[RFC Weston 00/10] Sub-surfaces v2

[Pekka Paalanen]

On Thu, 07 Mar 2013 07:25:17 +0100
Kai-Uwe Behrmann <ku.b at gmx.de> wrote:

> Hello Pekka,
> 
> Am 22.02.2013 16:07, schrieb Pekka Paalanen:
> > - A totally new demo client presenting sub-surfaces, including
> >    Cairo-image rendered window with a pure EGL/GL widget in a
> >    sub-surface, running independently, but still without glitches
> >    on resize (sans bugs).
> >    http://people.collabora.com/~pq/subsurface-2.png
> 
> The above example shows non overlapping regions. For a more throughout 
> test, I would expect overlapping regions with and without alpha to test 
> Z-order behaviour.

There's a huuuuge amount of test code that could be written. Z-order
code is largely untested, and actually still incomplete even in the
implementation (place_above/below are effective immediately instead of
on parent commit like they should be).

> > The biggest improvement over v1 is that we have some thought-out
> > commit behaviours. It is possible to resize a window so that all
> > surfaces stay in sync on screen, and it is also possible to have
> > sub-surfaces running on their own (i.e. without commit the
> > parent surface, too).
> 
> What is the default behaviour of repainting in regards to Z-order? Draw 
> all surfaces? I other words, is the possibility to have sub-surfaces 
> running on their own only optional?

Sorry, I don't understand the question.

In v2 proposal, which does not support nesting, all sub-surfaces are
siblings. They have no effect on each other's rendering. Also, as they
are all siblings, Z-order is a completely orthogonal attribute to
commit mode or rendering.

Nesting support is coming, though.

Could you rephrase the question?


Thanks,
pq