Providing these types tends to "lock in" the precision of the algorithms
used in VTK-m. Since we are using templating anyway, our templates
should be generic enough to handle difference precision in the data.
Usually the appropriate type can be determined by the data provided. In
the case where there is no hint on the precision of data to use (for
example, in the code that provides coordinates for uniform data), there
is a vtkm::FloatDefault.
Since we want our code to generally handle data of different precision
(for example either float or double) expand the types in our list types
to include multiple precision.
After a talk with Robert Maynard, we decided to change the name
ArrayContainerControl to Storage. There are several reasons for this
change.
1. The name ArrayContainerControl is unwieldy. It is long, hard for
humans to parse, and makes for long lines and wraparound. It is also
hard to distinguish from other names like ArrayHandleFoo and
ArrayExecutionManager.
2. The word container is getting overloaded. For example, there is a
SimplePolymorphicContainer. Container is being used for an object that
literally acts like a container for data. This class really manages
data.
3. The data does not necessarily have to be on the control side.
Implicit containers store the data nowhere. Derivative containers might
have all the real data on the execution side. It is possible in the
future to have storage on the execution environment instead of the
control (think interfacing with a simulator on the GPU).
Storage is not a perfect word (what does implicit storage really mean?),
but its the best English word we came up with.
Each type of point coordinates has its own class with the name
PointCoordinates*. Currently there is a PointCoordiantesArray that contains
an ArrayHandle holding the point coordinates and a PointCoordinatesUniform
that takes the standard extent, origin, and spacing for a uniform rectilinear
grid and defines point coordiantes for that. Creating new PointCoordinates
arrays is pretty easy, and we will almost definitely add more. For example,
we should have an elevation version that takes uniform coordinates for
a 2D grid and then an elevation in the third dimension. We can probably
also use a basic composite point coordinates that can build them from
other coordinates.
There is also a DynamicPointCoordinates class that polymorphically stores
an instance of a PointCoordinates class. It has a CastAndCall method that
behaves like DynamicArrayHandle; it can call a functor with an array handle
(possible implicit) that holds the point coordinates.
