More readable trapped rook condition

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 121f2c603293845e3b2ff29998a9e4a4e8c89fbb..1d52d30cd9ccdb8f746d11eb10d89ebc26ed3dc4 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -207,7 +207,7 @@ namespace {
   Score KingDanger[COLOR_NB][128];
 
 
-  // apply_weight() weights score v by score w trying to prevent overflow
+  // apply_weight() weighs score 'v' by weight 'w' trying to prevent overflow
   Score apply_weight(Score v, const Weight& w) {
     return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256);
   }
@@ -379,10 +379,10 @@ namespace {
             }
 
             // Give a bonus for a rook on a open or semi-open file
-            if (ei.pi->semiopen(Us, file_of(s)))
-                score += ei.pi->semiopen(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile;
+            if (ei.pi->semiopen_file(Us, file_of(s)))
+                score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile;
 
-            if (mob > 3 || ei.pi->semiopen(Us, file_of(s)))
+            if (mob > 3 || ei.pi->semiopen_file(Us, file_of(s)))
                 continue;
 
             Square ksq = pos.king_square(Us);
@@ -391,8 +391,8 @@ namespace {
             // king has lost its castling capability.
             if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
                 && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
-                && !ei.pi->semiopen_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E))
-                score -= (TrappedRook - make_score(mob * 8, 0)) * (pos.can_castle(Us) ? 1 : 2);
+                && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
+                score -= (TrappedRook - make_score(mob * 8, 0)) * (1 + !pos.can_castle(Us));
         }
 
         // An important Chess960 pattern: A cornered bishop blocked by a friendly
@@ -924,9 +924,8 @@ namespace {
 
 namespace Eval {
 
-  /// evaluate() is the main evaluation function. It always computes two
-  /// values, an endgame score and a middlegame score, and interpolates
-  /// between them based on the remaining material.
+  /// evaluate() is the main evaluation function. It returns a static evaluation
+  /// of the position always from the point of view of the side to move.
 
   Value evaluate(const Position& pos) {
     return do_evaluate<false>(pos);