[Spice-devel] [PATCH v2 08/10] gtk: require gtk+ 3.16

[Gerd Hoffmann]

  Hi,

> > Dropping wayland isn't an option I think.  Is it possible to build
> > with/without glarea support (depending on the installed gtk version) and
> > hiding that from applications without too much fuss?  I.e. with the
> > glarea widget being a child of the new gtkstack widget, can we swap that
> > for a drawingarea and render the old-style egl way in case we find old
> > gtk version, without that being visible outside spice-gtk?
> 
> I have spent some time trying to fit a manual egl window surface in
> gtk+. While it works pretty well on X, it turns out it is really hard
> to do the same thing on wayland. I managed to get some rendering
> displayed, but it was badly aligned, and full of flickering, and I
> couldn't find easy solution to all that. Then I decided to try
> gtkglarea and found out that it just worked. And since recent gtk+ is
> required for wayland, depending on gtkglarea sounds like the best move
> forward anyway. But anyone, feel free to fix gl support on wayland
> with gtk 3.10.

3.10 + wayland isn't going to work well, sure.  There is a reason why we
got the glarea widget in 3.16 ;)

I was thinking more along the lines of "if (gtk >= 3.16) { use glarea
and support x11+wayland } else { use drawingarea and support x11
only }".

> > Another reasonable option would be going for two git branches:  Using
> > last weeks release as base for a stable branch and plan to do bugfix
> > releases (possibly backporting support for new spice protocol features
> > too) for a year or two.
> 
> sure, although if we can avoid it, it's easier.

Avoids keeping compat code for pre-glarea gtk versions in the master
branch at the cost of maintaining two branches for a while.  So it's a
tradeoff ...

cheers,
  Gerd