Blender Git Loki

Project Paint: Add symmetry support

- Access from symmetry panel (as with sculpt)
- Supports multiple axis at once.
- Supports all brush types including clone.

Cleanup: const correctness

BLI_utildefines: add MEMSET_STRUCT_OFS macro

Cleanup: Move Cycles volume stack update for subsurface into kernel_volume.h.

Fix T44530 UV islands fail on subsurf after mirror modifier.

Caused by own commit that changed island detection code. In the case of
modifiers we don't want to take winding information into account, but
left the code since there are use cases (like painting) which could use
this.

Use gnu89 for GCC

GCC5 defaults to gnu11, which we may switch to later
but disable for now to prevent accidental use.

Fix for Clang type check

Added missing update tag to recalculate data after permutating materials

Cleanup: redundant checks

Add material slot reorder buttons

Cycles: Initialize portal variable directly, so we can avoid the one NULL check.

Math Lib: add range_vn_u

Cycles: Added support for light portals

This patch adds support for light portals: objects that help sampling the
environment light, therefore improving convergence. Using them tor other
lights in a unidirectional pathtracer is virtually useless.

The sampling is done with the area-preserving code already used for area lamps.
MIS is used both for combination of different portals and for combining portal-
and envmap-sampling.

The direction of portals is considered, they aren't used if the sampling point
is behind them.

Reviewers: sergey, dingto, #cycles

Reviewed By: dingto, #cycles

Subscribers: Lapineige, nutel, jtheninja, dsisco11, januz, vitorbalbio, candreacchio, TARDISMaker, lichtwerk, ace_dragon, marcog, mib2berlin, Tunge, lopataasdf, lordodin, sergey, dingto

Differential Revision: https://developer.blender.org/D1133

Cleanup: use strict flags

Cycles: Use native saturate function for CUDA

This more a workaround for CUDA optimizer which can't optimize clamp(x, 0, 1)
into a single instruction and uses 4 instructions instead.

Original patch by @lockal with own modification:

Don't make changes outside of the kernel. They don't make any difference
anyway and term saturate() has a bit different meaning outside of kernel.

This gives around 2% of speedup in Barcelona file, but in more complex shader
setups with lots of math nodes with clamping speedup could be much nicer.

Subscribers: dingto

Projects: #cycles

Differential Revision: https://developer.blender.org/D1224

BLI_array: add permute utility function

Usual UI messages fixes...

Fix double-free on copied Text compiled py-code

Fix T44464: Viewport mipmaps no longer toggle off

Cleanup: use bool for mipmap args