extern int SquareDistance[SQUARE_NB][SQUARE_NB];
-const Bitboard BlackSquares = 0xAA55AA55AA55AA55ULL;
+const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
/// Overloads of bitwise operators between a Bitboard and a Square for testing
/// whether a given bit is set in a bitboard, and for setting and clearing bits.
}
+/// squares_of_color() returns a bitboard representing all squares with the same
+/// color of the given square.
+
+inline Bitboard squares_of_color(Square s) {
+ return DarkSquares & s ? DarkSquares : ~DarkSquares;
+}
+
+
/// squares_aligned() returns true if the squares s1, s2 and s3 are aligned
/// either on a straight or on a diagonal line.
}
-/// same_color_squares() returns a bitboard representing all squares with
-/// the same color of the given square.
-
-inline Bitboard same_color_squares(Square s) {
- return BlackSquares & s ? BlackSquares : ~BlackSquares;
-}
-
-
/// Functions for computing sliding attack bitboards. Function attacks_bb() takes
/// a square and a bitboard of occupied squares as input, and returns a bitboard
/// representing all squares attacked by Pt (bishop or rook) on the given square.
#endif
+/// frontmost_sq() and backmost_sq() find the square corresponding to the
+/// most/least advanced bit relative to the given color.
+
+inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }
+inline Square backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); }
+
#endif // #ifndef BITBOARD_H_INCLUDED