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

  Program:   Visualization Toolkit
  Module:    vtkImageGaussianSource.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/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 notice for more information.

=========================================================================*/
#include "vtkImageGaussianSource.h"

#include "vtkImageData.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkStreamingDemandDrivenPipeline.h"

#include <math.h>

vtkStandardNewMacro(vtkImageGaussianSource);

//----------------------------------------------------------------------------
vtkImageGaussianSource::vtkImageGaussianSource()
{
  this->SetNumberOfInputPorts(0);
  this->Maximum = 1.0;
  this->Center[0] = 0.0;
  this->Center[1] = 0.0;
  this->Center[2] = 0.0;

  this->WholeExtent[0] = 0;  this->WholeExtent[1] = 255;
  this->WholeExtent[2] = 0;  this->WholeExtent[3] = 255;
  this->WholeExtent[4] = 0;  this->WholeExtent[5] = 0;
  this->StandardDeviation = 100.0;
}


//----------------------------------------------------------------------------
void vtkImageGaussianSource::SetWholeExtent(int xMin, int xMax, 
                                            int yMin, int yMax,
                                            int zMin, int zMax)
{
  int modified = 0;
  
  if (this->WholeExtent[0] != xMin)
    {
    modified = 1;
    this->WholeExtent[0] = xMin ;
    }
  if (this->WholeExtent[1] != xMax)
    {
    modified = 1;
    this->WholeExtent[1] = xMax ;
    }
  if (this->WholeExtent[2] != yMin)
    {
    modified = 1;
    this->WholeExtent[2] = yMin ;
    }
  if (this->WholeExtent[3] != yMax)
    {
    modified = 1;
    this->WholeExtent[3] = yMax ;
    }
  if (this->WholeExtent[4] != zMin)
    {
    modified = 1;
    this->WholeExtent[4] = zMin ;
    }
  if (this->WholeExtent[5] != zMax)
    {
    modified = 1;
    this->WholeExtent[5] = zMax ;
    }
  if (modified)
    {
    this->Modified();
    }
}

//----------------------------------------------------------------------------
int vtkImageGaussianSource::RequestInformation (
  vtkInformation * vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed( inputVector ),
  vtkInformationVector *outputVector)
{
  // get the info objects
  vtkInformation* outInfo = outputVector->GetInformationObject(0);

  outInfo->Set(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(),
               this->WholeExtent,6);
  vtkDataObject::SetPointDataActiveScalarInfo(outInfo, VTK_DOUBLE, 1);
  return 1;
}

//----------------------------------------------------------------------------
int vtkImageGaussianSource::RequestData(
  vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector),
  vtkInformationVector* outputVector)
{
  double *outPtr;
  int idxX, idxY, idxZ;
  int maxX, maxY, maxZ;
  vtkIdType outIncX, outIncY, outIncZ;
  int *outExt;
  double sum;
  double yContrib, zContrib;
  double temp, temp2;
  unsigned long count = 0;
  unsigned long target;
  
  vtkInformation *outInfo = outputVector->GetInformationObject(0);  
  vtkImageData *output = vtkImageData::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkImageData *data = this->AllocateOutputData(output);

  if (data->GetScalarType() != VTK_DOUBLE)
    {
    vtkErrorMacro("Execute: This source only outputs doubles");
    }
  
  outExt = data->GetExtent();
  
  // find the region to loop over
  maxX = outExt[1] - outExt[0];
  maxY = outExt[3] - outExt[2]; 
  maxZ = outExt[5] - outExt[4];
  
  // Get increments to march through data 
  data->GetContinuousIncrements(outExt, outIncX, outIncY, outIncZ);
  outPtr = static_cast<double *>(data->GetScalarPointer(outExt[0],outExt[2],outExt[4]));
  
  target = static_cast<unsigned long>((maxZ+1)*(maxY+1)/50.0);
  target++;

  // Loop through ouput pixels
  temp2 = 1.0 / (2.0 * this->StandardDeviation * this->StandardDeviation);

  for (idxZ = 0; idxZ <= maxZ; idxZ++)
    {
    zContrib = this->Center[2] - (idxZ + outExt[4]);
    zContrib = zContrib*zContrib;
    for (idxY = 0; !this->AbortExecute && idxY <= maxY; idxY++)
      {
      if (!(count%target))
        {
        this->UpdateProgress(count/(50.0*target));
        }
      count++;
      yContrib = this->Center[1] - (idxY + outExt[2]);
      yContrib = yContrib*yContrib;
      for (idxX = 0; idxX <= maxX; idxX++)
        {
        // Pixel operation
        sum = zContrib + yContrib;
        temp = this->Center[0] - (idxX + outExt[0]);
        sum = sum + (temp * temp);
        *outPtr = this->Maximum * exp(-sum * temp2);
        outPtr++;
        }
      outPtr += outIncY;
      }
    outPtr += outIncZ;
    }

  return 1;
}

void vtkImageGaussianSource::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);

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

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

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

}


