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

#ifndef __fpa__Image__RegionGrow__hxx__
#define __fpa__Image__RegionGrow__hxx__

#include <queue>

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
void fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
SetPredicate( TIntensityFunctor* functor )
{
  if( this->m_IntensityFunctor.GetPointer( ) != functor )
  {
    this->m_IntensityFunctor = functor;
    this->Modified( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
void fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
AddSeed( const TIndex& seed )
{
  if( this->m_Seeds.insert( seed ).second )
    this->Modified( );
}

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
RegionGrow( )
  : Superclass( ),
    m_InsideValue( TInputPixel( 0 ) ),
    m_OutsideValue( TInputPixel( 0 ) )
{
}

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
~RegionGrow( )
{
}

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
void fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
GenerateInputRequestedRegion( )
{
  this->Superclass::GenerateInputRequestedRegion( );
  if( this->GetInput( ) )
  {
    TInputImage* input =
      const_cast< TInputImage* >( this->GetInput( ) );
    input->SetRequestedRegionToLargestPossibleRegion( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
void fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
EnlargeOutputRequestedRegion( itk::DataObject* output )
{
  this->Superclass::EnlargeOutputRequestedRegion( output );
  output->SetRequestedRegionToLargestPossibleRegion( );
}

// -------------------------------------------------------------------------
template< class _TInputImage, class _TOutputImage >
void fpa::Image::RegionGrow< _TInputImage, _TOutputImage >::
GenerateData( )
{
  const TInputImage* input = this->GetInput( );
  TOutputImage* output = this->GetOutput( );
  TRegion region = input->GetRequestedRegion( );

  // Configure output
  output->SetBufferedRegion( region );
  output->Allocate( );
  output->FillBuffer( this->m_OutsideValue );

  // Init marks
  typedef itk::Image< bool, TInputImage::ImageDimension > _TMarks;
  typename _TMarks::Pointer marks = _TMarks::New( );
  marks->CopyInformation( input );
  marks->SetRequestedRegion( region );
  marks->SetBufferedRegion( input->GetBufferedRegion( ) );
  marks->Allocate( );
  marks->FillBuffer( false );

  // Init queue
  std::queue< TIndex > q;
  for( TIndex seed: this->m_Seeds )
    q.push( seed );

  // Main loop
  while( q.size( ) > 0 )
  {
    // Get next candidate
    TIndex node = q.front( );
    q.pop( );
    if( marks->GetPixel( node ) )
      continue;
    marks->SetPixel( node, true );

    // Apply inclusion predicate
    TInputPixel value = input->GetPixel( node );
    bool inside = false;
    if( this->m_IntensityFunctor.IsNotNull( ) )
      inside = this->m_IntensityFunctor->Evaluate( value );
    if( !inside )
      continue;

    // Ok, pixel lays inside region
    output->SetPixel( node, this->m_InsideValue );

    // Add neighborhood
    for( unsigned int d = 0; d < TInputImage::ImageDimension; ++d )
    {
      TIndex neigh = node;
      for( int i = -1; i <= 1; i += 2 )
      {
        neigh[ d ] = node[ d ] + i;
        if( region.IsInside( neigh ) )
          q.push( neigh );

      } // rof

    } // rof

  } // elihw
}

#endif // __fpa__Image__RegionGrow__hxx__

// eof - $RCSfile$