This is a start of moving the VTK-m User's Guide into the VTK-m source.
This is only the start of the process. There are several goals of this
work.
1. Integrate the documentation into the source code better to better
keep the code up to date.
2. Move the documentation over to Sphinx so that it can be posted online
and be more easily linked.
3. Incoporate Doxygen into the guide to keep the documentation
consistent.
4. Build the user guide examples as part of the VTK-m CI to catch
compatibility changes quickly.
Getting the number of components (or the number of flattened components)
from an `ArrayHandle` is usually trivial. However, if the `ArrayHandle` is
special in that the number of components is specified at runtime, then it
becomes much more difficult to determine.
Getting the number of components is most important when extracting
component arrays (or reconstructions using component arrays) with
`UnknownArrayHandle`. Previously, `UnknownArrayHandle` used a hack to get
the number of components, which mostly worked but broke down when wrapping
a runtime array inside another array such as `ArrayHandleView`.
To prevent this issue, the ability to get the number of components has been
added to `ArrayHandle` proper. All `Storage` objects for `ArrayHandle`s now
need a method named `GetNumberOfComponentsFlat`. The implementation of this
method is usually trivial. The `ArrayHandle` template now also provides a
`GetNumberOfComponentsFlat` method that gets this information from the
`Storage`. This provides an easy access point for the `UnknownArrayHandle`
to pull this information.
We have run into an issue with some Intel compilers where if a `union`
contains a `struct` that has some padding for byte alignment, the value
copy might skip over that padding even when the `union` contains a different
type where those bytes are valid. This breaks the value copy of our
`Variant` class.
This is not a unique problem. We have seen the same thing in other
compilers and already have a workaround for when this happens. The
workaround creates a special struct that has no padding placed at the front
of the `union`. The Intel compiler adds a fun twist in that this
placeholder structure only works if the alignment is at least as high as
the struct that follows it.
To get around this problem, make the alignment of the placeholder `struct`
at large as possible for the size of the `union`.
It was taking too long to compile with a device. Redesign the
placeholder to be simpler and compile faster.
In reflection, the `WarpScalar` filter is surprisingly a superset of the
`WarpVector` features. `WarpScalar` has the ability to displace in the
directions of the mesh normals. In VTK, there is a distinction of normals
to vectors, but in VTK-m it is a matter of selecting the correct one. As
such, it makes little sense to have two separate implementations for the
same operation. The filters have been combined and the interface names have
been generalized for general warping (e.g., "normal" or "vector" becomes
"direction").
In addition to consolidating the implementation, the `Warp` filter
implementation has been updated to use the modern features of VTK-m's
filter base classes. In particular, when the `Warp` filters were originally
implemented, the filter base classes did not support more than one active
scalar field, so filters like `Warp` had to manage multiple fields
themselves. The `FilterField` base class now allows specifying multiple,
indexed active fields, and the updated implementation uses this to manage
the input vectors and scalars.
The `Warp` filters have also been updated to directly support constant
vectors and scalars, which is common for `WarpScalar` and `WarpVector`,
respectively. Previously, to implement a constant field, you had to add a
field containing an `ArrayHandleConstant`. This is still supported, but an
easier method of just selecting constant vectors or scalars makes this
easier.
Internally, the implementation now uses tricks with extracting array
components to support many different array types (including
`ArrayHandleConstant`. This allows it to simultaneously interact with
coordinates, directions, and scalars without creating too many template
instances.
7992e1b6b Store constant AMR arrays with less memory
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Roxana Bujack <bujack@lanl.gov>
Merge-request: !3131
The `AmrArrays` filter generates some cell fields that specify information
about the hierarchy, which are constant across all cells in a partition.
These were previously stored as an array with the same value throughout.
Now, the field is stored as an `ArrayHandleConstant`, which does not
require any real storage. Recent changes to VTK-m allow code to extract the
array as a component efficiently without knowing the storage type.
Fixes#794
Previously, Clip was updated to remove unused points from the input.
This requires a re-mapping of point ids after compaction. This
re-mapping was missed for the points used for interpolation of centorid
points.
The flying edges algorithm (used when contouring uniform structured cell
sets) was not interpolating cell fields correctly. There was an indexing
issue where a shortcut in the stepping was not incrementing the cell index.
