/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2008-2009 Marco Costalba
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#if !defined(POSITION_H_INCLUDED)
#define POSITION_H_INCLUDED
-// Disable a silly and noisy warning from MSVC compiler
+// 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
////
#include "direction.h"
#include "move.h"
#include "piece.h"
-#include "phase.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";
+/// FEN string for the initial position
+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
/// maximum search depth is 100, and during position setup we reset the
-/// move counter for every non-reversible move):
+/// move counter for every non-reversible move).
const int MaxGameLength = 220;
//// Types
////
-/// Castle rights, encoded as bit fields:
+/// Castle rights, encoded as bit fields
enum CastleRights {
- NO_CASTLES = 0,
- WHITE_OO = 1,
- BLACK_OO = 2,
- WHITE_OOO = 4,
- BLACK_OOO = 8,
+ NO_CASTLES = 0,
+ WHITE_OO = 1,
+ BLACK_OO = 2,
+ WHITE_OOO = 4,
+ BLACK_OOO = 8,
ALL_CASTLES = 15
};
+/// Game phase
+enum Phase {
+ PHASE_ENDGAME = 0,
+ PHASE_MIDGAME = 128
+};
+
-/// The UndoInfo struct stores information we need to restore a Position
+/// 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 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.
+/// is made on the board (by calling Position::do_move), an StateInfo object
+/// must be passed as a parameter.
-struct UndoInfo {
- Bitboard pinners[2], pinned[2], dcCandidates[2], checkersBB;
+struct StateInfo {
Key key, pawnKey, materialKey;
int castleRights, rule50;
Square epSquare;
- Move lastMove;
Value mgValue, egValue;
+ Value npMaterial[2];
+
PieceType capture;
+ Bitboard checkersBB;
+ StateInfo* previous;
};
-/// The position data structure. A position consists of the following data:
+/// 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
+/// * For each color, a bitboard representing the squares occupied by
/// pieces of that color.
/// * A bitboard of all occupied squares.
/// * A bitboard of all checking pieces.
/// * A 64-entry array of pieces, indexed by the squares of the board.
/// * The current side to move.
/// * Information about the castling rights for both sides.
-/// * The initial files of the kings and both pairs of rooks. This is
+/// * The initial files of the kings and both pairs of rooks. This is
/// used to implement the Chess960 castling rules.
/// * The en passant square (which is SQ_NONE if no en passant capture is
/// possible).
/// * The squares of the kings for both sides.
-/// * The last move played.
/// * Hash keys for the position itself, the current pawn structure, and
/// the current material situation.
-/// * Hash keys for all previous positions in the game (for detecting
+/// * Hash keys for all previous positions in the game for detecting
/// repetition draws.
/// * A counter for detecting 50 move rule draws.
friend class EndgameFunctions;
public:
+ enum GamePhase {
+ MidGame,
+ EndGame
+ };
+
// Constructors
Position() {};
Position(const Position& pos);
void print(Move m = MOVE_NONE) const;
// Copying
- void copy(const Position &pos);
- void flipped_copy(const Position &pos);
+ void copy(const Position& pos);
+ void flipped_copy(const Position& pos);
// The piece on a given square
Piece piece_on(Square s) 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_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 do_move(Move m, UndoInfo &u);
- void undo_move(Move m, const UndoInfo &u);
- void do_null_move(UndoInfo &u);
- void undo_null_move(const UndoInfo &u);
+ void saveState();
+ void do_move(Move m, StateInfo& st);
+ void do_move(Move m, StateInfo& st, Bitboard dcCandidates);
+ 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;
Value eg_value() const;
Value non_pawn_material(Color c) const;
Phase game_phase() const;
- Value mg_pst_delta(Move m) const;
+ template<GamePhase> Value pst_delta(Piece piece, Square from, Square to) const;
// Game termination checks
bool is_mate() const;
static void init_piece_square_tables();
private:
+
// Initialization helper functions (used while setting up a position)
void clear();
void put_piece(Piece p, Square s);
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_capture_move(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();
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;
+ template<bool FindPinned>
+ Bitboard hidden_checkers(Color c) 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;
+ 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
Color sideToMove;
int gamePly;
Key history[MaxGameLength];
- Value npMaterial[2];
File initialKFile, initialKRFile, initialQRFile;
-
- // Info backed up in do_move()
- union {
- UndoInfo undoInfoUnion;
- struct { // Must have the same layout of UndoInfo
- mutable Bitboard pinners[2], pinned[2], dcCandidates[2];
- Bitboard checkersBB;
- Key key, pawnKey, materialKey;
- int castleRights, rule50;
- Square epSquare;
- Move lastMove;
- Value mgValue, egValue;
- PieceType capture;
- };
- };
+ StateInfo startState;
+ StateInfo* st;
// Static variables
static int castleRightsMask[64];
return bishops_and_queens() & pieces_of_color(c);
}
-inline Bitboard Position::sliders_of_color(Color c) const {
- return sliders() & pieces_of_color(c);
-}
-
inline int Position::piece_count(Color c, PieceType pt) const {
return pieceCount[c][pt];
}
}
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 {
return StepAttackBB[piece_of_color_and_type(c, PAWN)][s];
}
-template<>
-inline Bitboard Position::piece_attacks<PAWN>(Square s) const {
- return StepAttackBB[piece_of_color_and_type(opposite_color(sideToMove), PAWN)][s];
+template<PieceType Piece> // Knight and King
+inline Bitboard Position::piece_attacks(Square s) const {
+ return StepAttackBB[Piece][s];
}
template<>
-inline Bitboard Position::piece_attacks<KNIGHT>(Square s) const {
- return StepAttackBB[KNIGHT][s];
+inline Bitboard Position::piece_attacks<PAWN>(Square s) const {
+ return StepAttackBB[piece_of_color_and_type(opposite_color(sideToMove), PAWN)][s];
}
template<>
return piece_attacks<ROOK>(s) | piece_attacks<BISHOP>(s);
}
-template<>
-inline Bitboard Position::piece_attacks<KING>(Square s) const {
- return StepAttackBB[KING][s];
-}
-
inline Bitboard Position::checkers() const {
- return checkersBB;
+ return st->checkersBB;
}
inline bool Position::is_check() const {
- return checkersBB != EmptyBoardBB;
+ return st->checkersBB != EmptyBoardBB;
}
inline bool Position::pawn_attacks_square(Color c, Square f, Square t) const {
}
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;
-}
-
-inline Value Position::mg_pst(Color c, PieceType pt, Square s) const {
- return MgPieceSquareTable[piece_of_color_and_type(c, pt)][s];
+ return st->materialKey;
}
-inline Value Position::mg_pst_delta(Move m) const {
- return MgPieceSquareTable[piece_on(move_from(m))][move_to(m)]
- -MgPieceSquareTable[piece_on(move_from(m))][move_from(m)];
+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]);
}
-inline Value Position::eg_pst(Color c, PieceType pt, Square s) const {
- return 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 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 {
- return npMaterial[c];
+ return st->npMaterial[c];
}
inline Phase Position::game_phase() const {
- // The purpose of the Value(325) terms below is to make sure the difference
- // between MidgameLimit and EndgameLimit is a power of 2, which should make
- // the division at the end of the function a bit faster.
- static const Value MidgameLimit = 2 * QueenValueMidgame
- + 2 * RookValueMidgame
- + 6 * BishopValueMidgame
- + Value(325);
-
- static const Value EndgameLimit = 4 * RookValueMidgame - Value(325);
+ // Values modified by Joona Kiiski
+ static const Value MidgameLimit = Value(15713);
+ static const Value EndgameLimit = Value(4428);
Value npm = non_pawn_material(WHITE) + non_pawn_material(BLACK);
inline int Position::rule_50_counter() const {
- return rule50;
+ return st->rule50;
}
inline bool Position::opposite_colored_bishops() const {
return pawns(c) & relative_rank_bb(c, RANK_7);
}
+inline bool Position::move_is_capture(Move m) const {
+
+ // Move must not be MOVE_NONE !
+
+ return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
+}
#endif // !defined(POSITION_H_INCLUDED)