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
We had time unit conversion helpers (e.g. us2ms(), ns2us(), etc) in
multiple places. Clean that up by moving them all to a common file. That
file is clutter-private.h, as it's accessible by both from clutter/ and
src/.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Currently unused, but it's intention is to use as a initial refresh rate
for a with the stage view associated frame clock. It defaults to 60 Hz
if nothing sets it, but the native backend sets it to the associated
CRTCs current mode's refresh rate.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Without an associated actor, or explicit frame clock set, in the future
a timeline will not know how to progress, as there will be no singe
frame clock to assume is the main one. Thus, deprecate the construction
of timelines without either an actor or frame clock set.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The association is inactive, as in it doesn't do anything yet, but it
will later be used to determine what frame clock should be driving the
timeline by looking at what stage view the actor is currently on.
This also adapts sub types (ClutterPropertyTransition) to have
constuctors that takes an actor just as the new ClutterTimeline
constructor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
This is so something outside of clutter-stage.c (i.e.
clutter-stage-view.c) can eventually do various things
_clutter_stage_do_update() does now while not redrawing the whole stage.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Devices are updated (repicked) as part of the stage update phase, as
their stacking, position and transform might have changed since since
the last update.
The redraw clip was used to avoid unnecessary updating of devices, if
the device in question had it's position outside of the redraw clip. If
the device coordinate was outside of the redraw clip, what was
underneith the device couldn't have changed.
What it failed to do, however, was to update devices if a relayout had
happened in the same update, as it checked the state whether a layout
had happened before attempting to do a relayout, effectively delaying
the device updating to the next update.
This commit changes the behavior to always update the device given the
complete redraw clip caused by all possible relayouts of the same update
as the device update happens in.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
We'd check if there was any queued redraw on the stage, but this is
inappropriate for two reasons:
1) A monitor and area screen cast source only cares about damage on a
subset of the stage.
2) The global pending-redraw is going away when paint scheduling will be
more view centric.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
This will allow anyone to finish any queued redraws making their
corresponding damage end up being posted to the stage views. This will
allow units to check whether, so far, any updates are queued on a
particular stage view.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Add API to add and remove ClutterTimeline objects to the frame clock.
Just as the legacy master clock, having a timeline added to the frame
clock causes the frame clock to continuously reschedule updates until
the timeline is removed.
ClutterTimeline is adapted to be able to be driven by a
ClutterFrameClock. This is done by adding a 'frame-clock' property, and
if set, the timeline will add and remove itself to the frame clock
instead of the master clock.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The timestamp comes from the GSource, meaning it's a more accurate
representation of when the frame started to be dispatched compared to
getting the current time in any callback.
Currently unused.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
In certain scenarios, the frame clock needs to handle present feedback
long before the assumed presentation time happens. To avoid scheduling
the next frame to soon, avoid scheduling one if we were presented half a
frame interval within the last expected presentation time.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
This adds a current unused, apart from tests, frame clock. It just
reschedules given a refresh rate, based on presentation time feedback.
The aiming for it is to be used with a single frame listener (stage
views) that will notify when a frame is presented. It does not aim to
handle multiple frame listeners, instead, it's assumed that different
frame listeners will use their own frame clocks.
Also add a test that verifies that the basic functionality works.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
When a transition is created for the allocation change, it will delay
the new allocation box getting set depending on transition details.
This, however, means that e.g. the 'needs_allocation' flag never gets
cleared if a transition is created, causing other parts of the code to
get confused thinking it didn't pass through a layout step before paint.
Fix this by calling clutter_actor_allocate_internal() with the current
allocation box if a transition was created, so that we'll properly clear
'needs_allocation' flag.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1345
Since we now have the neccessary infrastructure to get notified about
changes to the absolute transformation matrix, we can also invalidate
the stage-views list on updates to this matrix.
So rename absolute_allocation_changed() to absolute_geometry_changed()
to make it clear this function is not only about allocations, and call
that function recursively for all children on changes to the
transformation matrix, too.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1343
If we want to invalidate the stage-views list reliably on changes to the
actors transformation matrices, we also need to get notified about
changes to the custom transformations applied using the
apply_transform() vfunc.
So provide a new API that allows invalidating the transformation matrix
for actors implementing custom transformations, too. This in turn allows
us to cache the matrix applied using the apply_transform() vfunc by
moving responsibility of keeping track of the caching from
clutter_actor_real_apply_transform() to
_clutter_actor_apply_modelview_transform().
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1343
For ClutterText, the resource scale the text is drawn with affects the
size of the allocation: ClutterText will choose a font scale based on
the resource scale, and that font scale can lead to a slight difference
in size compared to the unscaled font.
We currently handle that by queuing a relayout inside the
"resource-scale-changed" signal handler. This solution is a bit
problematic though since it will take one more allocation cycle until
the allocation is actually updated after a scale-change, so the actor is
painted using the wrong allocation for one frame.
Also the current solution can lead to relayout loops in a few cases, for
example if a ClutterText is located near the edge on a 1x scaled monitor
and is moved to intersect a 2x scaled monitor: Now the resource scale
will change to 2 and a new allocation box is calculated; if this
allocation box is slightly smaller than the old one because of the new
font scale, the allocation won't intersect the 2x scaled monitor again
and the resource scale switches back to 1. Now the allocation gets
larger again and intersects the 2x scaled monitor again.
This commit introduces a way to properly support those actors: In case
an actors resource scale might affect its allocation, it should call the
private function clutter_actor_queue_immediate_relayout(). This will
make sure the actor gets a relayout before the upcoming paint happens
afte every resource scale change. Also potential relayout loops can
be handled by the actors themselves using a "phase" argument that's
passed to implementations of the calculate_resource_scale() vfunc.
The new API is private because resource scales are not meant to be used
in a way where the scale affects the allocation. With ClutterText and
the current behavior of Pango, that can't be avoid though, so we need it
anyway.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1276
Since we now always return a resource scale, we can remove the boolean
return value from clutter_actor_get_resource_scale() and
_clutter_actor_get_real_resource_scale(), and instead simply return the
scale.
While at it, also remove the underscore from the
_clutter_actor_get_real_resource_scale() private API.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1276
Now that ClutterActor has a convenient API for getting the stage views
an actor is presented on, we can remove a large part of the code for
resource-scale calculation and instead rely on the stage-views list.
The way this works is a bit different from the old resource scales:
clutter_actor_get_resource_scale() always returns a scale, but this
value is only guaranteed to be correct when called from a vfunc_paint()
implementation, in all other cases the value is guessed using the scale
of the parent actor or the last valid scale. Now in case the value
previously reported by clutter_actor_get_resource_scale() turns out to
be wrong, "resource-scale-changed" will be emitted before the next paint
and the actor has a chance to update its resources.
The general idea behind this new implementation is for actors which only
need the scale during painting to continue using
clutter_actor_get_resource_scale() as they do right now, and for actors
which need the resource scale on other occasions, like during size
negotiation, to use the scale reported by
clutter_actor_get_resource_scale() but also listen to the
"resource-scale-changed" signal to eventually redo the work using the
correct scale.
The "guessing" of the scale is done with the intention of always giving
actors a scale to work with so they don't have to fall back to a scale
value the actor itself has to define, and also with the intention of
emitting the "resource-scale-changed" signal as rarely as possible, so
that when an actor is newly created, it won't have to load its resources
multiple times.
The big advantage this has over the old resource scales is that it's now
safe to call clutter_actor_get_resource_scale() from everywhere (before,
calling it from size negotiation functions would usually fail). It will
also make it a lot easier to use the resource scale for complex cases
like ClutterText without risking to get into relayout loops.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1276
Add private API to ClutterBackend to set a fallback resource scale
available to Clutter. This API will be used for "guessing" the
resource-scale of ClutterActors in case the actor is not attached to a
stage or not properly positioned yet.
We set this value from inside mutters MetaRenderer while creating new
stage-views for each logical monitor. This makes it possible to set the
fallback scale to the scale of the primary monitor, which is the monitor
where most ClutterActors are going to be positioned.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1276
We're going to refactor resource scales, making the notification of
changes to the resource scale a lot more important than it is right now
(we won't guarantee queried scales are correct outside the paint cycle
anymore).
Having a separate signal/vfunc for this will make the difference between
the new clutter_actor_get_resource_scale() API (which can return a
guessed value) and the notification of changes to the resource scale
(which will be guaranteed to return an up-to-date value) more obvious.
So replace the "resource-scale" property of ClutterActor with a
"resource-scale-changed" signal that's emitted when the resource scale
is recalculated.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1276
ClutterBoxLayout calculates the preferred size of the opposite
orientation (so for example the height if the orientation is horizontal)
by getting the preferred size of the real orientation first, and then
the preferred size of the opposite orientation, using the other size as
for_width/height when doing the request.
Right now, for non-homogeneous layouts this for_width/height does not
adjust for the spacing set on the box layout. This leads to children
being passed a slightly larger for_width/height, which in case of
ClutterText might cause the line to not wrap when it actually should.
This in turn means we can end up with an incorrect preferred size for
the opposite orientation, leading to a wrong allocation.
So fix that and adjust for the spacing just as we do for homogeneous
layouts by subtracting the total spacing from the available size that is
distributed between children.
This fixes the wrong height of the checkbox label reported in
https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2574.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1333
The property is deprecated and the current implementation simply
redirects it to ClutterActor::background-color, so remove it.
Also update the tests to set the background color directly.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1332
ClutterStage is the one and only subclass of ClutterGroup, but
it overrides basically everything specific to ClutterGroup to
mimic a ClutterActor. What a waste!
Subclass ClutterActor directly and remove all the now useless
vfunc overrides from ClutterStage. Adapt CallyStage to subclass
CallyActor as well.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1332
It is deprecated in favor of the 'z-position' property, and
the implementation itself redirects to the z-position, so
just drop it and replace all get|set_depth calls to their
z-position counterparts.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1332
I noticed my system would fall back to the slow unclipped (and
uncullable) paint path whenever a window touched the left edge of
the screen. Turns out that was a red herring. Just that
`use_clipped_redraw` was uninitialized so clipping/culling was used
randomly.
So the compiler failed to notice `use_clipped_redraw` was uninitialized.
Weirdly, as soon as you fix that it starts complaining that `buffer_age`
might be uninitialized, which appears to be wrong. So we initialize that
too, to shut up the compiler warnings/errors.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1323
The ClutterBindConstraint will change the preferred size an actor
reports so it returns the same size as the source actor in some cases.
This behavior was introduced recently with 4f8e518d.
This can lead to infinite loops in case the source actor is a parent of
the actor the BindConstraint is attached to, that's because calling
get_preferred_size() on the source will recursively call
get_preferred_size() on the actor again.
So to avoid those loops, check if the source is a parent of the actor
we're attached to and don't update the preferred size in that case.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1282
For ClutterClones we need to apply a scale to the texture of the clone
to ensure the painted texture of the source actor actually fits the
allocation of the clone. We're doing this using the transformation
matrix instead of using the scale_x/scale_y properties of ClutterActor
to allow users to scale ClutterClones using that API independently.
Now it's quite a bad idea to get the allocation boxes for calculating
that scale using clutter_actor_get_allocation_box(), since that method
will internally do an immediate relayout of the stage in case the actor
isn't allocated. Another side effect of that approach is that it makes
it impossible to invalidate the transform (which will be needed when we
start caching those matrices) properly.
So since we eventually allocate both the source actor and the clone
ourselves anyway, we can simply use the allocation box inside
clutter_clone_allocate() (which is definitely updated and valid at that
point) to calculate the scale factor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1181
It seems wrong to use the scale factor of the X axis on the Z axis and
it looks like this has been accidentally changed in commit 570fa3f044.
So use a factor of 1.0 instead to not scale the Z axis at all because
the layout machinery only works in X and Y coordinates.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1181
There are cases where a layout manager used by an actor also wants to
return a custom size when the actor has no children, for example in case
the layout manager requests a fixed size. This is currently impossible
because we only query the layout manager when calculating the preferred
size if the actor has children.
So fix that and also use the layout managers size negotiation functions
in case the actor has no children.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1322
The size of the buffer the texture will be written to by
paint_to_buffer() is determined based on
meta_screen_cast_area_stream_src_get_specs() which uses roundf() to
calculate the width and height after scaling. Because the size of the
texture to be written to that buffer is calculated using ceilf(), it
might exceed the allocated buffer when using fractional scaling.
In 3.36 paint_to_buffer() is used from capture_view() which also uses
roundf() to allocate its buffer. Here this leads to a memory corruption
resulting in a crash when taking screenshots of an area.
Fixes https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2842https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1320
The modifier state of the input device is supposed to be set to the
newest state, while the modifier state detail of the event is set to the
last state before the event (so not including the changes triggered by
the event).
So since the modifier state of the event is the last state anyway, the
state of the ClutterInputDevice is supposed to be set by the backend and
not by the stage while queuing the event, so stop setting the state
here.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1275
Make the clutter_input_device_get_actor() API public and remove
clutter_input_device_get_pointer_actor() in favour of the new function.
This allows also getting the "pointer" actor for a given touch sequence,
not only for real pointer input devices like mice.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1275
Switch from clutter_seat_list_devices() to the new peek_devices() method
of ClutterSeat in cases where we're only looping through the returned
list without manipulating it. This way we don't have to unnecessarily
copy around the list of devices.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1275
Add a method to ClutterSeat that allows peeking the list of input
devices and allow looping through devices a bit faster. The API left is
private so we can make use of peeking the GList internally, but don't
have to expose any details to the outside, which means we'd have to
eventually stick with a GList forever to avoid breaking API.
Since we now have the peek_devices() API internally, we can implement
ClutterSeats public list_devices() API using g_list_copy() on the list
returned by peek_devices().
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1275
While it's strongly discouraged, it is possible to queue a new relayout
of an actor in the middle of an allocation cycle, we warn about it but
don't forbid it.
With the introduction of the "shallow relayout" API, our handling of
those relayouts silently changed: Before introducing "shallow
relayouts", we'd handle them on the next stage update, but with the
priv->pending_relayouts hashtable and the
priv->pending_relayouts_version counter, we now do them immediately
during the same allocation cycle (the counter is increased by 1 when
queuing the relayout and we switch to a new GHashTableIter after
finishing the current relayout, which means we'll now do the newly
queued relayout).
This change in behavior was probably not intended and wasn't mentioned
in the commit message of 5257c6ecc2, so
switch back to the old behavior, which is more robust in preventing
allocation-loops. To do this, use a GSList instead of GHashTable for the
pending_relayouts list, and simply steal that list before doing the
relayouts in _clutter_stage_maybe_relayout().
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1267
ClutterAlignConstraint currently assumes the source actor is positioned
in the same coordinate system as the actor it's attached to and
automatically offsets the adjusted allocation by the origin of the
source actor.
This behavior is only valid though in case the source actor is a sibling
of the constraint actor. If the source actor is somewhere else in the
actor tree, the behavior gets annoying because the constraint actor is
offset by (seemingly) random positions.
To fix this, stop offsetting the constraint actors allocation by the
position of the source.
To still make it possible to align the constraint actors origin with the
origin of the source, no longer override the origin of the allocation
in the AlignConstraint. This allows users to align the origin using a
BindConstraint, binding the actor position to the position of the
source, which is more flexible and also more elegant.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/737
Add a new pivot-point property to the ClutterAlignConstraint, similar to
the pivot point used by ClutterActor, defining the point in the
constraint actor around which the aligning is applied to the actor.
Just as the ClutterActor property, this property is defined using a
GraphenePoint.
By default this property remains set to (-1, -1) and the actor
will always be aligned inside the source actor, preserving the existing
behavior of ClutterAlignConstraint.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/737
Now that we have a proper way to mark our allocation as uninitialized,
make use of that and only disallow implicit transitions of the
"allocation" property if that is the case.
This fixes a bug where easing the allocation of an actor is impossible
when someone queued a relayout on it (or a child of it) before.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1290
We currently initialize the ClutterActorBox of the actors allocation to
zero, but there's a difference between a valid zero-allocation and an
actor having never been allocated. Currently it's impossible for us to
detect the latter case in a reliable way and we use the needs_allocation
flag for this, which may also be set in other situations.
So initialize the allocation of actors to the newly added UNINITIALIZED
ClutterActorBox, which will make it easier to detect whether an actor
already got its initial allocation.
This also fixes another issue right now: Actors which get allocated a
(valid) zero allocation, will now notify the "allocation" property in
this case.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1290
Add support for an artificial UNINITIALIZED marking for ClutterActorBox,
done by setting the boxes origin to Infinity and its size to -Infinity.
That is a value that's considered an invalid allocation by Clutter and
which can never be set by sane code.
This will allow setting the allocation of ClutterActors to an
UNINITIALIZED box when creating actors or when removing them from the
scenegraph and makes it possible to explicitely detect uninitialized
allocations, which is useful in a few cases.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1290
We currently go through the whole tree of mapped actors on every paint
cycle to update the stage views actors are on. Even if no actors need
updating of their stage views, traversing the actor tree is still quite
expensive and shows up when using a profiler.
So tone down the amounts of full-tree traversals we have to do on every
paint cycle and only traverse a subtree if it includes an actor which
actually needs updating of its stage views.
We do that by setting the `needs_update_stage_views` flag to TRUE
recursively for all parents up to the stage when the stage-views list of
an actor gets invalidated. This way we end up updating a few more actors
than necessary, but can avoid searching the whole actor tree for actors
which have `needs_update_stage_views` set to TRUE.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1196
Add a new signal that's emitted when the stage views an actor being
painted on have changed, "stage-views-changed". For example this signal
can be helpful when tracking whether an actor is painted on multiple
stage views or only one.
Since we must clear the stage-views list when an actor leaves the stage
(actors that aren't attached to a stage don't get notified about the
stage views being changed/replaced), we also emit the new signal when an
actor gets detached from the stage (otherwise there would be an edge
case where no signal is emitted but it really should: An actor is
visible on a stage view, then detached from the stage, and then attached
again and immeditely moved outside the view).
Also skip the comparison of the old stage-views list and the new one if
nobody is listening to the signal to save some resources.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1196
There are certain rendering techniques and optimizations, for example
the unredirection of non-fullscreen windows, where information about the
output/stage-view an actor is on is needed to determine whether the
optimization can be enabled.
So add a new method to ClutterActor that allows listing the stage-views
the actor is being painted on: clutter_actor_peek_stage_views()
With the way Clutter works, the only point where we can reliably get
this information is during or right before the paint phase, when the
layout phase of the stage has been completed and no more changes to the
actors transformation matrices happen. So to get the stage views the
actor is on, introduce a new step that's done on every master clock tick
between layout and paint cycle: Traversing through the actor tree and
updating the stage-views the mapped actors are going to be painted on.
We're doing this in a separate step instead of inside
clutter_actor_paint() itself for a few reasons: It keeps the code
separate from the painting code, making profiling easier and issues
easier to track down (hopefully), it allows for a new
"stage-views-changed" signal that doesn't interfere with painting, and
finally, it will make it very easy to update the resource scales in the
same step in the future.
Currently, this list is only invalidated on allocation changes of
actors, but not on changes to the transformation matrices. That's
because there's no proper API to invalidate the transformation matrices
ClutterActor implementations can apply through the apply_transform()
vfunc.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1196
When the stage views the stage is shown on are changed, ClutterStage
currently provides a clutter_stage_update_resource_scales() method
that allows invalidating the resource scales of all actors. With the new
stage-views API that's going to be added to ClutterActor, we also need a
method to invalidate the stage-views lists of actors in case the stage
views are rebuilt and fortunately we can re-use the infrastructure for
invalidating resource scales for that.
So since resource scales depend on the stage views an actor is on,
rename clutter_stage_update_resource_scales() and related methods to
clutter_stage_clear_stage_views(), which also covers resource scales.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1196
