/*=========================================================================
 *
 *  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 itkSphereSpatialFunction_hxx
#define itkSphereSpatialFunction_hxx


namespace itk
{
template <unsigned int VImageDimension, typename TInput>
auto
SphereSpatialFunction<VImageDimension, TInput>::Evaluate(const InputType & position) const -> OutputType
{
  double acc = 0;

  for (unsigned int i = 0; i < VImageDimension; ++i)
  {
    acc += (position[i] - m_Center[i]) * (position[i] - m_Center[i]);
  }

  acc -= m_Radius * m_Radius;

  if (acc <= 0) // inside the sphere
  {
    return 1;
  }
  else
  {
    return 0; // outside the sphere
  }
}

template <unsigned int VImageDimension, typename TInput>
void
SphereSpatialFunction<VImageDimension, TInput>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  unsigned int i;
  os << indent << "Center: [";
  for (i = 0; i < VImageDimension - 1; ++i)
  {
    os << m_Center[i] << ", ";
  }
  os << ']' << std::endl;

  os << indent << "Radius: " << m_Radius << std::endl;
}
} // end namespace itk

#endif
