Blender Git Loki

After editing hair, apply the changes back to the active hair shape key.

This makes shape keys for hair actually usable by completing basic edit
mode integration.

Apply hair shape keys to the particle base data when entering edit mode
and when switching the active key during edit mode.

This is different from how shape key editing works on meshes: there the
edit data (BMEditMesh) stores customdata layers for shape keys, then
writes them back to the mesh. The hair edit mode is a lot more messy and
confusing, it has to update the base data immeditately (with potential
consequences for undo ...)

Merge branch 'master' into gooseberry

Merge branch 'master' into gooseberry

Initialize new hair shape keys with data from the current particle keys.

Merge branch 'master' into gooseberry

Merge branch 'master' into gooseberry

Requiring COMPAT_ENGINES for particle panels is stupid.

Merge branch 'master' into gooseberry

Merge branch 'master' into gooseberry

Merge branch 'master' into gooseberry

Merge branch 'master' into gooseberry

Conflicts:
source/blender/makesdna/DNA_customdata_types.h

Experimental: random colors for child hulls.

Fix for invalid cache index -1 in some cases, like virtual parents.

The code was assuming that child 0 is always valid, but in fact has to
be treated like all others that can be disable due to preview percentage,
virtual parents, etc.

Use the particle system material for OpenGL drawing.

This is probably not correct yet, the code is terribly confusing ...

Implemented caps for the convex hair bundle hulls.

The current algorithm generates a triangle strip to fill the end of
each child bundle. This is not quite ideal, because even though the
base child groups are constructed to be convex, the resulting child
paths can become concave again by clumping, roughness, hair dynamics
etc.. This can create face inversion as well as ugly shading artifacts,
so a nicer algorithm may be desirable.

Only perform the inner loop over one group of connected paths in macros.

This allows more customized handling of path drawing in the outer loop
(needed for drawing end caps).

Nicer iterating over pairs of connected neighboring child paths.

Removed parent path drawing code for hulls, this is never used anyway.

Completed the convex hull calculation for child paths.

Parent index is only stored for hull children as a means of identifying
them in the drawing code.