Rearrange evaluation constants definitions

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 5a28b286ae0a354c1f01eb6c445fb83fc85eaa13..98ecf72de59c4c32d84210f48ff2e4c7cc3dbf00 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -150,23 +150,24 @@ namespace {
     S(0, 0), S(0, 0), S(80, 119), S(80, 119), S(117, 199), S(127, 218)
   };
 
-  // Hanging contains a bonus for each enemy hanging piece
-  const Score Hanging = S(23, 20);
-
-  #undef S
-
-  const Score RookOnPawn       = make_score(10, 28);
-  const Score RookOpenFile     = make_score(43, 21);
-  const Score RookSemiopenFile = make_score(19, 10);
-  const Score BishopPawns      = make_score( 8, 12);
-  const Score MinorBehindPawn  = make_score(16,  0);
-  const Score TrappedRook      = make_score(92,  0);
-  const Score Unstoppable      = make_score( 0, 20);
+  // Assorted bonuses and penalties used by evaluation
+  const Score KingOnPawnOne    = S(0 , 64);
+  const Score KingOnPawnMany   = S(0 ,128);
+  const Score RookOnPawn       = S(10, 28);
+  const Score RookOpenFile     = S(43, 21);
+  const Score RookSemiOpenFile = S(19, 10);
+  const Score BishopPawns      = S( 8, 12);
+  const Score MinorBehindPawn  = S(16,  0);
+  const Score TrappedRook      = S(92,  0);
+  const Score Unstoppable      = S( 0, 20);
+  const Score Hanging          = S(23, 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
   // happen in Chess960 games.
-  const Score TrappedBishopA1H1 = make_score(50, 50);
+  const Score TrappedBishopA1H1 = S(50, 50);
+
+  #undef S
 
   // SpaceMask[Color] contains the area of the board which is considered
   // by the space evaluation. In the middlegame, each side is given a bonus
@@ -255,7 +256,7 @@ namespace {
             bonus += bonus / 2;
     }
 
-    return make_score(bonus, bonus);
+    return make_score(bonus * 2, bonus / 2);
   }
 
 
@@ -338,7 +339,7 @@ namespace {
 
             // Give a bonus for a rook on a open or semi-open file
             if (ei.pi->semiopen_file(Us, file_of(s)))
-                score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile;
+                score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiOpenFile;
 
             if (mob > 3 || ei.pi->semiopen_file(Us, file_of(s)))
                 continue;
@@ -498,6 +499,7 @@ namespace {
 
     Bitboard b, weakEnemies, protectedEnemies;
     Score score = SCORE_ZERO;
+    enum { Minor, Major };
 
     // Protected enemies
     protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them,PAWN))
@@ -505,7 +507,7 @@ namespace {
                       & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
 
     if(protectedEnemies)
-        score += Threat[0][type_of(pos.piece_on(lsb(protectedEnemies)))];
+        score += Threat[Minor][type_of(pos.piece_on(lsb(protectedEnemies)))];
 
     // Enemies not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)
@@ -517,16 +519,20 @@ namespace {
     {
         b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
         if (b)
-            score += Threat[0][type_of(pos.piece_on(lsb(b)))];
+            score += Threat[Minor][type_of(pos.piece_on(lsb(b)))];
 
         b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
         if (b)
-            score += Threat[1][type_of(pos.piece_on(lsb(b)))];
+            score += Threat[Major][type_of(pos.piece_on(lsb(b)))];
 
         b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES];
         if (b)
             score += more_than_one(b) ? Hanging * popcount<Max15>(b) : Hanging;
-    }
+
+        b = weakEnemies & pos.pieces(Them, PAWN) & ei.attackedBy[Us][KING];
+        if (b)
+            score += more_than_one(b) ? KingOnPawnMany : KingOnPawnOne;
+       }
 
     if (Trace)
         Tracing::terms[Us][Tracing::THREAT] = score;
@@ -574,22 +580,18 @@ namespace {
             // If the pawn is free to advance, then increase the bonus
             if (pos.empty(blockSq))
             {
-                squaresToQueen = forward_bb(Us, s);
-
-                // If there is an enemy rook or queen attacking the pawn from behind,
-                // add all X-ray attacks by the rook or queen. Otherwise consider only
-                // the squares in the pawn's path attacked or occupied by the enemy.
-                if (    unlikely(forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN))
-                    && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
-                    unsafeSquares = squaresToQueen;
-                else
-                    unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
-
-                if (    unlikely(forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN))
-                    && (forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
-                    defendedSquares = squaresToQueen;
-                else
-                    defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
+                // If there is a rook or queen attacking/defending the pawn from behind,
+                // consider all the squaresToQueen. Otherwise consider only the squares
+                // in the pawn's path attacked or occupied by the enemy.
+                defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s);
+
+                Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
+
+                if (!(pos.pieces(Us) & bb))
+                    defendedSquares &= ei.attackedBy[Us][ALL_PIECES];
+
+                if (!(pos.pieces(Them) & bb))
+                    unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them);
 
                 // If there aren't any enemy attacks, assign a big bonus. Otherwise
                 // assign a smaller bonus if the block square isn't attacked.