Method Initialize

Filters/FlowPaths/vtkAbstractInterpolatedVelocityField.cxx:84–195

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//------------------------------------------------------------------------------
void vtkAbstractInterpolatedVelocityField::Initialize(vtkCompositeDataSet* compDS, int initStrategy)
{
  // Clear the datasets info, subclasses may want to put stuff into it.
  this->DataSetsInfo.clear();

  // See whether the subclass should take over the initialization process.
  if (this->SelfInitialize())
  {
    return;
  }

  // Proceed to initialize the composite dataset
  this->InitializationState = initStrategy;

  // Obtain this find cell strategy or create the default one as necessary
  vtkSmartPointer<vtkFindCellStrategy> strategy = this->FindCellStrategy;
  vtkFindCellStrategy* strategyClone;
  if (strategy == nullptr)
  {
    strategy = vtkSmartPointer<vtkClosestPointStrategy>::New(); // default strategy if not provided
  }

  // These are the datasets to process from the input to the filter.
  auto datasets = vtkCompositeDataSet::GetDataSets(compDS);

  // For each dataset in the list of datasets, make sure a FindCell
  // strategy has been defined and initialized. The potential for composite
  // datasets which may contain instances of (vtkPointSet) make the process
  // more complex. We only care about find cell strategies if the dataset is
  // a vtkPointSet because the other dataset types (e.g., volumes) have their
  // own built-in FindCell() methods.
  vtkDataArray* vectors;
  for (auto& dataset : datasets)
  {
    if (!this->VectorsSelection) // if a selection is not specified,
    {
      // use the first one in the point set (this is a behavior for backward compatibility)
      vectors = dataset->GetPointData()->GetVectors(nullptr);
    }
    else
    {
      vectors =
        dataset->GetAttributesAsFieldData(this->VectorsType)->GetArray(this->VectorsSelection);
    }

    strategyClone = nullptr;
    if (vtkPointSet::SafeDownCast(dataset))
    {
      strategyClone = strategy->NewInstance();
    }
    this->AddToDataSetsInfo(dataset, strategyClone, vectors);
  } // for all datasets of composite dataset

  // Now initialize the new strategies
  for (auto& datasetInfo : this->DataSetsInfo)
  {
    if (auto pointSet = vtkPointSet::SafeDownCast(datasetInfo.DataSet))
    {