Make sure both GL renderers don't leave their contexts alive via the
current context, but ensure they dispose of them properly.
Fixes issues when the corresponding GL resources in the surfaces they
were attached to go away.
GLContexts marked as surface_attached are always attached to the surface
in make_current().
Other contexts continue to only get attached to their surface between
begin_frame() and end_frame().
All our renderer use surface-attached contexts now.
Public API only gives out non-surface-attached contexts.
The benefit here is that we can now choose whenever we want to
call make_current() because it will not cause a re-make_current() if we
call it outside vs inside the begin/end_frame() region.
Or in other words: I want to call make_current() before begin_frame()
without a performance penalty, and now I can.
... and pass the opaque region of the node.
We don't do anything with it yet, this is just the plumbing.
The original function still exists, it passes NULL which is the value
for no opaque region at all.
If an image description query is running while the surface gets
destroyed, we were not properly cleaning up, causing the callbacks to be
emitted on freed variables.
If we apply a rounded clip, we might change the clip in a way that makes
it intersectable with the scissor again, if both had diverged before.
So try and intersect with the clip.
I just spent an hour trying to figure out why things don't work. And it
was an optional dependency hidden 3 layers deep in some meson file.
This really has to stop.
And because just like in GTK, GStreamer's dmabuf APIs are always
available (they will just fail on Windows etc), there's no need to have
any conditions.
The only difference is that the GStreamer media backend now requires
GStreamer 1.24.
In the case of no offloading, we want to pass through to the child
(which is likely a big texture doing occlusion).
In the case of punching a hole, we want to punch the hole and not draw
anything behind it, so we start an occlusion pass with transparency.
And in the final case with offloading active, we don't draw anything,
so we don't draw anything.
This should fix concerns about drawing the background behind the video
as mentioned for example in
https://github.com/Rafostar/clapper/issues/343#issuecomment-1445425004
Container nodes save their opaque region, so it's quick to access. Use
that to check if the largest opaque region even qualifies for culling -
and if not, just exit.
Speeds up walking node trees by a lot.
Now that we can specify the min size for an occlusion pass, we can
specify that we want the full clip rect to be occluded for occlusion to
trigger.
The benefit of this is that for partial redraws we almost
always get the background color to cover the redrawn rectangle, so
occlusion will kick in.
When trying to cull, try culling from the largest rectangle of the
remaining draw region first. That region has the biggest chance of
containing a large area to skip.
As a side effect, we can stop trying to cull once the largest rectangle
isn't big enough anymore to contain anything worth culling.
