Give bonus for bishops that are alligned with enemy kingring.

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 8e8cc0912e57ddd4e37c12cb579631eaee9de289..dc7134a8818bdd6874ec555eeef935502a13eeaa 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -128,6 +128,7 @@ namespace {
 
   // Assorted bonuses and penalties
   constexpr Score BishopPawns         = S(  3,  7);
+  constexpr Score BishopOnKingRing    = S( 24,  0);
   constexpr Score BishopXRayPawns     = S(  4,  5);
   constexpr Score CorneredBishop      = S( 50, 50);
   constexpr Score FlankAttacks        = S(  8,  0);
@@ -235,7 +236,7 @@ namespace {
     mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them));
 
     // Initialize attackedBy[] for king and pawns
-    attackedBy[Us][KING] = pos.attacks_from<KING>(ksq);
+    attackedBy[Us][KING] = attacks_bb<KING>(ksq);
     attackedBy[Us][PAWN] = pe->pawn_attacks(Us);
     attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
     attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]);
@@ -243,7 +244,7 @@ namespace {
     // Init our king safety tables
     Square s = make_square(Utility::clamp(file_of(ksq), FILE_B, FILE_G),
                            Utility::clamp(rank_of(ksq), RANK_2, RANK_7));
-    kingRing[Us] = PseudoAttacks[KING][s] | s;
+    kingRing[Us] = attacks_bb<KING>(s) | s;
 
     kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
     kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
@@ -273,7 +274,7 @@ namespace {
         // Find attacked squares, including x-ray attacks for bishops and rooks
         b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN))
           : Pt ==   ROOK ? attacks_bb<  ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK))
-                         : pos.attacks_from<Pt>(s);
+                         : attacks_bb<Pt>(s, pos.pieces());
 
         if (pos.blockers_for_king(Us) & s)
             b &= LineBB[pos.square<KING>(Us)][s];
@@ -288,9 +289,13 @@ namespace {
             kingAttackersWeight[Us] += KingAttackWeights[Pt];
             kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
         }
+
         else if (Pt == ROOK && (file_bb(s) & kingRing[Them]))
             score += RookOnKingRing;
 
+        else if (Pt == BISHOP && (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & kingRing[Them]))
+            score += BishopOnKingRing;
+
         int mob = popcount(b & mobilityArea[Us]);
 
         mobility[Us] += MobilityBonus[Pt - 2][mob];
@@ -323,7 +328,7 @@ namespace {
                                      * (!(attackedBy[Us][PAWN] & s) + popcount(blocked & CenterFiles));
 
                 // Penalty for all enemy pawns x-rayed
-                score -= BishopXRayPawns * popcount(PseudoAttacks[BISHOP][s] & pos.pieces(Them, PAWN));
+                score -= BishopXRayPawns * popcount(attacks_bb<BISHOP>(s) & pos.pieces(Them, PAWN));
 
                 // Bonus for bishop on a long diagonal which can "see" both center squares
                 if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
@@ -438,7 +443,7 @@ namespace {
         unsafeChecks |= b2 & attackedBy[Them][BISHOP];
 
     // Enemy knights checks
-    knightChecks = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
+    knightChecks = attacks_bb<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
     if (knightChecks & safe)
         kingDanger += more_than_one(knightChecks & safe) ? KnightSafeCheck * 162/100
                                                          : KnightSafeCheck;
@@ -564,12 +569,12 @@ namespace {
         Square s = pos.square<QUEEN>(Them);
         safe = mobilityArea[Us] & ~stronglyProtected;
 
-        b = attackedBy[Us][KNIGHT] & pos.attacks_from<KNIGHT>(s);
+        b = attackedBy[Us][KNIGHT] & attacks_bb<KNIGHT>(s);
 
         score += KnightOnQueen * popcount(b & safe);
 
-        b =  (attackedBy[Us][BISHOP] & pos.attacks_from<BISHOP>(s))
-           | (attackedBy[Us][ROOK  ] & pos.attacks_from<ROOK  >(s));
+        b =  (attackedBy[Us][BISHOP] & attacks_bb<BISHOP>(s, pos.pieces()))
+           | (attackedBy[Us][ROOK  ] & attacks_bb<ROOK  >(s, pos.pieces()));
 
         score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]);
     }