Blender Git Loki

Simple infrastructure for registering particle modifier types, similar
to type registration of mesh modifiers.

Use the final hair state also as simulation input/output in hair sim.

Update the world space location of final hair keys after applying
modifiers.

Depsgraph: Fix previous workaround for driving bone by itself

- No relations needs to be added in this case at all
- COver RNA paths now as well

minor tweaks

- shorten text for message (no need to be toooo polite :) )
- use_center_bounds (matches Poly.calc_center_bounds)

Moved main shapekey evaluation for hair keys from the path caching
function to the new hair modifier evaluation.

This mirrors how shapekeys are treated as a "virtual" modifier at the
beginning of mesh modifier stack eval.

Depsgrpah: Adding/removing drivers should tag relations for update

TODO: There are more places to ensure proper relations, plus animation is
also to be checked.

Depsgraph: Use DEBUG_PRINTF for IK chain debug prints

Depsgraph: Avoid dependency cycle when driver is applied n the bone and uses same bone as target

This is more like a workaround and need much deeper re-consideration to support IK chains and so.

At least now we've got this noted in the code.

Fix for unfreed duplicated hair key arrays when the number of hair keys
stays the same.

Use the final hair state instead of the initial state for constructing
paths.

Enum for particle system flags instead of old-school #defines.

Reset function for the final hair state before calculating hair dynamics
and paths.

The integration with modifiers is still undefined: While it would be
nicer to have regular modifiers work on hair state as well, it is
probably not feasible with the current particle system, because all
these steps happen in a single update function. For integrating with
the modifier stack we would have to allow splitting this process into
individual parts, which is just not possible.

Added a second hair data layer to store modifier results.

This imitates the DerivedMesh principle from meshes. For hair the
modifiers will get the grooming or original growth result as input.
The result of the modifier eval will be written to the new data layer,
making a simple copy if modifiers are not used. Physics sim, rendering
and (depending of settings) drawing will then use the modified grooming
data.

Merge branch 'master' into gooseberry

Merge branch 'master' into gooseberry

cleanup: style

Depsgraph: Correction for depsgraph rebuild

Make sure tags are not getting lost after graph rebuild.

Merge branch 'master' into temp_custom_loop_normals

Fix for unfreed effector weights in hair dynamics.

The internal cloth modifier effector weights get replaced temporarily
to make the cloth sim use the particle weight settings instead. But
the particle sim was not putting back the original weights, which can be
non-NULL in case the cloth sim allocated these already. Messy design ...