#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 >::
SetImage( const TImage* img, R* rw )
{
  this->m_Image = img;
  this->m_RenderWindow = rw;

  unsigned int minD = TImage::ImageDimension;
  minD = ( minD < 3 )? minD: 3;

  int e[ 6 ] = { 0 };
  typename TImage::RegionType reg = this->m_Image->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 TImage::SpacingType spac = this->m_Image->GetSpacing( );
  double s[ 3 ] = { 1, 1, 1 };
  for( unsigned int i = 0; i < minD; i++ )
    s[ i ] = double( spac[ i ] );

  typename TImage::PointType orig = this->m_Image->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( );

  double nPix =
    double( this->m_Image->GetRequestedRegion( ).GetNumberOfPixels( ) );
  this->m_Percentage = ( unsigned long )( nPix * 0.01 );
  this->m_Number = 0;

  if( this->m_RenderWindow != NULL )
  {
    vtkRenderer* ren =
      this->m_RenderWindow->GetRenderers( )->GetFirstRenderer( );
    ren->AddActor( this->m_StencilActor );
    this->Render( );

  } // fi
}

// -------------------------------------------------------------------------
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 TImage::IndexType        TIndex;
  typedef typename TImage::PointType        TPoint;
  typedef typename TFilter::TEvent          TEvent;
  typedef typename TFilter::TFrontEvent     TFrontEvent;
  typedef typename TFilter::TMarkEvent      TMarkEvent;
  typedef typename TFilter::TCollisionEvent TCollisionEvent;
  typedef typename TFilter::TEndEvent       TEndEvent;

  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 }
    };

  if( this->m_RenderWindow == NULL )
    return;

  const TEvent* evt = dynamic_cast< const TEvent* >( &e );
  TFrontEvent fevt;
  TMarkEvent mevt;
  TCollisionEvent cevt;
  TEndEvent eevt;
  if( evt != NULL )
  {
    if( mevt.CheckEvent( evt ) )
      this->SetPixel(
        evt->Node.Vertex,
        Colors[ evt->Node.FrontId ][ 0 ],
        Colors[ evt->Node.FrontId ][ 1 ],
        Colors[ evt->Node.FrontId ][ 2 ],
        Colors[ evt->Node.FrontId ][ 3 ]
        );
    else if( fevt.CheckEvent( evt ) )
      this->SetPixel( evt->Node.Vertex, 255, 0, 0, 255 );
    if( cevt.CheckEvent( evt ) )
      this->SetPixel( evt->Node.Vertex, 100, 50, 25, 255 );

    // Update visualization
    if( this->m_Number == 0 || this->m_Percentage < 0 )
      this->Render( );
    this->m_Number++;
    this->m_Number %= this->m_Percentage;

    if( eevt.CheckEvent( evt ) )
    {
      if( this->m_RenderWindow != NULL )
      {
        /* TODO
           vtkRenderer* ren =
           this->m_RenderWindow->GetRenderers( )->GetFirstRenderer( );
           ren->RemoveActor( this->m_StencilActor );
        */
        this->Render( );

      } // fi

    } // fi
  }
  else
  {
    // TODO: Remove all!
    this->Render( );

  } // fi
}

#endif // __FPA__VTK__IMAGE2DOBSERVER__HXX__

// eof - $RCSfile$