itkSimplexMeshAdaptTopologyFilter.h

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/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkSimplexMeshAdaptTopologyFilter_h
#define itkSimplexMeshAdaptTopologyFilter_h
 
#include "itkPolygonCell.h"
#include "itkCellInterfaceVisitor.h"
 
#include "itkSimplexMesh.h"
#include "itkMeshToMeshFilter.h"
#include "itkVectorContainer.h"
 
#include "vxl_version.h"
#include "vnl/vnl_cross.h"
 
namespace itk
{
template <typename TInputMesh, typename TOutputMesh>
class ITK_TEMPLATE_EXPORT SimplexMeshAdaptTopologyFilter : public MeshToMeshFilter<TInputMesh, TOutputMesh>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(SimplexMeshAdaptTopologyFilter);

  using Self = SimplexMeshAdaptTopologyFilter;

  using Superclass = MeshToMeshFilter<TInputMesh, TOutputMesh>;

  using Pointer = SmartPointer<Self>;

  using ConstPointer = SmartPointer<const Self>;

  itkNewMacro(Self);

  itkOverrideGetNameOfClassMacro(SimplexMeshAdaptTopologyFilter);
 
  using InputMeshType = TInputMesh;
  using InputMeshPointer = typename InputMeshType::Pointer;
  using InputPointType = typename InputMeshType::PointType;
  using InputVectorType = typename InputMeshType::VectorType;
  using InputPixelType = typename InputMeshType::PixelType;
  using InputCellTraitsType = typename InputMeshType::MeshTraits::CellTraits;
  using InputCellType = typename InputMeshType::CellType;
  using PointIdentifier = typename InputMeshType::PointIdentifier;
  using CellIdentifier = typename InputMeshType::CellIdentifier;
  using InputCellPointIdIterator = typename InputCellType::PointIdIterator;
  using InputCellAutoPointer = typename InputCellType::CellAutoPointer;
  using CellAutoPointer = typename InputMeshType::CellAutoPointer;
  using InputPolygonType = itk::PolygonCell<InputCellType>;
  using InputPolygonPointIdIterator = typename InputPolygonType::PointIdIterator;
  using CovariantVectorType = CovariantVector<typename InputVectorType::ValueType, 3>;
  using OutputMeshType = TOutputMesh;
  using OutputMeshPointer = typename OutputMeshType::Pointer;
  using OutputCellType = typename OutputMeshType::CellType;
  using OutputPolygonType = itk::PolygonCell<OutputCellType>;
 
  using DoubleValueMapType = typename itk::MapContainer<CellIdentifier, double>;
  using DoubleContainerIterator = typename DoubleValueMapType::Iterator;

  class SimplexCellVisitor
  {
  public:
    InputMeshPointer                     mesh;
    double                               totalArea{ 0 };
    double                               totalCurvature{ 0 };
    double                               minCellSize;
    double                               maxCellSize{ 0 };
    typename DoubleValueMapType::Pointer areaMap;
    typename DoubleValueMapType::Pointer curvatureMap;
 
    double minCurvature;
    double maxCurvature{ 0 };
 
    SimplexCellVisitor()
      : minCellSize(NumericTraits<double>::max())
      , areaMap(DoubleValueMapType::New())
      , curvatureMap(DoubleValueMapType::New())
      , minCurvature(NumericTraits<double>::max())
 
    {}

    void
    Visit(CellIdentifier cellId, InputPolygonType * poly)
    {
      typename InputPolygonType::PointIdIterator it = poly->PointIdsBegin();
 
      double                meanCurvature = 0;
      const PointIdentifier refPoint = *it;
      double                val = mesh->GetMeanCurvature(*it++);
      meanCurvature += itk::Math::abs(val);
 
      PointIdentifier id1 = *it;
      val = mesh->GetMeanCurvature(*it++);
      meanCurvature += itk::Math::abs(val);
 
      double area = 0;
 
      int cnt = 0;
 
      while (it != poly->PointIdsEnd())
      {
        const PointIdentifier id2 = *it;
        area += ComputeArea(refPoint, id1, id2);
        id1 = id2;
        val = mesh->GetMeanCurvature(*it);
        meanCurvature += itk::Math::abs(val);
        ++cnt;
        ++it;
      }
 
      meanCurvature /= static_cast<double>(cnt);
      totalArea += area;
      totalCurvature += meanCurvature;
 
      areaMap->InsertElement(cellId, area);
      curvatureMap->InsertElement(cellId, meanCurvature);
 
      if (area > maxCellSize)
      {
        maxCellSize = area;
      }
      if (area < minCellSize)
      {
        minCellSize = area;
      }
      if (meanCurvature > maxCurvature)
      {
        maxCurvature = meanCurvature;
      }
      if (meanCurvature < minCurvature)
      {
        minCurvature = meanCurvature;
      }
    }
 
    double
    ComputeArea(PointIdentifier p1, PointIdentifier p2, PointIdentifier p3)
    {
      InputPointType v1{};
      InputPointType v2{};
      InputPointType v3{};
 
      mesh->GetPoint(p1, &v1);
      mesh->GetPoint(p2, &v2);
      mesh->GetPoint(p3, &v3);
      return itk::Math::abs(vnl_cross_3d((v2 - v1).GetVnlVector(), (v3 - v1).GetVnlVector()).two_norm() / 2.0);
    }
 
    typename DoubleValueMapType::Pointer
    GetAreaMap()
    {
      return areaMap;
    }
 
    typename DoubleValueMapType::Pointer
    GetCurvatureMap()
    {
      return curvatureMap;
    }
 
    double
    GetTotalMeshArea()
    {
      return totalArea;
    }
 
    double
    GetTotalMeanCurvature()
    {
      return totalCurvature / (curvatureMap->Size());
    }
 
    double
    GetMaximumCellSize()
    {
      return maxCellSize;
    }
 
    double
    GetMinimumCellSize()
    {
      return minCellSize;
    }
 
    double
    GetMaximumCurvature()
    {
      return maxCurvature;
    }
 
    double
    GetMinimumCurvature()
    {
      return minCurvature;
    }
  };
 
  // cell visitor stuff
  using SimplexVisitorInterfaceType =
    itk::CellInterfaceVisitorImplementation<InputPixelType, InputCellTraitsType, InputPolygonType, SimplexCellVisitor>;
 
  using SimplexVisitorInterfacePointer = typename SimplexVisitorInterfaceType::Pointer;
  using CellMultiVisitorType = typename InputCellType::MultiVisitor;
  using CellMultiVisitorPointer = typename CellMultiVisitorType::Pointer;
 
  itkSetMacro(Threshold, double);
  itkGetConstMacro(Threshold, double);
 
  itkSetMacro(SelectionMethod, int);
  itkGetConstMacro(SelectionMethod, int);
 
  itkGetConstMacro(ModifiedCount, int);
 
protected:
  SimplexMeshAdaptTopologyFilter();
  ~SimplexMeshAdaptTopologyFilter() override = default;
 
  void
  PrintSelf(std::ostream & os, Indent indent) const override;
 
  void
  GenerateData() override;

  void
  Initialize();

  void
  ComputeCellParameters();

  void
  CopyInputMeshToOutputMeshGeometryData();

  void
  ModifyNeighborCells(CellIdentifier id1, CellIdentifier id2, PointIdentifier insertPointId);

  InputPointType
  ComputeCellCenter(InputCellAutoPointer & simplexCell);

  CellIdentifier m_IdOffset{};

  double m_Threshold{ 0.5 };

  int m_SelectionMethod{ 0 };

  int m_ModifiedCount{ 0 };

  OutputMeshPointer m_Output{};
 
  InputCellAutoPointer m_NewSimplexCellPointer{};
};
} // namespace itk
 
#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkSimplexMeshAdaptTopologyFilter.hxx"
#endif
 
#endif // itkSimplexMeshAdaptTopologyFilter_h