/*=========================================================================
 *
 *  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 itkNeighborhoodInnerProduct_hxx
#define itkNeighborhoodInnerProduct_hxx
#include "itkNeighborhoodInnerProduct.h"

#include "itkNumericTraits.h"

namespace itk
{
template< typename TImage, typename TOperator, typename TComputation >
typename NeighborhoodInnerProduct< TImage, TOperator, TComputation >::OutputPixelType
NeighborhoodInnerProduct< TImage, TOperator, TComputation >
::Compute(
  const ConstNeighborhoodIterator< TImage > & it,
  const OperatorType & op,
  const unsigned start,
  const unsigned stride)
{
  typename OperatorType::ConstIterator o_it;

  using InputPixelType = typename TImage::PixelType;
  using InputPixelRealType = typename NumericTraits< InputPixelType >::RealType;
  using AccumulateRealType = typename NumericTraits< InputPixelRealType >::AccumulateType;

  AccumulateRealType sum = NumericTraits< AccumulateRealType >::ZeroValue();

  using OutputPixelValueType = typename NumericTraits<OutputPixelType>::ValueType;

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

  for ( unsigned int i = start; o_it < op_end; i += stride, ++o_it )
    {
    sum += static_cast< AccumulateRealType >(
      static_cast< OutputPixelValueType >( *o_it ) *
      static_cast< InputPixelRealType >( it.GetPixel(i) ) );
    }

  return static_cast< OutputPixelType >( sum );
}

template< typename TImage, typename TOperator, typename TComputation >
typename NeighborhoodInnerProduct< TImage, TOperator, TComputation >::OutputPixelType
NeighborhoodInnerProduct< TImage, TOperator, TComputation >
::Compute(
  /*           const ImageBoundaryCondition<TImage> *,*/
  const NeighborhoodType & N,
  const OperatorType & op,
  const unsigned start,
  const unsigned stride)
{
  typename OperatorType::ConstIterator o_it;

  using InputPixelType = typename TImage::PixelType;
  using InputPixelRealType = typename NumericTraits< InputPixelType >::RealType;
  using AccumulateRealType = typename NumericTraits< InputPixelRealType >::AccumulateType;

  AccumulateRealType sum = NumericTraits< AccumulateRealType >::ZeroValue();

  using OutputPixelValueType = typename NumericTraits<OutputPixelType>::ValueType;

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

  for ( unsigned int i = start; o_it < op_end; i += stride, ++o_it )
    {
    sum += static_cast< AccumulateRealType >(
      static_cast< OutputPixelValueType >( *o_it ) *
      static_cast< InputPixelRealType >( N[i] ) );
    }

  return static_cast< OutputPixelType >( sum );
}
} // end namespace itk
#endif
