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

  Program:   Visualization Toolkit
  Module:    vtkImageButterworthLowPass.cxx
  Language:  C++
  Date:      $Date$
  Version:   $Revision$
  Thanks:    Thanks to C. Charles Law who developed this class.

Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names
   of any contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

 * Modified source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/
#include <math.h>
#include "vtkImageButterworthLowPass.h"
#include "vtkObjectFactory.h"



//------------------------------------------------------------------------------
vtkImageButterworthLowPass* vtkImageButterworthLowPass::New()
{
  // First try to create the object from the vtkObjectFactory
  vtkObject* ret = vtkObjectFactory::CreateInstance("vtkImageButterworthLowPass");
  if(ret)
    {
    return (vtkImageButterworthLowPass*)ret;
    }
  // If the factory was unable to create the object, then create it here.
  return new vtkImageButterworthLowPass;
}






//----------------------------------------------------------------------------
vtkImageButterworthLowPass::vtkImageButterworthLowPass()
{
  int idx;
  
  for (idx = 0; idx < 3; ++idx)
    {
    this->CutOff[idx] = VTK_LARGE_FLOAT;
    }
  this->Order = 1;
}


//----------------------------------------------------------------------------
void vtkImageButterworthLowPass::SetXCutOff(float cutOff)
{
  if (cutOff == this->CutOff[0])
    {
    return;
    }
  this->CutOff[0] = cutOff;
  this->Modified();
}
//----------------------------------------------------------------------------
void vtkImageButterworthLowPass::SetYCutOff(float cutOff)
{
  if (cutOff == this->CutOff[1])
    {
    return;
    }
  this->CutOff[1] = cutOff;
  this->Modified();
}
//----------------------------------------------------------------------------
void vtkImageButterworthLowPass::SetZCutOff(float cutOff)
{
  if (cutOff == this->CutOff[2])
    {
    return;
    }
  this->CutOff[2] = cutOff;
  this->Modified();
}

//----------------------------------------------------------------------------
void vtkImageButterworthLowPass::ThreadedExecute(vtkImageData *inData, 
						 vtkImageData *outData,
						 int ext[6], int id)
{
  int idx0, idx1, idx2;
  int min0, max0;
  float *inPtr;
  float *outPtr;
  int *wholeExtent;
  float *spacing;
  int inInc0, inInc1, inInc2;
  int outInc0, outInc1, outInc2;
  float temp0, temp1, temp2, mid0, mid1, mid2;
  // normalization factors
  float norm0, norm1, norm2;
  float sum1, sum0;
  unsigned long count = 0;
  unsigned long target;

  // Error checking
  if (inData->GetNumberOfScalarComponents() != 2)
    {
    vtkErrorMacro("Expecting 2 components not " 
		  << inData->GetNumberOfScalarComponents());
    return;
    }
  if (inData->GetScalarType() != VTK_FLOAT || 
      outData->GetScalarType() != VTK_FLOAT)
    {
    vtkErrorMacro("Expecting input and output to be of type float");
    return;
    }
  
  wholeExtent = this->GetInput()->GetWholeExtent();
  spacing = inData->GetSpacing();

  inPtr = (float *)(inData->GetScalarPointerForExtent(ext));
  outPtr = (float *)(outData->GetScalarPointerForExtent(ext));

  inData->GetContinuousIncrements(ext, inInc0, inInc1, inInc2);
  outData->GetContinuousIncrements(ext, outInc0, outInc1, outInc2);  
  
  min0 = ext[0];
  max0 = ext[1];
  mid0 = (float)(wholeExtent[0] + wholeExtent[1] + 1) / 2.0;
  mid1 = (float)(wholeExtent[2] + wholeExtent[3] + 1) / 2.0;
  mid2 = (float)(wholeExtent[4] + wholeExtent[5] + 1) / 2.0;
  if ( this->CutOff[0] == 0.0)
    {
    norm0 = VTK_LARGE_FLOAT;
    }
  else
    {
    norm0 = 1.0 / ((spacing[0] * 2.0 * mid0) * this->CutOff[0]);
    }
  if ( this->CutOff[1] == 0.0)
    {
    norm1 = VTK_LARGE_FLOAT;
    }
  else
    {
    norm1 = 1.0 / ((spacing[1] * 2.0 * mid1) * this->CutOff[1]);
    }
  if ( this->CutOff[2] == 0.0)
    {
    norm2 = VTK_LARGE_FLOAT;
    }
  else
    {
    norm2 = 1.0 / ((spacing[2] * 2.0 * mid2) * this->CutOff[2]);
    }
  
  target = (unsigned long)((ext[5]-ext[4]+1)*(ext[3]-ext[2]+1)/50.0);
  target++;

  // loop over all the pixels (keeping track of normalized distance to origin.
  for (idx2 = ext[4]; idx2 <= ext[5]; ++idx2)
    {
    // distance to min (this axis' contribution)
    temp2 = (float)idx2;
    // Wrap back to 0.
    if (temp2 > mid2)
      {
      temp2 = mid2 + mid2 - temp2;
      }
    // Convert location into normalized cycles/world unit
    temp2 = temp2 * norm2;

    for (idx1 = ext[2]; !this->AbortExecute && idx1 <= ext[3]; ++idx1)
      {
      if (!id) 
	{
	if (!(count%target))
	  {
	  this->UpdateProgress(count/(50.0*target));
	  }
	count++;
	}
      // distance to min (this axis' contribution)
      temp1 = (float)idx1;
      // Wrap back to 0.
      if (temp1 > mid1)
	{
	temp1 = mid1 + mid1 - temp1;
	}
      // Convert location into cycles / world unit
      temp1 = temp1 * norm1;
      sum1 = temp2 * temp2 + temp1 * temp1;
      
      for (idx0 = min0; idx0 <= max0; ++idx0)
	{
	// distance to min (this axis' contribution)
	temp0 = (float)idx0;
	// Wrap back to 0.
	if (temp0 > mid0)
	  {
	  temp0 = mid0 + mid0 - temp0;
	  }
	// Convert location into cycles / world unit
	temp0 = temp0 * norm0;
	sum0 = sum1 + temp0 * temp0;
	
	// compute Butterworth1D function from sum = d^2
	if (this->Order == 1)
	  {
	  sum0 = 1.0 / (1.0 + sum0);
	  }
	else
	  {
	  sum0 = 1.0 / (1.0 + pow(sum0, (float)this->Order));
	  }	
	
	// real component
	*outPtr++ = *inPtr++ * sum0;
	// imaginary component	
	*outPtr++ = *inPtr++ * sum0;
	
	}
      inPtr += inInc1;
      outPtr += outInc1;
      }
    inPtr += inInc2;
    outPtr += outInc2;    
    }
}

void vtkImageButterworthLowPass::PrintSelf(ostream& os, vtkIndent indent)
{
  vtkImageToImageFilter::PrintSelf(os,indent);

  os << indent << "Order: " << this->Order << "\n";

  os << indent << "CutOff: ( "
     << this->CutOff[0] << ", "
     << this->CutOff[1] << ", "
     << this->CutOff[2] << " )\n";
}

