X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitboard.h;h=847132c499fdc41df9cddf97e44f01c90dd4bb7f;hb=8cd5cb930dd6737220ed83f787062cac13270298;hp=1222ddfa3f50be9051cf85a0e1aa0504f6707ac8;hpb=74f1efee263aadcceb1df716ebd87776b932238a;p=stockfish

diff --git a/src/bitboard.h b/src/bitboard.h
index 1222ddfa..847132c4 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -113,8 +113,8 @@ extern const Bitboard RankBB[8];
 extern const Bitboard RelativeRankBB[2][8];
 extern const Bitboard InFrontBB[2][8];
 
-extern Bitboard SetMaskBB[64];
-extern Bitboard ClearMaskBB[64];
+extern Bitboard SetMaskBB[65];
+extern Bitboard ClearMaskBB[65];
 
 extern Bitboard StepAttackBB[16][64];
 extern Bitboard RayBB[64][8];
@@ -236,6 +236,19 @@ inline Bitboard in_front_bb(Color c, Square s) {
 }
 
 
+/// behind_bb() takes a color and a rank or square as input, and returns a
+/// bitboard representing all the squares on all ranks behind of the rank
+/// (or square), from the given color's point of view.
+
+inline Bitboard behind_bb(Color c, Rank r) {
+  return InFrontBB[opposite_color(c)][r];
+}
+
+inline Bitboard behind_bb(Color c, Square s) {
+  return in_front_bb(opposite_color(c), square_rank(s));
+}
+
+
 /// ray_bb() gives a bitboard representing all squares along the ray in a
 /// given direction from a given square.