I work on a Gtkmm-3.0 project and I want to use the openGl Gtk exentsion Gtkglextmm. But it seems to me that the actual version of gtkglextmm-1.2 supports only gtkmm-2.x.
Which options I have to use openGl inside gtkmm-3.0?
Wait for Gtkmm 3.18 to be released; the OpenGL widget Gtk::GLArea
will be built-in to that release. You can see it (and an example of its use) here.