libhwcomposer: Enhance mixed mode composition.
While marking layers for cache, neglect the z-order when
possible, to improve the scope of mixed mode usage.
It is safe to neglect the z-order if a static layer
doesn't have any overlapping region with updating layers
in between static layer & contiguous static layers batch.
- if above layer doesn't have any overlapping with updating
layer in middle, push it to the batch.
- If above case fails, but layers below(existing batch) does not
have any overlapping region with the updating layer, bring the
batch to top and modify fb-zorder accordingly.
Change-Id: I4882a750d0a9a2e11272fcbb146202160673d04f
4 files changed