Atom half_slur (int dy, Real &dx, Direction dir, int xpart) const;
Atom half_slur_middlepart (Real &dx, Direction dir) const;
Atom big_slur (int dy, Real &dx, Direction dir) const;
Atom half_slur (int dy, Real &dx, Direction dir, int xpart) const;
Atom half_slur_middlepart (Real &dx, Direction dir) const;
Atom big_slur (int dy, Real &dx, Direction dir) const;