Blender Git Loki

Fix WITH_HEADLESS build.

Depsgraph: Fix missing relation from proxy_form's ID properties

Hopefully this will fix issue with camera rig where camera properties
(like, near/far clip) are driven by custom properties from bones, and
those bones are actually belong to proxied armature.

Fix build error with release + debug info build.

Fix assert for Image & Brush icon preview

Workbench: Add backface culling support

Basic Draw Engine: Cleanup unused code.

This engine is only used for selection and draw depth so no need for
anything else.

Also add backface culling support to selection.

Merge branch 'master' into blender2.8

Cleanup: Move 'WAVEFORM_LOADING' of sounds from flags to tags.

This is purely runtime data, so move it to new tags. ;)

Fix T55414: waveforms are reprocessed when undoing

Add new tag to bSound (runtime flags), and make read code to set a 'no
reload waveform' new tag, since it uses a mapping to get existing
waveform in undo case...

Make `draw_armature()` abort in case pose is not up-to-date.

Previously it was calling `BKE_pose_rebuild()`, such thing shall never
be called from drawing code! Hopefully this now works as expected and
that horrible hack is not needed anymore.

Fix T55973: [2.8] Crash when 'apply pose as rest pose' when bone scale is 0,0,0.

`BKE_pose_rebuild()` should (ideally) always trigger a rebuild of the
depsgraph, since it can add or remove posechannels.

This function now takes a Main parameter to ensure that related
depsgraphes are tagged as dirty (kept it optional, for some corner cases).

We should also probably double-check calls to that function, think in
theory it should only be called from depsgraph itself? But for now...

Subsurf: Add basic statistics to help benchmarking

Fix MSVC compilation error in a less hacky way

Fix compilation error with MSVC

Resolve the opposite vector ambiguity in Damped Track constraint.

Damped Track by specification attempts to arrive at the desired
direction via the shortest rotation. However with opposite vectors
there are infinitely many valid 180 degree rotations. Currently
it gives up and does nothing.

I think that it would be more reasonable to resolve the ambiguity
arbitrarily, so that Damped Track won't have a weird dead zone.
To make it more predictable I use a local axis.

In addition, the singularity area vicinity has some floating
point precision problems that result in significant jitter.
This applies workarounds for two causes of instability.

Differential Revision: https://developer.blender.org/D3530

Fix crash with previews of non-IDs, like pose library thumbnails.

GPU: Add GC to FBOs and UBOs and centralize all GCs

GPUFrameBuffers were being free when no context was attached or in the
wrong gl context. This make sure this does not happen again.

You can now safely free any gl resource from any thread (well as long as
it's not used anymore!).

Code cleanup and fixes

Subsurf: Fix wrong edge original index

Subsurf: Set original index for high-poly vertices