Method RequestData

Filters/ParallelDIY2/vtkAdaptiveResampleToImage.cxx:182–302

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//------------------------------------------------------------------------------
int vtkAdaptiveResampleToImage::RequestData(
  vtkInformation*, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  auto inputDO = vtkDataObject::GetData(inputVector[0], 0);

  // get resampling bounds.
  auto controller = this->GetController();
  const int num_partitions = (controller && this->GetNumberOfImages() == 0)
    ? controller->GetNumberOfProcesses()
    : this->GetNumberOfImages();

  vtkLogStartScope(TRACE, "generate-kdtree");
  auto boxes = vtkDIYKdTreeUtilities::GenerateCuts(
    inputDO, std::max(1, num_partitions), /*use_cell_centers=*/false, controller);
  vtkLogEndScope("generate-kdtree");
  // vtkLogF(TRACE, "num-boxes: %d", (int)(boxes.size()));
  // for (const auto& box : boxes)
  // {
  //   double bds[6];
  //   box.GetBounds(bds);
  //   vtkLogF(TRACE, "box: {%f:%f, %f:%f, %f:%f}", bds[0], bds[1], bds[2], bds[3], bds[4], bds[5]);
  // }

  diy::mpi::communicator comm = vtkDIYUtilities::GetCommunicator(this->Controller);
  diy::Master master(
    comm, 1, -1, []() { return static_cast<void*>(vtkImageData::New()); },
    [](void* b) { reinterpret_cast<vtkImageData*>(b)->Delete(); });

  auto assigner = vtkDIYKdTreeUtilities::CreateAssigner(comm, static_cast<int>(boxes.size()));
  diy::RegularDecomposer<diy::DiscreteBounds> decomposer(
    /*dim*/ 1, diy::interval(0, assigner.nblocks() - 1), assigner.nblocks());
  decomposer.decompose(comm.rank(), assigner, master);

  std::vector<std::vector<vtkSmartPointer<vtkImageData>>> resamples(boxes.size());
  vtkLogStartScope(TRACE, "local resample");

  const auto localBounds = vtkDIYUtilities::GetLocalBounds(inputDO);
  std::transform(boxes.begin(), boxes.end(), resamples.begin(),
    [&inputDO, &localBounds, this](const vtkBoundingBox& bbox)
    {
      std::vector<vtkSmartPointer<vtkImageData>> retval;
      vtkSmartPointer<vtkImageData> img =
        localBounds.Intersects(bbox) ? impl::resample(bbox, inputDO, this) : nullptr;
      if (img)
      {
        retval.push_back(img);
      }
      return retval;
    });
  vtkLogEndScope("local resample");

  vtkLogStartScope(TRACE, "global exchange");
  diy::all_to_all(master, assigner,
    [&resamples, &comm](vtkImageData*, const diy::ReduceProxy& rp)
    {
      if (rp.in_link().size() == 0)
      {
        // 1. enqueue