Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
return b & (b - 1);
}
-
/// rank_bb() and file_bb() return a bitboard representing all the squares on
/// the given file or rank.
/// shift() moves a bitboard one step along direction D. Mainly for pawns
-template<Square D>
+template<Direction D>
constexpr Bitboard shift(Bitboard b) {
return D == NORTH ? b << 8 : D == SOUTH ? b >> 8
: D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == SOUTH_EAST ? (b & ~FileHBB) >> 7
: 0;
}
+/// pawn_attacks_bb() returns the pawn attacks for the given color from the
+/// squares in the given bitboard.
+
+template<Color c>
+constexpr Bitboard 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.