The tetrahedralize algorithms have been changed to use the Scatter
classes to build indices rather than build them on their own.
To implement this efficiently with structured grids, a new ScatterUniform
class was made. I also added a new execution argument tag that allows
you to get the thread indices object from within the worklet.
This now allows for even more efficient construction of uniform point
coordinates when running under the 3d scheduler, since we don't need to go
from 3d index to flat index to 3d index, instead we stay in 3d index
Previously, all Fetch objects received an Invocation object in their
Load and Store methods. The point of this was that it allowed the Fetch
to get data from any of the execution objects. However, every Fetch
either just got data directly from its associated execution object or
else used a secondary execution object (the input domain) to get indices
into their own execution object.
This left two potential areas for improvement. First, pulling data out
of the Invocation object was unnecessarily complicated. It would be much
nicer to get data directly from the associated execution object. Second,
when getting index information from the input domain, it was often the
case that extra computations were necessary (particularly on structured
cell sets). There was no way to share the index information among
Fetches, and therefore the computations were replicated.
This change removes the Invocation from the Fetch Load and Store.
Instead, it passes the associated execution object and a new object type
called the ThreadIndices. The ThreadIndices are customized for the input
domain and therefore have all the information needed for a redirected
lookup. It is also a thread-local object so it can cache computed
indices and save on computation time.
This change removes the requirement to specify some maximum cell length
in each of the worklets, which is basically impossible. It also makes
some of the loading more lazy, which might help reduce the number of
registers required in a worklet.
Previously, all arrays passed to worklets were designated as either
input or output. No in-place operation was permitted. This change adds
the FieldInOut tag for ControlSignature in both WorkletMapField and
WorkletMapTopology that allows you to read and write from the same
array.
In the CellSet and related classes, a connection was referred to by a
"from" topology element and a "to" topology element. However, in the
worklet control signature tags the elements were referred to by "src"
and "dest." To make things consistent, use "from" and "to" everywhere.
Most of VTK-m follows the convention of calling the 0D topology elements
"points" (which follows the convention of VTK). However, there were
several places where they were referred to as "nodes." Make things
consistent by calling them points everywhere.
Also merged some redundant ExecutionSignature tags.
