/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, 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(ENDGAME_H_INCLUDED)
+#ifndef ENDGAME_H_INCLUDED
#define ENDGAME_H_INCLUDED
+#include <map>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <utility>
+
#include "position.h"
#include "types.h"
-enum EndgameType {
-
- // Evaluation functions
- 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
- KQKR, // KQ vs KR
- KBBKN, // KBB vs KN
- KNNK, // KNN vs K
- KmmKm, // K and two minors vs K and one or two minors
-
- // Scaling functions
- KBPsK, // KB+pawns vs K
- KQKRPs, // KQ vs KR+pawns
- KRPKR, // KRP vs KR
- KRPPKRP, // KRPP vs KRP
- KPsK, // King and pawns vs king
- KBPKB, // KBP vs KB
- KBPPKB, // KBPP vs KB
- KBPKN, // KBP vs KN
- KNPK, // KNP vs K
- KPKP // KP vs KP
+
+/// EndgameCode lists all supported endgame functions by corresponding codes
+
+enum EndgameCode {
+
+ EVALUATION_FUNCTIONS,
+ KNNK, // KNN vs K
+ 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
+ KNPK, // KNP vs K
+ KNPKB, // KNP vs KB
+ KPKP // KP vs KP
};
-/// Template abstract base class for all special endgame functions
+
+/// Endgame functions can be of two types depending on whether they return a
+/// Value or a ScaleFactor.
+
+template<EndgameCode E> using
+eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
+
+
+/// Base and derived functors for endgame evaluation and scaling functions
template<typename T>
-class EndgameFunctionBase {
-public:
- EndgameFunctionBase(Color c) : strongerSide(c), weakerSide(opposite_color(c)) {}
- virtual ~EndgameFunctionBase() {}
- virtual T apply(const Position&) const = 0;
- Color color() const { return strongerSide; }
+struct EndgameBase {
-protected:
- Color strongerSide, weakerSide;
-};
+ explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
+ virtual ~EndgameBase() = default;
+ virtual T operator()(const Position&) const = 0;
-typedef EndgameFunctionBase<Value> EndgameEvaluationFunctionBase;
-typedef EndgameFunctionBase<ScaleFactor> EndgameScalingFunctionBase;
+ const Color strongSide, weakSide;
+};
-/// Templates subclass for various concrete endgames
+template<EndgameCode E, typename T = eg_type<E>>
+struct Endgame : public EndgameBase<T> {
-template<EndgameType>
-struct EvaluationFunction : public EndgameEvaluationFunctionBase {
- typedef EndgameEvaluationFunctionBase Base;
- explicit EvaluationFunction(Color c): EndgameEvaluationFunctionBase(c) {}
- Value apply(const Position&) const;
+ explicit Endgame(Color c) : EndgameBase<T>(c) {}
+ T operator()(const Position&) const override;
};
-template<EndgameType>
-struct ScalingFunction : public EndgameScalingFunctionBase {
- typedef EndgameScalingFunctionBase Base;
- explicit ScalingFunction(Color c) : EndgameScalingFunctionBase(c) {}
- ScaleFactor apply(const Position&) const;
+
+/// The Endgames class stores 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().
+
+class Endgames {
+
+ template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
+ template<typename T> using Map = std::map<Key, Ptr<T>>;
+
+ template<typename T>
+ Map<T>& map() {
+ return std::get<std::is_same<T, ScaleFactor>::value>(maps);
+ }
+
+ template<EndgameCode E, typename T = eg_type<E>>
+ void add(const std::string& code) {
+
+ StateInfo st;
+ map<T>()[Position().set(code, WHITE, &st).material_key()] = Ptr<T>(new Endgame<E>(WHITE));
+ map<T>()[Position().set(code, BLACK, &st).material_key()] = Ptr<T>(new Endgame<E>(BLACK));
+ }
+
+ std::pair<Map<Value>, Map<ScaleFactor>> maps;
+
+public:
+ Endgames() {
+
+ add<KPK>("KPK");
+ add<KNNK>("KNNK");
+ add<KBNK>("KBNK");
+ add<KRKP>("KRKP");
+ add<KRKB>("KRKB");
+ add<KRKN>("KRKN");
+ add<KQKP>("KQKP");
+ add<KQKR>("KQKR");
+
+ add<KNPK>("KNPK");
+ add<KNPKB>("KNPKB");
+ add<KRPKR>("KRPKR");
+ add<KRPKB>("KRPKB");
+ add<KBPKB>("KBPKB");
+ add<KBPKN>("KBPKN");
+ add<KBPPKB>("KBPPKB");
+ add<KRPPKRP>("KRPPKRP");
+ }
+
+ template<typename T>
+ const EndgameBase<T>* probe(Key key) {
+ return map<T>().count(key) ? map<T>()[key].get() : nullptr;
+ }
};
-#endif // !defined(ENDGAME_H_INCLUDED)
+#endif // #ifndef ENDGAME_H_INCLUDED
projects / stockfish / blobdiff