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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkCentralDifferenceImageFunctionTest.cxx,v $
  Language:  C++
  Date:      $Date: 2003/09/10 14:30:08 $
  Version:   $Revision: 1.4 $

  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 "itkCentralDifferenceImageFunction.h"
#include "itkImage.h"
#include "itkImageRegionIterator.h"   

int itkCentralDifferenceImageFunctionTest(int, char* [] )
{
  const unsigned int ImageDimension = 2;
  typedef unsigned int PixelType;
  typedef itk::Image<PixelType,ImageDimension> ImageType;

  ImageType::Pointer image = ImageType::New();
  ImageType::SizeType size;
  size.Fill( 16 );
  ImageType::RegionType region( size );
  
  image->SetRegions( region );
  image->Allocate();

  // make a test image
  typedef itk::ImageRegionIterator<ImageType> Iterator;
  Iterator iter( image, region );
  iter.GoToBegin();
  unsigned int counter = 0;

  while ( !iter.IsAtEnd() )
    {
    iter.Set( counter++ );
    ++iter;
    }

  // set up central difference calculator
  typedef float CoordRepType;
  typedef itk::CentralDifferenceImageFunction<ImageType,CoordRepType> FunctionType;
  FunctionType::Pointer function = FunctionType::New();

  function->SetInputImage( image );

  ImageType::IndexType index;

  // pick an index inside the image
  index.Fill( 8 );
  std::cout << "Index: " << index << " Derivative: ";
  std::cout << function->EvaluateAtIndex( index ) << std::endl;

  if ( function->IsInsideBuffer( index ) )
    {
    std::cout << "Index: " << index << " is inside the BufferedRegion." << std::endl;
    }

  FunctionType::ContinuousIndexType cindex;
  cindex.Fill( 8.0 );
  std::cout << "ContinuousIndex: " << cindex << " Derivative: ";
  std::cout << function->EvaluateAtContinuousIndex( cindex ) << std::endl;
  
  FunctionType::PointType point;
  point.Fill( 8.0 );
  std::cout << "Point: " << cindex << " Derivative: ";
  std::cout << function->Evaluate( point ) << std::endl;

  // pick an index on the image edge
  index.Fill( 8 );
  index[0] = 15;
  std::cout << "Index: " << index << " Derivative: ";
  std::cout << function->EvaluateAtIndex( index ) << std::endl;

  if ( function->IsInsideBuffer( index ) )
    {
    std::cout << "Index: " << index << " is inside the BufferedRegion." << std::endl;
    }

  cindex.Fill( 8.0 );
  cindex[0] = 15.0;
  std::cout << "ContinuousIndex: " << cindex << " Derivative: ";
  std::cout << function->EvaluateAtContinuousIndex( cindex ) << std::endl;
  
  point.Fill( 8.0 );
  point[0] = 15.0;
  std::cout << "Point: " << cindex << " Derivative: ";
  std::cout << function->Evaluate( point ) << std::endl;


  std::cout << "Test passed." << std::endl;
  return EXIT_SUCCESS;

}
