Also, allow applying to obdata those modifiers, even with shapekeys, but do not allow applying them *as* shapekey (as shapekeys do not have CD layers).
Fix [#29636] Vertex Weight Mix modifier "apply" button don't work.
Note: applying whit shape keys currently always uses base shape, not current one (for apply to obdata as well as apply to shapekey), but this is another topic...
Quite oddly, for Proximity mod, this increases the performances of the apply func (about 20-25%, e.g. from 0.04 to 0.03 sec), but decreases the global framerate (e.g. in TEST_5 scene of testing file, I lose about 7%, from 4.6 to 4.3fps (open ATI driver)...).
* Added some RNA tooltips, now that they are supported by dropdown lists.
* Fixed some RNA num properties UI steps.
* Fixed a memory leak in Proximity modifier (when dm of "target" object had to be created, it wasn’t freed...).
* Added an optional array of MDeformModifier pointers, to avoid another search based on defgrp_idx.
* Split out "add/remove verts from vgroup" functions, preparing their move to deform.c (if their current form is validated!).
- use 'const float *' and array size in some function declarations.
- replace macros for BLI_math functions INPF, VECCOPY, VECADD etc.
- remove unused VertRen.clip struct member.
- remove static squared_dist() from 2 files, replace with BLI_math function len_squared_v3v3().
- use vertex arrays for drawing clipping background in the 3D viewport.
*Updated UI code (replaced “row columns” by splits ;) ).
*Clamped global influence to [0.0, 1.0] range!
*Added/edited some tooltips for Proximity.
*Proximity distance mapping can now be reversed by entering Lowest Dist > Highest Dist.
*Moved mapping before masking in Proximity, much more sensible this way!
*Added Smooth/Sharp/Root/etc. mappings to WeightVGEdit modifier, in addition to custom curve one.
*Added Smooth/Sharp/Root/etc. mappings to WeightVGProximity modifier, without the custom curve one!
*Factorized the common mapping code into MOD_weightvg_util.
- was doing NULL checks on freeing memory in cases where the values were already accessed (blender would have crashed anyway), so remove the NULL checks.
- use deform.c api weight functions to replace inline weight lookups in some cases.
- change if checks in weightvg_do_mask() so its more obvious whats going on.
*Removed curve init code in readfile (no more needed since the split broke anyway compatibility with earlier WeightVGroup files…).
*Updated get_ob2ob_distance() code (much simpler – I’m not a matrices’ god!).
*Enhanced a few RNA names (Campbell has others in mind here, though, I think).
