itkImageRandomConstIteratorWithOnlyIndex.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 itkImageRandomConstIteratorWithOnlyIndex_h
#define itkImageRandomConstIteratorWithOnlyIndex_h
 
#include "itkImageConstIteratorWithOnlyIndex.h"
#include "itkMersenneTwisterRandomVariateGenerator.h"
#include <type_traits> // For remove_const_t.
 
namespace itk
{
template <typename TImage>
class ITK_TEMPLATE_EXPORT ImageRandomConstIteratorWithOnlyIndex : public ImageConstIteratorWithOnlyIndex<TImage>
{
public:
  using Self = ImageRandomConstIteratorWithOnlyIndex;
  using Superclass = ImageConstIteratorWithOnlyIndex<TImage>;

  using typename Superclass::IndexType;
  using typename Superclass::SizeType;
  using typename Superclass::OffsetType;
  using typename Superclass::RegionType;
  using typename Superclass::ImageType;
  using typename Superclass::IndexValueType;
  using typename Superclass::OffsetValueType;
  using typename Superclass::SizeValueType;

  ImageRandomConstIteratorWithOnlyIndex() = default;
 
  ~ImageRandomConstIteratorWithOnlyIndex() override = default;

  ImageRandomConstIteratorWithOnlyIndex(const TImage * ptr, const RegionType & region);

  ImageRandomConstIteratorWithOnlyIndex(const ImageConstIteratorWithOnlyIndex<TImage> & it)
  {
    this->ImageConstIteratorWithOnlyIndex<TImage>::operator=(it);
  }

  void
  GoToBegin()
  {
    this->RandomJump();
    m_NumberOfSamplesDone = 0L;
  }

  void
  GoToEnd()
  {
    this->RandomJump();
    m_NumberOfSamplesDone = m_NumberOfSamplesRequested;
  }

  [[nodiscard]] bool
  IsAtBegin() const
  {
    return m_NumberOfSamplesDone == 0L;
  }

  [[nodiscard]] bool
  IsAtEnd() const
  {
    return m_NumberOfSamplesDone >= m_NumberOfSamplesRequested;
  }

  Self &
  operator++()
  {
    this->RandomJump();
    ++m_NumberOfSamplesDone;
    return *this;
  }

  Self &
  operator--()
  {
    this->RandomJump();
    --m_NumberOfSamplesDone;
    return *this;
  }

  void
  SetNumberOfSamples(SizeValueType number)
  {
    m_NumberOfSamplesRequested = number;
  }
 
  [[nodiscard]] SizeValueType
  GetNumberOfSamples() const
  {
    return m_NumberOfSamplesRequested;
  }

  void
  ReinitializeSeed();
 
  void
  ReinitializeSeed(int);
 
private:
  void
  RandomJump();
 
  using GeneratorPointer = Statistics::MersenneTwisterRandomVariateGenerator::Pointer;
  GeneratorPointer m_Generator{ Statistics::MersenneTwisterRandomVariateGenerator::New() };
  SizeValueType    m_NumberOfSamplesRequested{};
  SizeValueType    m_NumberOfSamplesDone{};
  SizeValueType    m_NumberOfPixelsInRegion{};
};
 
// Deduction guide for class template argument deduction (CTAD).
template <typename TImage>
ImageRandomConstIteratorWithOnlyIndex(SmartPointer<TImage>, const typename TImage::RegionType &)
  -> ImageRandomConstIteratorWithOnlyIndex<std::remove_const_t<TImage>>;
 
} // end namespace itk
 
#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkImageRandomConstIteratorWithOnlyIndex.hxx"
#endif
 
#endif