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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkAtan2ImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2009-04-01 14:36:08 $
  Version:   $Revision: 1.22 $

  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 __itkAtan2ImageFilter_h
#define __itkAtan2ImageFilter_h

#include "itkBinaryFunctorImageFilter.h"
#include "vnl/vnl_math.h"

namespace itk
{
  
/** \class Atan2ImageFilter
 * \brief Computes arctangent pixel-wise from two images.
 *
 * This class is parametrized over the types of the two 
 * input images and the type of the output image. 
 * Numeric conversions (castings) are done by the C++ defaults.
 * 
 * Both pixel input types are casted to \c double in order to be 
 * used as parameters of \c vcl_atan2(). The resulting \c double value
 * is casted to the output pixel type.
 *
 * \ingroup IntensityImageFilters Multithreaded
 */
namespace Functor {  
  
template< class TInput1, class TInput2, class TOutput>
class Atan2
{
public:
  Atan2() {};
  ~Atan2() {};
  bool operator!=( const Atan2 & ) const
    {
    return false;
    }
  bool operator==( const Atan2 & other ) const
    {
    return !(*this != other);
    }
  inline TOutput operator()( const TInput1 & A, const TInput2 & B) const
    {
    return static_cast<TOutput>( 
      vcl_atan2(
        static_cast<double>(A),
        static_cast<double>(B)  )
      );
    }
}; 
}

template <class TInputImage1, class TInputImage2, class TOutputImage>
class ITK_EXPORT Atan2ImageFilter :
    public
BinaryFunctorImageFilter<TInputImage1,TInputImage2,TOutputImage, 
                         Functor::Atan2< 
  typename TInputImage1::PixelType, 
  typename TInputImage2::PixelType,
  typename TOutputImage::PixelType>   >
{
public:
  /** Standard class typedefs. */
  typedef Atan2ImageFilter          Self;
  typedef BinaryFunctorImageFilter<TInputImage1,TInputImage2,TOutputImage, 
                                   Functor::Atan2< 
    typename TInputImage1::PixelType, 
    typename TInputImage2::PixelType,
    typename TOutputImage::PixelType>   
  >                                 Superclass;
  typedef SmartPointer<Self>        Pointer;
  typedef SmartPointer<const Self>  ConstPointer;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** Runtime information support. */
  itkTypeMacro(Atan2ImageFilter, 
               BinaryFunctorImageFilter);

#ifdef ITK_USE_CONCEPT_CHECKING
  /** Begin concept checking */
  itkConceptMacro(Input1ConvertibleToDoubleCheck,
    (Concept::Convertible<typename TInputImage1::PixelType, double>));
  itkConceptMacro(Input2ConvertibleToDoubleCheck,
    (Concept::Convertible<typename TInputImage2::PixelType, double>));
  itkConceptMacro(DoubleConvertibleToOutputCheck,
    (Concept::Convertible<double, typename TOutputImage::PixelType>));
  /** End concept checking */
#endif

protected:
  Atan2ImageFilter() {}
  virtual ~Atan2ImageFilter() {}

private:
  Atan2ImageFilter(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

};

} // end namespace itk


#endif
