ClutterLayerNode is the "offscreen framebuffer" node, that paints it's
child nodes in a separate framebuffer, and then copies that framebuffer
to the parent one.
It'll be useful to hand ClutterLayerNode which framebuffer and pipeline
to use, as this is a requirement for porting e.g. ClutterOffscreenEffect
and subclasses.
Add a new clutter_layer_node_new_to_framebuffer() API.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1340>
Some effects, such as ShellBlurEffect and ClutterOffscreenEffect, need
to make sure the actor is painted fully opaque. With ClutterActorNode,
however, that is currently not possible.
Add a new 'opacity' parameter to clutter_actor_node_new(). It follows
the opacity override heuristic, where -1 means disable, and anything
else is clamped to [0, 255].
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1340>
Introduce a new paint_node vfunc that, if implemented, allows
the effect to add nodes to a transient paint node that is
immediately painted. This is a transitional step until we
have fully delegated paint node rendering.
The most basic implementation of a ClutterEffect.paint_node
vfunc, and also the default implementation, is with an actor
node, as follows:
```
static void
foo_bar_paint_node (ClutterEffect *effect,
ClutterPaintNode *node,
ClutterPaintContext *paint_context,
ClutterEffectPaintFlags flags)
{
g_autoptr (ClutterPaintNode) actor_node = NULL;
actor_node = clutter_actor_node_new (effect->actor);
clutter_paint_node_add_child (node, actor_node);
}
```
This example gives the exact same behavior of simply calling
clutter_actor_continue_paint(). In the future, the paint node
itself will be a parameter of clutter_actor_continue_paint()
and we'll be able to simplify it event more.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1340>
ClutterEffectNode is a private ClutterPaintNode implementation
that does effectively nothing, but helps organizing the paint
node tree. It also helps debugging, since it can output the
effect class and name to the JSON debugging routines.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1340>
The idea of having a paint node tree is that we don't really need
to retrieve the framebuffer from ClutterPaintContext. For example,
ClutterLayerNode draws into an offscreen framebuffer; if any child
of a layer node needs to retrieve a framebuffer to draw, the layer
node's offscreen framebuffer should be used.
However, clutter_paint_node_get_framebuffer() goes straight to the
root node of the tree, skipping any potential paint nodes with a
custom framebuffer.
Modify clutter_paint_node_get_framebuffer() to walk up the paint
node tree until a node with a custom framebuffer appears. In many
cases, this will end up either in dummy or layer node's custom
framebuffer implementations.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1340>
Fixes a compiler warning with -Wmaybe-uninitialized enabled:
../../../../Source/gnome/mutter/clutter/clutter/clutter-actor.c: In function ‘clutter_actor_paint’:
../../../../Source/gnome/mutter/clutter/clutter/clutter-actor.c:3808:50: warning: ‘result’ may be used uninitialized in this function [-Wmaybe-uninitialized]
3808 | else if (result == CLUTTER_CULL_RESULT_OUT && success)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
Which might presumably happen in the unlikely case that there's no clip
frusta.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1624>
Instead of going through the event queue, stage handling code, and
back to the input device via a vmethod call, do this directly in the
MetaSeatImpl. This is not too different from X11, where everything
happens inside the backend.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
All that is left in the "public" struct is all state that ClutterStage
delegates on ClutterInputDevice. That should move somewhere else, but
not here, not now.
All private fields belong to construct-only properties, with only getter
API, and idempotent vmethods (except keyboard a11y, atm). This should
be enough to make ClutterInputDevice obviously thread safe, outside the
backend.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Depending on the backend, we want to integrate this object at different
levels. It will sit close to the MetaBackendX11/MetaSeatX11 in X11, but
it will be put deep down with MetaSeatImpl in the native backend, in a
separate thread.
Since we can't depend on a single object type, nor are able to track
ClutterSeat signals neatly, make this API something to be called
explicitly by backends.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
This will query a device state; position and modifiers.
Note that ClutterSeat subclasses don't implement the vmethod yet,
so calling clutter_seat_query_state() may crash ATM.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Testing points and rays against boxes is substantially cheaper - in
fact, almost trivial - compared to triangles. Check if the actor's
paint volume doesn't intersect with the current pick point / ray,
and skip recursing altogether in those cases.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1520>
The cached pick mode never actually cached anything, since it is
always, unconditionally reset when painting. Furthermore, next
commits will cull out actors during pick, which makes the pick
stack uncacheable.
Remove the cached pick mode.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1520>
Users of Debian arm64 (aarch64) report that on at least some GPUs
or screens, after time-based screen blanking has occurred, it is not
possible to unlock the screen. Bisection indicates that this regressed
in commit 209b1ba3, so presumably this is because a refresh rate of 0
is reported while the screen is blanked, leading to the frame clock
pausing forever.
Fixes: 209b1ba3 "clutter/frame-clock: Adapt refresh rate from to frame info"
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1536
Bug-Debian: https://bugs.debian.org/974172
Signed-off-by: Simon McVittie <smcv@debian.org>
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1601>
It's currently possible that some last_paint_volumes don't get updated
during a paint cycle, this can happen when a ClutterOffscreenEffect is
used: The offscreen effect might skip painting the content and the
children of an actor because it uses its own offscreened texture
instead. This means the offscreen effect doesn't call
clutter_actor_continue_paint(), and thus the the last_paint_volumes of
the children won't be updated.
Now one might think that isn't a problem, because as soon as a child
changes it's size or position, the offscreened texture would get
invalidated and clutter_actor_continue_paint() would get called. It's
not that easy though: Because the last_paint_volume includes all the
transformation matrices up to eye-coordinates, it has to be updated on
any changes to matrices, which includes position/transformation changes
to any actor up the hierarchy.
Now that's where get into problems with the offscreen effect: In case of
transformation changes to the offscreened actor or an actor up the
hierarchy, the offscreened texture won't get invalidated (that makes
sense, we can simply paint it transformed) and the last_paint_volumes
won't get updated even though they should.
This leaves us around with outdated last_paint_volumes where
last_paint_volume_valid is still set to TRUE. It can cause issues with
culling and clipped redraws.
So fix that by ensuring that all children that would get painted by
Clutter get their last_paint_volumes updated in case a ClutterEffect
decided not to call clutter_actor_continue_paint().
This ignores the case where a paint() vfunc override does the same and
doesn't call clutter_actor_paint() on children. Let's ignore this case
for now, there shouldn't be any implementation which does that and
ideally in a world that's painted solely by ClutterContent, we can get
rid of that vfunc in the future.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1591>
The first comment isn't really needed anymore since
the is_full_stage_redraw_queued() underneath is quite self-explaining.
Also rephrase the second comment a bit, including that
_clutter_paint_volume_get_stage_paint_box() does the aligning to the
pixel grid.
Finally, the last comment also looks out of date since we do that
rounding inside _clutter_paint_volume_get_stage_paint_box(), so remove
it.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1511>
We currently pass actors a reference to their associated
ClutterStageQueueRedrawEntry when queueing a redraw. This "splitting" of
the ownership of the entry has introduced quite a few bugs in the past
and is hard to follow.
So give up the "splitting" of the ownership and exclusively handle those
entries inside ClutterStage. To still allow removing the entry when an
actor gets unrealized introduce clutter_stage_dequeue_actor_redraw()
similar to what we already have for relayouts.
To be able to efficiently find entries when actors queue redraws, make
pending_queue_redraws a GHashTable, which fits quite nicely and also
allows removing the QueueRedrawEntries actor pointer in favour of the
key of the hashtable.
Since the struct is now private to ClutterStage, we can also rename it
to QueueRedrawEntry.
While at it, also sneak in the removal of the leading underscore from
clutter_stage_queue_actor_redraw().
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1511>
The "queue-redraw" signal is not used anywhere in Clutter and we now
also removed the vfunc implementation of the stage. So stop emitting it
and remove it, but keep the propagate_queue_redraw infrastructure to
make sure clones still get their redraws queued.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1511>
Since we now decoupled the "queue-redraw" signal from creating the stage
clip, we can move signal emission into
_clutter_actor_queue_redraw_full() and emit the signal right away when
queueing a redraw on an actor. With that we now no longer have to
accommodate for the stage pending_queue_redraws list changing while
iterating over it.
To ensure we don't emit the signal too often when multiple redraws are
queued on one actor, use the propagated_one_redraw flag to limit the
number of emissions to a single one for every update cycle.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1511>
Putting together the redraw clip of the stage never really fitted nicely
with the "queue-redraw" signal emission, it forces us to emit the
signals in a batch and we also use a weird trick to get the old paint
volume that's already on-screen into the final redraw clip (we call
_clutter_actor_propagate_queue_redraw() on the stage).
So start breaking up this association by making the stage explicitely
request the redraw clip from the actor and removing the
ClutterPaintVolume argument from _clutter_actor_finish_queue_redraw().
This is done by adding a private function
clutter_actor_get_redraw_clip() which returns our old (currently
visible) paint volume and the new paint volume.
This also allows removing the check whether a full stage redraw has been
queued in clutter_actor_real_queue_redraw() and we can now just stop the
signal emission if a propagation happened at least once.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1511>
The most common case for Clutter is 2D axis-aligned actors, which
maintain these properties even after projecting to eye coordinates.
In those cases, we can use a simpler hit test by checking against
boxes.
Not only this is simpler, but this maintains an important aspect
of picking that is a requirement for Clutter: watertightness. Even
though the triangles checks do work on x86_64, they do not guarantee
watertightness. This breaks tests on ARM.
Use graphene_box_t to hit-test axis-aligned 2D actors.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1599>
clutter_actor_paint() implements a clear preference for custom clips
over clip_to_allocation: If a custom clip is set, clip_to_allocation is
ignored.
Since the paint volume reflects what Clutter is going to paint, we
should handle it the same when putting together our paint volume: So
first handle custom clips, and if one is set, use that. Then handle
clip_to_allocation, and if that's set, use that. And finally, if both
aren't set, union our allocation with the children paint volumes to get
the building volume.
clutter_actor_paint() also doesn't check whether the custom clip is
empty: If that's the case, it will simply not paint anything. Given that
that's allowed by clutter_actor_paint(), the paint volume should also
follow here and return an empty paint volume in case the custom clip is
empty.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1592>
When a custom clip is set for an actor, this actor is not going to allow
any painting outside that clip. That includes the children, which may
also not paint outside that clip.
Now in case clip_to_allocation is set to TRUE, we already already do the
right thing and simply use the allocation as our paint volume, ignoring
the volumes of our children. The same should be done for the custom
clip, so also stop the process of building the paint volume once we see
that a custom clip is set and simply use that clip.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1592>
When using CLUTTER_DEBUG_PAINT_DAMAGE_REGION, the blue swap region is
always a superset of the red redraw region. So painting both in full (since
the previous commit) just meant the red region was overdrawn and came out
purple. That doesn't provide enough visual contrast, changes the user
experience unexpectedly and reduces performance.
So just subtract the redraw region from the swap region. This way the
red redraw region is always red, not purple.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1571>
Previously when CLUTTER_DEBUG_PAINT_DAMAGE_REGION was set, that would lead
to has_buffer_age==FALSE, which would lead to use_clipped_redraw==FALSE
which would mean swap_region was always empty. And so the blue region of
CLUTTER_DEBUG_PAINT_DAMAGE_REGION was always empty, *and* fb_clip_region
was always the full view rectangle which is not useful for debugging.
Now when CLUTTER_DEBUG_PAINT_DAMAGE_REGION is set, we don't let that
affect use_clipped_redraw, which means fb_clip_region is calculated
realistically.
But that's not enough. Calculating fb_clip_region properly with
CLUTTER_DEBUG_PAINT_DAMAGE_REGION would still lead to colouring artefacts
left on screen from previous frames that don't apply to the current frame.
So to fix that we also paint_stage for the whole screen every time when
using CLUTTER_DEBUG_PAINT_DAMAGE_REGION.
So now you will only ever see red and blue shading that's applicable to
the current frame, and no artefacts from the previous frames.
Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1535
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1571>
It was being painted without scaling and offsetting so would only look
right at scale 1.0 and only on the view with origin (0,0). Now we include
the framebuffer scale and view origin it will be painted in the correct
location.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1571>
As explained in https://gitlab.gnome.org/GNOME/mutter/-/issues/1494,
with commit 29caa5bea5 we stopped queueing
a relayout for the parent of the removed actor in
clutter_actor_remove_child_internal(). This relayout was, as opposed to
the relayout in clutter_actor_real_hide()/clutter_actor_real_unmap(),
queued unconditionally without looking at the parents NO_LAYOUT flag.
Now while that relayout in clutter_actor_remove_child_internal() would
do unnecessary work if the parent had the NO_LAYOUT flag set, it did
also queue a redraw of the parent, which is necessary in any case.
So by removing that relayout in clutter_actor_remove_child_internal(),
we stopped queueing redraws for NO_LAYOUT parents when a child gets
removed from the scenegraph. This caused bugs where the texture of the
child would be left visible on the screen even though the child got
destroyed.
To fix this, make sure again that we always queue a redraw on the parent
when unmapping a child.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1494
The redraw_pending boolean is used to schedule the first stage update
after starting Clutter. This flag is superfluous because we have the
pending_finish_queue_redraws flag which does the same.
While at it, also remove the redraw_count debug variable, since there
should be better ways to count the number of queued redraws nowadays,
for example Sysprof marks.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1527
Queueing a redraw with a clip is easy enough and this function is
private anyway, so remove it and call _clutter_actor_queue_redraw_full()
instead in the one function using it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1527
ClutterRedrawFlags are a way to give Clutter additional context
about what it needs to redraw. There currently is only one flag defined,
CLUTTER_REDRAW_CLIPPED_TO_ALLOCATION, this flag would clip the redraw to
the actors current allocation.
Since ClutterActor also provides the clip_to_allocation property (which
affects the paint volume of the actor instead of only one redraw), the
additional CLIPPED_TO_ALLOCATION flag seems unnecessary. It's also only
defined to be used privately in Clutter, which it never is, so let's
remove it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1527
Turns out the g_signal_has_handler_pending() call in
update_stage_views() is actually more expensive than comparing the
sorted list (which is usually very short), so remove that and simply
always emit the signal.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1524
This commit introduces a few important changes in order to
acommodate graphene_ray_t. Most of them are positive changes,
so don't panic :)
The first very visible change is that neither the actor box
nor the clip rectangles are projected before being pushed.
This required changing the parameters of the related functions
at both ClutterPickContext, and ClutterPickStack, to receive
boxes instead of vertices. These rectangles are projected on
demand now, so in the best case (first actor picked) only
one projection happens; and in the worst case, it projects
as much as it does now.
The second important change is that there are no more checks
for axis-alignment anymore. That's because picking now happens
in 3D space, using triangles.
Talking about triangles in 3D space, this is what is used now
for picking. We break down each actor rectangle in 2 triangles,
and check if the projected pick point is inside any one of them,
of if the ray intersects any one of them. The same check happens
for the clip rectangles.
Checking the projected pick point is both an optimization for the
2D case, and a workaround to graphene_ray_t problems with float
precision, which is specially visible on edges such as the top
bar.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1509
ClutterPickStack is a new boxed type that stores the vertices
and clip rectangles. It is meant to be a byproduct of picking,
and takes over most of what ClutterStage currently does.
It introduces a 'seal' system, inspired by MetaKmsUpdate. After
the pick operation is done, and the rectangles are collected,
the pick stack is sealed, and is not allowed to be externally
modified anymore. Internally, it still can invalidate pick
records when an actor is destroyed.
For now, it handles both the clip rectangles, and the matrix
stack, separatedly. Future commits will rearrange this.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1509
The "paint" signal of ClutterActor has been a pain for everyone involved
long enough now, turns out we actually use it nowhere except tests
anymore (which has been handled in the last commits), so get rid of it
for good before anyone starts using it again.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1522
This is a bit scattered around, with the setter/getter in Clutter, and
it only being only directly honored in Wayland (it goes straight through
device properties in X11).
Make this private native API, and out of public ClutterInputDevice API.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1486
Since commit eb9cd3857d we initialize the allocation of ClutterActors to
an UNINITIALIZED ClutterActorBox. We do that to ensure the actor even
emits notify::allocation in case it got a new valid allocation of
0,0,0,0.
Now there's still the case where an actor gets removed from the
scenegraph and added again to a different parent, in this case we still
don't emit notify::allocation right now in case the new allocation
equals the old one. There's two good reasons to do so though:
1) To Clutter, there's no difference between a newly created actor and
an actor which got removed from the scenegraph, it's not consistent to
always notify the allocation property in the former situation, but not
always notify it in the latter situation.
2) When an allocation changes, Clutter notifies the subtree of that
actor about an absolute geometry change (see the call to
transform_changed() in clutter_actor_set_allocation_internal()). Now
when an actor gets reparented, obviously the absolute geometry might
change, so to make sure transform_changed() is always called in that
case we need to make sure an allocation change happens.
So simply reset the allocation property of the actor to an UNINITIALIZED
ClutterActorBox as soon as it gets unrealized.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1498
We introduced the absolute_origin_changed flag when preparing for the
removal of ClutterAllocationFlags in commit dc8e5c7f8b. Turns out in the
mean-time commit df4eeff6f2 happened, which renders the whole
absolute_origin_changed flag moot.
That's because we now notify the whole subtree about the absolute origin
change by calling transform_changed() when the allocation of an actor
changes. transform_changed() traverses the subtree and calls
absolute_geometry_changed() on every actor immediately, which renders
the whole propagation of the absolute_origin_changed flag obsolete.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1498
Since we now moved the queuing of relayouts into the mapping and
unmapping functions, we no longer need to do it when adding or removing
a child, that's because removing a child always unmaps the child, and
adding it to a stage (if it's visible) will map it.
So remove those calls to queue_relayout() since they're no longer
needed.
With the above we no longer queue a relayout in
clutter_actor_add_child_internal(), that means there's one place where
we need to explicitely queue relayouts now: That's when using the
set_child_at_index/above/below() APIs, those are special because they
avoid unmapping and mapping of actors and would now no longer get a
relayout.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366
In theory there's no big difference between only handling mapped actors
vs only handling visible actors in clutter_actor_allocate(): The
function is called recursively starting with an actor that is attached
to a stage, so it should only be called on mapped actors anyway.
The behavior of skipping hidden actors was introduced as an optimization
with commit 0eab73dc. Since the last commit, we handle
enable_paint_unmapped a bit better and don't do unnecessary work when
mapping or unmapping, so we can now be a bit stricter enforcing our
invariants and only allow mapped actors in clutter_actor_allocate().
We need to exclude toplevel actors from this check since the stage has a
very different mapped state than normal actors, depending on the
mappedness of the x11 window. Also we need to make an exception for
clones (of course...): Those need their source actor to have an
allocation, which means they might try to force-allocate it, and in that
case we shouldn't bail out of clutter_actor_allocate().
Also moving the clutter_actor_queue_relayout() call from
clutter_actor_real_show() to clutter_actor_real_map() seems to fix a bug
where we don't queue redraws/relayouts on children when a parent gets
shown.
Fixes https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2973https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366
We currently support only one case where an actor can get mapped or
unmapped during painting, that is using
_clutter_actor_enable_paint_unmapped() (although we could arguably do a
better job explicitely forbidding it in other cases). This function is
called when painting ClutterClone or MetaWindowActors during
screensharing. It temporarily (fake) realizes and maps the actor and all
its children so it can get painted.
Now a problem will appear when we'll start coupling layout and the
mapped state of actors more closely with the next commit: Since
enable_paint_unmapped() is meant to be enabled and disabled during every
clone paint, we also notify the "mapped" property twice on every clone
paint. That means with the next commit we would queue a relayout for the
source actor on every clone paint.
To avoid this unnecessary work, check whether we're being painted while
unmapped using the new unmapped_paint_branch_counter. Then avoid queuing
relayouts or invalidating paint volumes in that case.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366
Add new private API to ClutterActor, returning TRUE in case the actor is
being painted while unmapped. This is useful for implementations of the
paint() vfunc or for signal handlers of the "notify::mapped" signal.
Use this API in CallyActor to properly detect "notify::mapped" emissions
while painting unmapped, this fixes detecting the case where
painting-unmapped is used for screencasting.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366
Just like the existing in_cloned_branch counter, add a property which
tracks whether the actor is part of a subtree that's being painted while
unmapped. This is going to be useful for a few things, for example
changing the clutter_actor_is_in_clone_paint() API to use
enable_paint_unmapped instead of in_clone_paint.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366
clutter_actor_queue_relayout() detects whether a parent has the
NO_LAYOUT flag set by itself and then queues a shallow relayout for us.
There's no need to duplicate that logic when showing actors, so simply
call clutter_actor_queue_relayout() and let that handle it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366
Apparently clutter_paint_volume_union() has problems building the union
of two paint volumes in eye coordinates, that's probably because of the
negative coordinates that come into play there.
Circumvent that by making even more use of Graphene and letting it take
care of computing the union. We do that by creating two graphene_box_t's
from the axis-aligned paint volumes and intersecting those boxes, then
setting our vertices to the new min and max points of the resulting box.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1507
Add a helper function to determine if a seat has a (physical)
touchscreen associated with it.
Currently src/backends/meta-backend.c has a private version of this
(check_has_physical_touchscreen) and further patches in this patch-set
need the same functionality. So add a generic helper for this to
avoid code duplication.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1506
_cogl_util_get_eye_planes_for_screen_poly() is quite a complicated beast. Ever
since Clutter became a compositor toolkit, and specially after we switched to
graphene_frustum_t on paint volumes, we can brutally simplify this function.
The new code assumes camera is at (0, 0, 0) at world coordinates (i.e. before
applying the projection). We also consider that the redraw clip are at stage
coordinates. That means that converting the clip rectangle to world rectangle
is simply a matter of projecting the corresponding vertices using the "view"
matrix. Furthermore, we only need to project the top-left, and bottom-right
vertices, since top-right and bottom-left can be derived from those two.
The frustum setup still uses triplets of vertices to setup the planes, except
now the first vertex is always the camera (hardcoded to 0, 0, 0), and the other
two vertices are the projected clip rectangle vertices.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
The redraw clip region may contain multiple clip rectangles. We currently
only use the extents of this region, but having multiple frusta for each
rectangle is a better alternative, and will allow us to remove the extra
projection we currently do.
Make the clip frustum an array, with multiple frusta.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
The clip planes / frustum are contextual to painting. In the past, for
the lack of a better place, it was added to ClutterStage, but now we
have an appropriate home for such data: ClutterPaintContext.
Move the frustum to the paint context.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
While refactoring the clipping planes / frustum code, it became more and
more evident that we do not need to update them while picking. Picking
nowadays goes through a completely different code path, that does not
rely on paint volume culling.
While it might be interesting to eventually also cull out based on paint
volumes, it certainly won't go through the painting code anymore.
Remove setting up the view when picking, and rename functions appropriatedly.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
Culling paint volumes don't give this level of detail anymore, and in
fact knowing whether it was partially or fully in was only being used
in a debug path. For the purposes of culling, it doesn't matter if a
given actor is partially or completely inside the frustum; either way,
it must be painted.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
Instead of 4 planes, use a graphene_frustum_t to store the clipping
planes.
The cautious reviewer might noticed that we are now setting up 6
planes: the 4 planes we were doing before, plus 2 extra planes in
the Z axis. These extra planes simulate an "infinite" Z far, and
an "on-camera" Z near.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
ClutterStage defines the 8 vertices of a frustum:
4 ----------------------------- 5
| \ / |
| \ / |
| 0 --------------------- 1 |
| | | |
| | | |
| 3 --------------------- 2 |
| / \ |
| / \ |
7 ----------------------------- 6
Then, it uses triplets of vertices to create each clipping plane.
It only sets up 4 planes (it doesn't clip based on depth), defined
by the following vertices:
* 0 - 4 - 5
* 1 - 5 - 6
* 2 - 6 - 7
* 0 - 7 - 4
The first 3 triplets are selected using the for-loop. However, the
last triplet is different, and is done out of the loop. It could
have been made simpler by using the "3 - 7 - 4" triplet.
Simplify the current code by using the suggested triplet, calculated
inside the for-loop.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
Instead of our own implementation that upscales, then downscales back,
use graphene_matrix_inverse() directly. This is possible after switching
to a z-near value that doesn't have problems with float precision.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
Picking is specially sensitive for float precision, and tests can
easily fail when something changes, even if ever so slightly. A
simple way to workaround this is by adjusting the projected points
using the same procedure described at 67cc60cbda.
Round projected points for picking to 256ths.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489
A first step towards abandoning the CoglObject type system: convert
CoglFramebuffer, CoglOffscreen and CoglOnscreen into GObjects.
CoglFramebuffer is turned into an abstract GObject, while the two others
are currently final. The "winsys" and "platform" are still sprinkled
'void *' in the the non-abstract type instances however.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1496
The timestamp sent with _NET_WM_FRAME_DRAWN should be in "high
resolution X server timestamps", meaning they should have the same scope
as the built in X11 32 bit unsigned integer timestamps, i.e. overflow at
the same time.
This was not done correctly when mutter had determined the X server used
the monotonic clock, where it'd just forward the monotonic clock,
confusing any client using _NET_WM_FRAME_DRAWN and friends.
Fix this by 1) splitting the timestamp conversiot into an X11 case and a
display server case, where the display server case simply clamps the
monotonic clock, as it is assumed Xwayland is always usign the monotonic
clock, and 2) if we're a X11 compositing manager, if the X server is
using the monotonic clock, apply the same semantics as the display
server case and always just clamp, or if not, calculate the offset every
10 seconds, and offset the monotonic clock timestamp with the calculated
X server timestamp offset.
This fixes an issue that would occur if mutter (or rather GNOME Shell)
would have been started before a X11 timestamp overflow, after the
overflow happened. In this case, GTK3 clients would get unclamped
timestamps, and get very confused, resulting in frames queued several
weeks into the future.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1494
Keeping track of the projected position is costly, and adds quite some complexity
to ClutterOffscreenEffect.pre_paint(). As far as research goes, there's not a
single consumer of this function that uses the position for anything - only size
is used.
Remove clutter_offscreen_effect_get_target_rect(), and drop the annoying position
field from ClutterOffscreenEffect as well. This allows us to stop projecting the
position on pre-paint, and simplify things.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1474
ClutterPipelineNode will be used by GNOME Shell in the future.
Fortunately for us, CoglPipeline is already usable from GJS,
so we don't need to skip the constructor for the pipeline node.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1474
Move unreffing the framebuffer to ClutterOffscreenEffect.pre_paint().
This will allow us to properly chain up ClutterOffscreenEffect.paint()
and not reimplement exactly what ClutterEffect does by default.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1474
In this case, since we are building the entire matrix by ourselves,
reverse the order of operations (translate + scale → scale + translate)
and build it using graphene-specific APIs.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
This is another instance of graphene reversing the order of operations (see
the commit notes of how ClutterActor was ported.) The tl;dr; here is that,
in the CoglMatrix past, we used to do:
(actor transforms) → scale
and now, it's the other way round:
scale → (actor transforms)
due to changing from right-handed multiplications (CoglMatrix) to left-handed
ones (graphene_matrix_t).
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
ClutterActor is a particularly heavy user of matrices, and
switching to graphene_matrix_* APIs means we had to change
the order of operations due to left-hand vs right-hand
differences.
When applying the actor transform, there are 2 main branches
that can be followed: the default transforms, and when a
custom transform is set.
To facilitate review, here's the table that I've made to
guide myself:
+--------------- Case 1: Default Transforms --------------+
| CoglMatrix | graphene_matrix_t |
+----------------------------+----------------------------+
| multiply (child transform) | translate (-pivot) |
| translate (allocation)¹ | rotate_x (angle) |
| translate (pivot)¹ | rotate_y (angle) |
| translate (translation)¹ | rotate_z (angle) |
| scale (sx, sy, sz) | scale (sx, sy, sz) |
| rotate_z (angle) | translate (translation)¹ |
| rotate_y (angle) | translate (pivot)¹ |
| rotate_x (angle) | translate (allocation)¹ |
| translate (-pivot) | multiply (child transform) |
+----------------------------+----------------------------+
¹ - these 3 translations are simplified as a single call
to translate(allocation + pivot + translation)
+---------------- Case 2: Custom Transform ---------------+
| CoglMatrix | graphene_matrix_t |
+----------------------------+----------------------------+
| multiply (child transform) | translate (-pivot) |
| translate (allocation)² | multiply (transform) |
| translate (pivot)² | translate (pivot)² |
| multiply (transform) | translate (allocation)² |
| translate (-pivot) | multiply (child transform) |
+----------------------------+----------------------------+
² - likewise, these 2 translations are simplified as a
single call to translate(allocation + pivot)
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
CoglMatrix already is a typedef to graphene_matrix_t. This commit
simply drops the CoglMatrix type, and align parameters. There is
no functional change here, it's simply a find-and-replace commit.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
Ideally, we would use Graphene to do that, however as of now Graphene
lacks these APIs so we still need these helpers. Since we're preparing
to get rid of CoglMatrix, move them to a separate file, and rename them
with the 'cogl_graphene' prefix.
Since I'm already touching the world with this change, I'm also renaming
cogl_matrix_transform_point() to cogl_graphene_matrix_project_point(),
as per XXX comment, to make it consistent with the transform/projection
semantics in place.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
Given that CoglMatrix is simply a typedef to graphene_matrix_t, we can
remove all the GType machinery and reuse Graphene's.
Also remove the clutter-cogl helper, and cogl_matrix_to_graphene_matrix()
which is now unused.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
It turns it to be quite easy to inverse the transform, and doing that
on ClutterActor level means we can actually think about removing
CoglMatrix entirely and using graphene_matrix_t everywhere.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
CoglMatrix doesn't have a 1:1 mapping of graphene functions, and
sometimes it's just not worth adding wrappers over it. It is easier
to expose the internal graphene_matrix_t and let callers use it
directly.
Add new cogl_matrix_get_graphene_matrix() helper function, and
simplify Clutter's matrix progress function.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
Rename cogl_matrix_get_array() to cogl_matrix_to_float(), and
make it copy the floats to an out argument instead of returning
a pointer to the casted CoglMatrix struct.
The naming change is specifically made to match graphene's,
and ease the transition.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
Graphene provides skewing as part of graphene_matrix_t API, and it'll
be easier for the transition to just expose similar API surfaces.
Move the matrix skew methods to CoglMatrix.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
Even when a direct client buffer has a compatible format, stride and
modifier for direct scanout, drmModePageFlip() may still fail sometimes.
From testing, it has been observed that it may seemingly randomly fail
with ENOSPC, where all subsequent attempts later on the same CRTC
failing with EBUSY.
Handle this by falling back to flipping after having composited a full
frame again.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1410
We already correctly set the font-dpi based on user settings in
MetaSettings at each user change and as part of backend initialization,
so there's no point to set it also during x11 backend post-parsing and
using X11 values, as this may happen at later point and lead to a wrong
clutter font DPI value.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1444
It'll allow subclasses to get notified of the before-paint
signal without having to connect to it. This will allow
MetaStage to have proper watches being fired there without
the cost of the signal handling machinery.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1421
Just because X11/XI uses a particular terminology doesn't mean we
have to use the same terms in our own API. The replacement terms
are in line with gtk@1c856a208, which seems a better precedent
for consistency.
Follow-up to commit 17417a82a5.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1425
These are not given directly to the input focus anymore, instead
queued up as events. This way, all actions triggered by the input
method (commit and preedit buffer ones, but also synthesized key
events) queue up the same way, and are thus processed in the exact
same order than they are given to us.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1286
The clutter_input_focus_filter_key_event() function has been made
a more generic filter_event(). Besides its old role about letting
key events go through the IM, it will also process the IM events
that are possibly injected as a result.
Users have been updated to these changes.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1286
Previously we only culled actors that didn't intersect the bounding box
of the redraw clip. Now we also cull those whose paint volume bounds don't
intersect the arbitrary shape of the redraw clip.
This was inspired by the activities overview where idle windows and
workspace previews were being needlessly repainted. In that particular
case this yields more than 10% reduction in render time. But it probably
helps in other situations too.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1359
Clutter device events are special events coming from the backend when an
input device is added or removed.
When such events are processed, we should make the seat to handle them by
calling vfunc that can be implemented by each backend and eventually
emitting the appropriate signal.
If a device is removed, we can also safely dispose it, as it can be
considered stale at this point.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1371
Add clutter device added and removed events to allow processing of them as
it happens in the backends, queuing them and performing actions in order.
This allows not to loose any event that is performed just before removing or
disabling a device, and still process the events in order in the event
queue.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1371
This was from the old clutter-as-application-library days, where it had
to try find a suitable backend. Now we already have a backend selected
(MetaBackend), and the clutter backend is already predecided depending
on that, so we don't need the code that auto detects an appropriate one
anymore.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364
There is no reason to use Xsettings for the X11 backend, as it comes
from the GSetting store anyway, so move the font setting reading to
ClutterSettings and read directly from GSettings.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364
The delete event was used for signalling the close button was clicked on
clutter windows. Being a compositor we should never see these, unless
we're running nested. Remove the plumbing of the DELETE event and just
directly call meta_quit() when we see it, if we're running nested.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364
We checked if we were using the usig the X11 backend to decide when to
deal with a11y event posting - in order to make the clutter code less
windowing system dependent, make this check a check whether we're a
display server or not, in contrast to a window/compositing manager
client. This is made into a vfunc ot ClutterBackendClass, implemented by
MetaClutterBackendNative and MetaClutterBackendX11.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364
When we pick the frame clock given the associated actor, that frame
clock in fact comes from a picked actor. In order to not end up with
stale frame clocks, which may happen on e.g. hotplugs, monitor layout
changes, or non-optimal frame clocks, which may happen when the parent
used for picking the clock moves to another view, lets listen to
'stage-views-changed' on the actor used for picking the clock too.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1327https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404
Let's not expose that outside of mutter quite yet; it's not used in
gnome-shell, and to avoid future breakage if it starts to be used, lets
move it to clutter-mutter.h so only mutter and clutter itself can use
it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404
This aims to make sure a view and its resources are destroyed when it
should. Using references might keep certain components (e.g frame clock)
alive for too long.
We currently don't take any long lived references to the stage view
anywhere, so this doesn't matter in practice, but this may change, and
will be used by a to be added test case.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404
Always force-track the cursor position (so that the X11 backend can keep
it up to date), and if the cursor wasn't part of the sampled
framebuffer when reading pixels into CPU memory, draw it in an extra
pass using cairo after the fact. The cairo based cursor painting only
happens on the X11 backend, as we otherwise inhibit the hw cursor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
On X11 we won't always receive cursor positions, as some other client
might have grabbed the pointer (e.g. for implementing a popup menu). To
make screen casting show a somewhat correct cursor position, we need to
actively poll the X server about the current cursor position.
We only really want to do this when screen casting or taking a
screenshot, so add an API that forces the cursor tracker to track the
cursor position.
On the native backend this is a no-op as we by default always track the
cursor position anyway.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
The clutter_actor_get_transformed_position returns the position of the
top left point of the actor, with the actor transformations. That means
that if the actor is rotated 180º it'll return the "screen" position top
right.
Using this to calculate if the actor is in the screen is causing
problems when it's transformted.
This patch adds a new function clutter_actor_get_transformed_extents,
that will return the transformed actor bounding rect.
This new function is used on the update_stage_views so the actor will
get updated. this way rotated actors will be updated if they are on the
screen.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1386
Make clutter_actor_allocate_preferred_size() convenient to use from
layout managers by not "automatically" honouring the fixed position of
the actor, but instead allowing to pass a position to allocate the
actor at.
This way we can move the handling of fixed positions to
ClutterFixedLayout, the layout manager which is responsible for
allocating actors using fixed positions.
This also makes clutter_actor_allocate_preferred_size() more similar to
clutter_actor_allocate_available_size().
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1310
It's currently a bit hard to get the fixed position of an actor. It can
be either done by using g_object_get() with the "fixed-x"/"fixed-y"
properties or by calling clutter_actor_get_position().
Calling clutter_actor_get_position() can return the fixed position, but
it might also return the allocated position if the allocation is valid.
The latter is not the best behavior when querying the fixed position
during an allocation, so introduce a new function
clutter_actor_get_fixed_position() which always gets the fixed position
and returns FALSE in case no fixed position is set.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1310
With the introduction of the shallow relayout mechanism another small
but severe regression sneaked into our layout machinery: We might
allocate an actor twice during the same allocation cycle, with one
allocation happening using the wrong parent.
This issue happens when reparenting an actor from a NO_LAYOUT parent to
a non-NO_LAYOUT parent, in particular it triggered a bug in gnome-shell
when DND reparents a child from the NO_LAYOUT uiGroup to the overviews
Workspace actor after a drag ended. The reason the issue happens is the
following chain of events:
1. child of a NO_LAYOUT parent queues a relayout, this child is added to
the priv->pending_relayouts list maintained by ClutterStage
2. child is reparented to a different parent which doesn't have the
NO_LAYOUT flag set, another relayout is queued, this time a different
actor is added to the priv->pending_relayouts list
3. the relayout happens and we go through the pending_relayouts list
backwards, that means the correct relayout queued during 2. happens
first, then the old one happens and we simply call
clutter_actor_allocate_preferred_size() on the actor, that allocation
overrides the other, correct one.
So fix that issue by adding a method to ClutterStage which removes
actors from the pending_relayouts list again and call this method as
soon as an actor with a NO_LAYOUT parent is detached from the stage.
With that in place, we can also remove the check whether an actor is
still on stage while looping through pending_relayouts. In case
something else is going wrong and the actor is not on stage,
clutter_actor_allocate() will warn anyway.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1356
When picking which frame clock to use, we traverse up in the actor
hierarchy until a suitable frame clock is found. ClutterTimeline
also listens to the 'stage-views-changed' to make sure it's always
attached to the correct frame clock.
However, there is one special situation where neither of them would
work: when the stage doesn't have a frame clock yet, and the actor
of the timeline is outside any stage view. When that happens, the
returned frame clock is NULL, and 'stage-views-changed' is never
emitted by the actor.
Monitor the stage for stage view changes when the frame clock is
NULL.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
An actor may be placed without being on any current stage view; in this
case, to get the ball rolling, walk up the actor tree to find the first
actor where a frame clock can be picked from.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The frame clock owner should be able to explicitly destroy (i.e. make
defunct) a frame clock, e.g. when a stage view is destructed. This is so
that other objects can keep reference to its without it being left
around even after stopped being usable.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Replace the default master clock with multiple frame clocks, each
driving its own stage view. As each stage view represents one CRTC, this
means we draw each CRTC with its own designated frame clock,
disconnected from all the others.
For example this means we when using the native backend will never need
to wait for one monitor to vsync before painting another, so e.g. having
a 144 Hz monitor next to a 60 Hz monitor, things including both Wayland
and X11 applications and shell UI will be able to render at the
corresponding monitor refresh rate.
This also changes a warning about missed frames when sending
_NETWM_FRAME_TIMINGS messages to a debug log entry, as it's expected
that we'll start missing frames e.g. when a X11 window (via Xwayland) is
exclusively within a stage view that was not painted, while another one
was, still increasing the global frame clock.
Addititonally, this also requires the X11 window actor to schedule
timeouts for _NET_WM_FRAME_DRAWN/_NET_WM_FRAME_TIMINGS event emitting,
if the actor wasn't on any stage views, as now we'll only get the frame
callbacks on actors when they actually were painted, while in the past,
we'd invoke that vfunc when anything was painted.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/903
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
We'd emit multiple "presented" signals per frame, one for "sync" and one
for "completion". Only the latter were ever used, and removing the
differentiation eases the avoidance of cogl onscreen framebuffer frame
callback details leaking into clutter.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Right now the stage only had a signal called 'after-paint' which was not
tied to painting but updating. Change this to offer 4 signals, for the 4
different stages:
* before-update - emitted in the beginning before the actual stage
updating
* before-paint - emitted before painting if there will be any stage
painting
* after-paint - emitted after painting if there was any stage painting
* after-update - emitted as a last step of updating, no matter whether
there were any painting or not
Currently there were only one listener, that should only really have
been called if there was any painting, so no changes to listeners are
needed.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The mutexes was used by ClutterTexture's async upload and to match GDK's
mutexes on X11. GDK's X11 connection does not share anything with
Clutter's, we don't have the Gdk Clutter backend left, and we have
already removed ClutterTexture, so lets remove these mutexes as well.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
A frame clock dispatch doesn't necessarily result in a frame drawn,
meaning we'll end up in the idle state. However, it may be the case that
something still requires another frame, and will in that case have
requested one to be scheduled. In order to not dead lock, try to
reschedule directly if requested after dispatching, if we ended up in
the idle state.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The frame clock wouldn't be useable yet, but none the less, add API to
get the frame clock best suited for driving the actor. Currently this
translates to the fastest one, but that might change.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The frame clock is meant to eventually drive the painting of the view,
in contrast to the master frame clock painting every view on the stage.
Right now it's a useless place holder.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The native backend had a plain counter, and the X11 backend used the
CoglOnscreen of the screen; change it into a plain counter in
ClutterStageCogl. This also moves the global frame count setting to the
frame info constuctor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
We currently have mutter set a global frame counter on the frame info in
the native backend, but in order to do this from clutter, change the
frame info construction from being implicitly done so when swapping
buffers to having the caller create the frame info and passing that to
the swap buffers call.
While this commit doesn't introduce any other changes than the API, the
intention is later to have the caller be able to pass it's own state
(e.g. the global frame count) along with the frame info.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
