Blender Git Loki

Ammend to rBea5326df86cb.

As suggested by @sergey, better use RECALC flag dedicated to pointcache.

Fix T58142: Crash when use Cycles to render stereoscopy

This is a quick workaround to prevent the crashes with multi-view.
The ultimate solution can be plenty, and would turn around refactoring
Cycles to handle multi-view internally, so that depsgraph could be freed
before render with no problems.

Reviewers: brecht, sergey

For the complete discussion check: https://developer.blender.org/D4239

Fix Freestyle (ASAN detected) crash

This was very simple to reproduce, just turn on Freestyle and press render.

Now to the truth of things. Most (if not all) of
~BlenderStrokeRenderer() can be removed. I believe this was done back
when freestyle was using G.main, and since we gave freestyle its own
main we can just leave the cleanup for later.

I will leave this for freestyle maintainers to think over though.

Note: There is a chance this was the issue reported on T57890. I will
wait for the reporter to confirm this as fixed though.

Fix T60783: (Certain) shapekeys stopped working in 2.8.

This commit adds another optional check (when `--debug-io` is set) on
write .blend process, to check and ensure all shape keys have their
'from' pointer properly set to their respective user ID.
This is intended to be used as debuging tool mostly (to try to detect
when/why some of those pointers can become NULL).

For now, it also systematically perform same checks/fixes when loading a
.blend file, to fix all broken ones laying around. Later we might move
that usage to a do_version instead, but for now think it's safer to
always perfom it (and it's rather cheap process anyway).

ShapeKey: add utils to say whether given ID type supports shapekeys.

Those kind of checks are handy to have for generic processing...

Cleanup: BLO: move validate code into own header.

Does not make sense to keep that with BLO_writefile.h, this can also be
used by read code, and some other parts of Blender (like ed_undo.c
currently)...

Fix T55462: Ungroup in Node editor crash Blender

If ID doesn't want to do user counting it shouldn't be in main.

Fix T60775: Stereo drawing in image editor broken (shows only right eye)

UI: Particles

Dupli Collection -> Instance Collection

UI: Particles. Open render type panels by default

Render-type panels are only shown when the relevant type is active anyway.
Saves a click especially when using object or collection as render, since
you _have_ to set an object or collection to use it.

UI: Particle. Remove unnecessary label for grid distribution

None of the other distribution modes have labels, and it's pretty clear
anyway since the fields below have the Grid word in them.

UI: Particles

Remove duplicate "Use Modifier Stack"

Fix T60204: Crash when opening a File

Missing code from 3d083f37. Need to ensure that ID properties
are properly allocated and restored on read.

Workbench: Depth Of Field: Optimisation

- Compute samples positions on CPU.
- Use 3x3 Box blur instead of 2x2.
- Implement bokeh parameters.

With this commit, dof performance is almost negligeable.
The quality is a bit lower than before but can be improve. Also now big
Circle of confusion are supported (up to 200px).
Cost is ~1.25ms on AMD Vega with a 2560p viewport than full HD and
pretty shallow depth of field.

Coc downsampling and dilation is not used anymore for now (commented).

Workbench: Depth Of Field: Initial Commit

The algorithm used is borrowed from :
http://tuxedolabs.blogspot.com/2018/05/bokeh-depth-of-field-in-single-pass.html

This makes it possible to have a decent blur for foreground over defocused
background in one pass only.

The algorithm is using a gather approach that is much faster
than the scatter approach used in Eevee. This makes it possible to have
custom bokeh shapes (not implemented yet) which would be impossible with
a separable gaussian technique.

The blur is done in 2 steps. The first one define the shape of the bokeh
and the second that fill the undersampling.

A downsample max-CoC tile texture speed up the gathering process.

T60745: GPU texture alloc failed when opening Preference Windows

Was generating INVALID_FRAMEBUFFER here instead of failled texture alloc.

Add safety asserts in gpu_texture.c and clamp minimum size to 1 inside
GPU_offscreen_create.

GP: Use Fill color when drawing strokes for no stroke materials

Artists requested to show the stroke while drawing a new stroke using a material with fill color only, because it's very difficult to see the stroke.

Now the stroke shows always but using the fill color, not the stroke color because maybe is not set.

Fix crash happening with hair step

The issue was caused by the hair step checking whether
particle system needs to have path cache. This was done
in a way which was traversing an entire scene and was
checking every object for particle instance modifier.

Ideally, path cache should be an own operation in the
dependency graph. Or at least, this flag should be set
by dependency graph builder, similar to curve's path.

Since the code was broken already (it was only checking
first particle instance modifier), it is easier to
remove the buggy code, solve the crash and move on for
now.

If this causes an issue, simply set particle system to
be rendered as path.

Fixes crash with playback of Spring scenes.

Fix texture paint accessing freed memory

Part of T60660

Correct last commit, wire xray is supported