itkRLEImageConstIterator.h

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/*=========================================================================
 *
 *  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 itkRLEImageConstIterator_h
#define itkRLEImageConstIterator_h

#include "itkImage.h"
#include "itkImageConstIterator.h"
#include "itkImageConstIteratorWithIndex.h"
#include "itkImageConstIteratorWithOnlyIndex.h"
#include "itkImageRegionIterator.h"
#include "itkIndex.h"
#include "itkNumericTraits.h"
#include "itkRLEImage.h"

class MultiLabelMeshPipeline;

namespace itk
{
template< typename TPixel, unsigned int VImageDimension, typename CounterType >
class ImageConstIterator< RLEImage< TPixel, VImageDimension, CounterType > >
{
  friend class ::MultiLabelMeshPipeline;

public:
  using Self = ImageConstIterator;

  static constexpr unsigned int ImageIteratorDimension = VImageDimension;

  itkTypeMacroNoParent( ImageConstIterator );

  using ImageType = RLEImage< TPixel, VImageDimension, CounterType >;

  using RLLine = typename ImageType::RLLine;

  using BufferType = typename ImageType::BufferType;

  using BufferIterator = ImageRegionIterator< BufferType >;

  using IndexType = typename ImageType::IndexType;

  using IndexValueType = typename ImageType::IndexValueType;

  using SizeType = typename ImageType::SizeType;

  using OffsetType = typename ImageType::OffsetType;

  using RegionType = typename ImageType::RegionType;

  using InternalPixelType = typename ImageType::InternalPixelType;

  using PixelType = typename ImageType::PixelType;

  ImageConstIterator()
    : m_RunLengthLine(nullptr),
    m_Buffer( nullptr )
  {
    m_Image = nullptr;
    m_Index0 = 0;
    m_BeginIndex0 = 0;
    m_EndIndex0 = 0;
    m_RealIndex = 0;
    m_SegmentRemainder = 0;
  }

  virtual ~ImageConstIterator() {}

  ImageConstIterator( const Self& it )
    : m_Buffer( const_cast< ImageType * >( it.GetImage() )->GetBuffer() )
  {
    m_RunLengthLine = it.m_RunLengthLine;
    m_Image = it.m_Image; // copy the smart pointer
    m_Index0 = it.m_Index0;
    this->m_BI = it.m_BI;

    m_RealIndex = it.m_RealIndex;
    m_SegmentRemainder = it.m_SegmentRemainder;
    m_BeginIndex0 = it.m_BeginIndex0;
    m_EndIndex0 = it.m_EndIndex0;
  }

  ImageConstIterator( const ImageType* ptr, const RegionType& region )
    : m_Buffer( const_cast< ImageType * >( ptr )->GetBuffer() )
  {
    m_Image = ptr;
    SetRegion( region );
  }

  Self &
  operator=( const Self& it )
  {
    if ( this != &it )
      {
      m_Buffer = it.m_Buffer;
      m_RunLengthLine = it.m_RunLengthLine;
      m_Image = it.m_Image; // copy the smart pointer
      m_Index0 = it.m_Index0;
      m_BI = it.m_BI;

      m_RealIndex = it.m_RealIndex;
      m_SegmentRemainder = it.m_SegmentRemainder;
      m_BeginIndex0 = it.m_BeginIndex0;
      m_EndIndex0 = it.m_EndIndex0;
      }
    return *this;
  }

  virtual void
  SetRegion( const RegionType& region )
  {
    // m_Region = region;

    if ( region.GetNumberOfPixels() > 0 ) // If region is non-empty
      {
      const RegionType& bufferedRegion = m_Image->GetBufferedRegion();
      itkAssertOrThrowMacro( ( bufferedRegion.IsInside( region ) ),
        "Region " << region << " is outside of buffered region " << bufferedRegion );
      }

    m_BI = BufferIterator( m_Buffer, region.Slice( 0 ) );
    m_Index0 = region.GetIndex( 0 );
    m_BeginIndex0 = m_Index0 - m_Image->GetBufferedRegion().GetIndex( 0 );
    m_EndIndex0 = m_BeginIndex0 + region.GetSize( 0 );
    SetIndexInternal( m_BeginIndex0 ); // sets m_RealIndex and m_SegmentRemainder
  }

  static unsigned int
  GetImageIteratorDimension()
  {
    return VImageDimension;
  }

  bool
  operator!=( const Self& it ) const
  {
    return m_BI != it.m_BI || m_Index0 + m_BeginIndex0 != it.m_Index0 + it.m_BeginIndex0;
  }

  bool
  operator==( const Self& it ) const
  {
    return m_BI == it.m_BI && m_Index0 + m_BeginIndex0 == it.m_Index0 + it.m_BeginIndex0;
  }

  bool
  operator<=( const Self& it ) const
  {
    if ( m_BI < it.m_BI )
      {
      return true;
      }
    else if ( m_BI > it.m_BI )
      {
      return false;
      }
    return m_Index0 + m_BeginIndex0 <= it.m_Index0 + it.m_BeginIndex0;
  }

  bool
  operator<( const Self& it ) const
  {
    if ( m_BI < it.m_BI )
      {
      return true;
      }
    else if ( m_BI > it.m_BI )
      {
      return false;
      }
    return m_Index0 + m_BeginIndex0 < it.m_Index0 + it.m_BeginIndex0;
  }

  bool
  operator>=( const Self& it ) const
  {
    if ( m_BI > it.m_BI )
      {
      return true;
      }
    else if ( m_BI < it.m_BI )
      {
      return false;
      }
    return m_Index0 + m_BeginIndex0 >= it.m_Index0 + it.m_BeginIndex0;
  }

  bool
  operator>( const Self& it ) const
  {
    if ( m_BI > it.m_BI )
      {
      return true;
      }
    else if ( m_BI < it.m_BI )
      {
      return false;
      }
    return m_Index0 + m_BeginIndex0 > it.m_Index0 + it.m_BeginIndex0;
  }

  const IndexType
  GetIndex() const
  {
    IndexType indR( m_Image->GetBufferedRegion().GetIndex() );

    indR[0] += m_Index0;
    typename BufferType::IndexType bufInd = m_BI.GetIndex();
    for ( IndexValueType i = 1; i < VImageDimension; i++ )
      {
      indR[i] = bufInd[i - 1];
      }
    return indR;
  }

  virtual void
  SetIndex( const IndexType& ind )
  {
    typename BufferType::IndexType bufInd;
    for ( IndexValueType i = 1; i < VImageDimension; i++ )
      {
      bufInd[i - 1] = ind[i];
      }
    m_BI.SetIndex( bufInd );
    SetIndexInternal( ind[0] - m_Image->GetBufferedRegion().GetIndex( 0 ) );
  }

  const RegionType
  GetRegion() const
  {
    RegionType r;

    r.SetIndex( 0, m_BeginIndex0 + m_Image->GetBufferedRegion().GetIndex( 0 ) );
    r.SetSize( 0, m_EndIndex0 - m_BeginIndex0 );
    typename BufferType::RegionType ir = m_BI.GetRegion();
    for ( IndexValueType i = 1; i < VImageDimension; i++ )
      {
      r.SetIndex( i, ir.GetIndex( i - 1 ) );
      r.SetSize( i, ir.GetSize( i - 1 ) );
      }
    return r;
  }

  const ImageType *
  GetImage() const
  {
    return m_Image.GetPointer();
  }

  PixelType
  Get( void ) const
  {
    return Value();
  }

  const PixelType &
  Value( void ) const
  {
    RLLine& line = const_cast< Self * >( this )->m_BI.Value();

    return line[m_RealIndex].second;
  }

  void
  GoToBegin()
  {
    m_BI.GoToBegin();
    SetIndexInternal( m_BeginIndex0 );
  }

  void
  GoToEnd()
  {
    m_BI.GoToEnd();
    m_Index0 = m_BeginIndex0;
  }

  bool
  IsAtBegin( void ) const
  {
    return m_Index0 == m_BeginIndex0 && m_BI.IsAtBegin();
  }

  bool
  IsAtEnd( void ) const
  {
    return m_Index0 == m_BeginIndex0 && m_BI.IsAtEnd();
  }

protected: // made protected so other iterators can access
  virtual void
  SetIndexInternal( const IndexValueType ind0 )
  {
    m_Index0 = ind0;
    m_RunLengthLine = &m_BI.Value();

    CounterType t = 0;
    SizeValueType x = 0;
    for (; x < ( *m_RunLengthLine ).size(); x++ )
      {
      t += ( *m_RunLengthLine )[x].first;
      if ( t > m_Index0 )
        {
        break;
        }
      }
    m_RealIndex = x;
    m_SegmentRemainder = t - m_Index0;
  } // SetIndexInternal

  typename ImageType::ConstWeakPointer m_Image;

  IndexValueType m_Index0; // index into the RLLine

  const RLLine* m_RunLengthLine;

  mutable SizeValueType  m_RealIndex; // index into line's segment
  mutable IndexValueType m_SegmentRemainder; // how many pixels remain in current segment

  IndexValueType m_BeginIndex0; // index to first pixel in region in relation to buffer start
  IndexValueType m_EndIndex0; // index to one pixel past last pixel in region in relation to buffer start
  BufferIterator m_BI;        // iterator over internal buffer image

  typename BufferType::Pointer m_Buffer;
};

template< typename TPixel, unsigned int VImageDimension, typename CounterType >
class ImageConstIteratorWithIndex< RLEImage< TPixel, VImageDimension, CounterType > > :
  public ImageConstIterator< RLEImage< TPixel, VImageDimension, CounterType > >
{
// just inherit constructors

public:
  using ImageType = RLEImage< TPixel, VImageDimension, CounterType >;

  using RegionType = typename itk::ImageConstIterator< RLEImage< TPixel, VImageDimension, CounterType > >::RegionType;

  void
  GoToReverseBegin()
  {
    this->m_BI.GoToReverseBegin();
    this->m_Index0 = this->m_EndIndex0 - 1;
    SetIndexInternal( this->m_Index0 );
  }

  bool
  IsAtReverseEnd()
  {
    return this->m_BI.IsAtReverseEnd();
  }

  ImageConstIteratorWithIndex()
    : ImageConstIterator< ImageType >()
  {}

  ImageConstIteratorWithIndex( const ImageConstIteratorWithIndex& it )
  {
    ImageConstIterator< ImageType >::operator=( it );
  }

  ImageConstIteratorWithIndex( const ImageType* ptr, const RegionType& region )
    : ImageConstIterator< ImageType >( ptr, region )
  {}
}; // no additional implementation required

template< typename TPixel, unsigned int VImageDimension, typename CounterType >
class ImageConstIteratorWithOnlyIndex< RLEImage< TPixel, VImageDimension, CounterType > > :
  public ImageConstIteratorWithIndex< RLEImage< TPixel, VImageDimension, CounterType > >
{
// just inherit constructors

public:
  using ImageType = RLEImage< TPixel, VImageDimension, CounterType >;

  using RegionType = typename itk::ImageConstIterator< RLEImage< TPixel, VImageDimension, CounterType > >::RegionType;

  ImageConstIteratorWithOnlyIndex()
    : ImageConstIterator< ImageType >()
  {}

  ImageConstIteratorWithOnlyIndex( const ImageConstIteratorWithOnlyIndex& it )
  {
    ImageConstIterator< ImageType >::operator=( it );
  }

  ImageConstIteratorWithOnlyIndex( const ImageType* ptr, const RegionType& region )
    : ImageConstIterator< ImageType >( ptr, region )
  {}
}; // no additional implementation required
} // end namespace itk

#endif // itkRLEImageConstIterator_h