Question about cairo-gl

[Pekka Paalanen]

On Wed, 14 May 2014 12:56:27 -0700
Bill Spitzak <spitzak at gmail.com> wrote:

> The wayland build instructions also include the building of pixman and 
> cairo in order to enable the cairo gl backend.
> 
> However I get the impression that weston does not use this unless a 
> switch --with-cairo=gl is passed to configure. Only then does it produce 
> calls to attempt to make a context (they fail on my machine so it uses 
> the image backend anyway). Also without this switch weston clients 
> happily link with and run with the system cairo which has no gl backend.

Yes.

> Since I am trying to figure out working build instructions, I was 
> wondering what to do with this step:
> 
> 1. Remove the compilation of pixmap & cairo

I'm not sure why the Pixman manual build is there still. Maybe simply
outdated, perhaps it was a dependency of the Cairo version required to
have working cairo-gl.

> 2. Add the --with-cairo=gl switch
> 
> 3. It actually works without that switch, it's just that it is broken on 
> my machine where no egl works.

I would be ok with just dropping the Cairo build instructions.
Personally I think cairo-gl/cairo-glesv2 are not useful for Weston
demos. You lose weston-gears and the screensaver, but I think those
should be ported away from cairo-gl anyway.

For reference:
http://lists.freedesktop.org/archives/wayland-devel/2014-April/014538.html

Summary: getting rid of cairo-egl (which is a requirement for cairo-gl
and cairo-glesv2, so these would get rid of too) seems to be accepted,
but the discussion on what should replace it is still open.

In that light, I think dropping the cairo-gl/glesv2 build instructions
would be nice, and it might kick the replacement issue discussion
forward.


Thanks,
pq