- const int QuadraticCoefficientsOppositeColor[][6] = {
- { 0, 0, 0, 0, 0, 0 }, { -4, 0, 0, 0, 0, 0 }, { -31, 21, 0, 0, 0, 0 },
- { 16, 23, -2, 0, 0, 0 }, { 9, -1, -18, -63, 0, 0 }, { 65, 60, -38, 110, 130, 0 } };
-
- // Named endgame evaluation and scaling functions, these
- // are accessed direcly and not through the function maps.
- EvaluationFunction<KmmKm> EvaluateKmmKm(WHITE);
- EvaluationFunction<KXK> EvaluateKXK(WHITE), EvaluateKKX(BLACK);
- ScalingFunction<KBPsK> ScaleKBPsK(WHITE), ScaleKKBPs(BLACK);
- ScalingFunction<KQKRPs> ScaleKQKRPs(WHITE), ScaleKRPsKQ(BLACK);
- ScalingFunction<KPsK> ScaleKPsK(WHITE), ScaleKKPs(BLACK);
- ScalingFunction<KPKP> ScaleKPKPw(WHITE), ScaleKPKPb(BLACK);
-
- typedef EndgameEvaluationFunctionBase EF;
- typedef EndgameScalingFunctionBase SF;
-}
-
-
-////
-//// Classes
-////
-
-/// EndgameFunctions class stores endgame evaluation and scaling functions
-/// in two std::map. Because STL library is not guaranteed to be thread
-/// safe even for read access, the maps, although with identical content,
-/// are replicated for each thread. This is faster then using locks.
-
-class EndgameFunctions {
-public:
- EndgameFunctions();
- ~EndgameFunctions();
- template<class T> T* get(Key key) const;
-
-private:
- template<class T> void add(const string& keyCode);
-
- static Key buildKey(const string& keyCode);
- static const string swapColors(const string& keyCode);
-
- // Here we store two maps, for evaluate and scaling functions
- pair<map<Key, EF*>, map<Key, SF*> > maps;
-
- // Maps accessing functions returning const and non-const references
- template<typename T> const map<Key, T*>& get() const { return maps.first; }
- template<typename T> map<Key, T*>& get() { return maps.first; }
-};
-
-// Explicit specializations of a member function shall be declared in
-// the namespace of which the class template is a member.
-template<> const map<Key, SF*>&
-EndgameFunctions::get<SF>() const { return maps.second; }
-
-template<> map<Key, SF*>&
-EndgameFunctions::get<SF>() { return maps.second; }
-
-
-////
-//// Functions
-////
+ const int QuadraticCoefficientsOppositeColor[][8] = {
+ { 41, 41, 41, 41, 41, 41 }, { 37, 41, 41, 41, 41, 41 }, { 10, 62, 41, 41, 41, 41 },
+ { 57, 64, 39, 41, 41, 41 }, { 50, 40, 23, -22, 41, 41 }, { 106, 101, 3, 151, 171, 41 } };
+
+ // Endgame evaluation and scaling functions accessed direcly and not through
+ // the function maps because correspond to more then one material hash key.
+ Endgame<KmmKm> EvaluateKmmKm[] = { Endgame<KmmKm>(WHITE), Endgame<KmmKm>(BLACK) };
+ Endgame<KXK> EvaluateKXK[] = { Endgame<KXK>(WHITE), Endgame<KXK>(BLACK) };
+
+ Endgame<KBPsK> ScaleKBPsK[] = { Endgame<KBPsK>(WHITE), Endgame<KBPsK>(BLACK) };
+ Endgame<KQKRPs> ScaleKQKRPs[] = { Endgame<KQKRPs>(WHITE), Endgame<KQKRPs>(BLACK) };
+ Endgame<KPsK> ScaleKPsK[] = { Endgame<KPsK>(WHITE), Endgame<KPsK>(BLACK) };
+ Endgame<KPKP> ScaleKPKP[] = { Endgame<KPKP>(WHITE), Endgame<KPKP>(BLACK) };
+
+ // Helper templates used to detect a given material distribution
+ template<Color Us> bool is_KXK(const Position& pos) {
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ return pos.non_pawn_material(Them) == VALUE_ZERO
+ && pos.piece_count(Them, PAWN) == 0
+ && pos.non_pawn_material(Us) >= RookValueMidgame;
+ }