These changes are to make the bmesh api more consistent and easier to learn, grouping similar functions which is convenient for autocomplete.
This uses similar convention to RNA.
* use face/loop/edge/vert as a prefix for functions.
* use 'elem' as a prefix too for functions that can take any type with a BMHeader.
* changed from camel case to underscore separated (like RNA).
In fact, we have to add a CD_WEIGHT_MCOL layer (if not yet present) when updating CD_WEIGHT_MLOOPCOL, else with modifiers modifying the topology (like subsurf), it will sigsev.
That step should probably be done at tesselation time, though…
Also simplifies DM_update_weight_mcol: no need to update CD_WEIGHT_MCOL here, as it is anyway recreated from CD_WEIGHT_MLOOPCOL at tesselation time. Only commented out code for now.
User side:
* Preview for DynamicPaint should keep the same behavior (for now). Weight preview should be somawhat quicker, though.
* Preview for WeightVG modifiers is only active in WeightPaint mode, and if the affected vgroup is the active one.
* Last active preview modifier in stack wins!
Note: that modifier preview topic is yet to be further refined, quite raw/incomplete for now.
Dev side:
* In draw code, renamed DRAW_DYNAMIC_PAINT_PREVIEW flag to DRAW_MODIFIERS_PREVIEW
* Removed use of MOD_DPAINT_PREVIEW_READY in DynamicPaint code (seems unecessary, and if it was, should be of more general scope).
* Added eModifierTypeFlag_UsesPreview to ModifierTypeFlag, for modifiers that can generate some preview data.
* Added three new modifier funcs, to handle preview modifiers in draw code / mod stack.
* For weights preview: added the generic DM_update_weight_mcol func, which can update WEIGHT_MCOL layer with either a given array of weights (currently used by DynamicPaint only), or from current active vgroup(s).
So now, draw code is fully generic (i.e. no more modifier-type checking in it). Mod stack code is generic to some extent, but will need more work.
- made editbmesh_calc_modifiers() ensure tessfaces, this has the advantage that if the tessfaces are already created they wont get re-made as was happening before.
through Object.dm_info('SOURCE/DEFORM/FINAL')
this is to help tracking down issues with modifiers where loosing data
layers between modifiers can cause bugs, also to helo with comparing
bmesh/trunk's modifier stack.
- in the case of deform modifiers this is very safe (assuming the mods themselves dont need tessface data), since the DM is freed right after, so this is an easy speedup.
- in the case of bevel and split edge modifiers this should still work out fine since mods that need tessface data will generate it.
Quick shows over 2x speedup in my tests, will give bigger speedup with more vertex groups.
If you happen to have vertices with no faces using them - vertex colors will be calculated unnecessarily, but this isnt a common use case for weight paint mode.
