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 itkChainCodePath_h
  #define itkChainCodePath_h
  
  #include "itkPath.h"
  #include "itkOffset.h"
  #include "itkObjectFactory.h"
  
  #include <vector>
  
  namespace itk
  {
  /** \class ChainCodePath
   * \brief  Represent a path as a sequence of connected image index offsets
   *
   * This class is intended to represent sequences of connected indices in an
   * image.  It does so by storing the offset of each index from its immediately
   * preceding, connected, index.  The only image index stored directly is that
   * of the first index.  ChainCodePath maps a 1D integer input (step number) to
   * an ND integer output (either an offset or an image index, depending on
   * whether Evaluate or EvaluateToIndex is called).
   *
   * \sa ChainCodePath2D
   * \sa ParametricPath
   * \sa Path
   * \sa Index
   * \sa Offset
   *
   * \ingroup PathObjects
   * \ingroup ITKPath
   */
  template< unsigned int VDimension >
  class ITK_TEMPLATE_EXPORT ChainCodePath:public
    Path< unsigned int, Offset< VDimension >, VDimension >
  {
  public:
    /** Dimension underlying input image. */
    itkStaticConstMacro(Dimension, unsigned int, VDimension);
  
    /** Standard class typedefs. */
    typedef ChainCodePath< VDimension >                            Self;
    typedef Path< unsigned int, Offset< VDimension >, VDimension > Superclass;
  
    typedef SmartPointer< Self >       Pointer;
    typedef SmartPointer< const Self > ConstPointer;
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(ChainCodePath, Path);
  
    /** OutputType typedef support. */
    typedef typename Superclass::OutputType OutputType;
    typedef typename Superclass::InputType  InputType;
  
    /** The output type of this function is an Index */
    typedef OutputType          OffsetType;
    typedef Index< VDimension > IndexType;
  
    typedef std::vector< OffsetType > ChainCodeType;
  
    typedef typename ChainCodeType::size_type ChainCodeSizeType;
  
    // Functions inherited from Path
  
    /** Evaluate the chaincode for the offset at the specified path-position. */
    virtual OutputType Evaluate(const InputType & input) const ITK_OVERRIDE
    {
      return m_Chain[input];
    }
  
    /** Like Evaluate(), but returns the index at the specified path-position. */
    virtual IndexType EvaluateToIndex(const InputType & input) const ITK_OVERRIDE;
  
    /** Increment the input variable passed by reference and then return the
     * offset stored at the new path-position.  If the chaincode is unable to be
     * incremented, input is not changed and an offset of zero is returned, which
     * may be used to check for the end of the chain code. */
    virtual OffsetType IncrementInput(InputType & input) const ITK_OVERRIDE;
  
    /** Where does the path end (what is the last valid input value)? */
    virtual InputType EndOfInput() const ITK_OVERRIDE
    {
      return static_cast<InputType>(NumberOfSteps());  // 0 is before the first step, 1 is after it
    }
  
    /** New() method for dynamic construction */
    itkNewMacro(Self);
  
    /** Set/Get the index associated with the initial position of the path */
    itkSetMacro(Start, IndexType);
    itkGetConstReferenceMacro(Start, IndexType);
  
    /** Insert a new step into the chaincode at a specified position */
    virtual inline void InsertStep(InputType position, OffsetType step)
    {
      m_Chain.insert(m_Chain.begin() + position, step);
      this->Modified();
    }
  
    /** Change the direction of a step in the chaincode */
    virtual inline void ChangeStep(InputType position, OffsetType step)
    {
      m_Chain[position] = step;
      this->Modified();
    }
  
    /** Remove all steps from the chain code */
    virtual inline void Clear()
    {
      m_Chain.clear();
      this->Modified();
    }
  
    /** How many steps in the chaincode? */
    virtual inline ChainCodeSizeType NumberOfSteps() const
    {
      return m_Chain.size();
    }
  
    /** Needed for Pipelining */
    virtual void Initialize(void) ITK_OVERRIDE
    {
      m_Start = this->GetZeroIndex();
      this->Clear();
    }
  
  protected:
    ChainCodePath();
    ~ChainCodePath() {}
    void PrintSelf(std::ostream & os, Indent indent) const ITK_OVERRIDE;
  
  private:
    ITK_DISALLOW_COPY_AND_ASSIGN(ChainCodePath);
  
    IndexType     m_Start;            // origin image index for the path
    ChainCodeType m_Chain;            // the chain code (vector of offsets)
  };
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkChainCodePath.hxx"
  #endif
  
  #endif
  