All the other math functions are in the vtkm package. This one was in
vtkm::exec because it uses a callback method. This can be problematic on
CUDA the the declaration of NewtonsMethod does not match the callback
method. However, we now have a VTKM_SUPPRESS_EXEC_WARNINGS macro that
allows a VTKM_EXEC_CONT_EXPORT function (like NewtonsMethod) to call
either a VTKM_EXEC_EXPORT or VTKM_CONT_EXPORT without a warning.
There are several switch statements in ParametricCoordinates.h that have
a default clause that is an error condition. The code was simply calling
the RaiseError method on the worklet before quiting. Although the
behavior is supposed to be similar to throwing an exception, flow
actually does still continue. These error default clauses kept going
without breaking from the switch or initializing the variables the
method is supposed to set. Although the values should not matter once
the error is raised, I was getting compiler warnings about it. It's also
bad practice as certain NaN values can cause the program to signal out,
so it is best to set the data to something.
These cell types are inherited from VTK, but they are basically the same
as quad and hexahedron, respectively. The only useful difference is that
pixel and voxel are supposed to be axis aligned, but you cannot
determine that by the cell shape alone (at least not just from the cell
set).
A big issue with these is that their indexing is different that of quad
and hex. The development team had a long discussion about the benefits
of the alternate indexing, but after consulting with Berk Geveci and
Will Schroder from the VTK team, that indexing is not really taken
advantage of at the cell level. Thus, it is really just a nuisance in
VTK-m.
The original way was overconstrained with respect to the number of
parametric coordinates.
Also implemented WorldCoordinatesToParametricCoordinates for polygons.
The general polygon version is not implemented yet because I need to
change the way it is interpolated.
To get wedge to work correctly, I had to change the interpolation
slightly there. Previously the interpolation had a singularity at
the tip.
The functions for doing interpolations and derivatives were called
CellInterpolate and CellDerivative, but the file names were
Interpolate.h and Derivative. Now the files are CellInterpolate.h and
CellDerivative.h so they are more consistent and a bit easier to find.
The interpolate and derivative functions has the shape tag at end of the
function arguments (just before the "worklet" parameter, which is just
the error handling mechanism). However, the parametric coordinate
functions had the shape tag at the beginning. Moved the shape tag to the
end to be more consistent within these functions and also in other uses
throughtout VTK-m.
