// SPDX-FileCopyrightText: Copyright (c) Kitware Inc.
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkHierarchicalFractal.h"

#include "vtkAMRBox.h"
#include "vtkCellData.h"
#include "vtkCompositeDataIterator.h"
#include "vtkCompositeDataPipeline.h"
#include "vtkDoubleArray.h"
#include "vtkImageMandelbrotSource.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkIntArray.h"
#include "vtkMinimalStandardRandomSequence.h"
#include "vtkMultiBlockDataSet.h"
#include "vtkMultiProcessController.h"
#include "vtkObjectFactory.h"
#include "vtkOverlappingAMR.h"
#include "vtkParallelAMRUtilities.h"
#include "vtkPointData.h"
#include "vtkRectilinearGrid.h"
#include "vtkSmartPointer.h"
#include "vtkUniformGrid.h"
#include "vtkUnsignedCharArray.h"

#include <algorithm>
#include <cassert>

vtkStandardNewMacro(vtkHierarchicalFractal);

//----------------------------------------------------------------------------
class HierarchicalFractalOutputUtil : public vtkObject
{
public:
  static HierarchicalFractalOutputUtil* New();
  vtkTypeMacro(HierarchicalFractalOutputUtil, vtkObject);

  void Initialize(int gridDescription, const double* topLevelSpacing)
  {
    this->GridDescription = gridDescription;
    for (int d = 0; d < 3; d++)
    {
      this->TopLevelSpacing[d] = topLevelSpacing[d];
    }
  }

  int AddDataSet(vtkDataObject* newData, unsigned int level)
  {
    vtkSmartPointer<vtkDataObject> data;
    data.TakeReference(newData);
    this->DataSets.push_back(data);
    this->Levels.push_back(level);
    int index = static_cast<int>(this->DataSets.size()) - 1;
    return index;
  }

  void SetAMRBox(int index, int ext[6])
  {
    vtkAMRBox box;
    box.SetDimensions(ext[0], ext[2], ext[4], ext[1], ext[3], ext[5], this->GridDescription);
    for (int i = static_cast<int>(this->Boxes.size()); i <= index; i++)
    {
      this->Boxes.emplace_back();
    }
    this->Boxes[index] = box;
  }

  ~HierarchicalFractalOutputUtil() override
  {
    this->DataSets.clear();
    this->Levels.clear();
  }

  void CreateOutput(vtkMultiBlockDataSet* mbs)
  {
    for (size_t i = 0; i < this->DataSets.size(); i++)
    {
      vtkDataObject* dataSet = DataSets[i];
      unsigned int level = this->Levels[i];
      vtkMultiBlockDataSet* block = vtkMultiBlockDataSet::SafeDownCast(mbs->GetBlock(level));
      if (!block)
      {
        block = vtkMultiBlockDataSet::New();
        mbs->SetBlock(level, block);
        block->Delete();
      }
      unsigned int index = block->GetNumberOfBlocks();
      block->SetBlock(index, dataSet);
    }
  }
  void CreateOutput(vtkOverlappingAMR* hbds)
  {
    std::vector<unsigned int> blocksPerLevel;
    double origin[3] = { DBL_MAX, DBL_MAX, DBL_MAX };
    for (size_t i = 0; i < this->Levels.size(); i++)
    {
      unsigned int level = this->Levels[i];
      vtkUniformGrid* grid = vtkUniformGrid::SafeDownCast(this->DataSets[i]);
      if (grid)
      {
        double* gridOrigin = grid->GetOrigin();
        for (int d = 0; d < 3; d++)
        {
          origin[d] = std::min(origin[d], gridOrigin[d]);
        }
      }
      for (unsigned int j = static_cast<unsigned int>(blocksPerLevel.size()); j <= level; j++)
      {
        blocksPerLevel.push_back(0);
      }
      blocksPerLevel[level]++;
    }

    std::vector<unsigned int> blockIds(
      blocksPerLevel.size(), 0); // keep track of the id at each level
    hbds->Initialize(blocksPerLevel);
    hbds->SetOrigin(origin);
    hbds->SetGridDescription(this->GridDescription);
    for (unsigned int level = 0; level < hbds->GetNumberOfLevels(); level++)
    {
      int spacingFactor = 1;
      spacingFactor = spacingFactor << level;
      double spacing[3];
      spacing[0] = this->TopLevelSpacing[0] / (double)(spacingFactor);
      spacing[1] = this->TopLevelSpacing[1] / (double)(spacingFactor);
      spacing[2] = this->TopLevelSpacing[2] / (double)(spacingFactor);
      hbds->SetSpacing(level, spacing);
    }

    for (size_t i = 0; i < this->Levels.size(); i++)
    {
      unsigned int level = this->Levels[i];
      unsigned int id = blockIds[level];
      vtkUniformGrid* grid = vtkUniformGrid::SafeDownCast(this->DataSets[i]);
      const vtkAMRBox& box = this->Boxes[i];
      assert(!box.IsInvalid());

      hbds->SetAMRBox(level, id, box);
      if (grid)
      {
        hbds->SetDataSet(level, id, grid);
      }
      blockIds[level]++;
    }
  }

private:
  HierarchicalFractalOutputUtil()
    : GridDescription(-1)
  {
  }
  std::vector<vtkSmartPointer<vtkDataObject>> DataSets;
  std::vector<unsigned int> Levels;
  std::vector<vtkAMRBox> Boxes;
  int GridDescription;
  double TopLevelSpacing[3];
};

vtkStandardNewMacro(HierarchicalFractalOutputUtil);

//----------------------------------------------------------------------------
vtkHierarchicalFractal::vtkHierarchicalFractal()
{
  this->SetNumberOfInputPorts(0);

  this->Dimensions = 10;
  this->FractalValue = 9.5;
  this->MaximumLevel = 6;
  this->GhostLevels = 0;

  this->Levels = vtkIntArray::New();
  this->TwoDimensional = 1;
  this->Asymetric = 1;
  this->Overlap = 1;

  this->TopLevelSpacing[0] = 1.0;
  this->TopLevelSpacing[1] = 1.0;
  this->TopLevelSpacing[2] = 1.0;

  this->TopLevelOrigin[0] = 0.0;
  this->TopLevelOrigin[1] = 0.0;
  this->TopLevelOrigin[2] = 0.0;

  this->GenerateRectilinearGrids = 0;

  this->TimeStep = 0;
  this->TimeStepRange[0] = 0;
  this->TimeStepRange[1] = 10;
}

//----------------------------------------------------------------------------
vtkHierarchicalFractal::~vtkHierarchicalFractal()
{
  this->Levels->Delete();
  this->Levels = nullptr;
}

//----------------------------------------------------------------------------
int vtkHierarchicalFractal::RequestDataObject(
  vtkInformation*, vtkInformationVector**, vtkInformationVector* outV)
{
  vtkInformation* outInfo = outV->GetInformationObject(0);
  vtkCompositeDataSet* outData = nullptr;

  if (this->GenerateRectilinearGrids)
  {
    outData = vtkMultiBlockDataSet::New();
  }
  else
  {
    outData = vtkOverlappingAMR::New();
  }

  outInfo->Set(vtkDataObject::DATA_OBJECT(), outData);
  outInfo->Set(vtkDataObject::DATA_EXTENT_TYPE(), outData->GetExtentType());
  outData->Delete();
  return 1;
}

//----------------------------------------------------------------------------
// This handles any alterations necessary for ghost levels.
void vtkHierarchicalFractal::SetBlockInfo(vtkUniformGrid* grid, int level, int* ext, int onFace[6])
{
  // onFace[0]:xmin
  // onFace[1]:xmax
  // onFace[2]:ymin
  // onFace[3]:ymax
  // onFace[4]:zmin
  // onFace[5]:zmax

  if (this->GhostLevels)
  {
    if (!onFace[0])
    {
      ext[0] -= 1;
    }
    if (!onFace[2])
    {
      ext[2] -= 1;
    }
    if (!onFace[4])
    {
      ext[4] -= 1;
    }
    if (!onFace[1])
    {
      ext[1] += 1;
    }
    if (!onFace[3])
    {
      ext[3] += 1;
    }
    if (!onFace[5])
    {
      ext[5] += 1;
    }
  }
  if (this->TwoDimensional)
  {
    ext[4] = ext[5] = 0;
  }

  double bds[6];
  double origin[3];
  double spacing[3];

  this->CellExtentToBounds(level, ext, bds);
  origin[0] = bds[0];
  origin[1] = bds[2];
  origin[2] = bds[4];
  spacing[0] = (bds[1] - bds[0]) / (double)(ext[1] - ext[0] + 1);
  spacing[1] = (bds[3] - bds[2]) / (double)(ext[3] - ext[2] + 1);
  spacing[2] = (bds[5] - bds[4]) / (double)(ext[5] - ext[4] + 1);

  // Handle Lower dimensions.  Assume that cell dimension of 1 is a collapsed
  // dimension.  Point dim equal 1 also.
  int dim[3];

  dim[0] = dim[1] = dim[2] = 1;
  if (ext[1] > ext[0])
  {
    dim[0] = ext[1] - ext[0] + 2;
  }
  if (ext[3] > ext[2])
  {
    dim[1] = ext[3] - ext[2] + 2;
  }
  if (ext[5] > ext[4])
  {
    dim[2] = ext[5] - ext[4] + 2;
  }

  grid->SetDimensions(dim);
  grid->SetSpacing(spacing);
  grid->SetOrigin(origin);

  if (this->GhostLevels > 0)
  {
    this->AddGhostLevelArray(grid, dim, onFace);
  }
}

//----------------------------------------------------------------------------
// This handles any alterations necessary for ghost levels.
void vtkHierarchicalFractal::SetRBlockInfo(
  vtkRectilinearGrid* grid, int level, int* ext, int onFace[6])
{
  if (this->GhostLevels)
  {
    if (!onFace[0])
    {
      ext[0] -= 1;
    }
    if (!onFace[2])
    {
      ext[2] -= 1;
    }
    if (!onFace[4])
    {
      ext[4] -= 1;
    }
    if (!onFace[1])
    {
      ext[1] += 1;
    }
    if (!onFace[3])
    {
      ext[3] += 1;
    }
    if (!onFace[5])
    {
      ext[5] += 1;
    }
  }
  if (this->TwoDimensional)
  {
    ext[4] = ext[5] = 0;
  }

  double bds[6];
  double origin[3];
  double spacing[3];

  this->CellExtentToBounds(level, ext, bds);
  origin[0] = bds[0];
  origin[1] = bds[2];
  origin[2] = bds[4];
  spacing[0] = (bds[1] - bds[0]) / (double)(ext[1] - ext[0] + 1);
  spacing[1] = (bds[3] - bds[2]) / (double)(ext[3] - ext[2] + 1);
  spacing[2] = (bds[5] - bds[4]) / (double)(ext[5] - ext[4] + 1);

  // Handle Lower dimensions.  Assume that cell dimension of 1 is a collapsed
  // dimension.  Point dim equal 1 also.
  int dim[3];

  dim[0] = dim[1] = dim[2] = 1;
  if (ext[1] > ext[0])
  {
    dim[0] = ext[1] - ext[0] + 2;
  }
  if (ext[3] > ext[2])
  {
    dim[1] = ext[3] - ext[2] + 2;
  }
  if (ext[5] > ext[4])
  {
    dim[2] = ext[5] - ext[4] + 2;
  }

  grid->SetDimensions(dim);

  vtkDoubleArray* coords[3];

  vtkNew<vtkMinimalStandardRandomSequence> rand;
  rand->Initialize(1234);
  int coord = 0;
  while (coord < 3)
  {
    coords[coord] = vtkDoubleArray::New();
    // grid->SetOrigin(origin);

    // first point
    coords[coord]->InsertNextValue(origin[coord]);

    double uniformCoordinate;

    int i = 1;
    int c;
    if (this->GhostLevels && !onFace[coord * 2 + 1])
    {
      c = dim[coord] - 2;
    }
    else
    {
      c = dim[coord] - 1;
    }
    uniformCoordinate = origin[coord];

    if (this->GhostLevels && !onFace[coord * 2])
    {
      uniformCoordinate += spacing[coord];
      coords[coord]->InsertNextValue(uniformCoordinate);
      ++i;
    }

    while (i < c)
    {
      uniformCoordinate += spacing[coord];
      // get a random number about 1/5 of the uniform spacing.
      rand->Next();
      double epsilon = (rand->GetValue() - 0.5) * spacing[coord] * 0.4;
      coords[coord]->InsertNextValue(uniformCoordinate + epsilon);
      ++i;
    }

    if (this->GhostLevels && !onFace[coord * 2 + 1])
    {
      uniformCoordinate += spacing[coord];
      coords[coord]->InsertNextValue(uniformCoordinate);
      ++i;
    }

    // last point
    uniformCoordinate += spacing[coord];
    coords[coord]->InsertNextValue(uniformCoordinate);

    ++coord;
  }

  //  grid->SetSpacing(spacing);
  grid->SetXCoordinates(coords[0]);
  grid->SetYCoordinates(coords[1]);
  grid->SetZCoordinates(coords[2]);
  coord = 0;
  while (coord < 3)
  {
    coords[coord]->Delete();
    ++coord;
  }

  if (this->GhostLevels > 0)
  {
    this->AddGhostLevelArray(grid, dim, onFace);
  }
}

//----------------------------------------------------------------------------
int vtkHierarchicalFractal::TwoDTest(double bds[6], int level, int target)
{
  // Test the 4 corners.  Refine if the blocks cross the border.
  int v0, v1, v2, v3;

  if (level == target)
  {
    return 0;
  }

  if (level < 2)
  {
    return 1;
  }

  v0 = this->MandelbrotTest(bds[0], bds[2]);
  v1 = this->MandelbrotTest(bds[1], bds[2]);
  v2 = this->MandelbrotTest(bds[0], bds[3]);
  v3 = this->MandelbrotTest(bds[1], bds[3]);
  if (v0 && v1 && v2 && v3)
  {
    return 0;
  }
  if (!v0 && !v1 && !v2 && !v3)
  {
    return 0;
  }
  return 1;
}

int vtkHierarchicalFractal::MandelbrotTest(double x, double y)
{
  unsigned short count = 0;
  double v1;
  double cReal, cImag, zReal, zImag;
  double zReal2, zImag2;

  cReal = x;
  cImag = y;
  zReal = 0.0;
  zImag = this->TimeStep / 10.0;

  zReal2 = zReal * zReal;
  zImag2 = zImag * zImag;
  v1 = (zReal2 + zImag2);
  while (v1 < 4.0 && count < 100)
  {
    zImag = 2.0 * zReal * zImag + cImag;
    zReal = zReal2 - zImag2 + cReal;
    zReal2 = zReal * zReal;
    zImag2 = zImag * zImag;
    ++count;
    v1 = (zReal2 + zImag2);
  }

  if (count == 100)
  {
    return 1;
  }

  return 0;
}

//----------------------------------------------------------------------------
// Description:
// This is called by the superclass.
// This is the method you should override.
int vtkHierarchicalFractal::RequestInformation(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (!this->Superclass::RequestInformation(request, inputVector, outputVector))
  {
    return 0;
  }

  vtkInformation* info = outputVector->GetInformationObject(0);
  info->Set(CAN_HANDLE_PIECE_REQUEST(), 1);

  return 1;
}

//----------------------------------------------------------------------------
// Description:
// This is called by the superclass.
// This is the method you should override.
int vtkHierarchicalFractal::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  vtkInformation* info = outputVector->GetInformationObject(0);
  vtkDataObject* doOutput = info->Get(vtkDataObject::DATA_OBJECT());
  vtkCompositeDataSet* output;
  output = vtkCompositeDataSet::SafeDownCast(doOutput);

  if (output == nullptr)
  {
    vtkErrorMacro("The output is not a HierarchicalDataSet");
    return 0;
  }
  if (!info->Has(vtkStreamingDemandDrivenPipeline::UPDATE_PIECE_NUMBER()) ||
    !info->Has(vtkStreamingDemandDrivenPipeline::UPDATE_NUMBER_OF_PIECES()))
  {
    vtkErrorMacro("Expected information not found. "
                  "Cannot provide update extent.");
    return 0;
  }

  output->Initialize(); // remove all previous blocks

  // By setting SetMaximumNumberOfPieces(-1)
  // then GetUpdateNumberOfPieces() should always return the number
  // of processors in the parallel job and GetUpdatePiece() should
  // return the specific process number
  int piece = info->Get(vtkStreamingDemandDrivenPipeline::UPDATE_PIECE_NUMBER());
  int numPieces = info->Get(vtkStreamingDemandDrivenPipeline::UPDATE_NUMBER_OF_PIECES());

  float ox = -1.75;
  float oy = -1.25;
  float oz = 0.0;
  float xSize = 2.5;
  float ySize = 2.5;
  float zSize = 2.0;
  int blockId = 0;

  // This is 10x10x10 in cells.
  this->SetTopLevelOrigin(ox, oy, oz);
  this->SetTopLevelSpacing(
    xSize / this->Dimensions, ySize / this->Dimensions, zSize / this->Dimensions);

  this->OutputUtil = vtkSmartPointer<HierarchicalFractalOutputUtil>::New();
  this->OutputUtil->Initialize(this->TwoDimensional ? vtkStructuredData::VTK_STRUCTURED_XY_PLANE
                                                    : vtkStructuredData::VTK_STRUCTURED_XYZ_GRID,
    this->TopLevelSpacing);

  int ext[6];
  ext[0] = ext[2] = ext[4] = 0;
  ext[1] = ext[3] = ext[5] = this->Dimensions - 1;
  if (this->Asymetric)
  { // The changes to an extra 2 in the next level.
    ext[1] += 1;
  }

  // Get a global (across all processes) count of the blocks.
  // Do not create the blocks.
  this->StartBlock = 0;
  this->EndBlock = -1;
  this->BlockCount = 0;
  int onFace[6];
  onFace[0] = 1;
  onFace[1] = 1;
  onFace[2] = 1;
  onFace[3] = 1;
  onFace[4] = 1;
  onFace[5] = 1;
  this->Traverse(blockId, 0, output, ext[0], ext[1], ext[2], ext[3], ext[4], ext[5], onFace);

  // Generate our share of the blocks.
  this->StartBlock = (int)((float)(piece * this->BlockCount) / (float)(numPieces));
  this->EndBlock = (int)((float)((piece + 1) * this->BlockCount) / (float)(numPieces)) - 1;
  this->BlockCount = 0;

  this->Levels->Initialize();
  this->Traverse(blockId, 0, output, ext[0], ext[1], ext[2], ext[3], ext[4], ext[5], onFace);

  if (vtkOverlappingAMR::SafeDownCast(output))
  {
    this->OutputUtil->CreateOutput(vtkOverlappingAMR::SafeDownCast(output));
  }
  else if (vtkMultiBlockDataSet::SafeDownCast(output))
  {
    this->OutputUtil->CreateOutput(vtkMultiBlockDataSet::SafeDownCast(output));
  }

  double bounds[6];

  bounds[0] = ox;
  bounds[1] = ox + xSize;
  bounds[2] = oy;
  bounds[3] = oy + ySize;
  bounds[4] = oz;
  if (this->TwoDimensional)
  {
    bounds[5] = oz;
  }
  else
  {
    bounds[5] = oz + zSize;
  }

  info->Set(vtkStreamingDemandDrivenPipeline::BOUNDS(), bounds, 6);

  if (!this->GenerateRectilinearGrids)
  {
    this->AddVectorArray(output);
    this->AddTestArray(output);
    this->AddBlockIdArray(output);
    vtkOverlappingAMR* hset = vtkOverlappingAMR::SafeDownCast(output);
    this->AddDepthArray(hset);
    vtkParallelAMRUtilities::BlankCells(hset, vtkMultiProcessController::GetGlobalController());
    info->Set(vtkCompositeDataPipeline::COMPOSITE_DATA_META_DATA(), hset);
  }
  this->AddFractalArray(output);

  this->OutputUtil = nullptr;

  return 1;
}

//----------------------------------------------------------------------------
int vtkHierarchicalFractal::LineTest2(
  float x0, float y0, float z0, float x1, float y1, float z1, double bds[6])
{
  // intersect line with plane.
  float x, y, z;
  float k;

  // Special case ane point is inside box.
  if (x0 > bds[0] && x0 < bds[1] && y0 > bds[2] && y0 < bds[3] && z0 > bds[4] && z0 < bds[5])
  {
    return 1;
  }
  if (x1 > bds[0] && x1 < bds[1] && y1 > bds[2] && y1 < bds[3] && z1 > bds[4] && z1 < bds[5])
  {
    return 1;
  }

  // Do not worry about divide by zero.
  // min x
  x = bds[0];
  k = (x - x0) / (x1 - x0);
  if (k >= 0.0 && k <= 1.0)
  {
    y = y0 + k * (y1 - y0);
    z = z0 + k * (z1 - z0);
    if (y >= bds[2] && y <= bds[3] && z >= bds[4] && z <= bds[5])
    {
      return 1;
    }
  }
  // max x
  x = bds[1];
  k = (x - x0) / (x1 - x0);
  if (k >= 0.0 && k <= 1.0)
  {
    y = y0 + k * (y1 - y0);
    z = z0 + k * (z1 - z0);
    if (y >= bds[2] && y <= bds[3] && z >= bds[4] && z <= bds[5])
    {
      return 1;
    }
  }
  // min y
  y = bds[2];
  k = (y - y0) / (y1 - y0);
  if (k >= 0.0 && k <= 1.0)
  {
    x = x0 + k * (x1 - x0);
    z = z0 + k * (z1 - z0);
    if (x >= bds[0] && x <= bds[1] && z >= bds[4] && z <= bds[5])
    {
      return 1;
    }
  }
  // max y
  y = bds[3];
  k = (y - y0) / (y1 - y0);
  if (k >= 0.0 && k <= 1.0)
  {
    x = x0 + k * (x1 - x0);
    z = z0 + k * (z1 - z0);
    if (x >= bds[0] && x <= bds[1] && z >= bds[4] && z <= bds[5])
    {
      return 1;
    }
  }
  // min z
  z = bds[4];
  k = (z - z0) / (z1 - z0);
  if (k >= 0.0 && k <= 1.0)
  {
    x = x0 + k * (x1 - x0);
    y = y0 + k * (y1 - y0);
    if (y >= bds[2] && y <= bds[3] && x >= bds[0] && x <= bds[1])
    {
      return 1;
    }
  }

  return 0;
}

//----------------------------------------------------------------------------
int vtkHierarchicalFractal::LineTest(
  float x0, float y0, float z0, float x1, float y1, float z1, double bds[6], int level, int target)
{
  if (level >= target)
  {
    return 0;
  }
  // First check to see if the line intersects this block.
  if (this->LineTest2(x0, y0, z0, x1, y1, z1, bds))
  {
    return 1;
  }

  // If the line intersects our neighbor, then our levels cannot differ by
  // more than one.
  // Assume that our neighbor is half our size.
  double bds2[6];
  memcpy(bds2, bds, 6 * sizeof(double));
  target = target - 1;
  float size;

  size = 0.5 * (bds[1] - bds[0]);
  bds2[0] = bds[0] - size;
  bds2[1] = bds[1] + size;
  if (this->LineTest(x0, y0, z0, x1, y1, z1, bds2, level, target))
  {
    return 1;
  }
  bds2[0] = bds[0];
  bds2[1] = bds[1];

  size = 0.5 * (bds[3] - bds[2]);
  bds2[2] = bds[2] - size;
  bds2[3] = bds[3] + size;
  if (this->LineTest(x0, y0, z0, x1, y1, z1, bds2, level, target))
  {
    return 1;
  }
  bds2[2] = bds[2];
  bds2[3] = bds[3];

  size = 0.5 * (bds[5] - bds[4]);
  bds2[4] = bds[4] - size;
  bds2[5] = bds[5] + size;
  if (this->LineTest(x0, y0, z0, x1, y1, z1, bds2, level, target))
  {
    return 1;
  }

  return 0;
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::Traverse(int& blockId, int level, vtkCompositeDataSet* output, int x0,
  int x3, int y0, int y3, int z0, int z3, int onFace[6])
{
  double bds[6];
  int x1, x2, y1, y2, z1, z2;
  int nextLevel = level + 1;
  if (this->TwoDimensional)
  {
    z0 = z3 = 0;
  }

  // Get the bounds of the proposed block.
  int ext[6];
  ext[0] = x0;
  ext[1] = x3;
  ext[2] = y0;
  ext[3] = y3, ext[4] = z0;
  ext[5] = z3;
  this->CellExtentToBounds(level, ext, bds);

  x0 = x0 * 2;
  x3 = (x3 + 1) * 2 - 1;
  y0 = y0 * 2;
  y3 = (y3 + 1) * 2 - 1;
  z0 = z0 * 2;
  z3 = (z3 + 1) * 2 - 1;

  x2 = x0 + this->Dimensions;
  x1 = x2 - 1;
  y2 = y0 + this->Dimensions;
  y1 = y2 - 1;
  z2 = z0 + this->Dimensions;
  z1 = z2 - 1;

  if (x3 - x2 - x1 + x0 > 2)
  { // balance asymetric blocks.
    x2 += 2;
    x1 += 2;
  }

  int subOnFace[6];
  int generateBlock = 1;
  if (this->TwoDimensional)
  {
    if (this->TwoDTest(bds, level, this->MaximumLevel))
    {
      if (!this->Overlap)
      {
        generateBlock = 0;
      }
      // Traverse the 4 new blocks.
      subOnFace[0] = onFace[0];
      subOnFace[1] = 0;
      subOnFace[2] = onFace[2];
      subOnFace[3] = 0;
      subOnFace[4] = 1;
      subOnFace[5] = 1;
      this->Traverse(blockId, nextLevel, output, x0, x1, y0, y1, z0, z0, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      //      subOnFace[2]=onFace[2];
      //      subOnFace[3]=0;
      this->Traverse(blockId, nextLevel, output, x2, x3, y0, y1, z0, z0, subOnFace);
      subOnFace[0] = onFace[0];
      subOnFace[1] = 0;
      subOnFace[2] = 0;
      subOnFace[3] = onFace[3];
      this->Traverse(blockId, nextLevel, output, x0, x1, y2, y3, z0, z0, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      //      subOnFace[2]=0;
      //      subOnFace[3]=onFace[3];
      this->Traverse(blockId, nextLevel, output, x2, x3, y2, y3, z0, z0, subOnFace);
    }
    if (generateBlock)
    {
      int realExt[6] = { ext[0], ext[1], ext[2], ext[3], ext[4], ext[5] };
      if (this->BlockCount >= this->StartBlock && this->BlockCount <= this->EndBlock)
      {
        vtkDataObject* newData(nullptr);
        if (this->GenerateRectilinearGrids)
        {
          vtkRectilinearGrid* grid = vtkRectilinearGrid::New();
          newData = grid;
          this->SetRBlockInfo(grid, level, ext, onFace);
        }
        else
        {
          vtkUniformGrid* grid = vtkUniformGrid::New();
          newData = grid;
          this->SetBlockInfo(grid, level, ext, onFace);
        }
        int newDataIndex = this->OutputUtil->AddDataSet(newData, level);
        if (!this->GenerateRectilinearGrids)
        {
          this->OutputUtil->SetAMRBox(newDataIndex, realExt);
        }
        this->Levels->InsertValue(blockId, level);
        ++blockId;
      }
      else if (this->EndBlock != -1)
      {
        int index = this->OutputUtil->AddDataSet(nullptr, level);
        if (!this->GenerateRectilinearGrids)
        {
          this->OutputUtil->SetAMRBox(index, realExt);
        }
      }
      ++this->BlockCount;
    }
  }
  else
  { // 3D
    if (this->LineTest(
          -1.64662, 0.56383, 1.16369, -1.05088, 0.85595, 0.87104, bds, level, this->MaximumLevel) ||
      this->LineTest(
        -1.05088, 0.85595, 0.87104, -0.61430, 1.00347, 0.59553, bds, level, this->MaximumLevel))
    { // break block into eight.
      if (!this->Overlap)
      {
        generateBlock = 0;
      }
      // Traverse the 8 new blocks.
      subOnFace[0] = onFace[0];
      subOnFace[1] = 0;
      subOnFace[2] = onFace[2];
      subOnFace[3] = 0;
      subOnFace[4] = onFace[4];
      subOnFace[5] = 0;
      this->Traverse(blockId, nextLevel, output, x0, x1, y0, y1, z0, z1, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      //      subOnFace[2]=onFace[2];
      //      subOnFace[3]=0;
      this->Traverse(blockId, nextLevel, output, x2, x3, y0, y1, z0, z1, subOnFace);
      subOnFace[0] = onFace[0];
      subOnFace[1] = 0;
      subOnFace[2] = 0;
      subOnFace[3] = onFace[3];
      this->Traverse(blockId, nextLevel, output, x0, x1, y2, y3, z0, z1, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      //      subOnface[2]=0;
      //      subOnFace[3]=onFace[3];
      this->Traverse(blockId, nextLevel, output, x2, x3, y2, y3, z0, z1, subOnFace);

      subOnFace[0] = onFace[0];
      subOnFace[1] = 0;
      subOnFace[2] = onFace[2];
      subOnFace[3] = 0;
      subOnFace[4] = 0;
      subOnFace[5] = onFace[5];
      this->Traverse(blockId, nextLevel, output, x0, x1, y0, y1, z2, z3, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      //      subOnFace[2]=onFace[2];
      //      subOnFace[3]=0;
      this->Traverse(blockId, nextLevel, output, x2, x3, y0, y1, z2, z3, subOnFace);
      subOnFace[0] = onFace[0];
      subOnFace[1] = 0;
      subOnFace[2] = 0;
      subOnFace[3] = onFace[3];
      this->Traverse(blockId, nextLevel, output, x0, x1, y2, y3, z2, z3, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      //      subOnFace[2]=0;
      //      subOnFace[3]=onFace[3];
      this->Traverse(blockId, nextLevel, output, x2, x3, y2, y3, z2, z3, subOnFace);
    }
    if (generateBlock)
    {
      if (this->BlockCount >= this->StartBlock && this->BlockCount <= this->EndBlock)
      {
        vtkDataObject* newData(nullptr);
        int realExt[6] = { ext[0], ext[1], ext[2], ext[3], ext[4], ext[5] };
        if (this->GenerateRectilinearGrids)
        {
          vtkRectilinearGrid* grid = vtkRectilinearGrid::New();
          newData = grid;
          this->SetRBlockInfo(grid, level, ext, onFace);
        }
        else
        {
          vtkUniformGrid* grid = vtkUniformGrid::New();
          newData = grid;
          this->SetBlockInfo(grid, level, ext, onFace);
        }
        int newDataIndex = this->OutputUtil->AddDataSet(newData, level);
        if (!this->GenerateRectilinearGrids)
        {
          this->OutputUtil->SetAMRBox(newDataIndex, realExt);
        }
        this->Levels->InsertValue(blockId, level);
        ++blockId;
      }
      ++this->BlockCount;
    }
  }
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::AddTestArray(vtkCompositeDataSet* output)
{
  double* origin = this->GetTopLevelOrigin();

  vtkSmartPointer<vtkCompositeDataIterator> iter;
  iter.TakeReference(output->NewIterator());
  for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
  {
    vtkUniformGrid* grid;
    grid = vtkUniformGrid::SafeDownCast(iter->GetCurrentDataObject());
    assert("check: grid_exists" && grid != 0);

    vtkDoubleArray* array = vtkDoubleArray::New();
    int numCells = grid->GetNumberOfCells();
    array->Allocate(numCells);
    array->SetNumberOfTuples(numCells);
    double* arrayPtr = static_cast<double*>(array->GetPointer(0));
    double spacing[3];
    grid->GetSpacing(spacing);
    int x, y, z;
    int ext[6];
    grid->GetExtent(ext);
    // we need cell extents bu we just get point extents
    if (ext[5] > 0)
    {
      --ext[5];
    }
    if (ext[3] > 0)
    {
      --ext[3];
    }
    if (ext[1] > 0)
    {
      --ext[1];
    }
    int debugcounter = 0;
    for (z = ext[4]; z <= ext[5]; ++z)
    {
      for (y = ext[2]; y <= ext[3]; ++y)
      {
        for (x = ext[0]; x <= ext[1]; ++x)
        {
          *arrayPtr++ = origin[0] + spacing[0] * (static_cast<double>(x) + 0.5) + origin[1] +
            spacing[1] * (static_cast<double>(y) + 0.5);
          ++debugcounter;
        }
      }
    }
    assert("check: valid_debugcounter" && debugcounter == numCells);
    array->SetName("TestX");
    grid->GetCellData()->AddArray(array);
    array->Delete();
  }
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::AddVectorArray(vtkCompositeDataSet* output)
{
  double* origin = this->GetTopLevelOrigin();

  vtkSmartPointer<vtkCompositeDataIterator> iter;
  iter.TakeReference(output->NewIterator());
  for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
  {
    vtkUniformGrid* grid;
    grid = vtkUniformGrid::SafeDownCast(iter->GetCurrentDataObject());
    assert("check: grid_exists" && grid != 0);

    vtkDoubleArray* array = vtkDoubleArray::New();
    array->SetNumberOfComponents(3);
    int numCells = grid->GetNumberOfCells();
    array->Allocate(numCells);
    array->SetNumberOfTuples(numCells);
    double* arrayPtr = static_cast<double*>(array->GetPointer(0));
    double spacing[3];
    grid->GetSpacing(spacing);
    int x, y, z;
    int ext[6];
    grid->GetExtent(ext);
    // we need cell extents bu we just get point extents
    if (ext[5] > 0)
    {
      --ext[5];
    }
    if (ext[3] > 0)
    {
      --ext[3];
    }
    if (ext[1] > 0)
    {
      --ext[1];
    }

    for (z = ext[4]; z <= ext[5]; ++z)
    {
      for (y = ext[2]; y <= ext[3]; ++y)
      {
        for (x = ext[0]; x <= ext[1]; ++x)
        {
          *arrayPtr++ = origin[0] + spacing[0] * (static_cast<double>(x) + 0.5);
          *arrayPtr++ = origin[1] + spacing[1] * (static_cast<double>(y) + 0.5);
          *arrayPtr++ = origin[2] + spacing[2] * (static_cast<double>(z) + 0.5);
        }
      }
    }
    array->SetName("VectorXYZ");
    grid->GetCellData()->AddArray(array);
    array->Delete();
  }
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::AddFractalArray(vtkCompositeDataSet* output)
{
  vtkImageMandelbrotSource* fractalSource = vtkImageMandelbrotSource::New();
  int dims[3];

  vtkSmartPointer<vtkCompositeDataIterator> iter;
  iter.TakeReference(output->NewIterator());
  for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
  {
    if (!this->GenerateRectilinearGrids)
    {
      vtkUniformGrid* grid;
      grid = vtkUniformGrid::SafeDownCast(iter->GetCurrentDataObject());
      assert("check: grid_exists" && grid != 0);

      vtkDoubleArray* array = vtkDoubleArray::New();
      int numCells = grid->GetNumberOfCells();
      array->Allocate(numCells);
      array->SetNumberOfTuples(numCells);
      double* arrayPtr = static_cast<double*>(array->GetPointer(0));
      double spacing[3];
      double origin[3];
      grid->GetSpacing(spacing);
      grid->GetOrigin(origin);
      grid->GetDimensions(dims);
      // we get the dimensions according to the points
      // we need the dimensions according to the cells

      if (dims[0] > 1)
      {
        --dims[0];
      }
      if (dims[1] > 1)
      {
        --dims[1];
      }
      if (dims[2] > 1)
      {
        --dims[2];
      }

      // Shift point to center of voxel.
      fractalSource->SetWholeExtent(0, dims[0] - 1, 0, dims[1] - 1, 0, dims[2] - 1);
      fractalSource->SetOriginCX(origin[0] + (spacing[0] * 0.5), origin[1] + (spacing[1] * 0.5),
        origin[2] + (spacing[2] * 0.5), this->TimeStep / 10.0);
      fractalSource->SetSampleCX(spacing[0], spacing[1], spacing[2], 0.1);
      fractalSource->Update();
      vtkDataArray* fractal;
      fractal = fractalSource->GetOutput()->GetPointData()->GetScalars();
      float* fractalPtr = static_cast<float*>(fractal->GetVoidPointer(0));

      for (int i = 0; i < fractal->GetNumberOfTuples(); ++i)
      {
        // Change fractal into volume fraction (iso surface at 0.5).
        *arrayPtr++ = *fractalPtr++ / (2.0 * this->FractalValue);
      }

      array->SetName("Fractal Volume Fraction");
      grid->GetCellData()->AddArray(array);
      array->Delete();
    }
    else // rectilinear grid
    {
      vtkRectilinearGrid* grid;
      grid = vtkRectilinearGrid::SafeDownCast(iter->GetCurrentDataObject());
      assert("check: grid_exists" && grid != 0);

      vtkDoubleArray* array = vtkDoubleArray::New();
      int numCells = grid->GetNumberOfCells();
      array->Allocate(numCells);
      array->SetNumberOfTuples(numCells);
      double* arrayPtr = static_cast<double*>(array->GetPointer(0));

      this->ExecuteRectilinearMandelbrot(grid, arrayPtr);
      array->SetName("Fractal Volume Fraction");
      grid->GetCellData()->AddArray(array);
      array->Delete();
    }
  }
  fractalSource->Delete();
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::AddBlockIdArray(vtkCompositeDataSet* output)
{
  int blockId = 0;
  vtkSmartPointer<vtkCompositeDataIterator> iter;
  iter.TakeReference(output->NewIterator());
  iter->SkipEmptyNodesOff();
  for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem(), blockId++)
  {
    vtkUniformGrid* grid;
    grid = vtkUniformGrid::SafeDownCast(iter->GetCurrentDataObject());
    if (!grid)
    {
      continue;
    }

    vtkIntArray* array = vtkIntArray::New();
    int numCells = grid->GetNumberOfCells();
    array->Allocate(numCells);
    int cell = 0;
    while (cell < numCells)
    {
      array->InsertNextValue(blockId);
      ++cell;
    }
    array->SetName("BlockId");
    grid->GetCellData()->AddArray(array);
    array->Delete();
  }
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::AddDepthArray(vtkOverlappingAMR* output)
{
  int levels = output->GetNumberOfLevels();
  int level = 0;
  while (level < levels)
  {
    int blocks = output->GetNumberOfBlocks(level);
    int block = 0;
    while (block < blocks)
    {
      vtkCartesianGrid* grid = output->GetDataSetAsCartesianGrid(level, block);
      if (grid)
      {
        vtkIntArray* array = vtkIntArray::New();
        int numCells = grid->GetNumberOfCells();
        array->Allocate(numCells);
        int cell = 0;
        while (cell < numCells)
        {
          array->InsertNextValue(level);
          ++cell;
        }
        array->SetName("Depth");
        grid->GetCellData()->AddArray(array);
        array->Delete();
      }
      ++block;
    }
    ++level;
  }
}

void vtkHierarchicalFractal::AddGhostLevelArray(vtkDataSet* grid, int dim[3], int onFace[6])
{
  vtkUnsignedCharArray* array = vtkUnsignedCharArray::New();
  // we just get the dimensions according to points
  // we need the dimensions according to cells

  int dims[3];
  dims[0] = dim[0];
  dims[1] = dim[1];
  dims[2] = dim[2];

  if (dims[0] > 1)
  {
    --dims[0];
  }
  if (dims[1] > 1)
  {
    --dims[1];
  }
  if (dims[2] > 1)
  {
    --dims[2];
  }

  int numCells = grid->GetNumberOfCells();
  array->SetNumberOfTuples(numCells);

  int i, j, k;
  int iLevel, jLevel, kLevel, tmp;
  unsigned char* ptr;

  ptr = (unsigned char*)(array->GetVoidPointer(0));

  for (k = 0; k < dims[2]; ++k)
  {
    // ghost level at the beginning
    if (onFace[4])
    {
      kLevel = this->GhostLevels - 1 - k; // or =-k
    }
    else
    {
      kLevel = this->GhostLevels - k;
    }
    // ghost level at the end.
    if (onFace[5])
    {
      tmp = k - dims[2] + 1 + this->GhostLevels - 1;
    }
    else
    {
      tmp = k - dims[2] + 1 + this->GhostLevels;
    }
    kLevel = std::max(kLevel, tmp);
    if (this->TwoDimensional)
    {
      kLevel = 0;
    }
    for (j = 0; j < dims[1]; ++j)
    {
      jLevel = kLevel;
      if (onFace[2])
      {
        tmp = this->GhostLevels - 1 - j;
      }
      else
      {
        tmp = this->GhostLevels - j;
      }
      jLevel = std::max(jLevel, tmp);
      if (onFace[3])
      {
        tmp = j - dims[1] + 1 + this->GhostLevels - 1;
      }
      else
      {
        tmp = j - dims[1] + 1 + this->GhostLevels;
      }
      jLevel = std::max(tmp, jLevel);
      for (i = 0; i < dims[0]; ++i)
      {
        iLevel = jLevel;
        if (onFace[0])
        {
          tmp = this->GhostLevels - 1 - i;
        }
        else
        {
          tmp = this->GhostLevels - i;
        }
        iLevel = std::max(iLevel, tmp);
        if (onFace[1])
        {
          tmp = i - dims[0] + 1 + this->GhostLevels - 1;
        }
        else
        {
          tmp = i - dims[0] + 1 + this->GhostLevels;
        }
        iLevel = std::max(iLevel, tmp);

        if (iLevel <= 0)
        {
          *ptr = 0;
        }
        else
        {
          *ptr = vtkDataSetAttributes::DUPLICATECELL;
        }
        ++ptr;
      }
    }
  }
  array->SetName(vtkDataSetAttributes::GhostArrayName());
  //      array->SetName("vtkNotGhostLevels");
  grid->GetCellData()->AddArray(array);
  array->Delete();
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::CellExtentToBounds(int level, int ext[6], double bds[6])
{
  int spacingFactor = 1;
  double spacing[3];
  spacingFactor = spacingFactor << level;

  spacing[0] = this->TopLevelSpacing[0] / (double)(spacingFactor);
  spacing[1] = this->TopLevelSpacing[1] / (double)(spacingFactor);
  spacing[2] = this->TopLevelSpacing[2] / (double)(spacingFactor);

  bds[0] = this->TopLevelOrigin[0] + (double)(ext[0]) * spacing[0];
  bds[1] = this->TopLevelOrigin[0] + (double)(ext[1] + 1) * spacing[0];
  bds[2] = this->TopLevelOrigin[1] + (double)(ext[2]) * spacing[1];
  bds[3] = this->TopLevelOrigin[1] + (double)(ext[3] + 1) * spacing[1];
  bds[4] = this->TopLevelOrigin[2] + (double)(ext[4]) * spacing[2];
  bds[5] = this->TopLevelOrigin[2] + (double)(ext[5] + 1) * spacing[2];
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::ExecuteRectilinearMandelbrot(vtkRectilinearGrid* grid, double* ptr)
{
  int a0 = 0;
  int a1 = 1;
  int a2 = 2;

  int dims[3];

  grid->GetDimensions(dims);
  // we get the dimensions according to the points
  // we need the dimensions according to the cells

  if (dims[0] > 1)
  {
    --dims[0];
  }
  if (dims[1] > 1)
  {
    --dims[1];
  }
  if (dims[2] > 1)
  {
    --dims[2];
  }

  int ext[6];
  double p[4];

  // Shift point to center of voxel.
  //  fractalSource->SetWholeExtent(0,dims[0]-1, 0,dims[1]-1, 0,dims[2]-1);
  ext[0] = 0;
  ext[1] = dims[0] - 1;
  ext[2] = 0;
  ext[3] = dims[1] - 1;
  ext[4] = 0;
  ext[5] = dims[2] - 1;

  int min0, max0;
  int idx0, idx1, idx2;
  vtkIdType inc0, inc1, inc2;

  //  fractalSource->SetOriginCX(origin[0]+(spacing[0]*0.5),
  //                             origin[1]+(spacing[1]*0.5),
  //                             origin[2]+(spacing[2]*0.5), 0.0);

  double origin[4];
  vtkDataArray* coords[3];
  coords[0] = grid->GetXCoordinates();
  coords[1] = grid->GetYCoordinates();
  coords[2] = grid->GetZCoordinates();

  origin[0] = coords[0]->GetTuple1(0) + 0.5 * (coords[0]->GetTuple1(1) - coords[0]->GetTuple1(0));
  origin[1] = coords[0]->GetTuple1(0) + 0.5 * (coords[1]->GetTuple1(1) - coords[1]->GetTuple1(0));
  origin[2] = coords[0]->GetTuple1(0) + 0.5 * (coords[2]->GetTuple1(1) - coords[2]->GetTuple1(0));
  origin[3] = this->TimeStep / 10.0;

  // Copy origin into pixel
  for (idx0 = 0; idx0 < 4; ++idx0)
  {
    p[idx0] = origin[idx0];
  }

  min0 = ext[0];
  max0 = ext[1];

  this->GetContinuousIncrements(ext, inc0, inc1, inc2);

  //  fractalSource->SetSampleCX(spacing[0], spacing[1], spacing[2], 0.1);

  for (idx2 = ext[4]; idx2 <= ext[5]; ++idx2)
  {
    //    p[a2] = (double)(origin[a2]) + (double)(idx2)*(sample[a2]);
    p[a2] = coords[a2]->GetTuple1(idx2) +
      0.5 * (coords[a2]->GetTuple1(idx2 + 1) - coords[a2]->GetTuple1(idx2));
    for (idx1 = ext[2]; idx1 <= ext[3]; ++idx1)
    {
      //      p[a1] = (double)(origin[a1]) + (double)(idx1)*(sample[a1]);
      p[a1] = coords[a1]->GetTuple1(idx1) +
        0.5 * (coords[a1]->GetTuple1(idx1 + 1) - coords[a1]->GetTuple1(idx1));
      for (idx0 = min0; idx0 <= max0; ++idx0)
      {
        //      p[a0] = (double)(origin[a0]) + (double)(idx0)*(sample[a0]);
        p[a0] = coords[a0]->GetTuple1(idx0) +
          0.5 * (coords[a0]->GetTuple1(idx0 + 1) - coords[a0]->GetTuple1(idx0));

        // Change fractal into volume fraction (iso surface at 0.5).
        *ptr = this->EvaluateSet(p) / (2.0 * this->FractalValue);

        ++ptr;
        // inc0 is 0
      }
      ptr += inc1;
    }
    ptr += inc2;
  }
}

//----------------------------------------------------------------------------
double vtkHierarchicalFractal::EvaluateSet(double p[4])
{
  unsigned short count = 0;
  double v0, v1;
  double cReal, cImag, zReal, zImag;
  double zReal2, zImag2;

  const int maximumNumberOfIterations = 100;

  cReal = p[0];
  cImag = p[1];
  zReal = p[2];
  zImag = p[3];

  zReal2 = zReal * zReal;
  zImag2 = zImag * zImag;
  v0 = 0.0;
  v1 = (zReal2 + zImag2);
  while (v1 < 4.0 && count < maximumNumberOfIterations)
  {
    zImag = 2.0 * zReal * zImag + cImag;
    zReal = zReal2 - zImag2 + cReal;
    zReal2 = zReal * zReal;
    zImag2 = zImag * zImag;
    ++count;
    v0 = v1;
    v1 = (zReal2 + zImag2);
  }

  if (count == maximumNumberOfIterations)
  {
    return (double)count;
  }

  return (double)count + (4.0 - v0) / (v1 - v0);
}

//----------------------------------------------------------------------------
void vtkHierarchicalFractal::GetContinuousIncrements(
  int extent[6], vtkIdType& incX, vtkIdType& incY, vtkIdType& incZ)
{
  int e0, e1, e2, e3;

  incX = 0;

  e0 = extent[0];
  e1 = extent[1];
  e2 = extent[2];
  e3 = extent[3];

  // Make sure the increments are up to date

  int idx;

  // vtkIdType inc = this->GetPointData()->GetScalars()->GetNumberOfComponents();
  vtkIdType inc = 1;

  int increments[3];

  for (idx = 0; idx < 3; ++idx)
  {
    increments[idx] = inc;
    inc *= (extent[idx * 2 + 1] - extent[idx * 2] + 1);
  }

  incY = increments[1] - (e1 - e0 + 1) * increments[0];
  incZ = increments[2] - (e3 - e2 + 1) * increments[1];
}

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

  os << indent << "Dimensions: " << this->Dimensions << endl;
  os << indent << "TwoDimensional: " << this->TwoDimensional << endl;
  os << indent << "FractalValue: " << this->FractalValue << endl;
  os << indent << "MaximumLevel: " << this->MaximumLevel << endl;
  os << indent << "GhostLevels: " << this->GhostLevels << endl;
  os << indent << "Asymetric: " << this->Asymetric << endl;
  os << indent << "GenerateRectilinearGrids: ";
  if (this->GenerateRectilinearGrids)
  {
    os << "True";
  }
  else
  {
    os << "False";
  }
  os << endl;
  os << indent << "TimeStep: " << this->TimeStep << endl;
  os << indent << "TimeStepRange: " << this->TimeStepRange[0] << " " << this->TimeStepRange[1]
     << endl;
}
