Blender Git Loki

Cycles: Actually implement work item functions for CPU

Didn't actually implement these yet, unfortunately we need to pass `kg` around
to a lot more functions for this.

Cycles: Fix atomics in split kernel after switching away from OpenCL atomics

Apparently Blender's atomics return the new value rather than the old value.

Mantaflow: Use Path objects instead of os.path.join()

File paths are passed into these functions, so convert passed path to pathlib.Path object to avoid internal/external conflicts. This should be easier to maintain and visually cleaner.

Reviewers: sebbas

Reviewed By: sebbas

Differential Revision: https://developer.blender.org/D2317

Merge remote-tracking branch 'refs/remotes/origin/blender-v2.78-release' into fracture_modifier

Conflicts:
source/blender/makesrna/intern/rna_modifier.c

Merge branch 'master' into cycles_split_kernel

Cycles: Add CPU split kernels

This adds all split kernels for CPU devices besides the `data_init` kernel
which still needs to be written for CPU. While the kernels build and load
properly they don't do anything yet.

Fixed glossy reflections and refractions for low roughness values and
cleaned up the code.

For low roughness values, the reflections had some strange behavior.

Merge branch 'master' into fluid-mantaflow

Cycles: Replace OpenCL atomic functions with own versions

Cycles: Replace OpenCL work item functions with own versions

Cycles: Rearrange split kernel code to move all logic out of OpenCL kernel files

We need all logic in a place that can be used when building for other devices
besides OpenCL. This leaves things a little messy at the moment, code
deduplication and general clean up can happen later.

Cycles: Add code to register kernel functions

Makes it easy to retrieve kernel functions for different architectures without
needing large ifdef chains everywhere.

Removed default values in setup functions and added extra functions for
GGX with fresnel.

Cycles: Add missing check for split kernel build error

Switched from uniform to cosine hemisphere sampling for the diffuse and
the sheen part.

Merge branch 'master' into cycles_split_kernel

Removed the color parameters from the diffuse and sheen shader and use
them as closure weights instead.

Cycles: Don't use guarded vector for statically initialized data

This will confuse hell of a guarded allocators because it is possible
to have allocation happened prior to Blender's guarded allocator is
fully initialized.

This was causing crashes and assert failures when running blender
with fully guarded memory allocator.

Cycles: Fix shadowing variable which also causes use of uninitialized variable

Was causing wrong aperture for panorama cameras.

Seems to be a regression in 371d357.

Fix: Grease Pencil palettes were missing a RNA path callback