// =========================================================================
// @author Leonardo Florez Valencia
// @email florez-l@javeriana.edu.co
// =========================================================================

#ifndef __fpa__Base__MarksInterface__hxx__
#define __fpa__Base__MarksInterface__hxx__

#include <queue>

// -------------------------------------------------------------------------
template< class _TVertex >
bool fpa::Base::MarksInterface< _TVertex >::
StopAtOneFront( ) const
{
  return( this->m_StopAtOneFront );
}

// -------------------------------------------------------------------------
template< class _TVertex >
void fpa::Base::MarksInterface< _TVertex >::
StopAtOneFrontOn( )
{
  this->SetStopAtOneFront( true );
}

// -------------------------------------------------------------------------
template< class _TVertex >
void fpa::Base::MarksInterface< _TVertex >::
StopAtOneFrontOff( )
{
  this->SetStopAtOneFront( false );
}

// -------------------------------------------------------------------------
template< class _TVertex >
void fpa::Base::MarksInterface< _TVertex >::
SetStopAtOneFront( bool v )
{
  if( this->m_StopAtOneFront != v )
  {
    this->m_StopAtOneFront = v;
    if( this->m_Filter != NULL )
      this->m_Filter->Modified( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TVertex >
fpa::Base::MarksInterface< _TVertex >::
MarksInterface( itk::ProcessObject* filter )
  : m_StopAtOneFront( false ),
    m_NumberOfFronts( 0 ),
    m_NumberOfSeeds( 0 ),
    m_Filter( filter )
{
}

// -------------------------------------------------------------------------
template< class _TVertex >
fpa::Base::MarksInterface< _TVertex >::
~MarksInterface( )
{
}

// -------------------------------------------------------------------------
template< class _TVertex >
void fpa::Base::MarksInterface< _TVertex >::
_InitMarks( unsigned long nSeeds )
{
  this->m_NumberOfFronts = this->m_NumberOfSeeds = nSeeds;
  TCollision coll( TVertex( ), false );
  TCollisionsRow row( this->m_NumberOfFronts, coll );
  this->m_Collisions.clear( );
  this->m_Collisions.resize( this->m_NumberOfFronts, row );
}

// -------------------------------------------------------------------------
template< class _TVertex >
unsigned long fpa::Base::MarksInterface< _TVertex >::
_Collisions( const TVertex& a, const TVertex& b )
{
  unsigned long ma = this->_GetMark( a );
  unsigned long mb = this->_GetMark( b );
  if( ma == mb || ma == 0 || mb == 0 )
    return( this->m_NumberOfFronts );

  // Mark collision, if it is new
  ma--; mb--;
  bool ret = false;
  bool exists = this->m_Collisions[ ma ][ mb ].second;
  exists     &= this->m_Collisions[ mb ][ ma ].second;
  if( !exists )
  {
    this->m_Collisions[ ma ][ mb ].first = a;
    this->m_Collisions[ ma ][ mb ].second = true;
    this->m_Collisions[ mb ][ ma ].first = b;
    this->m_Collisions[ mb ][ ma ].second = true;

    // Update number of fronts
    unsigned long count = 0;
    std::vector< bool > m( this->m_NumberOfSeeds, false );
    std::queue< unsigned long > q;
    q.push( 0 );
    while( !q.empty( ) )
    {
      unsigned long f = q.front( );
      q.pop( );

      if( m[ f ] )
        continue;
      m[ f ] = true;
      count++;

      for( unsigned int n = 0; n < this->m_NumberOfSeeds; ++n )
        if( this->m_Collisions[ f ][ n ].second && !m[ n ] )
          q.push( n );

    } // elihw
    this->m_NumberOfFronts = this->m_NumberOfSeeds - count + 1;

  } // fi
  return( this->m_NumberOfFronts );
}

#endif // __fpa__Base__MarksInterface__hxx__

// eof - $RCSfile$