For some blend modes there would be no effect with factor 1.0, even if factor
0.999 would give a very different image. Now the result should have no
discontinuity.
Differential Revision: https://developer.blender.org/D2925
It merely uses the new thread-safe iterators system of mempool, quite
straight forward.
Note that to avoid possible confusion with two void pointers as
parameters of the callback, a dummy opaque struct pointer is used
instead for the second parameter (pointer generated by iteration over
mempool), callback functions must explicitely convert it to expected
real type.
Also added a basic gtest for this new feature.
This will allow threaded tasks to 'consume' all mempool items in
parallel tasks, each one working on a whole chunk at once (to reduce
concurrency managing overhead).
Adapted from http://www.pixelbeat.org/programming/gcc/static_assert.html.
Note that this macro just discards error message, so error when building
is much less nice than with gcc's _Static_assert... But error log will
point to right place in code, so should still be OK.
This reverts commit d749320e3b.
It's possible the container struct is larger,
we could do sizeof checks that falls back to memmove
but rather avoid complicating things.
The issue was caused by SpinLock implementation in old pthreads we ar eusing on
Windows. Using newer one (2.10-rc) demonstrates same exact behavior. But likely
using own atomics and memory barrier based implementation solves the issue.
A bit annoying that we need to change such a core part of Blender just to make
specific CPU happy, but it's better to have artists happy on all computers.
There is no expected downsides of this change, but it is so called "works for
me" category. Let's see how it all goes.
