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

  Program:   Visualization Toolkit
  Module:    vtkImageNormalize.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 "vtkImageNormalize.h"

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

#include <cmath>

vtkStandardNewMacro(vtkImageNormalize);

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

//------------------------------------------------------------------------------
vtkImageNormalize::vtkImageNormalize()
{
  this->SetNumberOfInputPorts(1);
  this->SetNumberOfOutputPorts(1);
}

//------------------------------------------------------------------------------
int vtkImageNormalize::RequestInformation(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  // get the info objects
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  vtkDataObject::SetPointDataActiveScalarInfo(outInfo, VTK_FLOAT, -1);
  return 1;
}

//------------------------------------------------------------------------------
// This execute method handles boundaries.
// it handles boundaries. Pixels are just replicated to get values
// out of extent.
template <class T>
void vtkImageNormalizeExecute(
  vtkImageNormalize* self, vtkImageData* inData, vtkImageData* outData, int outExt[6], int id, T*)
{
  vtkImageIterator<T> inIt(inData, outExt);
  vtkImageProgressIterator<float> outIt(outData, outExt, self, id);
  int idxC, maxC;
  float sum;
  T* inVect;

  // find the region to loop over
  maxC = inData->GetNumberOfScalarComponents();

  // Loop through output pixels
  while (!outIt.IsAtEnd())
  {
    T* inSI = inIt.BeginSpan();
    float* outSI = outIt.BeginSpan();
    float* outSIEnd = outIt.EndSpan();
    while (outSI != outSIEnd)
    {
      // save the start of the vector
      inVect = inSI;

      // compute the magnitude.
      sum = 0.0;
      for (idxC = 0; idxC < maxC; idxC++)
      {
        sum += static_cast<float>(*inSI) * static_cast<float>(*inSI);
        inSI++;
      }
      if (sum > 0.0)
      {
        sum = 1.0 / sqrt(sum);
      }

      // now divide to normalize.
      for (idxC = 0; idxC < maxC; idxC++)
      {
        *outSI = static_cast<float>(*inVect) * sum;
        inVect++;
        outSI++;
      }
    }
    inIt.NextSpan();
    outIt.NextSpan();
  }
}

//------------------------------------------------------------------------------
// This method contains a switch statement that calls the correct
// templated function for the input data type.  The output data
// must match input type.  This method does handle boundary conditions.
void vtkImageNormalize::ThreadedExecute(
  vtkImageData* inData, vtkImageData* outData, int outExt[6], int id)
{
  vtkDebugMacro(<< "Execute: inData = " << inData << ", outData = " << outData);

  // this filter expects that input is the same type as output.
  if (outData->GetScalarType() != VTK_FLOAT)
  {
    vtkErrorMacro(<< "Execute: output ScalarType, " << outData->GetScalarType()
                  << ", must be float");
    return;
  }

  switch (inData->GetScalarType())
  {
    vtkTemplateMacro(
      vtkImageNormalizeExecute(this, inData, outData, outExt, id, static_cast<VTK_TT*>(nullptr)));
    default:
      vtkErrorMacro(<< "Execute: Unknown ScalarType");
      return;
  }
}
