SphinxExamples/src/Core/QuadEdgeMesh/ExtractVertexOnMeshBoundaries/Code.cxx

/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
 
#include "itkQuadEdgeMesh.h"
#include "itkVTKPolyDataReader.h"
#include "itkQuadEdgeMeshBoundaryEdgesMeshFunction.h"
 
int
main(int argc, char * argv[])
{
  if (argc != 2)
  {
    std::cerr << "Usage: " << argv[0] << " <InputFileName>" << std::endl;
    return EXIT_FAILURE;
  }
 
  constexpr unsigned int Dimension = 3;
  using CoordType = double;
 
  using MeshType = itk::QuadEdgeMesh<CoordType, Dimension>;
  using VTKReaderType = itk::VTKPolyDataReader<MeshType>;
 
  auto reader = VTKReaderType::New();
  reader->SetFileName(argv[1]);
 
  try
  {
    reader->Update();
  }
  catch (const itk::ExceptionObject & e)
  {
    std::cerr << e.what() << std::endl;
    return EXIT_FAILURE;
  }
 
  MeshType::Pointer mesh = reader->GetOutput();
 
  using BoundaryExtractorType = itk::QuadEdgeMeshBoundaryEdgesMeshFunction<MeshType>;
 
  auto extractor = BoundaryExtractorType::New();
 
  using MeshPointIdentifier = MeshType::PointIdentifier;
 
  using MeshQEType = MeshType::QEType;
  using MeshIteratorGeom = MeshQEType::IteratorGeom;
 
  using EdgeListType = MeshType::EdgeListType;
  using EdgeListPointer = MeshType::EdgeListPointerType;
  using EdgeListIterator = EdgeListType::iterator;
 
  EdgeListPointer list = extractor->Evaluate(*mesh);
 
  if (list->empty())
  {
    std::cerr << "There is no border on this mesh" << std::endl;
    return EXIT_FAILURE;
  }
 
  std::cout << "There are " << list->size() << " borders on this mesh" << std::endl;
 
  auto                   it = list->begin();
  const EdgeListIterator end = list->end();
 
  size_t i = 0;
  while (it != end)
  {
    std::cout << i << ": ";
 
    MeshIteratorGeom       eIt = (*it)->BeginGeomLnext();
    const MeshIteratorGeom eEnd = (*it)->EndGeomLnext();
 
    MeshPointIdentifier id = MeshType::m_NoPoint;
 
    while (eIt != eEnd)
    {
      MeshQEType * qe = eIt.Value();
 
      if (qe->GetOrigin() != id)
      {
        std::cout << qe->GetOrigin();
      }
 
      id = qe->GetDestination();
 
      std::cout << " -> " << id;
      ++eIt;
    }
 
    std::cout << std::endl;
 
    ++it;
  }
 
  return EXIT_SUCCESS;
}