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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkSymmetricEigenAnalysisImageFilterTest.cxx,v $
  Language:  C++
  Date:      $Date: 2006/01/15 04:28:36 $
  Version:   $Revision: 1.3 $

  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.

=========================================================================*/
#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#endif




#include "itkImage.h"
#include "itkSymmetricSecondRankTensor.h"
#include "itkImageRegionIteratorWithIndex.h"
#include "itkSymmetricEigenAnalysisImageFilter.h"


int itkSymmetricEigenAnalysisImageFilterTest(int, char* [] ) 
{

  // Define the dimension of the images
  const unsigned int myDimension = 3;

  // Define the symmetric tensor pixel type
  typedef itk::SymmetricSecondRankTensor< float, myDimension > myTensorType;
  
  // Declare the types of the images
  typedef itk::Image< myTensorType, myDimension >  myInputImageType;

  // Define the type for storing the eigen-value
  typedef itk::FixedArray< float, myDimension >  myValueArray;
  
  // Declare the types of the output images
  typedef itk::Image< myValueArray, myDimension >  myOutputImageType;

  // Declare the type of the index to access images
  typedef itk::Index<myDimension>             myIndexType;

  // Declare the type of the size 
  typedef itk::Size<myDimension>              mySizeType;

  // Declare the type of the Region
  typedef itk::ImageRegion<myDimension>        myRegionType;

  // Create the image
  myInputImageType::Pointer inputImage  = myInputImageType::New();

  
  // Define their size, and start index
  mySizeType size;
  size[0] = 8;
  size[1] = 8;
  size[2] = 8;

  myIndexType start;
  start.Fill(0);

  myRegionType region;
  region.SetIndex( start );
  region.SetSize( size );

  // Initialize Image A
  inputImage->SetLargestPossibleRegion( region );
  inputImage->SetBufferedRegion( region );
  inputImage->SetRequestedRegion( region );
  inputImage->Allocate();

  // Declare Iterator type for the input image
  typedef itk::ImageRegionIteratorWithIndex< 
                     myInputImageType>  myIteratorType;

  // Create one iterator for the Input Image A (this is a light object)
  myIteratorType it( inputImage, inputImage->GetRequestedRegion() );

  myTensorType tensorValue;
  
  tensorValue(0,0) = 19.0;
  tensorValue(0,1) = 23.0;
  tensorValue(0,2) = 29.0;
  tensorValue(1,1) = 31.0;
  tensorValue(1,2) = 37.0;
  tensorValue(2,2) = 39.0;
  
  it.GoToBegin();

  // Initialize the content of Image A
  while( !it.IsAtEnd() ) 
    {
    it.Set( tensorValue );
    ++it;
    }


  // Declare the type for the filter
  typedef itk::SymmetricEigenAnalysisImageFilter< 
                                     myInputImageType, 
                                     myOutputImageType 
                                               >  myFilterType;

            

  // Create a  Filter                                
  myFilterType::Pointer filter = myFilterType::New();
  filter->SetDimension( myTensorType::Dimension );

  // Connect the input images
  filter->SetInput( inputImage ); 

  
  // Execute the filter
  filter->Update();
  filter->SetFunctor(filter->GetFunctor());

  // Get the Smart Pointer to the Filter Output 
  // It is important to do it AFTER the filter is Updated
  // Because the object connected to the output may be changed
  // by another during GenerateData() call
  myOutputImageType::Pointer outputImage = filter->GetOutput();

  // Declare Iterator type for the output image
  typedef itk::ImageRegionIteratorWithIndex<
                                 myOutputImageType>  myOutputIteratorType;

  // Create an iterator for going through the output image
  myOutputIteratorType itg( outputImage, 
                            outputImage->GetRequestedRegion() );
  
  //  Print the content of the result image
  std::cout << " Result " << std::endl;
  itg.GoToBegin();
  while( !itg.IsAtEnd() ) 
    {
    std::cout << itg.Get();
    ++itg;
    }


  // All objects should be automatically destroyed at this point
  return EXIT_SUCCESS;

}




