X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=8651ab278db8e333c41ba613ca4d6093e7c16b0a;hb=805afcbf3d5db39c85b759232cfb99ab0a250311;hp=9be0bada8c0ee050d7ef0059b1d0af8ed8e565a7;hpb=eb20a87c67c1f7f8bef8895d1a848f8fa6fd9d96;p=stockfish

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 9be0bada..8651ab27 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -359,7 +359,7 @@ namespace {
         if (Pt == QUEEN)
         {
             // Penalty if any relative pin or discovered attack against the queen
-            if (pos.slider_blockers(pos.pieces(), pos.pieces(Them, ROOK, BISHOP), s))
+            if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s))
                 score -= WeakQueen;
         }
     }
@@ -481,6 +481,19 @@ namespace {
   // evaluate_threats() assigns bonuses according to the types of the attacking
   // and the attacked pieces.
 
+  const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB;
+  const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB;
+  const Bitboard QueenSide   = FileABB | FileBBB | FileCBB | FileDBB;
+  const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+  const Bitboard KingSide    = FileEBB | FileFBB | FileGBB | FileHBB;
+
+  const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
+    { QueenSide   & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
+      CenterFiles & WhiteCamp, KingSide  & WhiteCamp, KingSide  & WhiteCamp, KingSide    & WhiteCamp },
+    { QueenSide   & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
+      CenterFiles & BlackCamp, KingSide  & BlackCamp, KingSide  & BlackCamp, KingSide    & BlackCamp },
+  };
+
   template<Color Us, bool DoTrace>
   Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
 
@@ -558,6 +571,18 @@ namespace {
 
     score += ThreatByPawnPush * popcount(b);
 
+    // King tropism: firstly, find squares that we attack in the enemy king flank
+    b = ei.attackedBy[Us][ALL_PIECES] & KingFlank[Them][file_of(pos.square<KING>(Them))];
+
+    // Secondly, add to the bitboard the squares which we attack twice in that flank
+    // but which are not protected by a enemy pawn. Note the trick to shift away the
+    // previous attack bits to the empty part of the bitboard.
+    b =  (b & ei.attackedBy2[Us] & ~ei.attackedBy[Them][PAWN])
+       | (Us == WHITE ? b >> 4 : b << 4);
+
+    // Count all these squares with a single popcount
+    score += make_score(7 * popcount(b), 0);
+
     if (DoTrace)
         Trace::add(THREAT, Us, score);
 
@@ -678,10 +703,10 @@ namespace {
 
     // ...count safe + (behind & safe) with a single popcount
     int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
-    int weight =  pos.count<KNIGHT>(Us) + pos.count<BISHOP>(Us)
-                + pos.count<KNIGHT>(Them) + pos.count<BISHOP>(Them);
+    bonus = std::min(16, bonus);
+    int weight = pos.count<ALL_PIECES>(Us);
 
-    return make_score(bonus * weight * weight * 2 / 11, 0);
+    return make_score(bonus * weight * weight / 22, 0);
   }
 
 
@@ -733,9 +758,9 @@ namespace {
         // Endings where weaker side can place his king in front of the opponent's
         // pawns are drawish.
         else if (    abs(eg) <= BishopValueEg
-                 &&  ei.pi->pawn_span(strongSide) <= 1
+                 &&  pos.count<PAWN>(strongSide) <= 2
                  && !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
-            sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(51) : ScaleFactor(37);
+            sf = ScaleFactor(37 + 7 * pos.count<PAWN>(strongSide));
     }
 
     return sf;