text: /*
   * Copyright (C) 2005-2019 Centre National d'Etudes Spatiales (CNES)
   *
   * This file is part of Orfeo Toolbox
   *
   *     https://www.orfeo-toolbox.org/
   *
   * 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
   *
   * 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 otbPathMeanDistanceFunctor_h
  #define otbPathMeanDistanceFunctor_h
  
  #include "otbMacro.h"
  #include "otbMath.h"
  
  namespace otb
  {
  
  /** \class PathMeanDistanceFunctor
   *  \brief Functor to select path according to the average distance between points
   *
   * This functor compute the average distance between each point of a path
   * and return true is the distance is above the threshold, false otherwise.
   *
   * \sa UnaryFunctorObjectListBooleanFilter
   *
   *  \ingroup Functor
   *
   * \ingroup OTBPath
   */
  template <class TInput1>
  class PathMeanDistanceFunctor
  {
  public:
  
    void SetThreshold(double threshold)
    {
      m_Threshold = threshold;
    }
    double GetThreshold(void) const
    {
      return (m_Threshold);
    }
  
    PathMeanDistanceFunctor()
    {
      m_Threshold = 0.2;
    }
    ~PathMeanDistanceFunctor() {}
  
    inline bool operator ()(const TInput1& input)
    {
  
      double meanDistance = 0.0;
      typedef typename TInput1::ObjectType::VertexListType::ConstIterator VertexListConstIteratorType;
      typedef typename TInput1::ObjectType::VertexType                    VertexType;
      VertexListConstIteratorType beginIt = input->GetVertexList()->Begin();
  
      VertexType v1 = beginIt.Value();
      VertexType v2 = beginIt.Value();
      ++beginIt;
      while (beginIt != input->GetVertexList()->End())
        {
        v1 = v2;
        v2 = beginIt.Value();
        meanDistance += std::sqrt(std::pow(v1[0] - v2[0], 2) + std::pow(v1[1] - v2[1], 2));
        ++beginIt;
        }
  
      double nbVertices = static_cast<double>(input->GetVertexList()->Size());
      if (nbVertices > 1)
        {
        meanDistance = meanDistance / (nbVertices - 1);
        }
      else
        {
        itkGenericExceptionMacro(<< "Object with only one vertex!");
        }
  
      /*     std::cout << "Num vertex: " << nbVertices << std::endl;
           std::cout << "Mean dist: " << meanDistance << std::endl;
      */
      if (meanDistance > m_Threshold)
        {
        return true;
        }
      else
        {
        return false;
        }
    }
  
  private:
    double m_Threshold;
  };
  
  }
  
  #endif
  