DispatcherMapField was templated on the device adapter but it
actually doesn't need to be, only BasicInvoke and subsequent
methods need to be templated on the device.
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.
Previously there was a Connectivity* structure for both the control
environment and the execution environment. This was necessary before
because the connectivity is explicit to the from and to topology
elements, so you would get this structure from the appropriate call to
CellSet*. However, the symantics are changed so that the type of
connectivity is selected in the worklet's dispatcher. Thus, it is now
much cleaner to manage the CellSet structure in the CellSet class itself
and just have a single set of Connectivity* classes in the execution
environment.
Previously, the items used to identify parts of topology like points,
cells, faces, etc. were in an enumeration. However, they are only really
used in template specialization, and it is easier to use tags in this
case. So, change the enumeration to a set of tag structures. Also made
the following changes:
* Renamed TopologyType to TopologyElement, which is more indicative of
what we are referring to.
* Moved the structures from the vtkm::cont namespace to the vtkm
namespace. There is no reason not to be able to use them from either the
control or execution environments.
* Added a VTKM_IS_TOPOLOGY_ELEMENT_TAG macro to do type checks on
template arguments that are supposed to be topology element tags.
The Invoke of the topology dispatcher is also changed to expect a
concrete cell set (which the DynamicCellSet is automatically cast to)
rather than a connectivity structure. The dispatcher calls the
GetNodeToCellConnectivity method for you. (That is currently the only
one supported.)
