/*
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 StateInfo struct stores information we need to restore a Position
/// object to its previous state when we retract a move. Whenever a move
/// must be passed as a parameter.
struct StateInfo {
- Bitboard pinners[2], pinned[2], dcCandidates[2], checkersBB;
Key key, pawnKey, materialKey;
int castleRights, rule50;
Square epSquare;
Value mgValue, egValue;
+ Value npMaterial[2];
+
PieceType capture;
+ Bitboard checkersBB;
StateInfo* previous;
- Move lastMove;
};
-/// 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;
// Information about pawns
bool pawn_is_passed(Color c, Square s) const;
- bool pawn_is_isolated(Color c, Square s) const;
- bool pawn_is_doubled(Color c, Square s) const;
-
- // Open and half-open files
- bool file_is_open(File f) const;
- bool file_is_half_open(Color c, File f) 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 setStartState(const StateInfo& st);
+ 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();
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;
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 init_new_state(StateInfo& newSt);
- 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);
void do_ep_move(Move m);
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;
+ 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
- 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;
Color sideToMove;
int gamePly;
Key history[MaxGameLength];
- Value npMaterial[2];
File initialKFile, initialKRFile, initialQRFile;
StateInfo startState;
StateInfo* st;
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];
}
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::pinned_pieces(Color c) const {
- return st->pinned[c];
-}
-
-inline Bitboard Position::pinned_pieces(Color c, Bitboard& p) const {
- p = st->pinners[c];
- return st->pinned[c];
-}
-
-inline Bitboard Position::discovered_check_candidates(Color c) const {
- return st->dcCandidates[c];
-}
-
inline Bitboard Position::checkers() const {
return st->checkersBB;
}
return !(pawns(opposite_color(c)) & passed_pawn_mask(c, s));
}
-inline bool Position::pawn_is_isolated(Color c, Square s) const {
- return !(pawns(c) & neighboring_files_bb(s));
-}
-
-inline bool Position::pawn_is_doubled(Color c, Square s) const {
- return pawns(c) & squares_behind(c, s);
+inline bool Position::pawn_is_passed(Bitboard theirPawns, Color c, Square s) {
+ return !(theirPawns & passed_pawn_mask(c, s));
}
-inline bool Position::file_is_open(File f) const {
- return !(pawns() & file_bb(f));
+inline bool Position::pawn_is_isolated(Bitboard ourPawns, Square s) {
+ return !(ourPawns & neighboring_files_bb(s));
}
-inline bool Position::file_is_half_open(Color c, File f) const {
- return !(pawns(c) & file_bb(f));
+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 st->materialKey;
}
-template<Position::GamePhase Phase>
+template<Position::GamePhase Ph>
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]);
+ return (Ph == 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 {
- 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_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 {
}
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(15581);
+ static const Value EndgameLimit = Value(3998);
Value npm = non_pawn_material(WHITE) + non_pawn_material(BLACK);
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)