+ // PassedDanger[Rank] contains a term to weight the passed score
+ const int PassedDanger[RANK_NB] = { 0, 0, 0, 2, 7, 12, 19 };
+
+ // KingProtector[PieceType-2] contains a penalty according to distance from king
+ const Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
+
+ // Assorted bonuses and penalties
+ const Score BishopPawns = S( 8, 12);
+ const Score CloseEnemies = S( 7, 0);
+ const Score Hanging = S( 52, 30);
+ const Score HinderPassedPawn = S( 8, 1);
+ const Score KnightOnQueen = S( 21, 11);
+ const Score LongRangedBishop = S( 22, 0);
+ const Score MinorBehindPawn = S( 16, 0);
+ const Score PawnlessFlank = S( 20, 80);
+ const Score RookOnPawn = S( 8, 24);
+ const Score ThreatByPawnPush = S( 47, 26);
+ const Score ThreatByRank = S( 16, 3);
+ const Score ThreatBySafePawn = S(175,168);
+ const Score ThreatOnQueen = S( 42, 21);
+ const Score TrappedBishopA1H1 = S( 50, 50);
+ const Score TrappedRook = S( 92, 0);
+ const Score WeakQueen = S( 50, 10);
+ const Score WeakUnopposedPawn = S( 5, 25);
+
+#undef S
+
+ // Evaluation class computes and stores attacks tables and other working data
+ template<Tracing T>
+ class Evaluation {
+
+ public:
+ Evaluation() = delete;
+ explicit Evaluation(const Position& p) : pos(p) {}
+ Evaluation& operator=(const Evaluation&) = delete;
+ Value value();
+
+ private:
+ template<Color Us> void initialize();
+ template<Color Us, PieceType Pt> Score pieces();
+ template<Color Us> Score king() const;
+ template<Color Us> Score threats() const;
+ template<Color Us> Score passed() const;
+ template<Color Us> Score space() const;
+ ScaleFactor scale_factor(Value eg) const;
+ Score initiative(Value eg) const;
+
+ const Position& pos;
+ Material::Entry* me;
+ Pawns::Entry* pe;
+ Bitboard mobilityArea[COLOR_NB];
+ Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
+
+ // attackedBy[color][piece type] is a bitboard representing all squares
+ // attacked by a given color and piece type. Special "piece types" which
+ // are also calculated are QUEEN_DIAGONAL and ALL_PIECES.
+ Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
+
+ // attackedBy2[color] are the squares attacked by 2 pieces of a given color,
+ // possibly via x-ray or by one pawn and one piece. Diagonal x-ray through
+ // pawn or squares attacked by 2 pawns are not explicitly added.
+ Bitboard attackedBy2[COLOR_NB];
+
+ // kingRing[color] are the squares adjacent to the king, plus (only for a
+ // king on its first rank) the squares two ranks in front. For instance,
+ // if black's king is on g8, kingRing[BLACK] is f8, h8, f7, g7, h7, f6, g6
+ // and h6. It is set to 0 when king safety evaluation is skipped.
+ Bitboard kingRing[COLOR_NB];
+
+ // kingAttackersCount[color] is the number of pieces of the given color
+ // which attack a square in the kingRing of the enemy king.
+ int kingAttackersCount[COLOR_NB];
+
+ // kingAttackersWeight[color] is the sum of the "weights" of the pieces of the
+ // given color which attack a square in the kingRing of the enemy king. The
+ // weights of the individual piece types are given by the elements in the
+ // KingAttackWeights array.
+ int kingAttackersWeight[COLOR_NB];
+
+ // kingAdjacentZoneAttacksCount[color] is the number of attacks by the given
+ // color to squares directly adjacent to the enemy king. Pieces which attack
+ // more than one square are counted multiple times. For instance, if there is
+ // a white knight on g5 and black's king is on g8, this white knight adds 2
+ // to kingAdjacentZoneAttacksCount[WHITE].
+ int kingAdjacentZoneAttacksCount[COLOR_NB];
+ };