/*=========================================================================
 *
 *  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 itkMattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader_h
#define itkMattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader_h

#include "itkImageToImageMetricv4GetValueAndDerivativeThreader.h"

#include <mutex>

namespace itk
{

/** \class MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader
 * \brief Processes points for MattesMutualInformationImageToImageMetricv4 \c
 * GetValueAndDerivative.
 *
 * \ingroup ITKMetricsv4
 */
template < typename TDomainPartitioner, typename TImageToImageMetric, typename TMattesMutualInformationMetric >
class ITK_TEMPLATE_EXPORT MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader
  : public ImageToImageMetricv4GetValueAndDerivativeThreader< TDomainPartitioner, TImageToImageMetric >
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader);

  /** Standard class type aliases. */
  using Self = MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader;
  using Superclass = ImageToImageMetricv4GetValueAndDerivativeThreader< TDomainPartitioner, TImageToImageMetric >;
  using Pointer = SmartPointer< Self >;
  using ConstPointer = SmartPointer< const Self >;

  itkTypeMacro( MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader, ImageToImageMetricv4GetValueAndDerivativeThreader );

  itkNewMacro( Self );

  using DomainType = typename Superclass::DomainType;
  using AssociateType = typename Superclass::AssociateType;

  using ImageToImageMetricv4Type = typename Superclass::ImageToImageMetricv4Type;
  using VirtualPointType = typename Superclass::VirtualPointType;
  using VirtualIndexType = typename Superclass::VirtualIndexType;
  using FixedImagePointType = typename Superclass::FixedImagePointType;
  using FixedImageIndexType = typename Superclass::FixedImageIndexType;
  using FixedImagePixelType = typename Superclass::FixedImagePixelType;
  using FixedImageGradientType = typename Superclass::FixedImageGradientType;
  using MovingImagePointType = typename Superclass::MovingImagePointType;
  using MovingImagePixelType = typename Superclass::MovingImagePixelType;
  using MovingImageGradientType = typename Superclass::MovingImageGradientType;
  using MeasureType = typename Superclass::MeasureType;
  using DerivativeType = typename Superclass::DerivativeType;
  using DerivativeValueType = typename Superclass::DerivativeValueType;
  using NumberOfParametersType = typename Superclass::NumberOfParametersType;

  using MovingTransformType = typename ImageToImageMetricv4Type::MovingTransformType;

  using PDFValueType = typename TMattesMutualInformationMetric::PDFValueType;
  using JointPDFType = typename TMattesMutualInformationMetric::JointPDFType;
  using JointPDFRegionType = typename TMattesMutualInformationMetric::JointPDFRegionType;
  using JointPDFIndexType = typename TMattesMutualInformationMetric::JointPDFIndexType;
  using JointPDFValueType = typename TMattesMutualInformationMetric::JointPDFValueType;
  using JointPDFSizeType = typename TMattesMutualInformationMetric::JointPDFSizeType;
  using JointPDFDerivativesType = typename TMattesMutualInformationMetric::JointPDFDerivativesType;
  using JointPDFDerivativesIndexType = typename TMattesMutualInformationMetric::JointPDFDerivativesIndexType;
  using JointPDFDerivativesValueType = typename TMattesMutualInformationMetric::JointPDFDerivativesValueType;
  using JointPDFDerivativesRegionType = typename TMattesMutualInformationMetric::JointPDFDerivativesRegionType;
  using JointPDFDerivativesSizeType = typename TMattesMutualInformationMetric::JointPDFDerivativesSizeType;

  using CubicBSplineFunctionType = typename TMattesMutualInformationMetric::CubicBSplineFunctionType;
  using CubicBSplineDerivativeFunctionType = typename TMattesMutualInformationMetric::CubicBSplineDerivativeFunctionType;

  using JacobianType = typename TMattesMutualInformationMetric::JacobianType;

protected:
  MattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader() :
    m_MattesAssociate(nullptr)
  {}

  void BeforeThreadedExecution() override;

  void AfterThreadedExecution() override;

  /** This function computes the local voxel-wise contribution of
   *  the metric to the global integral of the metric/derivative.
   */
  bool ProcessPoint(
        const VirtualIndexType &          virtualIndex,
        const VirtualPointType &          virtualPoint,
        const FixedImagePointType &       mappedFixedPoint,
        const FixedImagePixelType &       mappedFixedPixelValue,
        const FixedImageGradientType &    mappedFixedImageGradient,
        const MovingImagePointType &      mappedMovingPoint,
        const MovingImagePixelType &      mappedMovingPixelValue,
        const MovingImageGradientType &   mappedMovingImageGradient,
        MeasureType &                     metricValueReturn,
        DerivativeType &                  localDerivativeReturn,
        const ThreadIdType                threadId ) const override;

  /** Compute PDF derivative contribution for each parameter of a displacement field. */
  virtual void ComputePDFDerivativesLocalSupportTransform(
                             const JacobianType &            jacobian,
                             const MovingImageGradientType & movingGradient,
                             const PDFValueType &            cubicBSplineDerivativeValue,
                             DerivativeValueType *           localSupportDerivativeResultPtr) const;

private:
  /** Internal pointer to the Mattes metric object in use by this threader.
   *  This will avoid costly dynamic casting in tight loops. */
  TMattesMutualInformationMetric * m_MattesAssociate;
};

} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkMattesMutualInformationImageToImageMetricv4GetValueAndDerivativeThreader.hxx"
#endif

#endif
