/*
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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined(POSITION_H_INCLUDED)
#define POSITION_H_INCLUDED
-// Disable some silly and noisy warning from MSVC compiler
-#if defined(_MSC_VER)
-
-// Forcing value to bool 'true' or 'false' (performance warning)
-#pragma warning(disable: 4800)
-
-// Conditional expression is constant
-#pragma warning(disable: 4127)
-
-
-#endif
-
-////
-//// Includes
-////
+#include <cassert>
#include "bitboard.h"
-#include "color.h"
-#include "direction.h"
#include "move.h"
-#include "piece.h"
-#include "square.h"
-#include "value.h"
-
-
-////
-//// Constants
-////
-
-/// FEN string for the initial position
-const std::string StartPosition = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+#include "types.h"
/// Maximum number of plies per game (220 should be enough, because the
/// maximum search depth is 100, and during position setup we reset the
/// move counter for every non-reversible move).
const int MaxGameLength = 220;
+class Position;
+
+/// struct checkInfo is initialized at c'tor time and keeps
+/// info used to detect if a move gives check.
+
+struct CheckInfo {
-////
-//// Types
-////
+ explicit CheckInfo(const Position&);
+
+ Bitboard dcCandidates;
+ Bitboard pinned;
+ Bitboard checkSq[8];
+};
/// Castle rights, encoded as bit fields
enum CastleRights {
- NO_CASTLES = 0,
- WHITE_OO = 1,
- BLACK_OO = 2,
- WHITE_OOO = 4,
- BLACK_OOO = 8,
- ALL_CASTLES = 15
+ CASTLES_NONE = 0,
+ WHITE_OO = 1,
+ BLACK_OO = 2,
+ WHITE_OOO = 4,
+ BLACK_OOO = 8,
+ ALL_CASTLES = 15
};
/// Game phase
/// must be passed as a parameter.
struct StateInfo {
- Key key, pawnKey, materialKey;
- int castleRights, rule50;
+ Key pawnKey, materialKey;
+ int castleRights, rule50, gamePly, pliesFromNull;
Square epSquare;
- Value mgValue, egValue;
+ Score value;
Value npMaterial[2];
- PieceType capture;
+ PieceType capturedType;
+ Key key;
Bitboard checkersBB;
StateInfo* previous;
};
class Position {
- friend class MaterialInfo;
- friend class EndgameFunctions;
+ Position(); // No default or copy c'tor allowed
+ Position(const Position& pos);
public:
enum GamePhase {
};
// Constructors
- Position() {}
- Position(const Position& pos);
- Position(const std::string& fen);
+ Position(const Position& pos, int threadID);
+ Position(const std::string& fen, bool isChess960, int threadID);
// Text input/output
- void from_fen(const std::string& fen);
+ void from_fen(const std::string& fen, bool isChess960);
const std::string to_fen() const;
void print(Move m = MOVE_NONE) const;
// Copying
- void copy(const Position& pos);
- void flipped_copy(const Position& pos);
+ void flip();
// The piece on a given square
Piece piece_on(Square s) const;
- PieceType type_of_piece_on(Square s) const;
- Color color_of_piece_on(Square s) const;
bool square_is_empty(Square s) const;
bool square_is_occupied(Square s) const;
- Value midgame_value_of_piece_on(Square s) const;
- Value endgame_value_of_piece_on(Square s) const;
// Side to move
Color side_to_move() 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 in_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 attackers_to(Square s, Bitboard occ) const;
+ Bitboard attacks_from(Piece p, Square s) const;
+ static Bitboard attacks_from(Piece p, Square s, Bitboard occ);
+ 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 move_is_check(Move m) const;
- bool move_is_check(Move m, Bitboard dcCandidates) const;
+ bool move_is_pl(const Move m) const;
+ bool move_gives_check(Move m, const CheckInfo& ci) const;
bool move_is_capture(Move m) const;
+ bool move_is_capture_or_promotion(Move m) const;
bool move_is_passed_pawn_push(Move m) const;
bool move_attacks_square(Move m, Square s) const;
+ // Piece captured with previous moves
+ PieceType captured_piece_type() 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 do_setup_move(Move m);
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();
// Static exchange evaluation
- int see(Square from, Square to) const;
int see(Move m) const;
- int see(Square to) const;
int see_sign(Move m) const;
// 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;
+ static Score pst_delta(Piece piece, Square from, Square to);
// Game termination checks
bool is_mate() const;
- bool is_draw() const;
-
- // Check if one side threatens a mate in one
- bool has_mate_threat(Color c);
+ template<bool SkipRepetition> bool is_draw() const;
- // Number of plies since the last non-reversible move
- int rule_50_counter() const;
+ // Number of plies from starting position
+ int full_moves() const;
// Other properties of the position
bool opposite_colored_bishops() const;
bool has_pawn_on_7th(Color c) const;
+ bool is_chess960() const;
- // Reset the gamePly variable to 0
- void reset_game_ply();
+ // Current thread ID searching on the position
+ int thread() const;
+
+ int64_t nodes_searched() const;
+ void set_nodes_searched(int64_t n);
// Position consistency check, for debugging
bool is_ok(int* failedStep = NULL) const;
- // Static member functions:
- static void init_zobrist();
- static void init_piece_square_tables();
+ // Global initialization
+ static void init();
private:
// Initialization helper functions (used while setting up a position)
void clear();
+ void detach();
void put_piece(Piece p, Square s);
- void allow_oo(Color c);
- void allow_ooo(Color c);
+ void set_castle_kingside(Color c);
+ void set_castle_queenside(Color c);
+ void set_castling_rights(char token);
+ bool move_is_pl_slow(const Move m) const;
// Helper functions for doing and undoing moves
- void do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep);
+ void do_capture_move(Key& key, PieceType capture, Color them, Square to, bool ep);
void do_castle_move(Move m);
void undo_castle_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;
+ static Score pst(Color c, PieceType pt, Square s);
+ 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]
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;
+ bool chess960;
+ int fullMoves;
+ int threadID;
+ int64_t nodes;
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;
};
-
-////
-//// Inline functions
-////
-
-inline Piece Position::piece_on(Square s) const {
- return board[s];
+inline int64_t Position::nodes_searched() const {
+ return nodes;
}
-inline Color Position::color_of_piece_on(Square s) const {
- return color_of_piece(piece_on(s));
+inline void Position::set_nodes_searched(int64_t n) {
+ nodes = n;
}
-inline PieceType Position::type_of_piece_on(Square s) const {
- return type_of_piece(piece_on(s));
+inline Piece Position::piece_on(Square s) const {
+ return board[s];
}
inline bool Position::square_is_empty(Square s) const {
- return piece_on(s) == EMPTY;
+ return piece_on(s) == PIECE_NONE;
}
inline bool Position::square_is_occupied(Square s) const {
return !square_is_empty(s);
}
-inline Value Position::midgame_value_of_piece_on(Square s) const {
- return piece_value_midgame(piece_on(s));
-}
-
-inline Value Position::endgame_value_of_piece_on(Square s) const {
- return piece_value_endgame(piece_on(s));
-}
-
inline Color Position::side_to_move() const {
return sideToMove;
}
}
inline Bitboard Position::empty_squares() const {
- return ~(occupied_squares());
+ return ~occupied_squares();
}
inline Bitboard Position::pieces_of_color(Color c) 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 st->castleRights & (1+int(side));
+inline bool Position::can_castle_kingside(Color c) const {
+ return st->castleRights & (WHITE_OO << c);
}
-inline bool Position::can_castle_queenside(Color side) const {
- return st->castleRights & (4+4*int(side));
+inline bool Position::can_castle_queenside(Color c) const {
+ return st->castleRights & (WHITE_OOO << c);
}
-inline bool Position::can_castle(Color side) const {
- return can_castle_kingside(side) || can_castle_queenside(side);
+inline bool Position::can_castle(Color c) const {
+ return st->castleRights & ((WHITE_OO | WHITE_OOO) << c);
+}
+
+inline void Position::set_castle_kingside(Color c) {
+ st->castleRights |= (WHITE_OO << c);
+}
+
+inline void Position::set_castle_queenside(Color c) {
+ st->castleRights |= (WHITE_OOO << c);
}
inline Square Position::initial_kr_square(Color c) const {
return relative_square(c, make_square(initialQRFile, RANK_1));
}
-inline Bitboard Position::pawn_attacks(Color c, Square s) const {
- return StepAttackBB[piece_of_color_and_type(c, PAWN)][s];
+template<>
+inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
+ return StepAttacksBB[make_piece(c, PAWN)][s];
}
-template<PieceType Piece> // Knight and King
-inline Bitboard Position::piece_attacks(Square s) const {
- return StepAttackBB[Piece][s];
+template<PieceType Piece> // Knight and King and white pawns
+inline Bitboard Position::attacks_from(Square s) const {
+ return StepAttacksBB[Piece][s];
}
template<>
-inline Bitboard Position::piece_attacks<PAWN>(Square s) const {
- return StepAttackBB[WP][s] | StepAttackBB[BP][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;
}
-inline bool Position::is_check() const {
+inline bool Position::in_check() 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>
-inline 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 !(pieces(PAWN, 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);
-}
-
inline bool Position::square_is_weak(Square s, Color c) const {
- return !(pieces(PAWN, c) & outpost_mask(opposite_color(c), s));
+ return !(pieces(PAWN, opposite_color(c)) & attack_span_mask(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) {
+ return PieceSquareTable[make_piece(c, pt)][s];
}
-inline Value Position::mg_value() const {
- return st->mgValue;
+inline Score Position::pst_delta(Piece piece, Square from, Square to) {
+ 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_passed_pawn_push(Move m) const {
Color c = side_to_move();
- return piece_on(move_from(m)) == piece_of_color_and_type(c, PAWN)
+ return piece_on(move_from(m)) == make_piece(c, PAWN)
&& pawn_is_passed(c, move_to(m));
}
-inline int Position::rule_50_counter() const {
-
- return st->rule50;
+inline int Position::full_moves() const {
+ return fullMoves;
}
inline bool Position::opposite_colored_bishops() const {
- 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));
+ return piece_count(WHITE, BISHOP) == 1 && piece_count(BLACK, BISHOP) == 1
+ && opposite_color_squares(piece_list(WHITE, BISHOP, 0), piece_list(BLACK, BISHOP, 0));
}
inline bool Position::has_pawn_on_7th(Color c) const {
+ return pieces(PAWN, c) & rank_bb(relative_rank(c, RANK_7));
+}
+
+inline bool Position::is_chess960() const {
+ return chess960;
+}
- return pieces(PAWN, c) & relative_rank_bb(c, RANK_7);
+inline bool Position::move_is_capture_or_promotion(Move m) const {
+
+ assert(m != MOVE_NONE && m != MOVE_NULL);
+ return move_is_special(m) ? !move_is_castle(m) : !square_is_empty(move_to(m));
}
inline bool Position::move_is_capture(Move m) const {
- // Move must not be MOVE_NONE !
+ assert(m != MOVE_NONE && m != MOVE_NULL);
+ // Note that castle is coded as "king captures the rook"
return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
}
+inline PieceType Position::captured_piece_type() const {
+ return st->capturedType;
+}
+
+inline int Position::thread() const {
+ return threadID;
+}
+
#endif // !defined(POSITION_H_INCLUDED)