text: /*=========================================================================
   *
   *  Copyright Insight Software Consortium
   *
   *  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
   *
   *         http://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 itkUpdateMalcolmSparseLevelSet_h
  #define itkUpdateMalcolmSparseLevelSet_h
  
  #include "itkImage.h"
  #include "itkDiscreteLevelSetImage.h"
  #include "itkMalcolmSparseLevelSetImage.h"
  #include "itkImageRegionIteratorWithIndex.h"
  #include "itkShapedNeighborhoodIterator.h"
  #include "itkNeighborhoodAlgorithm.h"
  #include "itkLabelMapToLabelImageFilter.h"
  #include "itkLabelImageToLabelMapFilter.h"
  
  namespace itk
  {
  /**
   *  \class UpdateMalcolmSparseLevelSet
   *  \brief Base class for updating the Malcolm representation of level-set function
   *
   *  \tparam VDimension Dimension of the input space
   *  \tparam TEquationContainer Container of the system of levelset equations
   *  \ingroup ITKLevelSetsv4
   */
  template< unsigned int VDimension,
            typename TEquationContainer >
  class ITK_TEMPLATE_EXPORT UpdateMalcolmSparseLevelSet : public Object
  {
  public:
    ITK_DISALLOW_COPY_AND_ASSIGN(UpdateMalcolmSparseLevelSet);
  
    using Self = UpdateMalcolmSparseLevelSet;
    using Pointer = SmartPointer< Self >;
    using ConstPointer = SmartPointer< const Self >;
    using Superclass = Object;
  
    /** Method for creation through object factory */
    itkNewMacro( Self );
  
    /** Run-time type information */
    itkTypeMacro( UpdateMalcolmSparseLevelSet, Object );
  
    static constexpr unsigned int ImageDimension = VDimension;
  
    using LevelSetType = MalcolmSparseLevelSetImage< ImageDimension >;
    using LevelSetPointer = typename LevelSetType::Pointer;
    using LevelSetInputType = typename LevelSetType::InputType;
    using LevelSetOutputType = typename LevelSetType::OutputType;
    using LevelSetOffsetType = typename LevelSetType::OffsetType;
  
    using LevelSetLabelMapType = typename LevelSetType::LabelMapType;
    using LevelSetLabelMapPointer = typename LevelSetType::LabelMapPointer;
  
    using LevelSetLabelObjectType = typename LevelSetType::LabelObjectType;
    using LevelSetLabelObjectPointer = typename LevelSetType::LabelObjectPointer;
    using LevelSetLabelObjectLengthType = typename LevelSetType::LabelObjectLengthType;
    using LevelSetLabelObjectLineType = typename LevelSetType::LabelObjectLineType;
  
    using LevelSetLayerType = typename LevelSetType::LayerType;
    using LevelSetLayerIterator = typename LevelSetType::LayerIterator;
    using LevelSetLayerConstIterator = typename LevelSetType::LayerConstIterator;
    using LevelSetOutputRealType = typename LevelSetType::OutputRealType;
  
    using LevelSetLayerMapType = typename LevelSetType::LayerMapType;
    using LevelSetLayerMapIterator = typename LevelSetType::LayerMapIterator;
    using LevelSetLayerMapConstIterator = typename LevelSetType::LayerMapConstIterator;
  
    using EquationContainerType = TEquationContainer;
    using EquationContainerPointer = typename EquationContainerType::Pointer;
    using TermContainerPointer = typename EquationContainerType::TermContainerPointer;
  
    itkGetModifiableObjectMacro(OutputLevelSet, LevelSetType );
  
    /** Update function for initializing and computing the output level set */
    void Update();
  
    /** Set/Get the sparse levet set image */
    itkSetObjectMacro( InputLevelSet, LevelSetType );
    itkGetModifiableObjectMacro(InputLevelSet, LevelSetType );
  
    /** Set/Get the RMS change for the update */
    itkGetMacro( RMSChangeAccumulator, LevelSetOutputRealType );
  
    /** Set/Get the Equation container for computing the update */
    itkSetObjectMacro( EquationContainer, EquationContainerType );
    itkGetModifiableObjectMacro(EquationContainer, EquationContainerType );
  
    /** Set/Get the current level set id */
    itkSetMacro( CurrentLevelSetId, IdentifierType );
    itkGetMacro( CurrentLevelSetId, IdentifierType );
  
  protected:
    UpdateMalcolmSparseLevelSet();
    ~UpdateMalcolmSparseLevelSet() override;
  
    // output
    LevelSetPointer   m_OutputLevelSet;
  
    LevelSetLayerType m_Update;
  
    IdentifierType           m_CurrentLevelSetId;
    LevelSetOutputRealType   m_RMSChangeAccumulator;
    EquationContainerPointer m_EquationContainer;
  
    using LabelImageType = Image< int8_t, ImageDimension >;
    using LabelImagePointer = typename LabelImageType::Pointer;
  
    LabelImagePointer m_InternalImage;
  
    using NeighborhoodIteratorType = ShapedNeighborhoodIterator< LabelImageType >;
  
    bool m_IsUsingUnPhasedPropagation;
  
    /** Compute the updates for all points in the 0 layer and store in UpdateContainer */
    void FillUpdateContainer();
  
    /** Update the zero layer for all points with values stored in UpdateContainer
     *  Move points to -1 or +1 layers */
    void EvolveWithUnPhasedPropagation();
  
    /** Update separately the zero layer for points with positive/negative update values
     *  Move points to -1 or +1 layers */
    void EvolveWithPhasedPropagation( LevelSetLayerType& ioList,
                                      LevelSetLayerType& ioUpdate,
                                      const bool& iContraction );
  
    /** Make sure the layers are of single pixel thickness only. This method is related
      to the minimal interface function described in the original paper. */
    void CompactLayersToSinglePixelThickness();
  
  private:
    // input
    LevelSetPointer   m_InputLevelSet;
  
    LevelSetOffsetType m_Offset;
  
    using NodePairType = std::pair< LevelSetInputType, LevelSetOutputType >;
  
  };
  }
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkUpdateMalcolmSparseLevelSet.hxx"
  #endif
  
  #endif // itkUpdateMalcolmSparseLevelSet_h
  