// kingAttackersWeight[color] is the sum of the "weight" 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 variables
- // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
- // KnightAttackWeight in evaluate.cpp
+ // 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 to squares
V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
};
- // Threat[attacking][attacked] contains bonuses according to which piece
- // type attacks which one.
- const Score Threat[][PIECE_TYPE_NB] = {
- { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) }, // Protected Minor attacks
- { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) }, // Protected Major attacks
- { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) }, // Weak Minor attacks
- { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } // Weak Major attacks
+ // Threat[defended/weak][minor/major attacking][attacked PieceType] contains
+ // bonuses according to which piece type attacks which one.
+ const Score Threat[][2][PIECE_TYPE_NB] = {
+ { { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) }, // Defended Minor
+ { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) } }, // Defended Major
+ { { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) }, // Weak Minor
+ { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } } // Weak Major
};
// ThreatenedByPawn[PieceType] contains a penalty according to which piece
};
// Assorted bonuses and penalties used by evaluation
- const Score KingOnOne = S(2 , 58);
- const Score KingOnMany = S(6 ,125);
- const Score RookOnPawn = S(7 , 27);
+ const Score KingOnOne = S( 2, 58);
+ const Score KingOnMany = S( 6,125);
+ const Score RookOnPawn = S( 7, 27);
const Score RookOpenFile = S(43, 21);
const Score RookSemiOpenFile = S(19, 10);
const Score BishopPawns = S( 8, 12);
ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
// Init king safety tables only if we are going to use them
- if (pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
+ if (pos.non_pawn_material(Us) >= QueenValueMg)
{
ei.kingRing[Them] = b | shift_bb<Down>(b);
b &= ei.attackedBy[Us][PAWN];
}
-
-
// evaluate_threats() assigns bonuses according to the type of attacking piece
// and the type of attacked one.
const Color Them = (Us == WHITE ? BLACK : WHITE);
- enum { Protected_Minor, Protected_Major, Minor, Major };
- Bitboard b, weakEnemies, protectedEnemies;
+ enum { Defended, Weak };
+ enum { Minor, Major };
+
+ Bitboard b, weak, defended;
Score score = SCORE_ZERO;
- // Enemies defended by a pawn and under our attack
- protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
- & ei.attackedBy[Them][PAWN]
- & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]);
+ // Non-pawn enemies defended by a pawn and under our attack
+ defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
+ & ei.attackedBy[Them][PAWN]
+ & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]);
- if (protectedEnemies)
+ // Add a bonus according to the kind of attacking pieces
+ if (defended)
{
- // Enemies defended by a pawn and under our attack by a minor piece
- b = protectedEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+ b = defended & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
while (b)
- score += Threat[Protected_Minor][type_of(pos.piece_on(pop_lsb(&b)))];
+ score += Threat[Defended][Minor][type_of(pos.piece_on(pop_lsb(&b)))];
- // Enemies defended by a pawn and under our attack by a ROOK
- b = protectedEnemies & (ei.attackedBy[Us][ROOK]);
+ b = defended & (ei.attackedBy[Us][ROOK]);
while (b)
- score += Threat[Protected_Major][type_of(pos.piece_on(pop_lsb(&b)))];
+ score += Threat[Defended][Major][type_of(pos.piece_on(pop_lsb(&b)))];
}
// Enemies not defended by a pawn and under our attack
- weakEnemies = pos.pieces(Them)
- & ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][ALL_PIECES];
+ weak = pos.pieces(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][ALL_PIECES];
- // Add a bonus according if the attacking pieces are minor or major
- if (weakEnemies)
+ // Add a bonus according to the kind of attacking pieces
+ if (weak)
{
- b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+ b = weak & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
while (b)
- score += Threat[Minor][type_of(pos.piece_on(pop_lsb(&b)))];
+ score += Threat[Weak][Minor][type_of(pos.piece_on(pop_lsb(&b)))];
- b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
+ b = weak & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
while (b)
- score += Threat[Major][type_of(pos.piece_on(pop_lsb(&b)))];
+ score += Threat[Weak][Major][type_of(pos.piece_on(pop_lsb(&b)))];
- b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES];
+ b = weak & ~ei.attackedBy[Them][ALL_PIECES];
if (b)
score += more_than_one(b) ? Hanging * popcount<Max15>(b) : Hanging;
- b = weakEnemies & ei.attackedBy[Us][KING];
+ b = weak & ei.attackedBy[Us][KING];
if (b)
score += more_than_one(b) ? KingOnMany : KingOnOne;
}
Square blockSq = s + pawn_push(Us);
// Adjust bonus based on the king's proximity
- ebonus += square_distance(pos.king_square(Them), blockSq) * 5 * rr
- - square_distance(pos.king_square(Us ), blockSq) * 2 * rr;
+ ebonus += distance(pos.king_square(Them), blockSq) * 5 * rr
+ - distance(pos.king_square(Us ), blockSq) * 2 * rr;
// If blockSq is not the queening square then consider also a second push
if (relative_rank(Us, blockSq) != RANK_8)
- ebonus -= square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr;
+ ebonus -= distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr;
// If the pawn is free to advance, then increase the bonus
if (pos.empty(blockSq))
projects / stockfish / blobdiff