/*=========================================================================
 *
 *  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 itkSphereSignedDistanceFunction_hxx
#define itkSphereSignedDistanceFunction_hxx

#include "itkMath.h"

namespace itk
{
// Constructor with default arguments
template <typename TCoordRep, unsigned int VSpaceDimension>
SphereSignedDistanceFunction<TCoordRep, VSpaceDimension>::SphereSignedDistanceFunction()
{
  this->GetParameters().SetSize(SpaceDimension + 1);
  this->GetParameters().Fill(0.0);
  this->GetParameters()[0] = 1.0;
  m_Translation.Fill(0.0);
  m_Radius = 1.0;
}

// Set the parameters
template <typename TCoordRep, unsigned int VSpaceDimension>
void
SphereSignedDistanceFunction<TCoordRep, VSpaceDimension>::SetParameters(const ParametersType & parameters)
{
  if (parameters != this->GetParameters())
  {
    this->m_Parameters = parameters;

    m_Radius = parameters[0];

    for (unsigned int i = 0; i < SpaceDimension; ++i)
    {
      m_Translation[i] = parameters[i + 1];
    }

    this->Modified();
  }
}

// Print self
template <typename TCoordRep, unsigned int VSpaceDimension>
void
SphereSignedDistanceFunction<TCoordRep, VSpaceDimension>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  os << indent << "Translation: " << m_Translation << std::endl;
  os << indent << "Radius: " << m_Radius << std::endl;
}

// Evaluate the signed distance
template <typename TCoordRep, unsigned int VSpaceDimension>
auto
SphereSignedDistanceFunction<TCoordRep, VSpaceDimension>::Evaluate(const PointType & point) const -> OutputType
{
  using RealType = typename NumericTraits<OutputType>::RealType;
  RealType output = 0.0;

  for (unsigned int j = 0; j < SpaceDimension; ++j)
  {
    output += itk::Math::sqr((point[j] - m_Translation[j]));
  }

  output = std::sqrt(output) - m_Radius;

  return output;
}
} // end namespace itk

#endif