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[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 55a4c4a2fa0e0ca56ae6fe3832a2649698ad3963..8f38493027b07e9f8c273ae95d73f046ea8026b3 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -411,11 +411,14 @@ const string Position::pretty(Move move) const {
 }
 
 
-/// Position:hidden_checkers() returns a bitboard of all pinned / discovered check
-/// pieces, according to the call parameters. Pinned pieces protect our king and
-/// discovered check pieces attack the enemy king.
+/// Position::check_blockers() returns a bitboard of all the pieces with color
+/// 'c' that are blocking check on the king with color 'kingColor'. A piece
+/// blocks a check if removing that piece from the board would result in a
+/// position where the king is in check. A check blocking piece can be either a
+/// pinned or a discovered check piece, according if its color 'c' is the same
+/// or the opposite of 'kingColor'.
 
-Bitboard Position::hidden_checkers(Color c, Color kingColor) const {
+Bitboard Position::check_blockers(Color c, Color kingColor) const {
 
   Bitboard b, pinners, result = 0;
   Square ksq = king_square(kingColor);
@@ -1074,7 +1077,6 @@ int Position::see(Move m) const {
 
       // Add the new entry to the swap list
       swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured];
-      ++slIndex;
 
       // Locate and remove the next least valuable attacker
       captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
@@ -1083,10 +1085,9 @@ int Position::see(Move m) const {
 
       // Stop before processing a king capture
       if (captured == KING && stmAttackers)
-      {
-          swapList[slIndex++] = QueenValueMg * 16;
           break;
-      }
+
+      ++slIndex;
 
   } while (stmAttackers);