/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
Stockfish 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.
Stockfish 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 .
*/
#ifndef ENDGAME_H_INCLUDED
#define ENDGAME_H_INCLUDED
#include
#include
#include
#include
#include
#include "position.h"
#include "types.h"
namespace Stockfish {
/// EndgameCode lists all supported endgame functions by corresponding codes
enum EndgameCode {
EVALUATION_FUNCTIONS,
KNNK, // KNN vs K
KNNKP, // KNN vs KP
KXK, // Generic "mate lone king" eval
KBNK, // KBN vs K
KPK, // KP vs K
KRKP, // KR vs KP
KRKB, // KR vs KB
KRKN, // KR vs KN
KQKP, // KQ vs KP
KQKR, // KQ vs KR
SCALING_FUNCTIONS,
KBPsK, // KB and pawns vs K
KQKRPs, // KQ vs KR and pawns
KRPKR, // KRP vs KR
KRPKB, // KRP vs KB
KRPPKRP, // KRPP vs KRP
KPsK, // K and pawns vs K
KBPKB, // KBP vs KB
KBPPKB, // KBPP vs KB
KBPKN, // KBP vs KN
KPKP // KP vs KP
};
/// Endgame functions can be of two types depending on whether they return a
/// Value or a ScaleFactor.
template using
eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
/// Base and derived functors for endgame evaluation and scaling functions
template
struct EndgameBase {
explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
virtual ~EndgameBase() = default;
virtual T operator()(const Position&) const = 0;
const Color strongSide, weakSide;
};
template>
struct Endgame : public EndgameBase {
explicit Endgame(Color c) : EndgameBase(c) {}
T operator()(const Position&) const override;
};
/// The Endgames namespace handles the pointers to endgame evaluation and scaling
/// base objects in two std::map. We use polymorphism to invoke the actual
/// endgame function by calling its virtual operator().
namespace Endgames {
template using Ptr = std::unique_ptr>;
template using Map = std::unordered_map>;
extern std::pair