This also renames `MutableArrayRef` to `MutableSpan`.
The name "Span" works better, because `std::span` will provide
similar functionality in C++20. Furthermore, a shorter, more
concise name for a common data structure is nice.
The current particle state is stored in a `CustomData` instance and
the cache is stored in `PointCache`.
The current state exists on the copy-on-write copies of the simulation,
while the cache only exists in the original data block.
This patch implements a temporary trivial particle simulation that does not
use the node system yet. It is used for testing and will be replaced soon.
`PointCache` still has some limitations that need to be overcome using
separate refactorings. For example, we need to be able to store the number
of particles in the point cache. Also we need to change which attributes
are stored for a particle system more dynamically than is currently possible afaik.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D7836
For now the "Simulation" modifier only exists for point cloud objects, because
we need this for the particle system. Right now, the modifier is doing nothing.
There is a new `DEG_add_simulation_relation` function that is used
by the modifier to make sure that the simulation is evaluated before
the modifier is executed.
Reviewers: brecht, sergey
Differential Revision: https://developer.blender.org/D7549
This adds an embedded node tree to the simulation data block dna.
The UI in the `Simulation Editor` has been updated to show a list
of simulation data blocks, instead of individual node trees.
The new `SpaceNodeEditor.simulation` property wraps the existing
`SpaceNodeEditor.id` property. It allows scripts to get and set
the simulation data block that is being edited.
Reviewers: brecht, mont29
Differential Revision: https://developer.blender.org/D7301
This data block will be the container for simulation node trees.
It will be used for the new particle node system (T73324).
The new data block has the type `ID_SIM`.
It is not visible to users and other developers by default yet.
To enable it, activate the cmake option `WITH_NEW_SIMULATION_TYPE`.
New simulation data blocks can be created by running `bpy.data.simulations.new("name")`.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D7225
