We don't actually need the host to be a container, so simply work on
actors saving us a few casts.
This'll simplify dropping ClutterContainer entirely later, and
StViewport/ShellWindowPreviewLayout will also need to be updated for the
new signatures
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3384>
The layout manager takes the generic ClutterActor expand/align
properties into account. Everyone should already use those instead
of the custom layout/child properties, so removing them should have
little fallout, while making for a nice cleanup.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3382>
This struct contains the pressed/latched/locked set of modifiers applying
to the event, and may be filled in by backends generating those events.
Other places where we forward modified key events, state may be normally
obtained from the original event.
Since this constructor is used in a variety of places, this commit
updates them all in one go.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3369>
This function may be used on key events to obtain the fully
detailed pressed/latched/locked modifiers that apply when the
event is received. No events have this detailed information
yet.
This API call may be compared to the clutter_event_get_state_full()
that existed in the past, although this getter has a stronger
predilection to it applying exclusively to key events.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3369>
Make CoglBuffer an abstract class and inherit the various Cogl*Buffer types from it.
As none of the subclasses is overriding the vtable functions, they were not turned into
vfuncs but plain function pointers in CoglBuffer.
We still use _cogl_buffer_initialize until we port the various params into actual construct-only
properties, similar to the previous commit for CoglTexture.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3193>
- Make Texture a parent GObject class and move the vtable funcs as vfuncs
instead of an interface as we would like to have dispose free the TextureLoader.
- Make the various texture sub-types inherit from it.
- Make all the sub-types constructors return a CoglTexture instead of their respective
specific type. As most of the times, the used functions accept a CoglTexture,
like all the GTK widgets constructors returning GtkWidget.
- Fix up the basics of gi-docgen for all these types.
- Remove CoglPrimitiveTexture as it is useless: It is just a texture underhood.
- Remove CoglMetaTexture: for the exact same reason as above.
- Switch various memory management functions to use g_ variant instead of the cogl_ one
Note we would still want to get rid of the _cogl_texture_init which is something
for the next commit
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3193>
My motivation was at first to replace cairo_rectangle_t with graphene_rect_t
but noticed nothing uses it anywhere: Shell/Kiosk/Gala; so it is safe
to just drop and people could still use the new_to_framebuffer ctor
and handle setting up things themselves if needed.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3240>
The helper doesn't do anything that makes it worth
to be exposed as public API. End-users, such as GNOME Shell could have
an in-tree helper if they end up using it that much.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3086>
For frame updates in response to sporadic user interaction, this results
in input → output latency somewhere between the minimum possible and the
minimum plus the length of one display refresh cycle (assuming the frame
update can complete within a refresh cycle).
Applying a max_render_time based deadline which corresponds to higher
than the minimum possible latency would result in higher effective
minimum latency for sporadic user interaction.
This was discovered by Ivan Molodetskikh, based on measurements
described in https://mastodon.online/@YaLTeR/110848066454900941 .
v2:
* Set min_render_time_allowed_us = 0 as well, to avoid unthrottled
frame events. (Robert Mader)
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3174>
When more than one refresh interval has passed since
last_presentation_time_us.
I honestly can't tell if the previous calculation was correct or not,
but I'm confident the new one is, and it's simpler.
v2:
* ASCII art diagram didn't make sense anymore, try to improve
(Ivan Molodetskikh)
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3330>
The absolute modelview contains OpenGL coordinates, which have a higher
chance to not be invertible or, when doing so, introduce rounding
errors. These again often result in relative transforms becoming 3D
instead of 2D, making us miss optimized code paths down the line.
Thus cache stage-relative matrices instead, improving correctness and
possibly performance.
While on it also add some fast paths for cases where we can skip
calculating inverted matrices altogether and change variable names to be
more precise.
Fixes: dfd58ca8f1 ("clutter/actor: Extend caching in apply_relative_transformation_matrix")
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3286>
When CLUTTER_ENABLE_DEBUG is not defined, then CLUTTER_NOTE is defined
as an empty block of code. As a result of that, jitter_us is in that
situation unused, and a compiler warning about this unused variable
appears.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3275>
Apart from a few edge cases we can avoid walking the tree and transform
to the ancestor coordinate space by multiplying the actor stage-relative
matrix with the inverse of the ancestor's stage-relative matrix.
Since the stage-relative matrices are cached, this reduces the number of
matrix multiplications we do in many situations considerably.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3259>
This used to be the HW device that triggered the crossing (i.e.
the mouse moving the pointer, etc), or the logical device if the
crossing event happened through other means than input device
events, e.g. relayouts.
The move to ClutterEvent constructors went a bit too far in
the simplifications and broke these expectations for input-generated
crossing events.
Make this event constructor behave like the other events: receive
a source device, and figure out the corresponding logical device from
there. Also pass the source device as it'd be expected, in the
input-induced crossing event generation paths.
Fixes: a8c62251f8 ("clutter: Port stage crossing events to new constructors")
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2981
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3256>
The stage has the knowledge about input that is ongoing over it
(incl. things like styli and touchpoints). Add an iterator API
for these devices/touchpoints, so they can be used for calculations
and heuristics in other places of the code.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3059>
So far, we expected all events to have input devices set on them, IM events
lost theirs with commit 6aa42d6dad. This somewhat made sense, because IM
events are not backed by any actual device, they are generated by us in
response to eg. an OSK key press.
To fullfil the assumption that all devices at least have a logical input
device set, pass the seat to the clutter_event_im_new() constructor and then
set the device to the logical keyboard device. The source_device we leave
empty, since there is no actual physical device that this event came from.
Fixes: 6aa42d6dad
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3236>
The assertion for !implicit_grab_cancelled in the
`grab_actor == old_grab_actor` case of
clutter_stage_notify_grab_on_pointer_entry() is meant to do a simple
sanity-check to ensure the grab machinery is working as intended: During a
seat grab, all input gets delivered to the tree inside the grab, and all
implicit grabs outside of that tree are cancelled.
When a new seat grab on the same actor as the existing one happens, we run
through the cancellation machinery for implicit grabs anyway, so we might as
well check that the assumption mentioned above holds true: By asserting that
no implicit grabs were cancelled, we know that no implicit grabs exist
outside of the existing seat grab tree.
This assertion is slightly over-eager though due to the way we set
implicit_grab_cancelled: We initialize it to TRUE in the
entry->press_count > 0 case and then only set it to FALSE once we find an
implicit grab that may remain active. If there are no implicit grabs though
(while entry->press_count is still >0), we never set implicit_grab_cancelled
to FALSE, triggering the assertion in question even though no implicit grabs
got cancelled.
There's two possible solutions for this: Either dropping the assertion, or
refactoring it so it observes the situation where the implicit grabs were
already undone. This commit implements the latter.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2700
Fixes: debbd88f8c ("clutter/stage: Cancel parts of implicit grabs when ClutterGrabs happen")
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3216>
Dropped obsolete Free Software Foundation address pointing
to the FSF website instead as suggested by
https://www.gnu.org/licenses/gpl-howto.html
keeping intact the important part of the historical notice
as requested by the license.
Resolving rpmlint reported issue E: incorrect-fsf-address.
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3155>
This is at best pointless, since the relayout will change pointer
picking conditions, and buggy at worst, since the actor being
relayout is not at an state that it can be asked during picking.
This specifically fixes warnings like:
Can't update stage views actor <unnamed>[<Gjs_ui_workspacesView_WorkspacesDisplay>:0x5601dd557050] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<Gjs_ui_workspacesView_WorkspacesView>:0x5601edcf6aa0] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<Gjs_ui_workspace_Workspace>:0x5601ee163dc0] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<Gjs_ui_workspace_WorkspaceBackground>:0x5601ee1c85b0] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<ClutterActor>:0x5601ee4db280] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<Gjs_ui_windowPreview_WindowPreview>:0x5601ee1840c0] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<Gjs_ui_workspace_Workspace>:0x5601ebe1d1b0] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<Gjs_ui_workspace_WorkspaceBackground>:0x5601edbd3420] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<ClutterActor>:0x5601ee3cd630] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<StLabel>:0x5601ee685730] is on because it needs an allocation.
Can't update stage views actor <unnamed>[<ClutterText>:0x5601ed5b5f20] is on because it needs an allocation.
When trying to dismiss the overview with a 3fg touchpad gesture
while the pointer is over a window clone.
Closes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/6935
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3220>
This are called when a clone directly attaches to an actor. While not
reliable to know whether a particular actor is cloned or not, one can at
least this way get notified about whether an actor in particular is
cloned.
This can be useful for e.g. the MetaWindowActor, as it's what's most
likely cloned, e.g. for alt-tab views etc.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3019>
Adds va_marshallers to the ClutterStage signals. This allows for better
stack traces to be retrieved when profiling. Additionally, since the
generic marshaller was using GBoxedCopy/GBoxedFree functions for the
GValue usage, the previous code was acquiring a global reader/writer
lock in GObject via g_boxed_free() usage.
With G_SIGNAL_TYPE_STATIC_SCOPE, the generated marshallers can avoid
the additional copy/free on the instance.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3204>
Same reasoning holds than with touchpad gesture events in the
previous commit, this will be the first event seen from a specific
device and will require early handling, or crashes may follow.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3198>
With commit be3bca01a7 in place, we now possibly skip early calls
to clutter_stage_repick_device() happening early during initialization.
These were also indirectly the ones that eventually ended up in
the first call to clutter_stage_pick_and_update_device() actually
initializing the PointerDeviceEntry.
With this no longer happening, we may end up with no PointerDeviceEntry
implicitly set up after initialization, which may fail if the first
event received from the seat pointer does not in fact trigger the
clutter_stage_pick_and_update_device() call necessary to make things
work from there on.
And this does indeed happen on touchpads, since the first input event
obtained after CLUTTER_DEVICE_ADDED is CLUTTER_TOUCHPAD_* instead
of CLUTTER_MOTION. This finds an unset PointerDeviceEntry and crashes
since the pointer device does still have no "presence" on the stage.
Fix this by making CLUTTER_TOUCHPAD_* events also trigger a
device update, so the fist event handled does always trigger the
necessary device update.
Fixes: be3bca01a7 ("clutter: Check that pointer has coordinates prior to repick")
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2978
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3198>
This data is commonplace enough that it makes sense to keep it
as generic event data. Make these fields take a hard refcount, like
the private data used to do, and drop these fields from the
ClutterEventPrivate struct.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3190>
In future commits, we will want to create DMA-BUFs with pixel
formats other than COGL_PIXEL_FORMAT_BGRX_8888. In preparation
for that, let's start passing a new pixel format parameter to
this function, and the corresponding winsys vfunc.
All callers of this function pass COGL_PIXEL_FORMAT_BGRX_8888
for now. Next commits will change that.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3175>
The device/sequence may not currently have a set of coordinates to return.
We correctly leave the out values uninitialized, but don't tell the upper
layers in any way.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3183>
We have a mechanism to trigger repick after animations on
clutter_actor_set_final_state(), but this will not happen if
animations are disabled.
In this case, shell transitions and other typically animatable
changes on the transform of actors will not naturally trigger
a pointer repick when those get instantly changed to the final
state, possibly preserving the cached state and missing the
just popped in actor altogether.
Trigger an instant repick on animation-less transform changes,
so that these situations are also handled correctly, and the
pointer drops the cached state and is able to find the new
actor.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2918
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3168>
The clutter_seat_handle_event_post() function wants to handle
CLUTTER_DEVICE_ADDED/REMOVED to perform signal emission, but
checks (and asserts) that every event going through it has a
source device.
This is no longer quite true for IM events (they are attached
to the ClutterSeat's keyboard, not a HW device), so the assert
can now fire off (of course undesiredly).
But anyways, for events built through
clutter_event_device_notification_new() (the ones this function
is interested in, after all), it is already a precondition check
that the device is proper at the time of creating the event, so
asserting for it here is redundant.
We can drop this overly generic assert, this is already ensured
for the events that matter, anyways.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3167>
With the ClutterEvent subtype structs sealed, this remains the only useful
struct type that is now usable on the Javascript side. Make all
ClutterActorClass event vmethods use ClutterEvent, and update all users
to this change.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3163>
All ClutterEvent users have been changed to use getter methods
instead of direct field access. We may now make the ClutterEvent
union/structs entirely opaque by moving the definitions out of
public headers.
All future usage of ClutterEvent data should be done through
getter methods.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
Move the string construction bits in the event logging happening in
MetaSeatImpl to a clutter_event_describe() call, so that it has more
freedom in fiddling with ClutterEvent internals, and may be potentially
reused in other places.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
Add methods, and change the API of some rarely used methods, in order
to make all event info currently held/necessary accessible through
ClutterEvent getters, instead of direct field access.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
The full decomposed modifier state is pretty much unused, relying
in keymap signals/properties to track latched modifiers state instead.
The events can be simplified without having this information, and if
it were ever needed in the future, it would be nicer that it had a
dedicated struct and didn't increase the number of arguments in
ClutterEvent constructors.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
We need to change at least event flags in the event we reinject after
it was let through by the IM, in order to avoid doubly handling.
Create a full event copy from the original event parameters.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
Avoid peeking in the stage for loosely related actors, since the same
event could be handled by different actors across the picking stack.
This getter is also unused, so there's wiggle room here for changes.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
These constructors take all the necessary arguments to build the
event from the get go, so the callers are not left up with the task
of setting up the event struct data.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
Despite the attempt to make this a generic interface, this was
pretty much used only by the X11 backend, and now it ported away
from it.
This now stands unused and may be removed, in favor of backends
each creating and injecting events as they please.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
It is a bit backwards that events contain information about
the stage they are being handled by. It makes more sense to
specify in the ClutterEvent handling entrypoint the stage
that will handle the event.
As a first step, add this ClutterStage argument, even though
the information is still carried through the event in order to
keep satisfying calls to the getter function.
This entrypoint has been also renamed to clutter_stage_handle_event(),
so that its ownership/namespace is clearer.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3153>
Measurements above 100% were originally allowed to show when frame skipping
was occurring so you didn't have to also check the frame rate. But that
also resulted in arbitrarily high jitter values being reported when
returning from idle. And those are frequent enough to look like a bug or
untrustworthy so let's not do that anymore.
Taking the remainder of a high jitter value is still a meaningful jitter
value.
Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2906
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3123>
clutter_frame_clock_compute_max_render_time_us clamps to the refresh
interval anyway, so the only effect a higher recorded maximum can have
is to delay it falling below the refresh interval again.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3090>
Instead of separate pairs of short- and long-term maxima for each
measured step of the frame update process.
This should result in the render time estimate rising less often:
Previously it did whenever the measurement of any of at least 3 out of
4 steps reached a new maximum, even if that didn't result in a new
maximum for the whole update duration. Now it's only in the latter
case.
This should also result in a lower render time estimate (and thus
input→output latency) in general, since the variability of
measurements for each 3/4 steps doesn't always add up anymore. The flip
side of this is that it might result in missing a display refresh cycle
more often.
v2:
* Fix coding style in maybe_update_longterm_max_duration_us.
(Robert Mader)
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3090>
This adds some plumbing to get the "default" paint flags for regular
stage painting, where one either wants to paint the overlay, or not.
If inhibited, the 'no-cursors' paint flag is used, otherwise the 'none'
flag. This will be used to allow having a per stage view hw cursor
state.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
When a relative pointer motion gets constrained (e.g. a monitor edge or
barrier), save the constrained relative motion delta too.
This will later be used to send the remaining motion delta to input
capture clients.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2628>
An input only grab is a ClutterGrab on the stage that doesn't have an
explicit actor associated with it. This is useful for cases where event
should be captured as if focus was stolen to some mysterious place that
doesn't have anything in the scene graph that represents it.
Internally, it's implemented using a 0x0 sized actor attached directly
to the stage, and a clutter action that consumes the events. An
input-only grab takes a handler, user data and a destroy function for
the user data. These are handed to the ClutterAction, which handles the
actual event handling.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2628>
A 2D actorless paint volume can't ever need `enlarge_for_effects` because
it has no depth. Clamping to the pixel boundary is sufficient in this case
and avoids extending volumes on the edge of the view into the next view.
Which then avoids unnecessary secondary monitor updates.
Paint volumes correctly become actorless where `clutter_actor_finish_layout`
calls `_clutter_paint_volume_transform_relative`.
Relates to: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/6819
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3112>
If an actor's expand properties haven't been set explicitly, its
expand flags are computed by traversing its children.
However we currently also traverse into children when explicitly
setting "expand" to FALSE, because that is the default value and
the properties are only marked as explicitly-set when the value
actually changed.
Fix this, so propagating expand flags can be stopped without
hacks like
```c
g_object_set (actor, "x-expand", TRUE, NULL);
g_object_set (actor, "x-expand", FALSE, NULL);
``
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3088>
This is expected for the common case of direct scanout of Wayland
buffers where transactions guarantee that all buffer fences are
signalled before a buffer is included in a frame.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3080>
Dispatch jitter is how much the dispatch interval has changed between
frames. It's a measure of sampling smoothness for events that are occurring
at a higher rate than the screen is refreshing:
* Mouse movement
* Clients rendering at swap interval zero
* Keyframe animation position
Zero jitter is ideal but will practically never happen, and a jitter value
of several thousand microseconds will be visible to the naked eye as stutter
even if you're maintaining a perfect frame rate.
To make the numbers easier to interpret we also log the jitter as a
percentage of the refresh interval.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3082>
This could happen when moving the cursor over GUIs that only redraw
in response to cursor movement. Mutter would experience alternating
cursor-only updates and page flips, and so the `max_render_time_allowed_us`
would jump between pessimised and optimised resulting in inconsistent
frame pacing.
Aside from fixing the smoothness problem this should also provide
lower latency cursor movement.
Fixes: https://launchpad.net/bugs/2023766
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3074>
Currently, we let the same function handle key event filtering as they
are passed to the IM, and the IM events resulting in actions like text
commit or preedit changes.
Split these two aspects into filter/process functions, and port
ClutterText to it. MetaWaylandTextInput still handles everything in
a single place, but that will be split in later commits.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3044>
This will consist of device-added events, meaning before init finishes,
we can derive some state that depends on the set of input devices
available on startup, such as cursor visibility.
This avoids cursor visibility switching between hidden and visibility
during startup.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3070>
This is different from "warping" as it doesn't necessarily result in a
pointer motion event. This can be helpful during initializing so we can
avoid faked pointer events that would otherwise need to be special cased
to not appear as actual pointer movements.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3070>
The stage already maintains its own list of stage-views via
clutter_stage_peek_stage_views(), it's a bit superfluous to copy that list
around all the time into priv->stage_views of ClutterActor. Let's deal with
that by returning clutter_stage_peek_stage_views() when
clutter_actor_peek_stage_views() gets called for the stage.
In order to make sure ClutterActor::stage-views-changed still gets emitted
correctly for the stage, always emit that signal on the ClutterStage when
the stage views get invalidated. This now depends on the backend only
actually invalidating the views and calling
clutter_stage_clear_stage_views() when things have actually changed, but
that should be the case.
This needs a change in one of the stage-views tests, namely the one which
tests stage-view-changed emission on the stage: Here we now see an emission
of stage-views-changed, but that signal emission actually seems correct.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2679>
While we're now doing a fairly good job at not needing those matrices
all the time anymore, we still need it multiple times during every paint
cycle, so it definitely makes sense to introduce some caching here.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2679>
With commit 5a565b4258, we changed
clutter_actor_finish_layout() to be not only about updating stage views,
but also take care of updating the visible_paint_volume, for that we
started doing a full tree traversal of all mapped actors.
This can be quite a performance issue, apparently especially on certain
ARM devices, where the simple tree traversal can take as long as 2ms.
This is precious time we need to paint our next frame, so lets do a bit
more work to avoid those useless traversals.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/2459
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2679>