To optimize for offloading success, the list of output layers can be
ordered by allocation priority, improving the chances of a higher
allocation score before the deadline.
The allocation algorithm picks DRM planes first, then tests output
layers against them. To reduce the number of tests, the layers can be
ordered such that it matches the DRM plane order. DRM planes in
libliftoff are ordered by primary, followed by all other planes in
descending z-order. We order the layers similarly, with the composition
layer first, followed by layers of descending priority.
In addition to layer priority, it's z-pos and intersection with other
layers are considered. Since to offload a high priority layer, all
intersection layers with higher z-pos will also need to be offloaded.
This also changes when reallocation is necessary. On top of the existing
criteria, reallocation is done when a layer's ordering changes.
With layer priority now considered, the priority test now passes --
enable it.
Makes sure libliftoff doesn't allocate a plane for the layer and doesn't crash.
References: 799f694587 ("Fix segfault when FB_ID isn't set")
References: 53a7bfebc9 ("Don't allocate planes for layers without a FB")
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
This is a pretty basic benchmark measuring the time spent in
liftoff_display_apply.
The current behaviour tries to reproduce the worst case scenario: layers don't
intersect and one plane is incompatible with all layers.
This test continuously updates a layer's FB for some time, and keeps another
layer static. The continously updated layer should be put in a plane.
The test is disabled for now because priorities aren't implemented yet.
Make sure we don't use planes with lower zpos for layers over the previous ones,
unless there is no collision.
This adds the last intersection check.
Closes: https://github.com/emersion/libliftoff/issues/3
And restore the original zpos-4x-disjoint test. Depending on the constraints on
the last two layers, one branch of the layer zpos check or the other is taken.
Fixes: 8617ddfd05 ("Add intersection check for planes under the current one")
has_composited_layer_on_top is now less strict and performs plane intersection
checks before returning true.
This allows for more layers to be assigned to planes, the relevant tests have
been enabled.
References: https://github.com/emersion/libliftoff/issues/3
This test makes sure composited layers make layers underneath fall back to
composition too, in a transitive manner. That is, if plane A is under plane B
which is itself under plane C, plane A falling back to composition means that
both planes B and C fall back to composition too (even if C isn't directly
underneath A).
If a layer cannot be mapped to a plane, make it so all layers under it also fail
plane allocation so that they can be properly composited on the primary plane.
A test was incorrect and has been fixed. Another test had two possible solutions
and has been updated with the one libliftoff yields.
zpos-3x maps three layers to primary, cursor and one of the overlays planes.
zpos-4x-partial sets up 4 layers but is only able to find a plane for 3 layers,
because ordering between the two overlay planes is undefined.
When testing the library, the libdrm dependency is swapped with a mock libdrm.
The test sets up the mock libdrm's internal state and then runs the test.
