Before this commit, next presentation time could end up behind now_us or
ahead of now_us depending on how presentation times happened to be
aligned relative to integer multiples of refresh_interval_us. It's not
clear whether this was originally intended because even if it the next
presentation time ends up behind now_us, it is moved ahead by a while
loop down below in this function.
Even though this difference in behavior didn't really matter, it made
reasoning about the subsequent branches more complex. It would also
potentially introduce bugs if the logic was to be modified. So this
commit makes it so next presentation time is always ahead of now_us.
It also adds a comment with a graph detailing the computations, and
adjusts the variable names to drop unfortunate terminology mistakes.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1707>
Last presentation time is mainly used to make sure predicted
presentation time is aligned with display refreshes. Even if it went
back in time, there will be no issue as next presentation time takes
current time into account. Synthetic presentation time is not exactly
aligned with display refreshes, so using it would only result in
inconsistent animations.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1707>
In constrast to notify_presented(), notify_ready() also returns the
state machine to the idle state, but without providing new frame
information, as no frame was actually presented.
This will happen for example with the simple KMS impl backend will do a
cursor movement, which will trigger a symbolic "page flip" reply in
order to emulate atomic KMS behavior. When this happen, we should just
try to reschedule again.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488>
Users of Debian arm64 (aarch64) report that on at least some GPUs
or screens, after time-based screen blanking has occurred, it is not
possible to unlock the screen. Bisection indicates that this regressed
in commit 209b1ba3, so presumably this is because a refresh rate of 0
is reported while the screen is blanked, leading to the frame clock
pausing forever.
Fixes: 209b1ba3 "clutter/frame-clock: Adapt refresh rate from to frame info"
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1536
Bug-Debian: https://bugs.debian.org/974172
Signed-off-by: Simon McVittie <smcv@debian.org>
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1601>
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
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
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
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
