// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-FileCopyrightText: Copyright (c) Kitware, Inc.
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkTemporalFractal.h"

#include "vtkCellData.h"
#include "vtkCompositeDataIterator.h"
#include "vtkCompositeDataPipeline.h"
#include "vtkDoubleArray.h"
#include "vtkHierarchicalBoxDataSet.h"
#include "vtkImageMandelbrotSource.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkIntArray.h"
#include "vtkMath.h"
#include "vtkMultiBlockDataSet.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkRectilinearGrid.h"
#include "vtkSmartPointer.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkUniformGrid.h"
#include "vtkUnsignedCharArray.h"

#include <cassert>

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

  void AddDataSet(vtkDataObject* newData, unsigned int level)
  {
    assert(newData);
    assert("Expect newData to be created by raw New()" && newData->GetReferenceCount() == 1);

    vtkSmartPointer<vtkDataObject> data;
    data.TakeReference(newData);
    this->DataSets.push_back(data);
    this->Levels.push_back(level);
  }
  ~TemporalFractalOutputUtil() 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(vtkHierarchicalBoxDataSet* hbds)
  {
    std::vector<int> blocksPerLevel;
    int gridDescription(-1);
    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]);
      assert(grid);
      gridDescription = grid->GetGridDescription();
      double* gridOrigin = grid->GetOrigin();
      for (int d = 0; d < 3; d++)
      {
        if (gridOrigin[d] < origin[d])
        {
          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(static_cast<int>(blocksPerLevel.size()), blocksPerLevel.data());
    hbds->SetOrigin(origin);
    hbds->SetGridDescription(gridDescription);
    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]);
      hbds->SetDataSet(level, id, grid);
      blockIds[level]++;
    }
  }

private:
  TemporalFractalOutputUtil() = default;
  std::vector<vtkSmartPointer<vtkDataObject>> DataSets;
  std::vector<unsigned int> Levels;
};

vtkStandardNewMacro(TemporalFractalOutputUtil);
//------------------------------------------------------------------------------

vtkStandardNewMacro(vtkTemporalFractal);

vtkTemporalFractal::vtkTemporalFractal()
{
  this->SetNumberOfInputPorts(0);
  this->SetNumberOfOutputPorts(1);

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

  this->Levels = vtkIntArray::New();
  this->TwoDimensional = 1;
  this->Asymmetric = 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->CurrentTime = 0;
  this->DiscreteTimeSteps = 0;

  this->AdaptiveSubdivision = 1;
}

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

int vtkTemporalFractal::FillOutputPortInformation(int vtkNotUsed(port), vtkInformation* info)
{
  info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkDataObject");
  return 1;
}

//------------------------------------------------------------------------------
// This handles any alterations necessary for ghost levels.
void vtkTemporalFractal::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 vtkTemporalFractal::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];

  vtkMath::RandomSeed(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.
      double epsilon = (vtkMath::Random() - 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 vtkTemporalFractal::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 || !this->AdaptiveSubdivision)
  {
    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 vtkTemporalFractal::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->CurrentTime / 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;
}

//------------------------------------------------------------------------------
vtkTypeBool vtkTemporalFractal::ProcessRequest(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{

  // create the output
  if (request->Has(vtkDemandDrivenPipeline::REQUEST_DATA_OBJECT()))
  {
    return this->RequestDataObject(request, inputVector, outputVector);
  }

  // generate the data
  if (request->Has(vtkCompositeDataPipeline::REQUEST_DATA()))
  {
    int retVal = this->RequestData(request, inputVector, outputVector);
    return retVal;
  }

  // execute information
  if (request->Has(vtkDemandDrivenPipeline::REQUEST_INFORMATION()))
  {
    vtkInformation* info = outputVector->GetInformationObject(0);
    info->Set(CAN_HANDLE_PIECE_REQUEST(), 1);

    return this->RequestInformation(request, inputVector, outputVector);
  }

  return this->Superclass::ProcessRequest(request, inputVector, outputVector);
}

int vtkTemporalFractal::RequestDataObject(
  vtkInformation*, vtkInformationVector**, vtkInformationVector* outputVector)
{
  vtkInformation* info = outputVector->GetInformationObject(0);

  vtkCompositeDataSet* dset = this->GenerateRectilinearGrids
    ? static_cast<vtkCompositeDataSet*>(vtkMultiBlockDataSet::New())
    : static_cast<vtkCompositeDataSet*>(vtkHierarchicalBoxDataSet::New());

  info->Set(vtkDataObject::DATA_OBJECT(), dset);
  dset->Delete();
  return 1;
}

//------------------------------------------------------------------------------
// Description:
// This is called by the superclass.
// This is the method you should override.
int vtkTemporalFractal::RequestInformation(
  vtkInformation*, vtkInformationVector**, vtkInformationVector* outputVector)
{
  vtkInformation* info = outputVector->GetInformationObject(0);

  if (this->DiscreteTimeSteps)
  {
    double tsteps[11];
    int i;
    for (i = 0; i < 11; ++i)
    {
      tsteps[i] = i;
    }
    info->Set(vtkStreamingDemandDrivenPipeline::TIME_STEPS(), tsteps, 11);
  }

  double trange[2];
  trange[0] = 0.0;
  trange[1] = 10.0;
  info->Set(vtkStreamingDemandDrivenPipeline::TIME_RANGE(), trange, 2);

  return 1;
}

//------------------------------------------------------------------------------
int vtkTemporalFractal::RequestData(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  vtkInformation* info = outputVector->GetInformationObject(0);
  vtkInformation* outInfo = outputVector->GetInformationObject(0);

  // get how many time steps were requested
  double timeStep = info->Get(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());

  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;
  }

  // now create the HierarchicalDataSet for each time step

  this->CurrentTime = timeStep;
  vtkCompositeDataSet* dset = this->GenerateRectilinearGrids
    ? static_cast<vtkCompositeDataSet*>(vtkMultiBlockDataSet::New())
    : static_cast<vtkCompositeDataSet*>(vtkHierarchicalBoxDataSet::New());

  this->RequestOneTimeStep(dset, request, inputVector, outputVector);
  dset->GetInformation()->Set(vtkDataObject::DATA_TIME_STEP(), timeStep);

  outInfo->Set(vtkDataObject::DATA_OBJECT(), dset);
  dset->Delete();

  return 1;
}

//------------------------------------------------------------------------------
int vtkTemporalFractal ::RequestOneTimeStep(vtkCompositeDataSet* output,
  vtkInformation* vtkNotUsed(request), vtkInformationVector** vtkNotUsed(inputVector),
  vtkInformationVector* outputVector)
{
  vtkInformation* info = outputVector->GetInformationObject(0);

  // 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());

  this->OutputUtil = vtkSmartPointer<TemporalFractalOutputUtil>::New();

  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);

  int ext[6];
  ext[0] = ext[2] = ext[4] = 0;
  ext[1] = ext[3] = ext[5] = this->Dimensions - 1;
  if (this->Asymmetric)
  { // 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 (vtkHierarchicalBoxDataSet::SafeDownCast(output))
  {
    this->OutputUtil->CreateOutput(vtkHierarchicalBoxDataSet::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)
  {
    vtkHierarchicalBoxDataSet* hbds = vtkHierarchicalBoxDataSet::SafeDownCast(output);
    this->AddVectorArray(hbds);
    this->AddTestArray(hbds);
    this->AddBlockIdArray(hbds);
    this->AddDepthArray(hbds);
  }
  this->AddFractalArray(output);

  this->OutputUtil = nullptr;
  return 1;
}

//------------------------------------------------------------------------------
int vtkTemporalFractal::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 and 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 vtkTemporalFractal::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;
  }

  if (!this->AdaptiveSubdivision)
  {
    return 1;
  }

  // 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 vtkTemporalFractal::Traverse(int& blockId, int level, vtkDataObject* 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;

  if (this->TwoDimensional)
  {
    z0 = z3 = 0;
  }

  // Get the bounds of the proposed block.
  int ext[6] = { x0, x3, y0, y3, z0, 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 asymmetric blocks.
    x2 += 2;
    x1 += 2;
  }

  int subOnFace[6];

  if (this->TwoDimensional)
  {
    if (this->TwoDTest(bds, level, this->MaximumLevel))
    {
      ++level;
      // 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, level, output, x0, x1, y0, y1, z0, z0, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      this->Traverse(blockId, level, 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, level, output, x0, x1, y2, y3, z0, z0, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      this->Traverse(blockId, level, output, x2, x3, y2, y3, z0, z0, subOnFace);
    }
    else
    {
      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);
        }
        this->OutputUtil->AddDataSet(newData, level);
        this->Levels->InsertValue(blockId, level);
        ++blockId;
      }
      ++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.
      ++level;
      // 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, level, output, x0, x1, y0, y1, z0, z1, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      this->Traverse(blockId, level, 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, level, output, x0, x1, y2, y3, z0, z1, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      this->Traverse(blockId, level, 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, level, output, x0, x1, y0, y1, z2, z3, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      this->Traverse(blockId, level, 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, level, output, x0, x1, y2, y3, z2, z3, subOnFace);
      subOnFace[0] = 0;
      subOnFace[1] = onFace[1];
      this->Traverse(blockId, level, output, x2, x3, y2, y3, z2, z3, subOnFace);
    }
    else
    {
      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);
        }
        this->OutputUtil->AddDataSet(newData, level);
        this->Levels->InsertValue(blockId, level);
        ++blockId;
      }
      ++this->BlockCount;
    }
  }
}

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

  int levels = output->GetNumberOfLevels();
  int level = 0;
  while (level < levels)
  {
    int blocks = output->GetNumberOfDataSets(level);
    int block = 0;
    while (block < blocks)
    {
      vtkUniformGrid* grid;
      grid = vtkUniformGrid::SafeDownCast(output->GetDataSet(level, block));
      assert("check: grid_exists" && grid != nullptr);

      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);
      (void)debugcounter;
      array->SetName("TestX");
      grid->GetCellData()->AddArray(array);
      array->Delete();
      ++block;
    }
    ++level;
  }
}

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

  int levels = output->GetNumberOfLevels();
  int level = 0;
  while (level < levels)
  {
    int blocks = output->GetNumberOfDataSets(level);
    int block = 0;
    while (block < blocks)
    {
      vtkUniformGrid* grid;
      grid = vtkUniformGrid::SafeDownCast(output->GetDataSet(level, block));
      assert("check: grid_exists" && grid != nullptr);

      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();
      ++block;
    }
    ++level;
  }
}

//------------------------------------------------------------------------------
void vtkTemporalFractal::AddFractalArray(vtkCompositeDataSet* output)
{
  vtkCompositeDataIterator* iter = output->NewIterator();

  vtkImageMandelbrotSource* fractalSource = vtkImageMandelbrotSource::New();
  int dims[3];

  for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
  {
    if (this->CheckAbort())
    {
      break;
    }
    if (!this->GenerateRectilinearGrids)
    {
      vtkUniformGrid* grid = vtkUniformGrid::SafeDownCast(iter->GetCurrentDataObject());
      assert("check: grid_exists" && grid != nullptr);

      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->CurrentTime / 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()->SetScalars(array);
      array->Delete();
    }
    else // rectilinear grid
    {
      vtkRectilinearGrid* grid = vtkRectilinearGrid::SafeDownCast(iter->GetCurrentDataObject());
      assert("check: grid_exists" && grid != nullptr);

      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()->SetScalars(array);
      array->Delete();
    }
  }
  fractalSource->Delete();
  iter->Delete();
}

//------------------------------------------------------------------------------
void vtkTemporalFractal::AddBlockIdArray(vtkHierarchicalBoxDataSet* output)
{
  int levels = output->GetNumberOfLevels();
  int level = 0;
  int blockId = 0;
  while (level < levels)
  {
    int blocks = output->GetNumberOfDataSets(level);
    int block = 0;
    while (block < blocks)
    {
      vtkUniformGrid* grid;
      grid = vtkUniformGrid::SafeDownCast(output->GetDataSet(level, block));
      assert("check: grid_exists" && grid != nullptr);

      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();
      ++block;
      ++blockId;
    }
    ++level;
  }
}

//------------------------------------------------------------------------------
void vtkTemporalFractal::AddDepthArray(vtkHierarchicalBoxDataSet* output)
{
  int levels = output->GetNumberOfLevels();
  int level = 0;
  while (level < levels)
  {
    int blocks = output->GetNumberOfDataSets(level);
    int block = 0;
    while (block < blocks)
    {
      vtkUniformGrid* grid;
      grid = vtkUniformGrid::SafeDownCast(output->GetDataSet(level, block));
      assert("check: grid_exists" && grid != nullptr);

      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 vtkTemporalFractal::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;
    }
    if (tmp > kLevel)
    {
      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;
      }
      if (tmp > jLevel)
      {
        jLevel = tmp;
      }
      if (onFace[3])
      {
        tmp = j - dims[1] + 1 + this->GhostLevels - 1;
      }
      else
      {
        tmp = j - dims[1] + 1 + this->GhostLevels;
      }
      if (tmp > jLevel)
      {
        jLevel = tmp;
      }
      for (i = 0; i < dims[0]; ++i)
      {
        iLevel = jLevel;
        if (onFace[0])
        {
          tmp = this->GhostLevels - 1 - i;
        }
        else
        {
          tmp = this->GhostLevels - i;
        }
        if (tmp > iLevel)
        {
          iLevel = tmp;
        }
        if (onFace[1])
        {
          tmp = i - dims[0] + 1 + this->GhostLevels - 1;
        }
        else
        {
          tmp = i - dims[0] + 1 + this->GhostLevels;
        }
        if (tmp > iLevel)
        {
          iLevel = tmp;
        }

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

//------------------------------------------------------------------------------
void vtkTemporalFractal::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 vtkTemporalFractal::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.
  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;

  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->CurrentTime / 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);

  for (idx2 = ext[4]; idx2 <= ext[5]; ++idx2)
  {
    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] = coords[a1]->GetTuple1(idx1) +
        0.5 * (coords[a1]->GetTuple1(idx1 + 1) - coords[a1]->GetTuple1(idx1));
      for (idx0 = min0; idx0 <= max0; ++idx0)
      {
        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 vtkTemporalFractal::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 vtkTemporalFractal::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 = 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 vtkTemporalFractal::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);

  os << indent << "Dimensions: " << this->Dimensions << endl;
  os << indent << "TwoDimensional: " << this->TwoDimensional << endl;
  os << indent << "AdaptiveSubdivision: " << this->AdaptiveSubdivision << endl;
  os << indent << "DiscreteTimeSteps: " << this->DiscreteTimeSteps << endl;
  os << indent << "FractalValue: " << this->FractalValue << endl;
  os << indent << "MaximumLevel: " << this->MaximumLevel << endl;
  os << indent << "GhostLevels: " << this->GhostLevels << endl;
  os << indent << "Asymmetric: " << this->Asymmetric << endl;
  os << indent
     << "GenerateRectilinearGrids: " << (this->GenerateRectilinearGrids ? "True" : "False") << endl;
}
VTK_ABI_NAMESPACE_END
