Blender Git Loki

Add substeps, used when projecting onto surface to get accurate depth

Avoid divide by zero, comment when its OK

Changes needed for building on MSVC

Patch by Mano-Wii with minor edits

Option to use the surface as starting point for the stroke

Similar to grease pencil end-points, however this only works for the first point.

Uses a plane calculated from the surface normal (so lines can be drawn perpendicular to the surface).

Merge branch 'master' into temp-curve-draw

Use regions depth values in-place

Flip handle length check to catch nan values

Merge branch 'master' into temp-curve-draw

Math Lib: ray_point_factor_v3 functions

Gives a bit better precision than creating a line in some cases,
use for ED_view3d_win_to_3d.

Cycles: Resolve ridiculous amount of memory used by spatial split builder

This was only visible on systems with lots of threads and root of the issue
was that we've been pre-allocating too much memory for all the threads.

Now we only pre-allocate data for the main thread and rest of the threads
does allocation on-demand.

This brings down memory usage from 36Gig to 6.9Gig when building spatial
split for the Bunny.blend file on our Intel beast.

Originally regression was happened by the threaded spacial split builder
commit.

Work in progress, initial drawing on surface option

Tweak corner detection

Only consider points above the angle limit to begin with.

Add orig-index argument to map the output curve back to the input data.

Corner handle calculation could fail (for larger curves especially)

Replace this with an optional return array of corner indices on final output curve.

Change curve fitting not to store duplicate points.

Return an array of [handle, knot, handle]'s instead of [knot, handle, handle, knot].

Add curve/pressure option

Add doxygen headers

Initial cubic fitting, curve freehand drawing