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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkCombinedImageToImageMetricAdaptor.h,v $
  Language:  C++
  Date:      $Date: 2003/09/10 14:30:08 $
  Version:   $Revision: 1.1 $

  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 __itkCombinedImageToImageMetricAdaptor_h
#define __itkCombinedImageToImageMetricAdaptor_h

#include "itkImageToImageMetric.h"
#include <vector>


namespace itk
{
  
/** \class CombinedImageToImageMetricAdaptor
 * \brief This class is an adaptor that combines several
 * metric together to behave like one metric
 * 
 * \ingroup Numerics Optimizers
 */
template < class TFixedImage, class TMovingImage> 
class ITK_EXPORT CombinedImageToImageMetricAdaptor: 
    public ImageToImageMetric< TFixedImage, TMovingImage>
{
public:
  /** Standard class typedefs. */
  typedef CombinedImageToImageMetricAdaptor     Self;
  typedef ImageToImageMetric<TFixedImage,TMovingImage>   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( CombinedImageToImageMetricAdaptor, ImageToImageMetric );

  /** Underlying metric type. */
  typedef Superclass                                MetricType;
  typedef typename MetricType::Pointer              MetricPointer;

  /** Scales typedef */
  typedef Array<double>                             ScalesType;

  /** Inherit typedef from superclass. */
  typedef typename Superclass::ParametersType       ParametersType;
  typedef typename Superclass::FixedImageType       FixedImageType;
  typedef typename Superclass::MovingImageType      MovingImageType;
  typedef typename Superclass::FixedImageMaskType   FixedImageMaskType;
  typedef typename Superclass::MovingImageMaskType  MovingImageMaskType;
  typedef typename Superclass::FixedImageRegionType FixedImageRegionType;
  typedef typename Superclass::TransformType        TransformType;
  typedef typename Superclass::InterpolatorType     InterpolatorType;
  typedef typename Superclass::MeasureType          MeasureType;
  typedef typename Superclass::DerivativeType       DerivativeType;

  /** Set the underlying metric */
  virtual void SetMetric( unsigned long idx, 
                          MetricType * metric, 
                          double weight = 0.0 );

  /** Get the underlying metric */
  MetricType * GetMetric( unsigned long idx );

  /** Set/Get metric weight */
  virtual void SetMetricWeight( unsigned long idx, double weight );
  double GetMetricWeight( unsigned long idx );
        
  /**  Delegate computation of the value to the underlying Metric. */
  virtual void GetDerivative( const ParametersType & parameters,
                              DerivativeType & derivative ) const;
    
  /**  Delegate computation of the gradient to the costFunction.  */
  virtual void GetValueAndDerivative( const ParametersType & parameters,
                                      MeasureType & value,
                                      DerivativeType & derivative ) const;

  /**  Delegate computation of the value to the costFunction.  */
  virtual MeasureType GetValue( const ParametersType & parameters ) const;

  /** Get the number of pixels considered in the computation. */
  virtual const unsigned long & GetNumberOfPixelsCounted() const;

  /** Initialize the Metric by making sure that all the components
   *  are present and plugged together correctly     */
  virtual void Initialize(void) throw ( ExceptionObject );

protected:
  CombinedImageToImageMetricAdaptor();
  virtual ~CombinedImageToImageMetricAdaptor() {};

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

  std::vector<MetricPointer> m_InternalMetrics;
  std::vector<double>        m_MetricWeights;

};  // end of Class CostFunction

    
} // end namespace itk

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

#endif