When Wayland clients send commits without a buffer attached ("empty"
commits), they may lead to stage updates that do not result in any
frame being submitted for presentation ("empty" updates).
Due to how frame scheduling is handled, there can be many such
"empty" updates in a single refresh cycle. If frame callbacks were
emitted after each of these "empty" updates, and if the client
sending "empty" commits was using frame callbacks to throttle the
same logic that results in these "empty" commits being sent, it would
result in a feedback loop between Mutter and the client where the
client would send "empty" commits and Mutter would reply almost
immediately with a frame callback causing the client to send "empty"
commits continuously.
As such, when an "empty" update is detected, frame callbacks are
scheduled to be emitted only once in every refresh cycle, avoiding the
feedback loop.
When a "non-empty" update is detected, frame callbacks are instead
emitted immediately to allow clients to draw their next frame as soon
as possible. It is safe to emit frame callbacks in this case because
the frame for the current refresh cycle is already "finalized" and
that any commit sent by the client at that point would only be handled
in a future refresh cycle.
To implement this, the previous logic had used
meta_frame_native_had_kms_update() to detect "non-empty" updates,
assuming that those would always result in a KMS presentation with the
native backend.
However, this approach misses the fact that virtual monitors do not
use KMS, and as such do not result in KMS presentation even for
"non-empty" updates. As a result, frame callbacks would not be emitted
immediately, resulting in unintended throttling of client rendering.
Instead, assume that it is safe to emit frame callbacks immediately
whenever an update results in the frame clock waiting to be notified
of presentation, since this is also when commits sent by clients are
scheduled to be handled in a future refresh cycle.
This issue was mostly hidden because frame callbacks would be sent
immediately when the target presentation time for the frame had
changed compared to the previous frame. However, this behavior was
removed in 26d8b9c69 ("wayland: Remove unnecessary dispatch of frame
callback source"), exposing the issue.
Fixes: a7a7933e0 ("wayland: Emit frame events in GSource after "empty" updates")
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3263
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3549>
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>
To avoid communicating lower frame rate to clients through frame
callbacks, it is important to avoid delaying the source dispatch when
a dispatch is already scheduled.
To that end, the previous logic would emit pending frame callbacks
immediately in case a source dispatch was still scheduled for the
previous refresh cycle and then (potentially) schedule another source
dispatch for the current refresh cycle.
However, emitting pending frame callbacks immediately would send
frame events for every pending frame callback, including for the
current "empty" update. Scheduling another source dispatch for the
current cycle was then unnecessary and potentially undesirable
because there may not even be another "empty" update during the cycle.
Instead, let the already-scheduled source dispatch handle emitting any
pending frame callbacks, and do not schedule an additional source
dispatch for the current cycle as it may not be needed.
This approach is useful because it removes an implicit assumption
that the refresh rate is fixed and that target presentation time
remains constant within a refresh cycle. This assumption does not
apply for VRR.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3521>
The value of this variable represents the last point in time in
which an update would be allowed to scheduled for the given frame.
Rename it for clarity and in preparation for the next commits.
No change in behavior.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3521>
The value returned from clutter_frame_get_target_presentation_time()
is always same as the value returned from
clutter_frame_get_min_render_time_allowed() when they are called
consecutively because both functions effectively return the value of
frame->has_target_presentation_time. This is with the assumption
that this variable is only ever modified by the same thread that
also executes on_after_update().
As such, a case where the former returns FALSE after the latter
returned TRUE is not possible, which means the line that sets
"target_presentation_time_us = 0;" is effectively unreachable.
Acknowledging this fact allows the call to
clutter_frame_get_target_presentation_time() to be moved outside the
"else" case and into the "if" condition itself. This is done in
preparation for the next commits.
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>
It adds the following clarification:
```
Starting from version 5, the invalid_format protocol error is sent if
all planes don't use the same modifier.
```
We already send an error, just the wrong one.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3450>
Set the deadline timer state as "inhibited" in case a permission error
is returned while attempting to arm the deadline timer. This makes each
device enable its deadline timer again after a VT switch.
Also print a note in this case instead of a warning as such errors are
expected during a VT switch and should not raise concerns.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3259
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3534>
For now, this function only enables the deadline timer in case it was
inhibited. This would result in an attempt to use the deadline timer
again after a device is resumed.
If the conditions that resulted in the timer becoming inhibited
remain, it is expected to return to this state after the next frame
and before being armed.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3534>
The "disabled" state indicates that the deadline timer is disabled
for the lifetime of the device, while the "inhibited" state indicates
that it is disabled temporarily for the device.
This distinction is needed to handle each state differently in a
following commit. For now, only "disabled" is used.
No change in behavior.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3534>
This allows GNOME Shell to communicate the user desired XKB model
to the compositor instead of sticking with the pc105 default.
Particularly useful for those with a custom keyboard layout/irregular
keyboards.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2760>
Transient dialogs are meant to be placed centered over their
parent. However as we don't use the DIALOG window type on
wayland, this currently only works for modal dialogs.
To fix this, also apply the policy to NORMAL windows for
wayland clients.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3533>
Some panels only support fixed resolutions and fixed refresh rate with reduced blanking:
Established Timings I & II: none
Standard Timings: none
Detailed Timing Descriptors:
DTD 1: 2560x1600 120.001823 Hz 8:5 203.283 kHz 552.930000 MHz (345 mm x 215 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 6 Vback 85 Vpol N
DTD 2: 2560x1600 48.000295 Hz 8:5 81.312 kHz 221.170000 MHz (345 mm x 215 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 6 Vback 85 Vpol N
...
Minimum Pixel Clock: 552922 kHz
Maximum Pixel Clock: 552922 kHz
When using mirror mode, resolutions like 2560x1440 120Hz can be too high
to meet the pixelclock limitation, so 2560x1440 90Hz is selected
instead. However, the panel only supports 120Hz so using 90Hz result to
failed mode set.
So add reduced blanking to fallback mode, so correct refresh rate can be
used.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3449>
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>
COGL_DEBUG_ENABLED is a macro to check if a debug flag is set.
COGL_ENABLE_DEBUG is set by the build system if it's a debug build. The
check `#ifdef COGL_DEBUG_ENABLED` always evaluates to true. Use the
appropriate macro to guard some debugging code.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3446>
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>
To paraphrase jadahl: we have a dedicated KMS thread now, which also
has realtime scheduling enabled unconditionally. realtime scheduling
on the main thread isn't too great of an idea, considering GC can
take a hot minute.
And to quote rmader: we most likely won't be able to make the main
thread rt as long as we use GJS and thus have GC.
So let's get rid of it! It's just been breaking things anyways.
This just ignores the setting; we'll fully remove it when GNOME 46
comes around.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3296>
