// -------------------------------------------------------------------------
// @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
// -------------------------------------------------------------------------

#ifndef __CPEXTENSIONS__ALGORITHMS__IMAGEFUNCTIONFILTER__H__
#define __CPEXTENSIONS__ALGORITHMS__IMAGEFUNCTIONFILTER__H__

#include <itkImageToImageFilter.h>
#include <itkImageScanlineConstIterator.h>
#include <itkImageScanlineIterator.h>
#include <itkProgressReporter.h>

namespace cpExtensions
  {
    namespace Algorithms
    {
      /**
       */
      template< class I, class O, class F >
      class ImageFunctionFilter
        : public itk::ImageToImageFilter< I, O >
      {
      public:
        typedef ImageFunctionFilter             Self;
        typedef itk::ImageToImageFilter< I, O > Superclass;
        typedef itk::SmartPointer< Self >       Pointer;
        typedef itk::SmartPointer< const Self > ConstPointer;

        typedef I TInputImage;
        typedef O TOutputImage;
        typedef F TFunction;

        typedef typename O::RegionType TRegion;

      public:
        itkNewMacro( Self );
        itkTypeMacro( ImageFunctionFilter, itkImageToImageFilter );

        itkGetObjectMacro( Function, F );
        itkSetObjectMacro( Function, F );

      protected:
        ImageFunctionFilter( )
          : Superclass( )
          {
          }
        virtual ~ImageFunctionFilter( )
          {
          }

        virtual void ThreadedGenerateData(
          const TRegion& region,
          itk::ThreadIdType threadId
          )
          {
            const typename TRegion::SizeType& regionSize = region.GetSize( );
            if( regionSize[ 0 ] == 0 )
              return;
            const I* in = this->GetInput( );
            O* out = this->GetOutput( 0 );

            const size_t nLines = region.GetNumberOfPixels( ) / regionSize[ 0 ];
            itk::ProgressReporter progress( this, threadId, nLines );

            // Define the iterators
            itk::ImageScanlineConstIterator< I > inIt( in, region );
            itk::ImageScanlineIterator< O > outIt( out, region );

            inIt.GoToBegin( );
            outIt.GoToBegin( );
            while( !inIt.IsAtEnd( ) )
            {
              while( !inIt.IsAtEndOfLine( ) )
              {
                outIt.Set( this->m_Function->EvaluateAtIndex( inIt.GetIndex( ) ) );
                ++inIt;
                ++outIt;

              } // elihw
              inIt.NextLine( );
              outIt.NextLine( );
              progress.CompletedPixel( );

            } // elihw
          }

      private:
        // Purposely not implemented.
        ImageFunctionFilter( const Self& );
        void operator=( const Self& );

      protected:
        typename F::Pointer m_Function;
      };

    } // ecapseman

} // ecapseman

// TODO: #include <cpExtensions/Algorithms/ImageFunctionFilter.hxx>

#endif // __CPEXTENSIONS__ALGORITHMS__IMAGEFUNCTIONFILTER__H__

// eof - $RCSfile$