`vtkm::VecFlat` is a wrapper around a `Vec`-like class that may be a
nested series of vectors. For example, if you run a gradient operation
on a vector field, you are probably going to get a `Vec` of `Vec`s that
looks something like `vtkm::Vec<vtkm::Vec<vtkm::Float32, 3>, 3>`. That
is fine, but what if you want to treat the result simply as a `Vec` of
size 9?
The `VecFlat` wrapper class allows you to do this. Simply place the
nested `Vec` as an argument to `VecFlat` and it will behave as a flat
`Vec` class. (In fact, `VecFlat` is a subclass of `Vec`.) The `VecFlat`
class can be copied to and from the nested `Vec` it is wrapping.
There is a `vtkm::make_VecFlat` convenience function that takes an
object and returns a `vtkm::VecFlat` wrapped around it.
Added a BaseComponentType to VecTraits that recursively finds the base
(non-Vec) type of a Vec. This is useful when dealing with potentially
nested Vec's (e.g. Vec<Vec<T, M>, N>) and you need to keep the structure
but know the base type.
Also added a couple of templates for keeping the structure but changing
the type. These are ReplaceComponentType and ReplaceBaseComponentType.
These allow you to create new Vec's with the same structure as the query
Vec but with differen component types.
These changes now allow VTK-m to compile on CUDA 7.5 by using const arrays,
when compiling with CUDA 8+ support we upgrade to static const arrays, and
lastly when CUDA is disabled we fully elevate to static constexpr.
If a global static array is declared with VTKM_EXEC_CONSTANT and the code
is compiled by nvcc (for multibackend code) then the array is only accesible
on the GPU. If for some reason a worklet fails on the cuda backend and it is
re-executed on any of the CPU backends, it will continue to fail.
We couldn't find a simple way to declare the array once and have it available
on both CPU and GPU. The approach we are using here is to declare the arrays
as static inside some "Get" function which is marked as VTKM_EXEC_CONT.
There are still some warnings left:
* Some text in markdown files are incorrectly picked up as
doxygen commands
* ArrayPortalTransform weirdly inherits from a specialized
version of itself. It's technically correct C++ code, but
gives doxygen fits.
Sandia National Laboratories recently changed management from the
Sandia Corporation to the National Technology & Engineering Solutions
of Sandia, LLC (NTESS). The copyright statements need to be updated
accordingly.
