const Score TrappedRook = S(92, 0);
const Score Unstoppable = S( 0, 20);
const Score Hanging = S(31, 26);
+ const Score PawnAttackThreat = S(20, 20);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
template<Color Us, bool Trace>
Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
+ const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
enum { Defended, Weak };
enum { Minor, Major };
score += more_than_one(b) ? KingOnMany : KingOnOne;
}
+ // Add bonus for safe pawn pushes which attacks an enemy piece
+ b = pos.pieces(Us, PAWN) & ~TRank7BB;
+ b = shift_bb<Up>(b | (shift_bb<Up>(b & TRank2BB) & ~pos.pieces()));
+
+ b &= ~pos.pieces()
+ & ~ei.attackedBy[Them][PAWN]
+ & (ei.attackedBy[Us][PAWN] | ~ei.attackedBy[Them][ALL_PIECES]);
+
+ b = (shift_bb<Left>(b) | shift_bb<Right>(b))
+ & pos.pieces(Them)
+ & ~ei.attackedBy[Us][PAWN];
+
+ if (b)
+ score += popcount<Max15>(b) * PawnAttackThreat;
+
if (Trace)
Tracing::write(Tracing::THREAT, Us, score);