ExtractFaces

#include <vtkCellIterator.h>
#include <vtkCellTypes.h>
#include <vtkGenericCell.h>
#include <vtkPointSet.h>
#include <vtkXMLGenericDataObjectReader.h>

#include <iostream>
#include <map>
#include <string>

int main(int argc, char* argv[])
{
  std::map<std::string, int> cellMap;

  for (int arg = 1; arg < argc; ++arg)
  {
    auto reader = vtkSmartPointer<vtkXMLGenericDataObjectReader>::New();
    reader->SetFileName(argv[arg]);
    reader->Update();

    //    vtkPointSet *pointSet =
    //    vtkPointSet::SafeDownCast(reader->GetOutput());;
    vtkPointSet* pointSet = dynamic_cast<vtkPointSet*>(reader->GetOutput());
    ;
    auto it = pointSet->NewCellIterator();
    for (it->InitTraversal(); !it->IsDoneWithTraversal(); it->GoToNextCell())
    {
      auto cell = vtkSmartPointer<vtkGenericCell>::New();
      it->GetCell(cell);
      std::string cellName =
          vtkCellTypes::GetClassNameFromTypeId(cell->GetCellType());
      if (cellMap.count(cellName) == 0)
      {
        std::cout << "Type: " << cellName << " has " << cell->GetNumberOfFaces()
                  << " faces" << std::endl;
      }
      cellMap[cellName]++;
    }
    it->Delete();
  }
  for (auto itm = cellMap.begin(); itm != cellMap.end(); ++itm)
  {
    std::cout << itm->first << " occurs " << itm->second << " times"
              << std::endl;
  }

  return EXIT_SUCCESS;
}

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(ExtractFaces)

find_package(VTK COMPONENTS 
  CommonDataModel
  IOXML
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "ExtractFaces: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(ExtractFaces MACOSX_BUNDLE ExtractFaces.cxx )
  target_link_libraries(ExtractFaces PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS ExtractFaces
  MODULES ${VTK_LIBRARIES}
)

cd ExtractFaces/build

cmake ..

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

make

./ExtractFaces