateInfo* st;
// Static variables
- static int castleRightsMask[64];
static Key zobrist[2][8][64];
static Key zobEp[64];
static Key zobCastle[16];
static Key zobMaterial[2][8][16];
static Key zobSideToMove;
- static Value MgPieceSquareTable[16][64];
- static Value EgPieceSquareTable[16][64];
+ static Score PieceSquareTable[16][64];
+ static Key zobExclusion;
};
return byColorBB[c];
}
-inline Bitboard Position::pieces_of_type(PieceType pt) const {
+inline Bitboard Position::pieces(PieceType pt) const {
return byTypeBB[pt];
}
-inline Bitboard Position::pieces_of_color_and_type(Color c, PieceType pt) const {
- return pieces_of_color(c) & pieces_of_type(pt);
-}
-
-inline Bitboard Position::pawns() const {
- return pieces_of_type(PAWN);
-}
-
-inline Bitboard Position::knights() const {
- return pieces_of_type(KNIGHT);
-}
-
-inline Bitboard Position::bishops() const {
- return pieces_of_type(BISHOP);
+inline Bitboard Position::pieces(PieceType pt, Color c) const {
+ return byTypeBB[pt] & byColorBB[c];
}
-inline Bitboard Position::rooks() const {
- return pieces_of_type(ROOK);
+inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
+ return byTypeBB[pt1] | byTypeBB[pt2];
}
-inline Bitboard Position::queens() const {
- return pieces_of_type(QUEEN);
-}
-
-inline Bitboard Position::kings() const {
- return pieces_of_type(KING);
-}
-
-inline Bitboard Position::rooks_and_queens() const {
- return rooks() | queens();
-}
-
-inline Bitboard Position::bishops_and_queens() const {
- return bishops() | queens();
-}
-
-inline Bitboard Position::sliders() const {
- return bishops() | queens() | rooks();
-}
-
-inline Bitboard Position::pawns(Color c) const {
- return pieces_of_color_and_type(c, PAWN);
-}
-
-inline Bitboard Position::knights(Color c) const {
- return pieces_of_color_and_type(c, KNIGHT);
-}
-
-inline Bitboard Position::bishops(Color c) const {
- return pieces_of_color_and_type(c, BISHOP);
-}
-
-inline Bitboard Position::rooks(Color c) const {
- return pieces_of_color_and_type(c, ROOK);
-}
-
-inline Bitboard Position::queens(Color c) const {
- return pieces_of_color_and_type(c, QUEEN);
-}
-
-inline Bitboard Position::kings(Color c) const {
- return pieces_of_color_and_type(c, KING);
-}
-
-inline Bitboard Position::rooks_and_queens(Color c) const {
- return rooks_and_queens() & pieces_of_color(c);
-}
-
-inline Bitboard Position::bishops_and_queens(Color c) const {
- return bishops_and_queens() & pieces_of_color(c);
+inline Bitboard Position::pieces(PieceType pt1, PieceType pt2, Color c) const {
+ return (byTypeBB[pt1] | byTypeBB[pt2]) & byColorBB[c];
}
inline int Position::piece_count(Color c, PieceType pt) const {
return pieceCount[c][pt];
}
-inline Square Position::piece_list(Color c, PieceType pt, int index) const {
- return pieceList[c][pt][index];
+inline Square Position::piece_list(Color c, PieceType pt, int idx) const {
+ return pieceList[c][pt][idx];
+}
+
+inline const Square* Position::piece_list_begin(Color c, PieceType pt) const {
+ return pieceList[c][pt];
}
inline Square Position::ep_square() const {
}
inline Square Position::king_square(Color c) const {
- return kingSquare[c];
+ return pieceList[c][KING][0];
}
inline bool Position::can_castle_kingside(Color side) const {
return relative_square(c, make_square(initialQRFile, RANK_1));
}
-inline Bitboard Position::pawn_attacks(Color c, Square s) const {
+template<>
+inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
return StepAttackBB[piece_of_color_and_type(c, PAWN)][s];
}
-template<PieceType Piece> // Knight and King
-inline Bitboard Position::piece_attacks(Square s) const {
+template<PieceType Piece> // Knight and King and white pawns
+inline Bitboard Position::attacks_from(Square s) const {
return StepAttackBB[Piece][s];
}
template<>
-inline Bitboard Position::piece_attacks<PAWN>(Square s) const {
- return StepAttackBB[piece_of_color_and_type(opposite_color(sideToMove), PAWN)][s];
-}
-
-template<>
-inline Bitboard Position::piece_attacks<BISHOP>(Square s) const {
+inline Bitboard Position::attacks_from<BISHOP>(Square s) const {
return bishop_attacks_bb(s, occupied_squares());
}
template<>
-inline Bitboard Position::piece_attacks<ROOK>(Square s) const {
+inline Bitboard Position::attacks_from<ROOK>(Square s) const {
return rook_attacks_bb(s, occupied_squares());
}
template<>
-inline Bitboard Position::piece_attacks<QUEEN>(Square s) const {
- return piece_attacks<ROOK>(s) | piece_attacks<BISHOP>(s);
+inline Bitboard Position::attacks_from<QUEEN>(Square s) const {
+ return attacks_from<ROOK>(s) | attacks_from<BISHOP>(s);
}
inline Bitboard Position::checkers() const {
return st->checkersBB != EmptyBoardBB;
}
-inline bool Position::pawn_attacks_square(Color c, Square f, Square t) const {
- return bit_is_set(pawn_attacks(c, 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 Bitboard Position::attacks_to(Square s, Color c) const {
-
- return attacks_to(s) & pieces_of_color(c);
-}
-
-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 {
- return !(pawns(opposite_color(c)) & passed_pawn_mask(c, s));
-}
-
-inline bool Position::pawn_is_passed(Bitboard theirPawns, Color c, Square s) {
- return !(theirPawns & passed_pawn_mask(c, s));
-}
-
-inline bool Position::pawn_is_isolated(Bitboard ourPawns, Square s) {
- return !(ourPawns & neighboring_files_bb(s));
-}
-
-inline bool Position::pawn_is_doubled(Bitboard ourPawns, Color c, Square s) {
- return ourPawns & squares_behind(c, s);
+ return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
}
inline bool Position::square_is_weak(Square s, Color c) const {
- return !(pawns(c) & outpost_mask(opposite_color(c), s));
+ return !(pieces(PAWN, c) & outpost_mask(opposite_color(c), s));
}
inline Key Position::get_key() const {
return st->key;
}
+inline Key Position::get_exclusion_key() const {
+ return st->key ^ zobExclusion;
+}
+
inline Key Position::get_pawn_key() const {
return st->pawnKey;
}
return st->materialKey;
}
-template<Position::GamePhase Ph>
-inline Value Position::pst(Color c, PieceType pt, Square s) const {
- return (Ph == MidGame ? MgPieceSquareTable[piece_of_color_and_type(c, pt)][s]
- : EgPieceSquareTable[piece_of_color_and_type(c, pt)][s]);
-}
-
-template<Position::GamePhase Ph>
-inline Value Position::pst_delta(Piece piece, Square from, Square to) const {
- return (Ph == MidGame ? MgPieceSquareTable[piece][to] - MgPieceSquareTable[piece][from]
- : EgPieceSquareTable[piece][to] - EgPieceSquareTable[piece][from]);
+inline Score Position::pst(Color c, PieceType pt, Square s) const {
+ return PieceSquareTable[piece_of_color_and_type(c, pt)][s];
}
-inline Value Position::mg_value() const {
- return st->mgValue;
+inline Score Position::pst_delta(Piece piece, Square from, Square to) const {
+ return PieceSquareTable[piece][to] - PieceSquareTable[piece][from];
}
-inline Value Position::eg_value() const {
- return st->egValue;
+inline Score Position::value() const {
+ return st->value;
}
inline Value Position::non_pawn_material(Color c) const {
return st->npMaterial[c];
}
-inline Phase Position::game_phase() const {
-
- // Values modified by Joona Kiiski
- static const Value MidgameLimit = Value(15581);
- static const Value EndgameLimit = Value(3998);
-
- Value npm = non_pawn_material(WHITE) + non_pawn_material(BLACK);
-
- if (npm >= MidgameLimit)
- return PHASE_MIDGAME;
- else if(npm <= EndgameLimit)
- return PHASE_ENDGAME;
- else
- return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
-}
-
-inline bool Position::move_is_deep_pawn_push(Move m) const {
-
- Color c = side_to_move();
- 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)) == 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();
&& 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)) == piece_of_color_and_type(c, PAWN)
- && pawn_is_passed(c, move_to(m));
-}
-
inline int Position::rule_50_counter() const {
return st->rule50;
inline bool Position::has_pawn_on_7th(Color c) const {
- return pawns(c) & relative_rank_bb(c, RANK_7);
+ return pieces(PAWN, c) & relative_rank_bb(c, RANK_7);
}
inline bool Position::move_is_capture(Move m) const {
// Move must not be MOVE_NONE !
+ return (m & (3 << 15)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+}
+
+inline bool Position::move_is_capture_or_promotion(Move m) const {
+
+ // Move must not be MOVE_NONE !
+ return (m & (0x1F << 12)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+}
- return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
+inline PieceType Position::captured_piece() const {
+ return st->capture;
}
#endif // !defined(POSITION_H_INCLUDED)