Re: GTK + Clutter next step(s)

[Benjamin Otte <otte gnome org>]

On Sun, Oct 30, 2011 at 8:38 AM, Kristian Rietveld <kris loopnest org> wrote:
> I find this a rather weird statement.  To me, GL support is an important requirement for a windowing toolkit.  There are very valid reasons to use GL in GTK+ applications, such as CAD and scientific visualization, as Peter Clifton has also pointed out in this thread.
>
> Even though Cairo is clearly preferred for 2D drawing, I don't see a reason to "force" people who already have portable 2D drawing code (for e.g. visualization) to Cairo or to make it harder to use such existing code.  For 3D, Cairo is not an option at all.
>
> I don't believe that people would use OpenGL instead of Cairo without sufficient reason for newly written code or for writing widgets, so I don't agree with your reasoning attached to the quote of Larry Wall.
>
I think Cairo did that job reasonably well. You can still do your own
drawing if you want to, and it's not even hard to get that going, but
it's noticeably harder than using Cairo. So nobody would want to go
direct X unless they had a very good reason.

And I want to achieve that same situation for OpenGL. Of course it
should be possible to use OpenGL, and it doesn't have to be really
complicated and tricky, but anyone wondering what to do should pick
Clutter/Cogl over raw GL every time.

But I think in the GL world this is quite a bit harder because the
number of people that do know how to get GL to draw something but have
never used Clutter/Cogl is quite a lot larger than the amount of
people that know X but not Cairo. So there'll be a bunch of people
that is naturally drawn towards OpenGL. Now that wouldn't be bad in
itself, but it gets really bad when you consider that custom GL
shenanigans blow up your performance and reduce your smooth
application to a pile of stuttering pixel mush when you don't know
what you're doing.

In fact, it is so bad that there is not a single library in use on the
Linux desktop that I know of that doesn't take complete control of GL
rendering the moment you start using it - and that currently includes
Clutter, Cogl and cairo-gl.

Benjamin