#ifndef __FPA__VTK__IMAGE2DOBSERVER__HXX__
#define __FPA__VTK__IMAGE2DOBSERVER__HXX__

#include <vtkCellArray.h>
#include <vtkPolyDataMapper.h>
#include <vtkPoints.h>
#include <vtkPointData.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRendererCollection.h>

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image2DObserver< F, R >::
SetRenderWindow( R* rw )
{
  this->m_RenderWindow = rw;
}

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image2DObserver< F, R >::
SetPixel(
  typename TImage::IndexType idx,
  unsigned char red,
  unsigned char green,
  unsigned char blue,
  unsigned char alpha
  )
{
  this->m_Stencil->SetScalarComponentFromDouble
    ( idx[ 0 ], idx[ 1 ], 0, 0, red );
  this->m_Stencil->SetScalarComponentFromDouble
    ( idx[ 0 ], idx[ 1 ], 0, 1, green );
  this->m_Stencil->SetScalarComponentFromDouble
    ( idx[ 0 ], idx[ 1 ], 0, 2, blue );
  this->m_Stencil->SetScalarComponentFromDouble
    ( idx[ 0 ], idx[ 1 ], 0, 3, alpha );
  this->m_Stencil->Modified( );
  this->m_StencilActor->Modified( );
}

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image2DObserver< F, R >::
Render( )
{
  if( this->m_RenderWindow != NULL )
    this->m_RenderWindow->Render( );
}

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image2DObserver< F, R >::
Execute( const itk::Object* c, const itk::EventObject& e )
{
  typedef typename F::TStartEvent     _TStartEvent;
  typedef typename F::TStartLoopEvent _TStartLoopEvent;
  typedef typename F::TEndEvent       _TEndEvent;
  typedef typename F::TEndLoopEvent   _TEndLoopEvent;
  typedef typename F::TAliveEvent     _TAliveEvent;
  typedef typename F::TFrontEvent     _TFrontEvent;
  typedef typename F::TFreezeEvent    _TFreezeEvent;

  static unsigned char Colors[][4] =
    {
      {   0,   0, 127, 127 },
      {   0, 127, 127, 127 },
      { 127,   0, 127, 127 },
      { 127, 127,   0, 127 },
      {   0,   0,  63, 127 },
      {   0,  63,  63, 127 },
      {  63,   0,  63, 127 },
      {  63,  63,   0, 127 },
      {  63,  63, 127, 127 },
      {  63, 127, 127, 127 },
      { 127,  63, 127, 127 },
      { 127, 127,  63, 127 },
      { 127, 127,  63, 127 },
      { 127,  63,  63, 127 },
      {  63, 127,  63, 127 },
      {  63,  63, 127, 127 }
    };

  const F* filter = dynamic_cast< const F* >( c );
  if( this->m_RenderWindow == NULL || filter == NULL )
    return;

  const _TStartEvent* startEvt = dynamic_cast< const _TStartEvent* >( &e );
  if( startEvt != NULL )
  {
    const typename F::TInputImage* img = filter->GetInput( );
    unsigned int minD = F::TInputImage::ImageDimension;
    minD = ( minD < 3 )? minD: 3;

    int e[ 6 ] = { 0 };
    typename F::TInputImage::RegionType reg = img->GetRequestedRegion( );
    for( unsigned int i = 0; i < minD; i++ )
    {
      e[ ( i << 1 ) + 0 ] = reg.GetIndex( )[ i ];
      e[ ( i << 1 ) + 1 ] = reg.GetIndex( )[ i ] + reg.GetSize( )[ i ] - 1;

    } // rof

    typename F::TInputImage::SpacingType spac = img->GetSpacing( );
    double s[ 3 ] = { 1, 1, 1 };
    for( unsigned int i = 0; i < minD; i++ )
      s[ i ] = double( spac[ i ] );

    typename F::TInputImage::PointType orig = img->GetOrigin( );
    double o[ 3 ] = { 0 };
    for( unsigned int i = 0; i < minD; i++ )
      o[ i ] = double( orig[ i ] );

    this->m_Stencil->SetExtent( e );
    this->m_Stencil->SetSpacing( s );
    this->m_Stencil->SetOrigin( o );
    this->m_Stencil->AllocateScalars( VTK_UNSIGNED_CHAR, 4 );
    for( unsigned int i = 0; i < 3; i++ )
      this->m_Stencil->GetPointData( )->
        GetScalars( )->FillComponent( i, 255 );
    this->m_Stencil->GetPointData( )->GetScalars( )->FillComponent( 3, 0 );

    this->m_StencilActor->SetInputData( this->m_Stencil );
    this->m_StencilActor->InterpolateOff( );

    this->m_Count = 0;
    this->m_RenderCount = reg.GetNumberOfPixels( );

    vtkRenderer* ren =
      this->m_RenderWindow->GetRenderers( )->GetFirstRenderer( );
    ren->AddActor( this->m_StencilActor );
    return;

  } // fi

  const _TAliveEvent* aliveEvt = dynamic_cast< const _TAliveEvent* >( &e );
  const _TFrontEvent* frontEvt = dynamic_cast< const _TFrontEvent* >( &e );
  if( aliveEvt != NULL || frontEvt != NULL )
  {
    if( aliveEvt != NULL )
      this->SetPixel(
        aliveEvt->Vertex,
        Colors[ aliveEvt->FrontId ][ 0 ],
        Colors[ aliveEvt->FrontId ][ 1 ],
        Colors[ aliveEvt->FrontId ][ 2 ],
        Colors[ aliveEvt->FrontId ][ 3 ]
        );
    else if( frontEvt != NULL )
      this->SetPixel( frontEvt->Vertex, 255, 0, 0, 255 );
    this->m_Count++;

    // Render visual debug
    double per = double( this->m_RenderCount ) * this->m_RenderPercentage;
    if( double( this->m_Count ) >= per )
      this->Render( );
    if( double( this->m_Count ) >= per )
      this->m_Count = 0;

    return;

  } // fi

  const _TEndEvent* endEvt = dynamic_cast< const _TEndEvent* >( &e );
  if( endEvt != NULL )
  {
    vtkRenderer* ren =
      this->m_RenderWindow->GetRenderers( )->GetFirstRenderer( );
    ren->RemoveActor( this->m_StencilActor );
    this->Render( );
    return;

  } // fi
}

// -------------------------------------------------------------------------
template< class F, class R >
fpa::VTK::Image2DObserver< F, R >::
Image2DObserver( )
  : Superclass( ),
    m_RenderWindow( NULL ),
    m_RenderPercentage( double( 0.01 ) )
{
  this->m_Stencil = vtkSmartPointer< vtkImageData >::New( );
  this->m_StencilActor = vtkSmartPointer< vtkImageActor >::New( );
}

// -------------------------------------------------------------------------
template< class F, class R >
fpa::VTK::Image2DObserver< F, R >::
~Image2DObserver( )
{
}

#endif // __FPA__VTK__IMAGE2DOBSERVER__HXX__

// eof - $RCSfile$