text: /*=========================================================================
   *
   *  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
   *
   *         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 itkComplexToModulusImageAdaptor_h
  #define itkComplexToModulusImageAdaptor_h
  
  #include "itkImageAdaptor.h"
  #include <complex>
  
  namespace itk
  {
  namespace Accessor
  {
  /**
   *\class ComplexToModulusPixelAccessor
   * \brief Give access to the Modulus of a std::complex<> value.
   *
   * ComplexToModulusPixelAccessor is templated over an internal type and an
   * external type representation. The internal type is an std::complex<T> and
   * the external part is a type T. This class casts the input, applies the function
   * to it, and casts the result according to the types defined as template
   * parameters.
   *
   * \ingroup ImageAdaptors
   * \ingroup ITKImageAdaptors
   */
  template <typename TInternalType, typename TExternalType>
  class ComplexToModulusPixelAccessor
  {
  public:
    /** External type alias. It defines the external aspect
     * that this class will exhibit. */
    using ExternalType = TExternalType;
  
    /** Internal type alias. It defines the internal modulus
     * representation of data. */
    using InternalType = TInternalType;
  
    static inline void
    Set(TInternalType & output, const TExternalType & input)
    {
      output = (TInternalType)(input);
    }
  
    static inline TExternalType
    Get(const TInternalType & input)
    {
      return (TExternalType)(std::sqrt(input.real() * input.real() + input.imag() * input.imag()));
    }
  };
  } // end namespace Accessor
  
  /**
   *\class ComplexToModulusImageAdaptor
   * \brief Presents a complex image as being composed of std::abs() part
   * of its pixels.
   *
   * Additional casting is performed according to the input and output image
   * types following C++ default casting rules.
   *
   * \ingroup ImageAdaptors
   * \ingroup ITKImageAdaptors
   */
  template <typename TImage, typename TOutputPixelType>
  class ComplexToModulusImageAdaptor
    : public ImageAdaptor<TImage, Accessor::ComplexToModulusPixelAccessor<typename TImage::PixelType, TOutputPixelType>>
  {
  public:
    ITK_DISALLOW_COPY_AND_MOVE(ComplexToModulusImageAdaptor);
  
    /** Standard class type aliases. */
    using Self = ComplexToModulusImageAdaptor;
    using Superclass =
      ImageAdaptor<TImage, Accessor::ComplexToModulusPixelAccessor<typename TImage::PixelType, TOutputPixelType>>;
  
    using Pointer = SmartPointer<Self>;
    using ConstPointer = SmartPointer<const Self>;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(ComplexToModulusImageAdaptor, ImageAdaptor);
  
  protected:
    ComplexToModulusImageAdaptor() = default;
    ~ComplexToModulusImageAdaptor() override = default;
  };
  } // end namespace itk
  
  #endif
  