/*
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) 2004-2023 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-#if !defined(MATERIAL_H_INCLUDED)
+#ifndef MATERIAL_H_INCLUDED
#define MATERIAL_H_INCLUDED
-////
-//// Includes
-////
-
#include "endgame.h"
+#include "misc.h"
#include "position.h"
-#include "scale.h"
-
+#include "types.h"
-////
-//// Types
-////
+namespace Stockfish::Material {
-/// MaterialInfo is a class which contains various information about a
-/// material configuration. It contains a material balance evaluation,
-/// a function pointer to a special endgame evaluation function (which in
-/// most cases is NULL, meaning that the standard evaluation function will
-/// be used), and "scale factors" for black and white.
+/// Material::Entry contains various information about a material configuration.
+/// It contains a material imbalance evaluation, a function pointer to a special
+/// endgame evaluation function (which in most cases is nullptr, meaning that the
+/// standard evaluation function will be used), and scale factors.
///
-/// The scale factors are used to scale the evaluation score up or down.
-/// For instance, in KRB vs KR endgames, the score is scaled down by a factor
-/// of 4, which will result in scores of absolute value less than one pawn.
-
-class MaterialInfo {
-
- friend class MaterialInfoTable;
-
-public:
- Value mg_value() const;
- Value eg_value() const;
- ScaleFactor scale_factor(const Position& pos, Color c) const;
- int space_weight() const;
- bool specialized_eval_exists() const;
- Value evaluate(const Position& pos) const;
-
-private:
- void clear();
+/// The scale factors are used to scale the evaluation score up or down. For
+/// instance, in KRB vs KR endgames, the score is scaled down by a factor of 4,
+/// which will result in scores of absolute value less than one pawn.
+
+struct Entry {
+
+ Score imbalance() const { return score; }
+ Phase game_phase() const { return (Phase)gamePhase; }
+ bool specialized_eval_exists() const { return evaluationFunction != nullptr; }
+ Value evaluate(const Position& pos) const { return (*evaluationFunction)(pos); }
+
+ // scale_factor() takes a position and a color as input and returns a scale factor
+ // for the given color. We have to provide the position in addition to the color
+ // because the scale factor may also be a function which should be applied to
+ // the position. For instance, in KBP vs K endgames, the scaling function looks
+ // for rook pawns and wrong-colored bishops.
+ ScaleFactor scale_factor(const Position& pos, Color c) const {
+ ScaleFactor sf = scalingFunction[c] ? (*scalingFunction[c])(pos)
+ : SCALE_FACTOR_NONE;
+ return sf != SCALE_FACTOR_NONE ? sf : ScaleFactor(factor[c]);
+ }
Key key;
- int16_t mgValue;
- int16_t egValue;
- uint8_t factor[2];
- EndgameEvaluationFunctionBase* evaluationFunction;
- EndgameScalingFunctionBase* scalingFunction[2];
- int spaceWeight;
+ const EndgameBase<Value>* evaluationFunction;
+ const EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB]; // Could be one for each
+ // side (e.g. KPKP, KBPsK)
+ Score score;
+ int16_t gamePhase;
+ uint8_t factor[COLOR_NB];
};
+using Table = HashTable<Entry, 8192>;
-/// EndgameFunctions class stores the endgame evaluation functions std::map.
-/// Because STL library is not thread safe even for read access, the maps,
-/// although with identical content, are replicated for each thread. This
-/// is faster then using locks with an unique set of global maps.
-
-class EndgameFunctions;
-
-
-/// The MaterialInfoTable class represents a pawn hash table. It is basically
-/// just an array of MaterialInfo objects and a few methods for accessing these
-/// objects. The most important method is get_material_info, which looks up a
-/// position in the table and returns a pointer to a MaterialInfo object.
-
-class MaterialInfoTable {
-
-public:
- MaterialInfoTable(unsigned numOfEntries);
- ~MaterialInfoTable();
- void clear();
- MaterialInfo* get_material_info(const Position& pos);
-
-private:
- unsigned size;
- MaterialInfo* entries;
- EndgameFunctions* funcs;
-};
-
-
-////
-//// Inline functions
-////
-
-/// MaterialInfo::mg_value and MaterialInfo::eg_value simply returns the
-/// material balance evaluation for the middle game and the endgame.
-
-inline Value MaterialInfo::mg_value() const {
-
- return Value(mgValue);
-}
-
-inline Value MaterialInfo::eg_value() const {
-
- return Value(egValue);
-}
-
-
-/// MaterialInfo::clear() resets a MaterialInfo object to an empty state,
-/// with all slots at their default values.
-
-inline void MaterialInfo::clear() {
-
- mgValue = egValue = 0;
- factor[WHITE] = factor[BLACK] = uint8_t(SCALE_FACTOR_NORMAL);
- spaceWeight = 0;
- evaluationFunction = NULL;
- scalingFunction[WHITE] = scalingFunction[BLACK] = NULL;
-}
-
-
-/// MaterialInfo::scale_factor takes a position and a color as input, and
-/// returns a scale factor for the given color. We have to provide the
-/// position in addition to the color, because the scale factor need not
-/// to be a constant: It can also be a function which should be applied to
-/// the position. For instance, in KBP vs K endgames, a scaling function
-/// which checks for draws with rook pawns and wrong-colored bishops.
-
-inline ScaleFactor MaterialInfo::scale_factor(const Position& pos, Color c) const {
-
- if (scalingFunction[c] != NULL)
- {
- ScaleFactor sf = scalingFunction[c]->apply(pos);
- if (sf != SCALE_FACTOR_NONE)
- return sf;
- }
- return ScaleFactor(factor[c]);
-}
-
-
-/// MaterialInfo::space_weight() simply returns the weight for the space
-/// evaluation for this material configuration.
-
-inline int MaterialInfo::space_weight() const {
-
- return spaceWeight;
-}
-
-
-/// MaterialInfo::specialized_eval_exists decides whether there is a
-/// specialized evaluation function for the current material configuration,
-/// or if the normal evaluation function should be used.
-
-inline bool MaterialInfo::specialized_eval_exists() const {
-
- return evaluationFunction != NULL;
-}
-
-
-/// MaterialInfo::evaluate applies a specialized evaluation function
-/// to a given position object. It should only be called when
-/// specialized_eval_exists() returns 'true'.
-
-inline Value MaterialInfo::evaluate(const Position& pos) const {
+Entry* probe(const Position& pos);
- return evaluationFunction->apply(pos);
-}
+} // namespace Stockfish::Material
-#endif // !defined(MATERIAL_H_INCLUDED)
+#endif // #ifndef MATERIAL_H_INCLUDED