Re: gtk3, wayland, opengl, glew and epoxy

Hey,

On Tue, Nov 29, 2016 at 1:20 PM, Caolán McNamara <caolanm@redhat.com> wrote:

> locally I have our opengl slideshow transitions working[1] under gtk3
> on wayland and I'd like to merge this to master. The gtk3 part is
> fairly trivial as it turns out. But glew doesn't work under wayland.
> epoxy does however (and it's what gtk3 itself uses). epoxy claims to
> support all of our platforms. One little snag is that libgltf uses glew
> in its headers, so I had to patch it to port it over to epoxy.
>
> Is there any objection to the principle of dropping glew in favour of
> epoxy, or do I need to go down a more complicated conditional approach.
> Or any other snags I haven't considered ?

Sadly I don't recall why I chose glew instead of libepoxy back then.
However looking at it now it seems like libepoxy is the smarter choice as
long as it works correctly on Mac.

For gltf as we control the code we can of course also switch from glew to
libepoxy. I would need to check what collada2gltf is using.

One thing to check is whether our windows code suffers from
https://github.com/anholt/libepoxy#windows-issues as well as actually
testing all the OpenGL features on all 3 platforms. Based on experience
working OpenGL code on one system does not mean that it is not going to
break somewhere else. As this change affects all the OpenGL code in our
codebase this requires testing at least the OGL transitions, chart OGL (if
it is still working in master), 3D models in impress (if they are still
working), OGL canvas and the normal OpenGL rendering.

Regards,
Markus