text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkTreeLevelsFilter.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.
  
  =========================================================================*/
  /*-------------------------------------------------------------------------
    Copyright 2008 Sandia Corporation.
    Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
    the U.S. Government retains certain rights in this software.
  -------------------------------------------------------------------------*/
  
  #include "vtkTreeLevelsFilter.h"
  
  #include "vtkCellArray.h"
  #include "vtkCellData.h"
  #include "vtkDataArray.h"
  #include "vtkInformation.h"
  #include "vtkInformationVector.h"
  #include "vtkIntArray.h"
  #include "vtkMath.h"
  #include "vtkObjectFactory.h"
  #include "vtkPointData.h"
  
  #include "vtkGraph.h"
  #include "vtkTree.h"
  
  vtkStandardNewMacro(vtkTreeLevelsFilter);
  
  vtkTreeLevelsFilter::vtkTreeLevelsFilter() = default;
  
  int vtkTreeLevelsFilter::RequestData(vtkInformation* vtkNotUsed(request),
    vtkInformationVector** inputVector, vtkInformationVector* outputVector)
  {
    // get the info objects
    vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
    vtkInformation* outInfo = outputVector->GetInformationObject(0);
  
    // Storing the inputTree and outputTree handles
    vtkTree* inputTree = vtkTree::SafeDownCast(inInfo->Get(vtkDataObject::DATA_OBJECT()));
    vtkTree* outputTree = vtkTree::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));
  
    // Copy the input to the output.
    outputTree->ShallowCopy(inputTree);
  
    // Add the 1-tuple array that will store the level from
    // the root down (root = 0, and +1 for each level down)
    vtkIntArray* levelArray = vtkIntArray::New();
    levelArray->SetName("level");
    levelArray->SetNumberOfComponents(1);
    levelArray->SetNumberOfTuples(outputTree->GetNumberOfVertices());
    vtkDataSetAttributes* data = outputTree->GetVertexData();
    data->AddArray(levelArray);
  
    // Add the 1-tuple array that will marks each
    // leaf with a '1' and everything else with a '0'
    vtkIntArray* leafArray = vtkIntArray::New();
    leafArray->SetName("leaf");
    leafArray->SetNumberOfComponents(1);
    leafArray->SetNumberOfTuples(outputTree->GetNumberOfVertices());
    data->AddArray(leafArray);
  
    for (vtkIdType i = 0; i < outputTree->GetNumberOfVertices(); i++)
    {
      levelArray->SetValue(i, outputTree->GetLevel(i));
      leafArray->SetValue(i, outputTree->IsLeaf(i));
    }
  
    // Set levels as the active point scalar
    data->SetActiveScalars("level");
  
    // Clean up
    levelArray->Delete();
    leafArray->Delete();
  
    return 1;
  }
  
  void vtkTreeLevelsFilter::PrintSelf(ostream& os, vtkIndent indent)
  {
    this->Superclass::PrintSelf(os, indent);
  }
  