14 Gtk::SpinButton *sp_mass =
nullptr;
15 Gtk::SpinButton *sp_springyness =
nullptr;
16 Gtk::SpinButton *sp_damping =
nullptr;
17 Gtk::SpinButton *sp_time =
nullptr;
19 Gtk::DrawingArea *area =
nullptr;
21 Glib::RefPtr<Pango::Layout> layout;
26 bool draw_graph(
const Cairo::RefPtr<Cairo::Context> &cr);