Re: [GtkGLExt] on_realize() vs. on_configure_event()

[Jonathan Brandmeyer <jbrandmeyer earthlink net>]

First off, the Gtk docs are probably the best source for these
questions.  Second up are the examples.

On Wed, 2006-04-26 at 00:08 -0700, Andrew Speirs wrote:
> Sorry if this is a bit of a newbie question, but I've
> only just started playing with gtkglextmm, and I can't
> find much in the various documentation.
> In e.g. simple.cc, the Gtk::GL:DrawingArea has 
> on_realize() and on_configure_event() member
> functions. My guess is the former is called when the
> object is created (instantiated)

Yes.

>  and the latter is
> called (immediately?

Don't know, but I think so.

> ) afterwards to set the properties
> of the object.

Yes.

> Is the on_realize() called only once per object?

Yes.

> Is the on_configure_event() called anytime the
> object's properties are changed e.g. a window resize?

Yes.

> Are there guidelines as to what to put into these
> functions?

get_gl_context() will not work until on_realize() is called (I could
have that wrong - it might be get_gl_drawable() that returns a NULL
Glib::RefPtr<>.  Point being, no GL calls will have any effect until the
on_realize signal has been delivered).  If you override on_realize() in
a child, you must call the parent's impl as the first task in the child.

It is common to call glViewPort() in on_configure(), but not required.

HTH,
-Jonathan