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stockfish/src/pawns.h

131 lines
3.3 KiB
C++

/*
Glaurung, a UCI chess playing engine.
Copyright (C) 2004-2008 Tord Romstad
Glaurung 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,
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(PAWNS_H_INCLUDED)
#define PAWNS_H_INCLUDED
////
//// Includes
////
#include "position.h"
////
//// Types
////
/// PawnInfo is a class which contains various information about a pawn
/// structure. Currently, it only includes a middle game and an end game
/// pawn structure evaluation, and a bitboard of passed pawns. We may want
/// to add further information in the future. A lookup to the pawn hash table
/// (performed by calling the get_pawn_info method in a PawnInfoTable object)
/// returns a pointer to a PawnInfo object.
class PawnInfo {
friend class PawnInfoTable;
public:
Value mg_value() const;
Value eg_value() const;
Value kingside_storm_value(Color c) const;
Value queenside_storm_value(Color c) const;
Bitboard passed_pawns() const;
bool file_is_half_open(Color c, File f) const;
bool has_open_file_to_left(Color c, File f) const;
bool has_open_file_to_right(Color c, File f) const;
private:
void clear();
Key key;
Bitboard passedPawns;
int16_t mgValue, egValue;
int8_t ksStormValue[2], qsStormValue[2];
uint8_t halfOpenFiles[2];
};
/// The PawnInfoTable class represents a pawn hash table. It is basically
/// just an array of PawnInfo objects and a few methods for accessing these
/// objects. The most important method is get_pawn_info, which looks up a
/// position in the table and returns a pointer to a PawnInfo object.
class PawnInfoTable {
public:
PawnInfoTable(unsigned numOfEntries);
~PawnInfoTable();
void clear();
PawnInfo *get_pawn_info(const Position &pos);
private:
unsigned size;
PawnInfo *entries;
};
////
//// Inline functions
////
inline Value PawnInfo::mg_value() const {
return Value(mgValue);
}
inline Value PawnInfo::eg_value() const {
return Value(egValue);
}
inline Bitboard PawnInfo::passed_pawns() const {
return passedPawns;
}
inline Value PawnInfo::kingside_storm_value(Color c) const {
return Value(ksStormValue[c]);
}
inline Value PawnInfo::queenside_storm_value(Color c) const {
return Value(qsStormValue[c]);
}
inline bool PawnInfo::file_is_half_open(Color c, File f) const {
return (halfOpenFiles[c] & (1 << int(f)));
}
inline bool PawnInfo::has_open_file_to_left(Color c, File f) const {
return halfOpenFiles[c] & ((1 << int(f)) - 1);
}
inline bool PawnInfo::has_open_file_to_right(Color c, File f) const {
return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
}
inline void PawnInfo::clear() {
mgValue = egValue = 0;
passedPawns = EmptyBoardBB;
ksStormValue[WHITE] = ksStormValue[BLACK] = 0;
qsStormValue[WHITE] = qsStormValue[BLACK] = 0;
halfOpenFiles[WHITE] = halfOpenFiles[BLACK] = 0xFF;
}
#endif // !defined(PAWNS_H_INCLUDED)