Previously, the lifetimes of anonymous attributes were determined by
reference counts which were non-deterministic when multiple threads
are used. Now the lifetimes of anonymous attributes are handled
more explicitly and deterministically. This is a prerequisite for any kind
of caching, because caching the output of nodes that do things
non-deterministically and have "invisible inputs" (reference counts)
doesn't really work.
For more details for how deterministic lifetimes are achieved, see D16858.
No functional changes are expected. Small performance changes are expected
as well (within few percent, anything larger regressions should be reported as
bugs).
Differential Revision: https://developer.blender.org/D16858
* Support bidirectional type lookups. E.g. finding the base type of a
field was supported, but not the other way around. This also removes
the todo in `get_vector_type`. To achieve this, types have to be
registered up-front.
* Separate `CPPType` from other "type traits". For example, previously
`ValueOrFieldCPPType` adds additional behavior on top of `CPPType`.
Previously, it was a subclass, now it just contains a reference to the
`CPPType` it corresponds to. This follows the composition-over-inheritance
idea. This makes it easier to have self-contained "type traits" without
having to put everything into `CPPType`.
Differential Revision: https://developer.blender.org/D16479
Attribute copying often uses identical logic for copying selected
elements or copying with an index map. Instead of reimplementing
this in each file, use the common implementation in the array_utils
namespace. This makes the commonality more obvious, gives improved
performance (this implementation is multithreaded), reduces binary
size (I observed a 173KB reduction), and probably reduces compile time.
This makes instance handling more consistent with all the other geometry
component types. For example, `MeshComponent` contains a `Mesh *` and
now `InstancesComponent` has a `Instances *`.
Differential Revision: https://developer.blender.org/D16137
