When cloning an actor we were applying a global scale to it, based on
the size of the clone itself and of the cloned actor.
This implied that the transformed size of the clone was not the one that
was set, but it was taking taking in account the actor scaling too.
So in practice we were scaling it twice.
While this had no visual implications it indeed was causing troubles
when a ClutterClone was reactive because in such case only the scaled
area of the scaled clone was considered reactive.
Assume you had an actor of 100x100 pixels, scaling it to a clone of
50x50 pixels:
- The scale applied to the clone was 0.5
- The transformed size of the clone was: 25x25 pixels
- The clone was reactive only in that sub-area
To avoid this, never touch the clone transformation matrix, but only
transform it at paint time.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2959>
ClutterInputMethods content hint or purpose will be set again (even to the
same values) whenever a wayland client sends us a new content type/purpose.
Gtk appears to always set a content purpose on wl_text_input changes, so we
currently set and notify the "content-purpose" property on every change in a
gtk text field.
Since the OSK is gnome-shell listens to this property and re-generates its
entire layout when the content-purpose prop gets notified, this is currently
causing lag/freezes on every keypress in the OSK in gnome-shell.
So ensure to not notify these properties in case they're equal and set the
properties in the same way as we usually set them instead of going via
GObject.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3645>
Gestures are independent from each other when they are on different
actors and when they don't have a conflict over input with each other: For
example a gesture on one window and a gesture on another window will
recognize at the same time perfectly fine right now.
For those gestures (let's call them "independent gestures") we don't want
to control how the conflicting input should be handled, i.e. whether one
gesture wins over another or whether both can be recognizing using the
same touchpoint (e.g. zoom+rotate on the same actor). Instead we want
to control whether they are allowed to start while another one is running.
For now, make it impossible for two gestures to recognize globally at
the same time in all cases. This helps prevent subtle bugs and makes life
easier for users of the API. We can introduce API for fine grained control
over the behavior later.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2389>
With the next commit, we'll need a list of all gestures that currently are
active globally. Since actors and actions (and therefore also gestures) in
Clutter are bound to a stage, it makes sense for this list to exist on the
ClutterStage level.
The list itself is a simple GPtrArray (to allow for quick searches) that
doesn't reference the gestures and is not manipulated by the stage itself.
All manipulation of the array is left to ClutterGestures.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2389>
Quite often there are situations where multiple gestures try to
recognize, keeping track of the same set of points (for example an edge
drag gesture on the stage and a click gesture somewhere in the
scenegraph). Usually what's wanted here is that the first gesture to
move to RECOGNIZING wins over all other active gestures and "claims" the
point for itself.
We implement this by introducing a concept called "influencing". It
works by making all gestures operating on a shared set of points aware
of each other using ClutterAction->register_sequence().
ClutterGesture uses this vfunc to keep track of all other
ClutterGestures that are potentially conflicting, and keeps a list
(priv->cancel_on_recognizing) of those. As soon as the move to
RECOGNIZING happens, all gestures inside this list get moved to
CANCELLED.
To allow fine-grained control over this behavior, two APIs are
introduced:
1) on the implementation level (should_influence() and
should_be_influenced_by()): This is a vfunc that gets called as soon as
a potential conflict is detected. It's helpful when a specific gesture
always behaves the same towards another gesture, for example to make
sure a LongPress gesture never cancels a DragGesture.
2) on the gesture user level, clutter_gesture_can_not_cancel() is
introduced: This allows control for the user of a gesture to specify
that a specific instance of a gesture won't cancel another gesture.
Calling this twice so that both gestures can't cancel each other allows
for things like simultaneous recognition of a pinch-to-zoom and rotate
gesture.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2389>
Introduce ClutterGesture, a new ClutterAction subclass and the successor
of ClutterGestureAction that brings the necessary tools to handle
sequences of events and abstract touch and mouse gestures from those.
The big difference compared to ClutterGestureAction is that ClutterGesture
provides the implementation with point_added/moved/ended and
sequences_cancelled events and expects the implementation to move the
ClutterGesture through the ClutterGestureState state machine. This state
machine is then used internally by ClutterGesture to coordinate with other
gestures.
With the next commits, ClutterGesture will handle relationships between
conflicting gestures completely by itself, allowing the implementation or
the user to specify the details of the relationship between two gestures.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2389>
clutter_event_get_source() is still valid for the case of crossing events,
just like clutter_event_get_related(). The latter is not deprecated, so the
former shouldn't be either.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2389>
ClutterStage will unref an action in the middle of its own event handler in
case the action causes its own actor to be destroyed. In this case the
action would get freed underneath our feet. To avoid it, take a ref on the
action while calling its handle_event() vfunc, just as we do in
clutter_actor_event() while emitting an event to an actor.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2389>
Since commit e30eb78891 `ClutterFrameClock` assumes that a valid CPU time
implies timestamp query support, which is also checked in
`cogl_onscreen_egl_swap_buffers_with_damage()`.
Unconditionally setting the CPU time on direct scanout meant that the
compositing path would be stuck on the last (direct scanout optimized)
result on GL implementations without timestamp query support since.
be0aa2976e (clutter/frame-clock: Avoid rapidly toggling dynamic max render time)
Fix that by explicitly marking the gpu rendering duration as valid when
querying the GPU timestamps is supported and check for it ClutterFrameClock.
Fixes: 56580ea7c9 ("backends/native: Assume zero rendering time for direct scanout buffers")
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3655>
Currently, ClutterFrameClock uses g_source_set_ready_time() to determine
the usec timing of the next frame. That translates into a poll() with a
millisecond timeout if no trigger occurs to break the poll() out early.
To avoid spinning the CPU, GLib always rounds *up* to the next millisecond
value unless a timeout of 0 was provided by a GSource.
This means that timeouts for the ClutterFrameClock can easily skew beyond
their expected time as the precision is too coarse.
This applies the same concept as GNOME/glib!3949 but just for the
ClutterFrameClock. That may be more ideal than adding a timerfd for every
GMainContext, but we'll see if that lands upstream. I wanted to provide
this here because it could easily be cherry-picked in the mean time if
this is found to be useful.
From a timer stability perspective, this improves things from erratically
jumping between 100s and 1000s off of the expected awake time to single
or low double digits.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3636>
A new variable scheduling mode is introduced which allows lower
priority updates to be scheduled on a timeout which represents a lower
refresh rate, while allowing high priority updates to be scheduled to
occur as soon as possible.
This mode will be used by following commits to implement
synchronization of page flips to the update rate of specifc surface
actors.
High priorty updates are either scheduled to occur "now" if they
arrive at a rate which is lower than the maximum refresh rate, or
according to the measured maximum render time if they arrive at a
rate which meets or exceeds the maximum refresh rate. This approach
allows achieving low input latency in both scenarios.
Seperate handling for low priority updates is needed to avoid visible
stutter in the content of the surface that drives the refresh rate. An
example for a low priority update is cursor movement when the KMS
deadline timer is disabled.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1154>
This is conditionally toggled by grabs on the current key focus depending
on whether the current key focus actor would receive events according
to the grab or not. Which means it's no longer a reliable method for an
actor to know it does have focus, without asking the stage about it.
Avoid this check and ask the stage for the key focus, in order to make
key focus actors able to unset themselves despite the presence of grabs.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3629>
The min height reported by ClutterText when ellipsize and line-wrapping are
enabled was too small to fit the text.
The coordinates from `pango_layout_get_line_extents()` are baseline relative,
so the `y` coordinate means that the highest ascent would be `-y` above the
baseline and height gives the span between the ascent above the baseline and
the descent below it, so `logical_line_rect.y + logical_line_rect.height`
gives us the size of the descent. This is the wrong height to use for the
height of the actor.
The coordinates of the layout extents don't seems to be related to the baseline
and are just for offsets when rendering, that's probably how this bug got
initially introduced.
Therefore, the `y` coordinate from the layout is the correct offset to use,
even though, when looking at `pango_layout_get_extends_internal()`, it appears
that `y` is always set to 0.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3610>
Do not include it at header side as it is not part of the installed headers.
Only keep it in cogl-gl-headers.h as it is a private header.
Add it to all the source files that depend on it.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3593>
Users of Clutter grabs may listen for notify::revoked changes in
order to know that their grab is no longer in charge of event
propagation, without the use of crossing events.
Since a ClutterGrab may stay in the stack and regain effects,
this notification also happens the other way around.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3420>
The MetaWaylandPointer used to put this together through
MetaCursorTracker cursor visibility, and ClutterSeat-level
inhibition API, applying the pointer focus changes due to
visibility logically to Wayland clients.
In order to make this work over all Clutter widgetry
instead of just Wayland clients, make the ClutterSeat-level
inhibition API control this feature at the ClutterStage picking
level, and leave/enter the seat pointer as appropriate.
By default, the seat pointer has (un)focus inhibited. The
MetaCursorTracker has been made another player in unfocus
inhibition, simply asking for the pointer to get its focus
while the cursor is visible.
This in practice means that picking code may return a NULL
actor, some asserts and preconditions had to be changed to
handle this, plus some test code slightly.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3420>
The new CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW state is almost
identical to CLUTTER_FRAME_CLOCK_STATE_SCHEDULED, with one important
difference being that it avoids updates from being repeatedly
rescheduled "now" when multiple calls to
clutter_frame_clock_schedule_update_now() are done before the source
is actually dispatched.
Such repeated calls to schedule an update "now" may actually postpone
the dispatch if the CPU is very busy and the source dispatch is
delayed, defeating the purpose of scheduling a frame "now".
It also allows rescheduling "now" when the frame clock is uninhibited
after being inhibited while an update was scheduled "now". This may
be important in cases where the frame clock is inhibited for very
short periods in which it would otherwise lose the state of being
scheduled "now".
Scenarios such as this would become more common with the introduction
of variable refresh rate since it makes scheduling "now" a commonplace
occurrence.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3561>
Currently, the paint-volumes/redraws debug flags displays the actor
debug
names on top of the paint volume making it very unusable. Especially
that you can easily get the relevant actor from looking glass.
The motivation is to reduce the usage of pango (through the text node)
in order to possibly move all the fonts bits to gnome shell
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3571>
This removes an incorrect implicit assumption in
calculate_next_update_time_us() that a frame may only be scheduled
once in the duration of a refresh cycle. It accomplishes this by
setting last_next_presentation_time_us on presentation feedback
instead of calculating it every time an update is scheduled.
Specifically, it corrects the intended scheduling logic in scenarios
like the following, when all of the below occur in the context of a
single refresh cycle:
1. Frame update (1) is scheduled normally, and
"is_next_presentation_time_valid" is set to TRUE
2. Frame update (1) is dispatched but ends up being "empty" (no
presentation necessary)
3. Frame update (2) is scheduled "now" and
"is_next_presentation_time_valid" is set to FALSE
4. Frame update (2) is dispatched but ends up being "empty" (no
presentation necessary)
5. Frame update (3) is scheduled normally, and since
"is_next_presentation_time_valid" is set to FALSE, the
"early presented event" logic is unintentionally skipped in
calculate_next_update_time_us().
6. Frame update (3) is dispatched and ends up being a "non-empty"
update, but its update time was calculated incorrectly because
some logic was skipped.
Scenarios such as this would become more common with the introduction
of variable refresh rate since it makes scheduling "now" a commonplace
occurrence.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3560>
Calculate the frame deadline in ClutterFrameClock's
calculate_next_update_time_us() rather than in MetaWaylandCompositor's
on_after_update().
The specifics of the deadline calculation for a given frame should be
implementation detail of the frame clock and and remain internal to
allow extensibility.
This extensibility is specifically useful for scenarios where a
different deadline calculation is needed due to alternative frame
scheduling logic, such as for VRR.
No change in behavior.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3521>
In various public APIs, Clutter used to return a PangoDirection
while we have a text direction enum defined in Clutter.
This allows us to drop pango dependency from meta making it specific
to cogl-pango & clutter
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3531>
Since StDrawingArea in gnome-shell is the only user of ClutterCanvas,
it is possible to move ClutterCanvas completely out of Mutter to
gnome-shell. This allows to remove another Cairo dependency from
Mutter.
This patch removes ClutterCanvas code from Mutter.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3470>
Since StDrawingArea in gnome-shell is the only user of ClutterCanvas,
it is possible to move ClutterCanvas completely out of Mutter to
gnome-shell. This allows to remove another Cairo dependency from
Mutter.
This patch makes clutter_actor_create_texture_paint_node() function
public to be used by StDrawingArea in gnome-shell that replaces
ClutterCanvas.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3507>
On one hand this avoids crashes early after startup if the very first
pointer event is a scroll event, since the stage did not pick an actor
for the pointer device yet.
On the other hand, scroll events have some likelihood to change the
actor under the pointer even though it doesn't move. We still want to
cross towards the new actor under the pointer ASAP, without waiting
for later events.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3112
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3517>
The slightly different styles in the different build files make it
harder to reason about or share c_args.
This notably ensures we never set any extra c_args for plain builds and
fixes the cc.get_supported_arguments() check in Cogl, Clutter and Mtk.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3333>
clutter_actor_get_transformed_position() would write the uninitialized
values of v2 when clutter_actor_apply_transform_to_point() fails in
_clutter_actor_fully_transform_vertices() because the actor has not been
added to the stage yet.
When called from JS this would overwrite the zero initialized values
passed in from gjs. If the uninitialized values now happen to correspond
to one of the NaN float values used by mozjs to represent a pointer
type, this would lead to seemingly random crashes in mozjs code later
on.
Avoid this by using _clutter_actor_fully_transform_vertices() directly,
which allows us to check if it failed.
Related: https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/issues/469
Related: https://gitlab.gnome.org/GNOME/gjs/-/issues/591
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3453>
Although they're in the same units, `radius` is easier to understand than
`sigma` and makes the public API independent of the blur algorithm used
behind the scenes. We now only keep the `sigma` terminology where the
implementation is Gaussian-specific.
The assumption that `sigma = radius / 2.0` is actually not new here. We
just move it from `_st_create_shadow_pipeline` (gnome-shell!1905) into
`clutter_blur_new`.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1908>
Some actors have a well-defined layout manager other than FixedLayout.
If they do, we can handle the layout manager creation at the
ClutterActor instantiation, like GTK does for widget layout managers.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3445>
Tracy can filter its statistics by user text, in our case by span
description. It's useful to filter by actor type and name, and not so
much by the pointer. So, remove it, and also reduce the amount of
punctuation.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3417>
Transfer none was achieved using a stack GArray in the stage which
would get resized to 0 at the end of every frame to "free" it.
In the case of direct scanout however, painting the next frame only
happens after leaving fullscreen again. Until then the array just kept
growing and because GArrays don't reallocate when shrunk, this memory
remained allocated even after leaving fullscreen.
There is no cache benefit from storing paint volumes this way, because
nothing accesses them after their immediate use in the calling code.
Also the reduced overhead from avoiding malloc calls seems negligible as
according to heaptrack this only makes up about 2-3% of the temporary
allocations.
Changing this to transfer full and removing the stack array simplifies
the code and fixes the "leak".
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3191
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3442>
It was for a failed expriment that tried to mmap() dmabuf memory and
find damaged regions to decrease the amount that was eventually used to
write to an onscreen, but mmap:ing is only fast enough on intel, and
it's only relevant on various server GPUs. For it to be achievable, we
need to render to system memory in a way that we don't need to copy it
out of OpenGL, but that's currently not possible.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3443>
This is a step in cleaning up the Clutter context management. By making
it a GObject it's easier to add e.g. properties and features that helps
with introspection.
For now, this means the context creation is changed to go via a
"constructor" (clutter_create_context()). This is so that the global
context singleton can be mantained outsid of ClutterContext, until it
can be removed.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2016>
The original purpose of being able to report errors is no longer
relevant, since the Clutter backend is now practically a thin wrapper
around the actual backend, which has already dealt with error reporting.
Thus move this to the regular constructor path.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2016>
The intention for ClutterContext is to be more or less the MetaContext
or CoglContext equivalent. Lets rename the type so that it becomes more
consistent with the other similar types.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2016>
We might pick an actor that needs relayout. I've seen this happen inside
hiding / unmapping in particular. In this case, calculate_clear_area ()
will call clutter_actor_get_abs_allocation_vertices () which in turn
will force a relayout. However, this is not what we want, because:
1. We don't want to run layout during picking.
2. If the actor needs an allocation, then the pick stack could not have
used an up-to-date allocation, because it is not computed. Therefore
this clear area would use a potentially completely different
allocation than the one stored in the pick stack.
Thankfully, clear area seems to be used as a cache/optimization, so
let's just avoid computing it if the actor is not allocated.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3425>
In profilers with a timeline or flame graph views it is a very common
scenario that a span name must be displayed in an area too short to fit
it. In this case, profilers may implement automatic shortening to show
the most important part of the span name in the available area. This
makes it easier to tell what's going on without having to zoom all the
way in.
The current trace span names in Mutter don't really follow any system
and cannot really be shortened automatically.
The Tracy profiler shortens with C++ in mind. Consider an example C++
name:
SomeNamespace::SomeClass::some_method(args)
The method name is the most important part, and the arguments with the
class name will be cut if necessary in the order of importance.
This logic makes sence for other languages too, like Rust. I can see it
being implemented in other profilers like Sysprof, since it's generally
useful.
Hence, this commit adjusts our trace names to look like C++ and arrange
the parts of the name in the respective order of importance.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3402>
NULL actor pointers seem to arise sometimes in `clutter_stage_update_device`
when using a touchscreen, but that's only fatal with `CLUTTER_DEBUG=event`.
So just handle NULL where it was crashing: `_clutter_actor_get_debug_name`.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3413>
Scoped traces are less error prone, and they can still be ended
prematurely if needed (this commit makes that work). The only case this
doesn't support is starting a trace inside a scope but ending outside,
but this is pretty unusual, plus we have anchored traces for a limited
variation of that.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3396>
Allow only specific files to use those deprecated APIs making
it easier to find where deprecated APIs are still in use
and avoid introducing new usages without being noticed
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3400>
Group all the three config files from clutter/cogl/meta into one
and also remove unnused configurations and replace duplicated ones
This also fixes Cogl usage of HAS_X11/HAS_XLIB to match the expected
build options
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3368>
clutter_keyval_name() returns a pointer to a static array, not
newly allocated memory. Add a transfer annotation to indicate
that callers must not free the returned memory.
While add it, make the return value const to stress further that
callers shouldn't touch the returned memory.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3386>
Currently, nothing uses the dumped json of the paint nodes tree. So
let us drop them in a separate commit so it can easily be reverted
if someone ends up wanting to build a tool to consume and inspect
the JSON.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3354>
Currently, json-glib is used for two things:
- For loading scripts, nothing seems to use that in real life other
than some tests
- For debugging paint nodes
For now, the PR drops the first use case and only require json-glib
if it is a debug build
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3354>
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>