itkCrossHelper.h

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkCrossHelper.h,v $
  Language:  C++
  Date:      $Date: 2009-03-27 14:51:44 $
  Version:   $Revision: 1.6 $

  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 __itkCrossHelper_h
#define __itkCrossHelper_h

#include "itkNumericTraits.h"

namespace itk
{
template< typename TVector >
class CrossHelper
{
public:
  typedef TVector                           VectorType;
  typedef typename VectorType::ValueType    ValueType;

  itkStaticConstMacro ( Dimension, unsigned int, VectorType::Dimension );

  VectorType operator ( ) ( const VectorType& iU,
                            const VectorType& iV ) const
    {
    VectorType oCross;

    if( Dimension > 2 )
      {
      oCross[0] = iU[1] * iV[2] - iV[1] * iU[2];
      oCross[1] = iV[0] * iU[2] - iU[0] * iV[2];
      oCross[2] = iU[0] * iV[1] - iV[0] * iU[1];

      for( unsigned int dim = 3; dim < Dimension; dim++ )
        {
        oCross[dim] = 0.0;
        }
      }
    else
      {
      oCross.Fill( 0. );
      }

    return oCross;
    }
};
}

#endif