Now that we have a uniform consistent behavior in all our ID duplicate
funtions, we can easily factorize it greatly. Code gets cleaner,
smaller, and less error-prone.
Note that ultimately, this duplicate/deep copy behavior could be added
as a callback of IDTypeInfo.
We could also rethink the duplicate flags (some data, even some obdata,
like Lattice, are not coverred currently).
And so on. But at least code should now be much more easily maintainable
and extendable.
Main change from user side, besides that all pointers should now be
properly remapped to new IDs, is that linked objects are no longer
preserved when doing a full copy of scenes.
Will open a task to check whether we actually still want that behavior
(and re-code it in a more correct way then).
This is the main part of work done here, it aims at uniformizing and
sanitizing that 'deep copy' process for supported IDs (currently scenes,
collections and objects).
Note that there will be more follow up commits after that one, but this
should be the most risky and changing one.
Remove resetting of ID uuid session counter, it is not really needed
anymore, and not trivial to do this properly everytime.
Thanks @brecht for investigating this.
Surrounding includes with an 'extern "C"' block is not necessary anymore.
Also that made it harder to add any C++ code to some headers, or include headers
that have "optional" C++ code like `MEM_guardedalloc.h`.
I tested compilation on linux and windows (and got help from @LazyDodo).
If this still breaks compilation due to some linker error, the header containing
the symbol in question is probably missing an 'extern "C"' block.
Differential Revision: https://developer.blender.org/D7653
We need to re-generate a new session uuid for the UI-related data-blocks
that are kept across file reading, when load UI is disabled. Otherwise
there will be several IDs with same uuid, which is an ensured way to
crash in new undo code.
"session-wise" here mean while editing a same .blend file. So creating
or opening a new one will reset the uuid counter. This should avoid any
overflow in practice.
Only IDs added to Main database get an uuid, runtime-only ones are not
affected.
This is intended to provide undo with a way to find IDs across several
'memory realms' (undo speedup project).
No behavior change is expected from this commit itself.
Part of T60695.
Differential Revision: https://developer.blender.org/D7007
Instead of using anonymous booleans flags, also allows to keep the same
behavior in all cases, without needing special handling from calling
code for our beloved oddballs object proxies...
Even though we do not have much of those, this might change in the
future, and in any case having specific functions for this ID type in
generic `BKE_lib` area was really confusing.
