Blender Git Loki

Draw Manager: cleanup, use doxy categories

Also add DRW_state for accessing current draw state.

Draw Manager: use engine drawing for depth drawing

View3D: move depth drawing into own function

No functional changes

Merge branch 'master' into 28

Merge commit 'master@6ed15c5a41130b55cb57a43a8a9470a91d38c3d5' into blender2.8

# Conflicts:
# source/blender/alembic/intern/abc_exporter.cc

Cycles: Allow samples to finish in split kernel to avoid artifacts when canceling

Previously canceling a render done by the split kernel could cause artifacts
such as very bright or dark tiles. This was caused by unfinished samples
being included in the output buffer. To avoid this we now wait till all the
currently rendering samples have finished, up to a limit of twice the
expected time for them to finish (currently this is no more than 20 seconds,
but usually its much less). If samples still haven't finished by then we
stop anyways in case there's an endless loop occurring.

Cycles: Change OpenCL split kernel to use single program by default

Single program builds twice as fast as multi programs, so its better for
users to have it as the default.

Cycles: Enable Correlated Multi Jitter for OpenCL and split kernel

Testing showed no issues so there's no reason to not have this.

[msvc/make.bat] Provide a convenience rebuild.cmd in the build folder for easy rebuilds.

Move depth select loop into its own function

Useful for splitting out draw logic in 2.8x

Cycles: Fix over-allocation of triangles storage for triangle primitive hair

Was also causing some bad memory access caused by read data from non-initialized
arrays.

Repoted by bzztploink in IRC, thanks!

Fix race condition invalidating object data's bounding box

Ensure task scheduler exists before any threading starts in Blender

Avoid race condition copying Scene for off-thread OpenGL image save

User preferences: Use checkbox for Cycles device selection

It was totally unclear whether the device is enabled or disabled.
Lots of people got fully lost in the current interface.

While the solution is not fully ideal, it is at least solves
ambiguity in the interface.

Threading: Remove thread lock which seems useless

Render data is never guarded by image drawe lock.

Alembic export: support simple child hairs (Fix T51144)

Simple child hairs don't have a face index number assigned, so the
call to dm->getTessFaceData(dm, num, CD_MFACE) would cause a crash. To
work around this, UV and normal vectors are copied from the parent
hair.

I've also removed an unnecessary call to dm->getTessFaceArray(dm);

Reviewers: kevindietrich

Differential Revision: https://developer.blender.org/D2638

Alembic: fixed indentation

Alembic: fixed memory leaks

Alembic: fixed refcount issue when duplicating imported objects

Duplicating an imported object didn't increment the cache reader's refcount,
whereas removing the duplicate did decrement it. This caused problems.