Better document king safety evaluation

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index 09c630062dd3984ea5a2fcc0ffaa647c7ff4fe2a..f6e49687de45c7b7bf2e5cb04ef61c5ff5ee9b5f 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -63,6 +63,18 @@ const int MaxGameLength = 220;
 //// Types
 ////
 
+/// struct checkInfo is initialized at c'tor time and keeps
+/// info used to detect if a move gives check.
+
+struct CheckInfo {
+
+    CheckInfo(const Position&);
+
+    Square ksq;
+    Bitboard dcCandidates;
+    Bitboard checkSq[8];
+};
+
 /// Castle rights, encoded as bit fields
 
 enum CastleRights {
@@ -206,7 +218,7 @@ public:
   bool pl_move_is_legal(Move m, Bitboard pinned) const;
   bool pl_move_is_evasion(Move m, Bitboard pinned) const;
   bool move_is_check(Move m) const;
-  bool move_is_check(Move m, Bitboard dcCandidates) const;
+  bool move_is_check(Move m, const CheckInfo& ci) const;
   bool move_is_capture(Move m) const;
   bool move_is_capture_or_promotion(Move m) const;
   bool move_is_passed_pawn_push(Move m) const;
@@ -224,7 +236,7 @@ public:
   // Doing and undoing moves
   void saveState();
   void do_move(Move m, StateInfo& st);
-  void do_move(Move m, StateInfo& st, Bitboard dcCandidates);
+  void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
   void do_null_move(StateInfo& st);
   void undo_null_move();
@@ -284,9 +296,6 @@ private:
   void undo_castle_move(Move m);
   void find_checkers();
 
-  template<PieceType Piece>
-  void update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates);
-
   template<bool FindPinned>
   Bitboard hidden_checkers(Color c) const;