The contents of the ModifierEvalContext struct are constant while iterating
over the modifier stack. The struct thus should be only created once, outside
any loop over the modifiers.
This commit introduces `EditMeshData`. The fields in this struct are
extracted from `EditDerivedBMesh` into their own struct `EditMeshData`,
which can then also be used by the `Mesh` struct. This allows passing
deformed vertices efficiently to the draw routines.
The modifier code constructs a new Mesh instead of writing to ob->data;
even when ob->data is a CoW copy, it can still be used by different
objects and thus shouldn't be modified by a modifier.
Makes the follow changes:
- Add new `deform*` and `apply*` function pointers to `ModifierTypeInfo` that take `Mesh`, and rename the old functions to indicate that they take `DerivedMesh`. These new functions are currently set to `NULL` for all modifiers.
- Add wrapper `modifier_deform*` and `modifier_apply*` functions in two variants: one that works with `Mesh` and the other which works with `DerivedMesh` that is named with `*_DM_depercated`. These functions check which type of data the modifier supports and converts if necessary
- Update the rest of Blender to be aware and make use of these new functions
The goal of these changes is to make it possible to port to using `Mesh` incrementally without ever needing to enter into a state where modifiers don't work. After everything has been ported over the old functions and wrappers could be removed.
Reviewers: campbellbarton, sergey, mont29
Subscribers: sybren
Tags: #bf_blender_2.8
Differential Revision: https://developer.blender.org/D3155
We use 'reference' to designate the linked ID which is being overridden
by the local one, so using 'reference' to designate the stored local ID
in apply RNA code was... not a good idea. ;)
Actions shouldn't be copying by new library management code.
Or at least should be possible to make it to not copy actions
or do unneeded user management.
This way we avoid modification of original data which could
and does cause threading conflict with copy-on-write which
could be happening for viewport.
Skip access to any evaluated data when operator is run on file load,
we don't have depsgraph evaluated yet. In this case we skip part of
sculpt session initialization, since it will be done during depsgraph
evaluation which happens after DEG_on_visible_update().
We can not skip sculpt session initialization since during normal
operation we want all the data to be initialized on mode change,
and not on initial brush stroke.
