// Bonus for having a mate threat, initialized from UCI options
int MateThreatBonus;
+ // ThreatBonus[][] contains bonus according to which piece type
+ // attacks which one.
+ const Value MidgameThreatBonus[8][8] = {
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0),V(18), V(0),V(37), V(55), V(55), V(0), V(0) }, // KNIGHT attacks
+ { V(0),V(18),V(37), V(0), V(55), V(55), V(0), V(0) }, // BISHOP attacks
+ { V(0), V(9),V(27),V(27), V(0), V(37), V(0), V(0) }, // ROOK attacks
+ { V(0),V(27),V(27),V(27), V(27), V(0), V(0), V(0) }, // QUEEN attacks
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) } // not used
+ };
+
+ const Value EndgameThreatBonus[8][8] = {
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0),V(37), V(0),V(47), V(97), V(97), V(0), V(0) }, // KNIGHT attacks
+ { V(0),V(37),V(47), V(0), V(97), V(97), V(0), V(0) }, // BISHOP attacks
+ { V(0),V(27),V(47),V(47), V(0), V(47), V(0), V(0) }, // ROOK attacks
+ { V(0),V(37),V(37),V(37), V(37), V(0), V(0), V(0) }, // QUEEN attacks
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, // not used
+ { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) } // not used
+ };
+
+ // ThreatedByPawnPenalty[] contains a penalty according to which piece
+ // type is attacked by an enemy pawn.
+ const Value MidgameThreatedByPawnPenalty[8] = {
+ V(0), V(0), V(56), V(56), V(76), V(86), V(0), V(0)
+ };
+
+ const Value EndgameThreatedByPawnPenalty[8] = {
+ V(0), V(0), V(70), V(70), V(99), V(118), V(0), V(0)
+ };
+
// InitKingDanger[] contains bonuses based on the position of the defending
// king.
const int InitKingDanger[64] = {
template<Color Us, bool HasPopCnt>
void evaluate_king(const Position& pos, EvalInfo& ei);
+ template<Color Us>
+ void evaluate_threats(const Position& pos, EvalInfo& ei);
+
template<Color Us, bool HasPopCnt>
void evaluate_space(const Position& pos, EvalInfo& ei);
evaluate_king<WHITE, HasPopCnt>(pos, ei);
evaluate_king<BLACK, HasPopCnt>(pos, ei);
+ // Evaluate tactical threats, we need full attack info
+ evaluate_threats<WHITE>(pos, ei);
+ evaluate_threats<BLACK>(pos, ei);
+
// Evaluate passed pawns. We evaluate passed pawns for both sides at once,
// because we need to know which side promotes first in positions where
// both sides have an unstoppable passed pawn. To be called after all attacks
// evaluate_mobility() computes mobility and attacks for every piece
template<PieceType Piece, Color Us, bool HasPopCnt>
- int evaluate_mobility(const Position& pos, Bitboard b, EvalInfo& ei) {
+ int evaluate_mobility(Bitboard b, Bitboard mob_area, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus };
static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus };
- static const int lastIndex[] = { 0, 0, 8, 15, 15, 31 };
// Update attack info
ei.attackedBy[Us][Piece] |= b;
ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
}
- // Remove squares protected by enemy pawns or occupied by our pieces
- b &= ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
-
- // The squares occupied by enemy pieces (not defended by pawns) will be
- // counted two times instead of one. The shift (almost) guarantees that
- // intersection of the shifted value with b is zero so that after or-ing
- // the count of 1s bits is increased by the number of affected squares.
- b |= Us == WHITE ? ((b & pos.pieces_of_color(Them)) >> 1)
- : ((b & pos.pieces_of_color(Them)) << 1);
-
// Mobility
- int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b)
- : count_1s<HasPopCnt>(b));
-
- if (mob > lastIndex[Piece])
- mob = lastIndex[Piece];
+ int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b & mob_area)
+ : count_1s<HasPopCnt>(b & mob_area));
ei.mgMobility += Sign[Us] * MgBonus[Piece][mob];
ei.egMobility += Sign[Us] * EgBonus[Piece][mob];
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square* ptr = pos.piece_list_begin(Us, Piece);
+ // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
+ const Bitboard mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+
while ((s = *ptr++) != SQ_NONE)
{
if (Piece == KNIGHT || Piece == QUEEN)
assert(false);
// Attacks and mobility
- mob = evaluate_mobility<Piece, Us, HasPopCnt>(pos, b, ei);
+ mob = evaluate_mobility<Piece, Us, HasPopCnt>(b, mob_area, ei);
+
+ // Decrease score if we are attacked by an enemy pawn. Remaining part
+ // of threat evaluation must be done later when we have full attack info.
+ if (bit_is_set(ei.attackedBy[Them][PAWN], s))
+ {
+ ei.mgValue -= Sign[Us] * MidgameThreatedByPawnPenalty[Piece];
+ ei.egValue -= Sign[Us] * EndgameThreatedByPawnPenalty[Piece];
+ }
// Bishop and knight outposts squares
if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
}
+ // evaluate_threats<>() assigns bonuses according to the type of attacking piece
+ // and the type of attacked one.
+
+ template<Color Us>
+ void evaluate_threats(const Position& pos, EvalInfo& ei) {
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b;
+ Value mgBonus = Value(0);
+ Value egBonus = Value(0);
+
+ // Enemy pieces not defended by a pawn and under our attack
+ Bitboard weakEnemies = pos.pieces_of_color(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][0];
+ if (!weakEnemies)
+ return;
+
+ // Add bonus according to type of attacked enemy pieces and to the
+ // type of attacking piece, from knights to queens. Kings are not
+ // considered because are already special handled in king evaluation.
+ for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
+ {
+ b = ei.attackedBy[Us][pt1] & weakEnemies;
+ if (b)
+ for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
+ if (b & pos.pieces(pt2))
+ {
+ mgBonus += MidgameThreatBonus[pt1][pt2];
+ egBonus += EndgameThreatBonus[pt1][pt2];
+ }
+ }
+ ei.mgValue += Sign[Us] * mgBonus;
+ ei.egValue += Sign[Us] * egBonus;
+ }
+
+
// evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
// pieces of a given color.
projects / stockfish / blobdiff