The functors in the ForEach, StaticTransform, and DynamicTransform
methods sometimes can use the index of the parameter that they are
operating on. This can be a helpful diagnostic in compile and run-time
errors. It is also helpful when linking parameters from one
FunctionInterface with those of another.
This new features are now replacing implementations using the Zip
functionality that was removed earlier. The implementation is actually
simplified a bit.
When fixing a problem where the disabled test had left some unused
classes, which some compilers picked up on (SHA
eae8921dc714c9bdb12058db365f890425291ea2), I used a preprocessor wrapper
to enable/disable the code (mostly to preserve history). However, I
forgot to leave the code disabled. Disable that here.
There is a test that tries to determine that the Invoke methods in
FunctionInterface do not add an unreasonable overhead. However, this
test is unreliable. Also, the most critical performance hit would be in
invoking a worklet operation, but that is now done elsewhere anyway.
The zip capability allows you to parameter-wise combine two
FunctionInterface objects. The result is another FunctionInterface with
each parameter a Pair containing the respective values of the two
inputs.
Being able to zip allows you to do transforms and invokes on data that
is divided among multiple function interface objects.
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.
We have a test for FunctionInterface to make sure that calling a function
indirectly through that is about as fast as directly. On MSVC we sometimes
observe that this timing fails in debug mode. This is probably the compiler
adding some code to each function invocation. That won't happen in production
compiles, so we don't care about it too much. Make an exception in this case.
There is a special version of the testing methods for use in the control
environment that handles execeptions that can be thrown there. There are
tests to make sure you are using the correct version of the testing
framework, but it was broken until the last commit. Now that it's fixed,
here are two places where the wrong testing method was used.
This will allow a faster conversion than the dynamic transform and will
allow you to define compile-time types for transformation unlike dynamic
transform or invoke with transform.
The FunctionInterface class is a convienient way to wrap up a variable
number of arguments and pass them around templated interfaces without
requiring variadic template arguments. It also correctly hands return
arguments.
