#ifndef __fpa__Image__EndPointsFilter__hxx__
#define __fpa__Image__EndPointsFilter__hxx__

#include <functional>
#include <map>
#include <queue>
#include <itkImageRegionConstIteratorWithIndex.h>

// -------------------------------------------------------------------------
template< class _TDistanceMap, class _TCostMap >
const typename fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
TIndices& fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
GetBifurcations( ) const
{
  return( this->m_Bifurcations );
}

// -------------------------------------------------------------------------
template< class _TDistanceMap, class _TCostMap >
const typename fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
TIndices& fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
GetEndPoints( ) const
{
  return( this->m_EndPoints );
}

// -------------------------------------------------------------------------
template< class _TDistanceMap, class _TCostMap >
void fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
Compute( )
{
  typedef itk::ImageRegionConstIteratorWithIndex< _TDistanceMap > _TDistMapIt;
  typedef itk::ImageRegionConstIteratorWithIndex< _TCostMap > _TCostMapIt;
  typedef std::multimap< double, TIndex, std::greater< double > > _TQueue;
  typedef typename _TQueue::value_type _TQueueValue;
  typedef itk::Image< unsigned char, _TCostMap::ImageDimension > _TMarks;

  // Some values
  typename _TDistanceMap::RegionType region =
    this->m_DistanceMap->GetRequestedRegion( );
  typename _TMarks::Pointer marks = _TMarks::New( );
  marks->SetLargestPossibleRegion( this->m_DistanceMap->GetLargestPossibleRegion( ) );
  marks->SetRequestedRegion( this->m_DistanceMap->GetRequestedRegion( ) );
  marks->SetBufferedRegion( this->m_DistanceMap->GetBufferedRegion( ) );
  marks->SetSpacing( this->m_DistanceMap->GetSpacing( ) );
  marks->SetOrigin( this->m_DistanceMap->GetOrigin( ) );
  marks->SetDirection( this->m_DistanceMap->GetDirection( ) );
  marks->Allocate( );
  marks->FillBuffer( 0 );

  // Create queue
  _TQueue queue;
  _TDistMapIt dIt( this->m_DistanceMap, region );
  _TCostMapIt cIt( this->m_CostMap, region );
  dIt.GoToBegin( );
  cIt.GoToBegin( );
  for( ; !dIt.IsAtEnd( ) && !cIt.IsAtEnd( ); ++dIt, ++cIt )
  {
    double d = double( dIt.Get( ) );
    if( d > 0 )
    {
      double v = double( cIt.Get( ) ) / ( d * d );
      queue.insert( _TQueueValue( v, dIt.GetIndex( ) ) );

    } // fi

  } // rof

  // BFS from maximum queue
  while( queue.size( ) > 0 )
  {
    // Get node
    auto nIt = queue.begin( );
    auto n = *nIt;
    queue.erase( nIt );

    unsigned char m = marks->GetPixel( n.second );
    if( ( m & 0x01 ) == 0x01 )
      continue;

    // Mark it
    m |= 0x01;
    marks->SetPixel( n.second, m );
    this->m_EndPoints.insert( n.second );

    // Get path
    typename TMST::TPath::Pointer path;
    this->m_MST->GetPath( path, n.second );
    for( unsigned long i = 0; i < path->GetSize( ); ++i )
    {
      TIndex idx = path->GetVertex( path->GetSize( ) - 1 - i );
      typename _TCostMap::PointType cnt;
      this->m_CostMap->TransformIndexToPhysicalPoint( idx, cnt );
      double d = double( this->m_DistanceMap->GetPixel( idx ) );
      d *= double( 2 );

      // Mark sphere
      std::queue< TIndex > q;
      q.push( idx );
      while( q.size( ) > 0 )
      {
        TIndex v = q.front( );
        q.pop( );
        unsigned char m = marks->GetPixel( v );
        if( ( m & 0x02 ) == 0x02 )
          continue;
        m |= 0x03;
        marks->SetPixel( v, m );

        for( unsigned int x = 0; x < _TCostMap::ImageDimension; ++x )
        {
          for( int y = -1; y <= 1; y += 2 )
          {
            TIndex w = v;
            w[ x ] += y;
            if( region.IsInside( w ) )
            {
              typename _TCostMap::PointType p;
              this->m_CostMap->TransformIndexToPhysicalPoint( w, p );
              if( cnt.EuclideanDistanceTo( p ) <= d )
                q.push( w );

            } // fi

          } // rof

        } // rof

      } // elihw

    } // rof

  } // elihw
}

// -------------------------------------------------------------------------
template< class _TDistanceMap, class _TCostMap >
fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
EndPointsFilter( )
  : Superclass( )
{
}

// -------------------------------------------------------------------------
template< class _TDistanceMap, class _TCostMap >
fpa::Image::EndPointsFilter< _TDistanceMap, _TCostMap >::
~EndPointsFilter( )
{
}

#endif // __fpa__Image__EndPointsFilter__hxx__

// eof - $RCSfile$