// A non-king move is legal if and only if it is not pinned or it
// is moving along the ray towards or away from the king.
- return ( !pinned
- || !bit_is_set(pinned, from)
- || (direction_between_squares(from, king_square(us)) == direction_between_squares(move_to(m), king_square(us))));
+ return !pinned
+ || !bit_is_set(pinned, from)
+ || squares_aligned(from, move_to(m), king_square(us));
}
{
// For pawn and king moves we need to verify also direction
if ( (pt != PAWN && pt != KING)
- ||(direction_between_squares(from, ci.ksq) != direction_between_squares(to, ci.ksq)))
+ || !squares_aligned(from, to, ci.ksq))
return true;
}