We have made several improvements to adding data into an `ArrayHandle`.
## Moving data from an `std::vector`
For numerous reasons, it is convenient to define data in a `std::vector`
and then wrap that into an `ArrayHandle`. It is often the case that an
`std::vector` is filled and then becomes unused once it is converted to an
`ArrayHandle`. In this case, what we really want is to pass the data off to
the `ArrayHandle` so that the `ArrayHandle` is now managing the data and
not the `std::vector`.
C++11 has a mechanism to do this: move semantics. You can now pass
variables to functions as an "rvalue" (right-hand value). When something is
passed as an rvalue, it can pull state out of that variable and move it
somewhere else. `std::vector` implements this movement so that an rvalue
can be moved to another `std::vector` without actually copying the data.
`make_ArrayHandle` now also takes advantage of this feature to move rvalue
`std::vector`s.
There is a special form of `make_ArrayHandle` named `make_ArrayHandleMove`
that takes an rvalue. There is also a special overload of
`make_ArrayHandle` itself that handles an rvalue `vector`. (However, using
the explicit move version is better if you want to make sure the data is
actually moved.)
## Make `ArrayHandle` from initalizer list
A common use case for using `std::vector` (particularly in our unit tests)
is to quickly add an initalizer list into an `ArrayHandle`. Now you can
by simply passing an initializer list to `make_ArrayHandle`.
## Deprecated `make_ArrayHandle` with default shallow copy
For historical reasons, passing an `std::vector` or a pointer to
`make_ArrayHandle` does a shallow copy (i.e. `CopyFlag` defaults to `Off`).
Although more efficient, this mode is inherintly unsafe, and making it the
default is asking for trouble.
To combat this, calling `make_ArrayHandle` without a copy flag is
deprecated. In this way, if you wish to do the faster but more unsafe
creation of an `ArrayHandle` you should explicitly express that.
This requried quite a few changes through the VTK-m source (particularly in
the tests).
## Similar changes to `Field`
`vtkm::cont::Field` has a `make_Field` helper function that is similar to
`make_ArrayHandle`. It also features the ability to create fields from
`std::vector`s and C arrays. It also likewise had the same unsafe behavior
by default of not copying from the source of the arrays.
That behavior has similarly been depreciated. You now have to specify a
copy flag.
The ability to construct a `Field` from an initializer list of values has
also been added.
We now use SumYAxis when executing with CUDA for better memory patterns.
Instead of using the heavy Pass4/Pass4WithNormals, CUDA now uses a
2 pass approach with the second pass outputting the normals and
coordinates using with significantly less warp divergence
First the Pass1 now uses WorkletVisitPointsWithCells as it is
faster since it doesn't compute some implicit boundary / neighborhood
info.
Second we reworked the logic around using `Fill` and a conditional
write of the edge case. The requirements of SMP when on a NUMA
machine is the complete opposite of what works great with CUDA.
Fixed error in one entry of number_of_triangles table for MarchineCells that results in missing triangles for wedge cell type as reported by issue #496.
91c56d680 Update Contour tests to be aware of flying edge output
1b256281f Convert contour worklet to expect isovalues to a std::vector
c2bab6c6b Introduce FlyingEdges for 3d structured datasets
1995e5204 Correct minor issues from refactoring MarchingCells worklets
d3512879d Remove unneeded template parameters from Gradient.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Kenneth Moreland <kmorel@sandia.gov>
Merge-request: !2005
The `ArrayHandleStreaming` class stems from an old research project
experimenting with bringing data from an `ArrayHandle` in parts and
overlapping device transfer and execution. It works, but only in very
limited contexts. Thus, it is not actually used today. Plus, the feature
requires global indexing to be permutated throughout the worklet
dispatching classes of VTK-m for no further reason.
Because it is not really used, there are other more promising approaches
on the horizon, and it makes further scheduling improvements difficult,
we are removing this functionality.
Marked the old versions of PrepareFor* that do not use tokens as
deprecated and moved all of the code to use the new versions that
require a token. This makes the scope of the execution object more
explicit so that it will be kept while in use and can potentially be
reclaimed afterward.