/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkUnaryFunctorImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2006/01/15 04:28:36 $
  Version:   $Revision: 1.23 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef __itkUnaryFunctorImageFilter_h
#define __itkUnaryFunctorImageFilter_h

#include "itkInPlaceImageFilter.h"
#include "itkImageRegionIteratorWithIndex.h"

namespace itk
{
  
/** \class UnaryFunctorImageFilter
 * \brief Implements pixel-wise generic operation on one image.
 *
 * This class is parameterized over the type of the input image and
 * the type of the output image.  It is also parameterized by the
 * operation to be applied, using a Functor style.
 *
 * UnaryFunctorImageFilter allows the output dimension of the filter
 * to be larger than the input dimension. Thus subclasses of the
 * UnaryFunctorImageFilter (like the CastImageFilter) can be used
 * to promote a 2D image to a 3D image, etc.
 * 
 * \ingroup   IntensityImageFilters     Multithreaded
 */
template <class TInputImage, class TOutputImage, class TFunction >
class ITK_EXPORT UnaryFunctorImageFilter : public InPlaceImageFilter<TInputImage,TOutputImage> 
{
public:
  /** Standard class typedefs. */
  typedef UnaryFunctorImageFilter  Self;
  typedef InPlaceImageFilter<TInputImage,TOutputImage>  Superclass;
  typedef SmartPointer<Self>   Pointer;
  typedef SmartPointer<const Self>  ConstPointer;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);
  
  /** Run-time type information (and related methods). */
  itkTypeMacro(UnaryFunctorImageFilter, InPlaceImageFilter);

  /** Some typedefs. */
  typedef TFunction   FunctorType;
  typedef TInputImage InputImageType;
  typedef typename    InputImageType::ConstPointer    InputImagePointer;
  typedef typename    InputImageType::RegionType InputImageRegionType; 
  typedef typename    InputImageType::PixelType  InputImagePixelType; 
  typedef TOutputImage OutputImageType;
  typedef typename     OutputImageType::Pointer    OutputImagePointer;
  typedef typename     OutputImageType::RegionType OutputImageRegionType;
  typedef typename     OutputImageType::PixelType  OutputImagePixelType;

  /** Get the functor object.  The functor is returned by reference.
   * (Functors do not have to derive from itk::LightObject, so they do
   * not necessarily have a reference count. So we cannot return a
   * SmartPointer.) */
  FunctorType& GetFunctor() { return m_Functor; };
  const FunctorType& GetFunctor() const { return m_Functor; };

  /** Set the functor object.  This replaces the current Functor with a
   * copy of the specified Functor. This allows the user to specify a
   * functor that has ivars set differently than the default functor.
   * This method requires an operator!=() be defined on the functor
   * (or the compiler's default implementation of operator!=() being
   * appropriate). */
  void SetFunctor(const FunctorType& functor)
  {
    if (m_Functor != functor)
      {
      m_Functor = functor;
      this->Modified();
      }
  }
  
protected:
  UnaryFunctorImageFilter();
  virtual ~UnaryFunctorImageFilter() {};

  /** UnaryFunctorImageFilter can produce an image which is a different
   * resolution than its input image.  As such, UnaryFunctorImageFilter
   * needs to provide an implementation for
   * GenerateOutputInformation() in order to inform the pipeline
   * execution model.  The original documentation of this method is
   * below.
   *
   * \sa ProcessObject::GenerateOutputInformaton()  */
  virtual void GenerateOutputInformation();

  /** UnaryFunctorImageFilter can be implemented as a multithreaded filter.
   * Therefore, this implementation provides a ThreadedGenerateData() routine
   * which is called for each processing thread. The output image data is
   * allocated automatically by the superclass prior to calling
   * ThreadedGenerateData().  ThreadedGenerateData can only write to the
   * portion of the output image specified by the parameter
   * "outputRegionForThread"
   *
   * \sa ImageToImageFilter::ThreadedGenerateData(),
   *     ImageToImageFilter::GenerateData()  */
  void ThreadedGenerateData(const OutputImageRegionType& outputRegionForThread,
                            int threadId );

private:
  UnaryFunctorImageFilter(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

  FunctorType m_Functor;
};

} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkUnaryFunctorImageFilter.txx"
#endif

#endif
