ENH: Add itk::PointSetBase as abstract base class of itk::PointSet

[N-Dekker]

Allows an algorithm to process the points of a PointSet object, without having to know its PixelType at compile-time. The algorithm may then just use a pointer or reference to its abstract base class, PointSetBase. Doing so may reduce the "code bloat" caused by template instantiations, and ease wrapping the algorithm for Python.

With this commit, its PixelType and its PointData container are still defined inside itk::PointSet, while the other properties (its points and its region information) are moved to its base class, PointSetBase.

[N-Dekker]

/azp run ITK.macOS.Python

[dzenanz]

still preferable to wrap the base class before the derived class

Yes.

[N-Dekker]

FYI, my intention is to pave the way for adding functions like SetFixedPointSet(const PointSetBaseType * pointSet) and SetMovingPointSet(const PointSetBaseType * pointSet) to the itk::ElastixRegistrationMethod of elastix. These functions might then support PointSet objects of any PixelType or PointData.

[dzenanz]

I was wondering what was the main purpose of this refactoring. 😄

[thewtex]

Awesome! 🚀

[N-Dekker]

Even though this PR successfully passed the CI, it now looks like it made ITK.Windows.Python unhappy! It says at https://open.cdash.org/viewBuildError.php?type=1&buildid=9948358

itkQuadEdgeMeshBase: warning(4): ITK type not wrapped, or currently not known: itk::PointSetBase< itk::MapContainer< unsigned long long, itk::QuadEdgeMeshPoint< float, 2, itk::GeometricalQuadEdge< unsigned long long, unsigned long long, bool, bool > > > >
itkQuadEdgeMeshBase: warning(4): ITK type not wrapped, or currently not known: itk::MapContainer< unsigned long long, itk::QuadEdgeMeshPoint< float, 2 > >
itkQuadEdgeMeshBase: warning(4): ITK type not wrapped, or currently not known: itk::QuadEdgeMeshPoint< float, 2 >

I tried to locally build ITK + Python wrapping, using VS2022, then I got:

------ Build started: Project: ITKQuadEdgeMeshPython, Configuration: Release x64 ------
Generating itkQuadEdgeMeshBasePython.cpp, ../../Generators/Python/itk/itkQuadEdgeMeshBasePython.py
Bin\ITK\Wrapping\Typedefs\itkQuadEdgeMeshBase.i(1220): warning 401: Nothing known about base class 'itk::PointSetBase< itk::MapContainer< unsigned long long,itk::QuadEdgeMeshPoint< float,2,itk::GeometricalQuadEdge< unsigned long long,unsigned long long,bool,bool > > > >'. Ignored.
Bin\ITK\Wrapping\Typedefs\itkQuadEdgeMeshBase.i(1220): warning 401: Maybe you forgot to instantiate 'itk::PointSetBase< itk::MapContainer< unsigned long long,itk::QuadEdgeMeshPoint< float,2,itk::GeometricalQuadEdge< unsigned long long,unsigned long long,bool,bool > > > >' using %template.
Bin\ITK\Wrapping\Typedefs\itkQuadEdgeMeshBase.i(1304): warning 401: Nothing known about base class 'itk::PointSetBase< itk::MapContainer< unsigned long long,itk::QuadEdgeMeshPoint< float,3,itk::GeometricalQuadEdge< unsigned long long,unsigned long long,bool,bool > > > >'. Ignored.
Bin\ITK\Wrapping\Typedefs\itkQuadEdgeMeshBase.i(1304): warning 401: Maybe you forgot to instantiate 'itk::PointSetBase< itk::MapContainer< unsigned long long,itk::QuadEdgeMeshPoint< float,3,itk::GeometricalQuadEdge< unsigned long long,unsigned long long,bool,bool > > > >' using %template.
C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Microsoft\VC\v170\Microsoft.CppCommon.targets(254,5): error MSB8066: Custom build for 'Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\itkQuadEdgeMeshBasePython.cpp.rule;Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\itkQuadEdgeMeshLineCellPython.cpp.rule;Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\itkQuadEdgeMeshPointPython.cpp.rule;Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\itkQuadEdgeMeshToQuadEdgeMeshFilterPython.cpp.rule;Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\itkQuadEdgeMeshTraitsPython.cpp.rule;Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\itkQuadEdgePython.cpp.rule;Bin\ITK\CMakeFiles\e1de2d8bd1732bb23f7a07883dd8477b\ITKQuadEdgeMeshPython.cpp.rule' exited with code 1.

Any idea?

Update: I think the itk::MapContainer< ${ITKT_IT}... should have been a itk::MapContainer< unsigned long long..., it isn't clear to me what ${ITKT_IT} evaluates to.

[dzenanz]

Isn't ITKT_IT specifier for IdentifierType, which should in turn be unsigned long long on MSVC?

[dzenanz]

After a quick look, nothing jumps out as wrong. Best way to debug this is to set up a local Python build, and then iteratively tweak the wrap file and build.

[N-Dekker]

Isn't ITKT_IT specifier for IdentifierType, which should in turn be unsigned long long on MSVC?

Thanks @dzenanz, looks like you're right 👍 I still wonder why itk::IdentifierType isn't just spelled out in the wrap files. "${ITKT_IT}" isn't very readable, is it?

[dzenanz]

All of those ITKT_IT-style specifiers are abbreviated. The list is here: https://itk.org/ITKSoftwareGuide/html/Book1/ITKSoftwareGuide-Book1ch9.html#x55-1520009.5

See also a PR which fixes ITKT_IT: InsightSoftwareConsortium/ITKSoftwareGuide#215

[N-Dekker]

Thanks @dzenanz I still find it hard to grasp all those ${ITKA_B}...${ITKY_Z} abbreviations, but maybe it's just me 🤷

[dzenanz]

I guess that PointSetBase should be wrapped with equivalent parameters to QuadEdgeMeshTraits. I guess it is not so right now?

[N-Dekker]

For every PointSet wrapping, there should be a PointSetBase wrapping. (But PointSetBase does not need as many wrappings as PointSet, because PointSetBase does not need to have a separate wrapping for each PixelType.)

[N-Dekker]

Should we also in this case use ${ITKT_F} instead of float? But then, is ${ITKT_F} anything more than just an "abbreviation" for float?

[thewtex]

@N-Dekker thanks for the follow-up.

Yes, this is likely related to the difference between the definition of itk::IdentifierType on Windows and other platforms. On Windows it resolves to unsigned long long to ensure 64-bit, on Unix unsigned long, which is already always 64-bit.