X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.h;h=941cb31017a6ef0c3d373c9ba17abfea9036dc5d;hp=dabf233e7058f2f367f429badf25bcd00f4fd40e;hb=b54bcfddaa2a5f6c5d4d5b54243a682a098f49a3;hpb=d3600c39a745179ed6b094b305d0645e83a1ee86

diff --git a/src/endgame.h b/src/endgame.h
index dabf233e..941cb310 100644
--- a/src/endgame.h
+++ b/src/endgame.h
@@ -1,243 +1,145 @@
 /*
   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) 2008-2015 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
   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 <http://www.gnu.org/licenses/>.
 */
 
-
-#if !defined(ENDGAME_H_INCLUDED)
+#ifndef ENDGAME_H_INCLUDED
 #define ENDGAME_H_INCLUDED
 
-////
-//// Includes
-////
+#include <map>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <utility>
 
 #include "position.h"
-#include "scale.h"
-#include "value.h"
-
+#include "types.h"
 
-////
-//// Types
-////
 
-/// Abstract base class for all special endgame evaluation functions:
+/// EndgameCode lists all supported endgame functions by corresponding codes
 
-class EndgameEvaluationFunction {
-public:
-  EndgameEvaluationFunction(Color c);
-  virtual ~EndgameEvaluationFunction() { }
+enum EndgameCode {
 
-  virtual Value apply(const Position &pos) =0;
+  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
 
-protected:
-  Color strongerSide, weakerSide;
+  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
 };
 
 
-/// Subclasses for various concrete endgames:
+/// Endgame functions can be of two types depending on whether they return a
+/// Value or a ScaleFactor.
 
-// Generic "mate lone king" eval:
-class KXKEvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KXKEvaluationFunction(Color c);
-  Value apply(const Position &pos);
-};
+template<EndgameCode E> using
+eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
 
-// KBN vs K:
-class KBNKEvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KBNKEvaluationFunction(Color c);
-  Value apply(const Position &pos);
-};
 
-// KP vs K:
-class KPKEvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KPKEvaluationFunction(Color c);
-  Value apply(const Position &pos);
-};
+/// Base and derived functors for endgame evaluation and scaling functions
 
-// KR vs KP:
-class KRKPEvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KRKPEvaluationFunction(Color c);
-  Value apply(const Position &pos);
-};
+template<typename T>
+struct EndgameBase {
 
-// KR vs KB:
-class KRKBEvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KRKBEvaluationFunction(Color c);
-  Value apply(const Position &pos);
-};
+  explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
+  virtual ~EndgameBase() = default;
+  virtual T operator()(const Position&) const = 0;
 
-// KR vs KN:
-class KRKNEvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KRKNEvaluationFunction(Color c);
-  Value apply(const Position &pos);
+  const Color strongSide, weakSide;
 };
 
-// KQ vs KR:
-class KQKREvaluationFunction : public EndgameEvaluationFunction {
-public:
-  KQKREvaluationFunction(Color c);
-  Value apply(const Position &pos);
-};
-
-
-/// Abstract base class for all evaluation scaling functions:
 
-class ScalingFunction {
-public:
-  ScalingFunction(Color c);
-  virtual ~ScalingFunction() { }
-
-  virtual ScaleFactor apply(const Position &pos) =0;
+template<EndgameCode E, typename T = eg_type<E>>
+struct Endgame : public EndgameBase<T> {
 
-protected:
-  Color strongerSide, weakerSide;
+  explicit Endgame(Color c) : EndgameBase<T>(c) {}
+  T operator()(const Position&) const override;
 };
 
 
-/// Subclasses for various concrete endgames:
+/// 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().
 
-// KBP vs K:
-class KBPKScalingFunction : public ScalingFunction {
-public:
-  KBPKScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
+class Endgames {
 
-// KQ vs KRP:
-class KQKRPScalingFunction: public ScalingFunction {
-public:
-  KQKRPScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
+  template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
+  template<typename T> using Map = std::map<Key, Ptr<T>>;
 
-// KRP vs KR:
-class KRPKRScalingFunction : public ScalingFunction {
-public:
-  KRPKRScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
+  template<typename T>
+  Map<T>& map() {
+    return std::get<std::is_same<T, ScaleFactor>::value>(maps);
+  }
 
-// KRPP vs KRP:
-class KRPPKRPScalingFunction : public ScalingFunction {
-public:
-  KRPPKRPScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
+  template<EndgameCode E, typename T = eg_type<E>>
+  void add(const std::string& code) {
 
-// King and pawns vs king:
-class KPsKScalingFunction : public ScalingFunction {
-public:
-  KPsKScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
-
-// KBP vs KB:
-class KBPKBScalingFunction : public ScalingFunction {
-public:
-  KBPKBScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
+    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));
+  }
 
-// KBP vs KN:
-class KBPKNScalingFunction : public ScalingFunction {
-public:
-  KBPKNScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
+  std::pair<Map<Value>, Map<ScaleFactor>> maps;
 
-// KNP vs K:
-class KNPKScalingFunction : public ScalingFunction {
 public:
-  KNPKScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
-
-// KP vs KP:
-class KPKPScalingFunction : public ScalingFunction {
-public:
-  KPKPScalingFunction(Color c);
-  ScaleFactor apply(const Position &pos);
-};
-
-
-////
-//// Constants and variables
-////
-
-// Generic "mate lone king" eval:
-extern KXKEvaluationFunction EvaluateKXK, EvaluateKKX;
-
-// KBN vs K:
-extern KBNKEvaluationFunction EvaluateKBNK, EvaluateKKBN;
-
-// KP vs K:
-extern KPKEvaluationFunction EvaluateKPK, EvaluateKKP;
+  Endgames() {
 
-// KR vs KP:
-extern KRKPEvaluationFunction EvaluateKRKP, EvaluateKPKR;
+    add<KPK>("KPK");
+    add<KNNK>("KNNK");
+    add<KBNK>("KBNK");
+    add<KRKP>("KRKP");
+    add<KRKB>("KRKB");
+    add<KRKN>("KRKN");
+    add<KQKP>("KQKP");
+    add<KQKR>("KQKR");
 
-// KR vs KB:
-extern KRKBEvaluationFunction EvaluateKRKB, EvaluateKBKR;
-
-// KR vs KN:
-extern KRKNEvaluationFunction EvaluateKRKN, EvaluateKNKR;
-
-// KQ vs KR:
-extern KQKREvaluationFunction EvaluateKQKR, EvaluateKRKQ;
-
-// KBP vs K:
-extern KBPKScalingFunction ScaleKBPK, ScaleKKBP;
-
-// KQ vs KRP:
-extern KQKRPScalingFunction ScaleKQKRP, ScaleKRPKQ;
-
-// KRP vs KR:
-extern KRPKRScalingFunction ScaleKRPKR, ScaleKRKRP;
-
-// KRPP vs KRP:
-extern KRPPKRPScalingFunction ScaleKRPPKRP, ScaleKRPKRPP;
-
-// King and pawns vs king:
-extern KPsKScalingFunction ScaleKPsK, ScaleKKPs;
-
-// KBP vs KB:
-extern KBPKBScalingFunction ScaleKBPKB, ScaleKBKBP;
-
-// KBP vs KN:
-extern KBPKNScalingFunction ScaleKBPKN, ScaleKNKBP;
-
-// KNP vs K:
-extern KNPKScalingFunction ScaleKNPK, ScaleKKNP;
-
-// KP vs KP:
-extern KPKPScalingFunction ScaleKPKPw, ScaleKPKPb;
-
-
-////
-//// Prototypes
-////
-
-extern void init_bitbases();
+    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