Re: OpenGL support in GTK+

[Tristan Van Berkom <vantr touchtunes com>]

Sven Neumann wrote:

> > - api/abi changes will be easier to propagate across branches
> >  (example: A decission passes that all gtk_signal_* should
> >   be changed to g_signal_* calls, developer "A" implements
> >   this effortlessly because of his particular knowlage of the
> >   signal system and GtkGLExt is also updated accordingly).
> >
> > - one can respond to the question "does gtk have support for
> >  graphics acceleration ?" with the simple answer "yes" instead
> >  of "well there's some dudes on sourceforge..."
> >    
>
> These two points can be easily achieved by putting the GL library into
> GNOME CVS so that everyone who has access to gtk+ may contribute to
> gtk+-gl as well. 
>
> > IMHO, the centralization of such related libraries will always increase
> > the perfection of the end product.
> >    
>
> IMHO, libraries improve by modularizing them. GTK+ has already grown
> too large and I would welcome if it would be split into smaller pieces
> instead of more stuff being added. Other people have expressed similar
> opinions.
>  
Much in the same way that glib/gdk/gtk/atk/pango are seperate libraries ?
              *nodding agreement*

Of course there are two ways of looking at the name "GTK+".

   A.)  A widget kit that uses gdk/glib/gobject....
   B.)  An ensemble of libraries including gdk/glib/gobject...

I think its clear that is makes no sence to add OpenGL API
accesability to the "definition A" (Is that how I came across ? oh well).

It may even be wise to avoid writing widgets (in the gtk+ library 
itself) that
depend on (or make use of) gdk-gl.

> > I think the question here is:
> > - "What is the scope of a multi-platform graphics based user
> > interface tool kit ?"
> > and
> > - "Does hardware graphics acceleration accessability enter that scope ?"
> >    
>
> First of all, unless I am completely mistaken, we are not talking about
> hardware graphics acceleration here. We are talking about adding a way
> to use OpenGL 3D API from GTK+. On some platforms the 3D functions may
> be hardware accelerated but this is completely out of our scope here.
>
> 3D support is not something a lot of applications need. The scope of
> GTK+ should be to provide a framework for applications to build
> on. This means that it should offer a couple of widely useful widgets
> and the framework to extend this set.
>
> If you argue that GL support belongs into GTK+, you can also argue
> that there should be a HTML renderer, an application server, a
> database as well as video and audio support. But all these things
> exist and they integrate nicely with GTK+, although they are not part
> of the toolkit.

> > unnecessary bloat for a linux distribution to include ? or unnecessary
> > bloat for an application to have to link against ? or unnecessary
> > bloat to maintained in the same package ?
> >    
>
> The latter is indeed an important point. The more code lives in GTK+,
> the more bugs are there and the more work has to be put into
> maintainance.
>
> What I really meant here is for example unnecessary bloat for people
> trying to use GTK+ on embedded devices. Due to the size of GTK2, a
> couple of projects decided against porting their software to the GTK2
> platform. If we could manage to split GTK+ into a number of smaller
> packages or at least allow to configure what widgets to include, GTK+
> would become a lot more interesting for the rather large area of
> software development on embedded devices.
>  
>
> > On one hand; OpenGL is a standard which already has a few
> > implementations so by consiquence it should be relatively easy to
> > port from one system to another provided that the implementation
> > already exists for that platform, and even if there isnt, (excuse me
> > I'm a little rusty, its been a while since I read that code) there
> > is a software fallback already implemented in the glx libraries
> > (thats what I forget...  was it the "dri" branch that has the
> > software fallback operations ?).
> >    
>
> You are raising another point here. OpenGL (especially with hardware
> acceleration) has always been a nightmare to install. People are
> already having a hard time with all the dependencies that have been
> added lately. I'm sure that a dependency on some OpenGL implementation
> would not improve this situation.
>
> Please don't get me wrong. I believe that it should be easy to
> integrate 3D into your GTK+ application and I would welcome if there
> was an officially supported GTK+ GL widget library, but I don't think
> that it should be part of GTK+ itself.
>
>  
Hmmm, I have the feeling that for the most part.... correct me if I'm 
wrong...
we are arguing the same point ;-)

Cheers,
                       -Tristan