-Skyline_pair::Skyline_pair (Box const &b, Real padding, Axis a)
- : skylines_ (Skyline (b, padding, a, DOWN), Skyline (b, padding, a, UP))
+Skyline_pair::Skyline_pair (vector<Drul_array<Offset> > const &buildings, Axis a)
+ : skylines_ (Skyline (buildings, a, DOWN), Skyline (buildings, a, UP))
+{
+}
+
+Skyline_pair::Skyline_pair (vector<Skyline_pair> const &skypairs)
+ : skylines_ (Skyline (skypairs, DOWN), Skyline (skypairs, UP))
+{
+}
+
+Skyline_pair::Skyline_pair (Box const &b, Axis a)
+ : skylines_ (Skyline (b, a, DOWN), Skyline (b, a, UP))