#ifndef __fpa__Base__FastMarching__hxx__
#define __fpa__Base__FastMarching__hxx__

// -------------------------------------------------------------------------
template< class _TSuperclass >
fpa::Base::FastMarching< _TSuperclass >::
FastMarching( )
  : Superclass( )
{
}

// -------------------------------------------------------------------------
template< class _TSuperclass >
fpa::Base::FastMarching< _TSuperclass >::
~FastMarching( )
{
}

// -------------------------------------------------------------------------
template< class _TSuperclass >
bool fpa::Base::FastMarching< _TSuperclass >::
_UpdateValue( _TQueueNode& v, const _TQueueNode& p )
{
  // Compute quadratic coefficients
  double a = double( 0 );
  double b = double( 0 );
  double c = double( 0 );
  TFastMarchingNeighborhood neighs = this->_FastMarchingNeighbors( v.Vertex );
  for( unsigned int i = 0; i < neighs.size( ); i += 2 )
  {
    double tn = double( this->_GetResult( neighs[ i ].first ) );
    double tp = double( this->_GetResult( neighs[ i + 1 ].first ) );
    double dd = double( 0 );
    double td = this->m_InitResult;
    if( tn < tp )
    {
      td = tn;
      dd = neighs[ i ].second;
    }
    else
    {
      td = tp;
      dd = neighs[ i + 1 ].second;

    } // fi

    if( td < double( this->m_InitResult ) )
    {
      dd = double( 1 ) / ( dd * dd );
      a += dd;
      b += td * dd;
      c += td * td * dd;

    } // fi

  } // rof
  double F = double( this->_GetInputValue( v, p ) );
  c -= double( 1 ) / ( F * F );

  // Solve quadratic equation
  double d = ( b * b ) - ( a * c );
  if( d >= double( 0 ) )
  {
    d = std::sqrt( d );
    b *= double( -1 );
    double s1 = std::fabs( ( b + d ) / a );
    double s2 = std::fabs( ( b - d ) / a );
    v.Result = TOutput( ( s2 < s1 )? s1: s2 );
    if( v.Result < this->_GetResult( v.Vertex ) )
      this->_UpdateResult( v );
  }
  else
  {
    std::cout << std::endl << "-- FM --> " << v.Vertex << " " << d << std::endl;
    std::exit( 1 );
  }
  return( true );
}

#endif // __fpa__Base__FastMarching__hxx__

// eof - $RCSfile$