Policy here is a bit more complicated, if tree becomes too deep we're
forced to create a leaf node and size of that leaf wouldn't be so well
predicted, which means it's quite tricky to use single stack array for
that.
Made it more official feature that StackAllocator will fall-back to
heap when running out of stack memory.
It's still much better than always using heap allocator.
We had per-tree statistics already, but it's a bit tricky to see overall
time because trees could be building in parallel.
In fact, we can now print statistics for any TaskPool.
Currently they're staying at 1 (actual size over capacity), but we
will be changing it quite soon in order to avoid having too much
memory re-allocation happening at a BVH build time and will be
playing with different policies for that.
Note that we may want to review that some day, we have quite a bit of ID types here that are
'blend file' view only, might be worth splitting the check based on this.
In some files stack memory was overruning the pre-allocated stack.
Perhaps we should fall-back to a hep-allocated stack so release builds
don't crash in works case but just becoming slower.
That might consider a bit more objects to be considered deform modified,
but it covers common case of using taper object without require of doing
recursive checks.
In worst case it'll be just some extra synchronization time, no render
time difference will happen for false-positive because of extra checks
happening in Cycles.
The improved Hosek / Wilkie model was added during my GSoC 2013 and the default since then.
The older model was kinda kept for compatibility, but after more than 2 years it's time to remove it.
The Hosek / Wilkie model is more realistic anyway, and people who really want a day / night transition can mix the Sky Shader with another one (e.g. color) and fade between the two.
There are in fact some missing parts to it (Split BVH builder should
be creating bins from result of Object Split constructor).
Doable, but need to quickly fix issue for the studio here, easier to
revert for now.
Main use case of this ID will be to emulate TLS which otherwise
would require having some platform-specific implementations which
is not always really optimal.
See notes about the argument in util_task.h.
They were never running anyway since there's no checkout of
tests folder. We should either make tweaks to buildbot master
to make it to send cloning commands for tests folder and keep
tests working (currently some of them are broken).
Currently unused, but will be handy for an upcoming changes.
It'll also be nice to be able to do scoped_lock() for both
Mutex and Spin, but currently it's not really easy to do,
need some changes in typedefs and such, will happen as a
separate commit.
