text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkImageThreshold.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 "vtkImageThreshold.h"
  
  #include "vtkImageData.h"
  #include "vtkImageProgressIterator.h"
  #include "vtkInformation.h"
  #include "vtkInformationVector.h"
  #include "vtkObjectFactory.h"
  #include "vtkStreamingDemandDrivenPipeline.h"
  #include "vtkDataSetAttributes.h"
  
  vtkStandardNewMacro(vtkImageThreshold);
  
  //----------------------------------------------------------------------------
  // Constructor sets default values
  vtkImageThreshold::vtkImageThreshold()
  {
    this->UpperThreshold = VTK_FLOAT_MAX;
    this->LowerThreshold = -VTK_FLOAT_MAX;
    this->ReplaceIn = 0;
    this->InValue = 0.0;
    this->ReplaceOut = 0;
    this->OutValue = 0.0;
  
    this->OutputScalarType = -1; // invalid; output same as input
  }
  
  //----------------------------------------------------------------------------
  void vtkImageThreshold::SetInValue(double val)
  {
    if (val != this->InValue || this->ReplaceIn != 1)
    {
      this->InValue = val;
      this->ReplaceIn = 1;
      this->Modified();
    }
  }
  
  //----------------------------------------------------------------------------
  void vtkImageThreshold::SetOutValue(double val)
  {
    if (val != this->OutValue || this->ReplaceOut != 1)
    {
      this->OutValue = val;
      this->ReplaceOut = 1;
      this->Modified();
    }
  }
  
  //----------------------------------------------------------------------------
  // The values greater than or equal to the value match.
  void vtkImageThreshold::ThresholdByUpper(double thresh)
  {
    if (this->LowerThreshold != thresh || this->UpperThreshold < VTK_FLOAT_MAX)
    {
      this->LowerThreshold = thresh;
      this->UpperThreshold = VTK_FLOAT_MAX;
      this->Modified();
    }
  }
  
  //----------------------------------------------------------------------------
  // The values less than or equal to the value match.
  void vtkImageThreshold::ThresholdByLower(double thresh)
  {
    if (this->UpperThreshold != thresh || this->LowerThreshold > -VTK_FLOAT_MAX)
    {
      this->UpperThreshold = thresh;
      this->LowerThreshold = -VTK_FLOAT_MAX;
      this->Modified();
    }
  }
  
  //----------------------------------------------------------------------------
  // The values in a range (inclusive) match
  void vtkImageThreshold::ThresholdBetween(double lower, double upper)
  {
    if (this->LowerThreshold != lower || this->UpperThreshold != upper)
    {
      this->LowerThreshold = lower;
      this->UpperThreshold = upper;
      this->Modified();
    }
  }
  
  //----------------------------------------------------------------------------
  int vtkImageThreshold::RequestInformation (
    vtkInformation * vtkNotUsed(request),
    vtkInformationVector **inputVector,
    vtkInformationVector *outputVector)
  {
    // get the info objects
    vtkInformation *outInfo = outputVector->GetInformationObject(0);
    vtkInformation *inInfo = inputVector[0]->GetInformationObject(0);
  
    if (this->OutputScalarType == -1)
    {
      vtkInformation *inScalarInfo = vtkDataObject::GetActiveFieldInformation(inInfo,
        vtkDataObject::FIELD_ASSOCIATION_POINTS, vtkDataSetAttributes::SCALARS);
      if (!inScalarInfo)
      {
        vtkErrorMacro("Missing scalar field on input information!");
        return 0;
      }
      vtkDataObject::SetPointDataActiveScalarInfo(outInfo,
        inScalarInfo->Get( vtkDataObject::FIELD_ARRAY_TYPE() ), -1 );
    }
    else
    {
      vtkDataObject::SetPointDataActiveScalarInfo(outInfo, this->OutputScalarType, -1);
    }
    return 1;
  }
  
  //----------------------------------------------------------------------------
  // This templated function executes the filter for any type of data.
  template <class IT, class OT>
  void vtkImageThresholdExecute(vtkImageThreshold *self,
                                vtkImageData *inData,
                                vtkImageData *outData,
                                int outExt[6], int id, IT *, OT *)
  {
    vtkImageIterator<IT> inIt(inData, outExt);
    vtkImageProgressIterator<OT> outIt(outData, outExt, self, id);
    IT  lowerThreshold;
    IT  upperThreshold;
    int replaceIn = self->GetReplaceIn();
    OT  inValue;
    int replaceOut = self->GetReplaceOut();
    OT  outValue;
    IT temp;
  
    // Make sure the thresholds are valid for the input scalar range
    if (static_cast<double>(self->GetLowerThreshold())
        < inData->GetScalarTypeMin())
    {
      lowerThreshold = static_cast<IT>(inData->GetScalarTypeMin());
    }
    else
    {
      if (static_cast<double>(self->GetLowerThreshold()) >
          inData->GetScalarTypeMax())
      {
        lowerThreshold = static_cast<IT>(inData->GetScalarTypeMax());
      }
      else
      {
        lowerThreshold = static_cast<IT>(self->GetLowerThreshold());
      }
    }
    if (static_cast<double>(self->GetUpperThreshold())
        > inData->GetScalarTypeMax())
    {
      upperThreshold = static_cast<IT>(inData->GetScalarTypeMax());
    }
    else
    {
      if (static_cast<double>(self->GetUpperThreshold())
          < inData->GetScalarTypeMin())
      {
        upperThreshold = static_cast<IT>(inData->GetScalarTypeMin());
      }
      else
      {
        upperThreshold = static_cast<IT>(self->GetUpperThreshold());
      }
    }
  
    // Make sure the replacement values are within the output scalar range
    if (static_cast<double>(self->GetInValue()) < outData->GetScalarTypeMin())
    {
      inValue = static_cast<OT>(outData->GetScalarTypeMin());
    }
    else
    {
      if (static_cast<double>(self->GetInValue()) > outData->GetScalarTypeMax())
      {
        inValue = static_cast<OT>(outData->GetScalarTypeMax());
      }
      else
      {
        inValue = static_cast<OT>(self->GetInValue());
      }
    }
    if (static_cast<double>(self->GetOutValue()) > outData->GetScalarTypeMax())
    {
      outValue = static_cast<OT>(outData->GetScalarTypeMax());
    }
    else
    {
      if (static_cast<double>(self->GetOutValue()) < outData->GetScalarTypeMin())
      {
        outValue = static_cast<OT>(outData->GetScalarTypeMin());
      }
      else
      {
        outValue = static_cast<OT>(self->GetOutValue());
      }
    }
  
    // Loop through output pixels
    while (!outIt.IsAtEnd())
    {
      IT* inSI = inIt.BeginSpan();
      OT* outSI = outIt.BeginSpan();
      OT* outSIEnd = outIt.EndSpan();
      while (outSI != outSIEnd)
      {
        // Pixel operation
        temp = (*inSI);
        if (lowerThreshold <= temp && temp <= upperThreshold)
        {
          // match
          if (replaceIn)
          {
            *outSI = inValue;
          }
          else
          {
            *outSI = static_cast<OT>(temp);
          }
        }
        else
        {
          // not match
          if (replaceOut)
          {
            *outSI = outValue;
          }
          else
          {
            *outSI = static_cast<OT>(temp);
          }
        }
        ++inSI;
        ++outSI;
      }
      inIt.NextSpan();
      outIt.NextSpan();
    }
  }
  
  //----------------------------------------------------------------------------
  template <class T>
  void vtkImageThresholdExecute1(vtkImageThreshold *self,
                                 vtkImageData *inData,
                                 vtkImageData *outData,
                                 int outExt[6], int id, T *)
  {
    switch (outData->GetScalarType())
    {
      vtkTemplateMacro(
        vtkImageThresholdExecute(self, inData,
                                 outData, outExt, id,
                                 static_cast<T *>(0),
                                 static_cast<VTK_TT *>(0)));
      default:
        vtkGenericWarningMacro("Execute: Unknown input ScalarType");
        return;
    }
  }
  
  //----------------------------------------------------------------------------
  // This method is passed a input and output data, and executes the filter
  // algorithm to fill the output from the input.
  // It just executes a switch statement to call the correct function for
  // the datas data types.
  void vtkImageThreshold::ThreadedRequestData(
    vtkInformation *vtkNotUsed(request),
    vtkInformationVector **vtkNotUsed(inputVector),
    vtkInformationVector *vtkNotUsed(outputVector),
    vtkImageData ***inData,
    vtkImageData **outData,
    int outExt[6], int id)
  {
    switch (inData[0][0]->GetScalarType())
    {
      vtkTemplateMacro(
        vtkImageThresholdExecute1(this,
                                  inData[0][0],
                                  outData[0],
                                  outExt,
                                  id,
                                  static_cast<VTK_TT *>(0)));
      default:
        vtkErrorMacro(<< "Execute: Unknown input ScalarType");
        return;
    }
  }
  
  //----------------------------------------------------------------------------
  void vtkImageThreshold::PrintSelf(ostream& os, vtkIndent indent)
  {
    this->Superclass::PrintSelf(os,indent);
  
    os << indent << "OutputScalarType: " << this->OutputScalarType << "\n";
    os << indent << "InValue: " << this->InValue << "\n";
    os << indent << "OutValue: " << this->OutValue << "\n";
    os << indent << "LowerThreshold: " << this->LowerThreshold << "\n";
    os << indent << "UpperThreshold: " << this->UpperThreshold << "\n";
    os << indent << "ReplaceIn: " << this->ReplaceIn << "\n";
    os << indent << "ReplaceOut: " << this->ReplaceOut << "\n";
  }
  