Previously, we would reallocate when any CRTC_* property changes. This
leads to unnecessary reallocations when a plane moves or resizes. Cursor
movements would reallocate on every update, for example.
What we really care about is if a layer's intersection status with
another plane changes, so do that.
The default limit of 1ms might be too short if the compositor
calls liftoff_output_apply() early in the vblank cycle, or too
long if the refresh rate is high. The compositor is in a better
spot to decide how much time should be spent on atomic tests, so
add an option for that.
Closes: https://gitlab.freedesktop.org/emersion/libliftoff/-/issues/78
Introduce a function to swap elements in a doubly linked list. This will
be helpful when keeping the list of output layers sorted by priority.
v2: re-define in terms of list_inserts and list_removes
Right now, compositors are expected to query liftoff_layer_get_plane_id to
decide whether a layer needs to be composited.
However there are cases where a layer has no plane, but still doesn't need
composition (e.g. when FB_ID is zero or when alpha is zero, in the future when
the layer is out of CRTC bounds etc).
Add a new API to make users' life simpler.
Closes: https://github.com/emersion/libliftoff/issues/54
When the caller wants to perform a modeset, they will need to pass
DRM_MODE_ATOMIC_ALLOW_MODESET in the atomic commit flags, otherwise the driver
will fail the commit. libliftoff also needs to provide these flags in its
test-only commits.
On debug verbosity logging every reuse of planes is spamming the log making it
difficult to debug the process.
With this patch only the change of reusing the same allocation is logged and
how often the allocation was reused after this changed back again.
Compositors need to drive multiple connectors, each with its own vblank timings.
For each device, there's one separate rendering loop per output.
It's not possible to call liftoff_device_apply each time we want to submit a new
frame to one output, because this could touch another's output state, submitting
a new frame there in the process. When the other output will submit a new frame,
it'll get EBUSY (can't submit two frames without waiting for vblank).
Closes: https://github.com/emersion/libliftoff/issues/21
Start from scratch since we may be able to come up with a better allocation
(if the layer made another layer fall back to composition for instance).
Closes: https://github.com/emersion/libliftoff/issues/30
Keep track of the number of layer updates per 60 page-flips.
We could implement a more fine-grained tracking, for instance with a sliding
window. However it's a lot more complex than the current solution and the gains
are not clear. I'd prefer to keep the current solution and experiment with other
solutions once we have a good test-bed.
References: https://github.com/emersion/libliftoff/issues/22
This commit adds basic per-property change tracking.
When only FB_ID has changed, we try to re-use the previous allocation. If that
fails, go on with regular plane allocation.
Closes: https://github.com/emersion/libliftoff/issues/6
This lets the library user define a layer where composition will happen. At the
moment there can be at most one composition layer per output, on the primary
plane. It should be possible to remove these restrictions in the future if
desirable.
The composition layer will be put on a plane if and only if composition is
needed.
The compositor needs to know where composited layers will be blended to resolve
zpos conflicts.
Closes: https://github.com/emersion/libliftoff/issues/9
This will be useful for implementing optimizations in case planes don't collide.
In these cases we can ignore some zpos constraints.
References: https://github.com/emersion/libliftoff/issues/3
