/*=========================================================================
 *
 *  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 itkVectorNeighborhoodInnerProduct_hxx
#define itkVectorNeighborhoodInnerProduct_hxx

namespace itk
{
template <typename TImage>
auto
VectorNeighborhoodInnerProduct<TImage>::operator()(const std::slice &                        s,
                                                   const ConstNeighborhoodIterator<TImage> & it,
                                                   const OperatorType &                      op) const -> PixelType
{
  PixelType sum{};

  typename OperatorType::ConstIterator       o_it = op.Begin();
  const typename OperatorType::ConstIterator op_end = op.End();

  const auto start = static_cast<unsigned int>(s.start());
  const auto stride = static_cast<unsigned int>(s.stride());
  for (unsigned int i = start; o_it < op_end; i += stride, ++o_it)
  {
    const auto & neighborPixel = it.GetPixel(i);

    for (unsigned int j = 0; j < VectorDimension; ++j)
    {
      sum[j] += *o_it * neighborPixel[j];
    }
  }

  return sum;
}

template <typename TImage>
auto
VectorNeighborhoodInnerProduct<TImage>::operator()(const std::slice &       s,
                                                   const NeighborhoodType & it,
                                                   const OperatorType &     op) const -> PixelType
{
  PixelType sum{};

  typename OperatorType::ConstIterator       o_it = op.Begin();
  const typename OperatorType::ConstIterator op_end = op.End();

  const auto start = static_cast<unsigned int>(s.start());
  const auto stride = static_cast<unsigned int>(s.stride());
  for (unsigned int i = start; o_it < op_end; i += stride, ++o_it)
  {
    const auto & neighborPixel = it[i];

    for (unsigned int j = 0; j < VectorDimension; ++j)
    {
      sum[j] += *o_it * neighborPixel[j];
    }
  }

  return sum;
}
} // end namespace itk
#endif
