extern Bitboard SquareBB[SQUARE_NB];
extern Bitboard FileBB[FILE_NB];
extern Bitboard RankBB[RANK_NB];
-extern Bitboard AdjacentFilesBB[FILE_NB];
extern Bitboard ForwardRanksBB[COLOR_NB][RANK_NB];
extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
return b & (b - 1);
}
+inline bool opposite_colors(Square s1, Square s2) {
+ return bool(DarkSquares & s1) != bool(DarkSquares & s2);
+}
+
/// rank_bb() and file_bb() return a bitboard representing all the squares on
/// the given file or rank.
}
+/// double_pawn_attacks_bb() returns the pawn attacks for the given color
+/// from the squares in the given bitboard.
+
+template<Color C>
+constexpr Bitboard double_pawn_attacks_bb(Bitboard b) {
+ return C == WHITE ? shift<NORTH_WEST>(b) & shift<NORTH_EAST>(b)
+ : shift<SOUTH_WEST>(b) & shift<SOUTH_EAST>(b);
+}
+
+
/// adjacent_files_bb() returns a bitboard representing all the squares on the
/// adjacent files of the given one.
inline Bitboard adjacent_files_bb(File f) {
- return AdjacentFilesBB[f];
+ return shift<EAST>(FileBB[f]) | shift<WEST>(FileBB[f]);
}