Method GetSelectedCompositeIds

Common/DataModel/vtkDataAssemblyUtilities.cxx:654–736

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std::vector<unsigned int> vtkDataAssemblyUtilities::GetSelectedCompositeIds(
  const std::vector<std::string>& selectors, vtkDataAssembly* hierarchyOrAssembly,
  vtkPartitionedDataSetCollection* data, bool leaf_nodes_only)
{
  if (hierarchyOrAssembly == nullptr || selectors.empty())
  {
    return {};
  }

  const auto root = vtkDataAssembly::GetRootNode();
  const bool isHierarchy =
    (strcmp(hierarchyOrAssembly->GetAttributeOrDefault(root, CATEGORY_ATTRIBUTE_NAME, ""),
       CATEGORY_HIERARCHY) == 0);
  if (!isHierarchy && data == nullptr)
  {
    vtkLogF(ERROR, "Missing required `data` argument.");
    return {};
  }

  if (isHierarchy && leaf_nodes_only)
  {
    const auto dataType = hierarchyOrAssembly->GetAttributeOrDefault(root, "vtk_type", -1);
    // for now we only support MBs. we could support AMR and PDC,
    // but I don't see the point in doing so right now.
    if (!vtkDataObjectTypes::TypeIdIsA(dataType, VTK_MULTIBLOCK_DATA_SET))
    {
      vtkLogF(ERROR, "Hierarchy does not represent a supported composite dataset type (%s)",
        vtkDataObjectTypes::GetClassNameFromTypeId(dataType));
      return {};
    }

    // the worst case: we need to traverse the hierarchy and determine composite
    // ids.
    const auto nodes = hierarchyOrAssembly->SelectNodes(selectors);
    vtkNew<vtkGenerateIdsVisitor> visitor;
    std::copy(nodes.begin(), nodes.end(),
      std::inserter(visitor->SelectedNodes, visitor->SelectedNodes.end()));
    hierarchyOrAssembly->Visit(visitor);
    return visitor->CompositeIndices;
  }

  // here, we only traverse the subtree if not a hierarchy. Otherwise, the
  // dataset indices are directly composite ids so we don't need to traverse
  // substree.
  auto dsIndices = hierarchyOrAssembly->GetDataSetIndices(
    hierarchyOrAssembly->SelectNodes(selectors), /*traverse_subtree=*/!isHierarchy);

  if (isHierarchy)
  {
    assert(leaf_nodes_only == false);

    // in this case, dsIndices directly correspond to the composite ids;
    // nothing more to do.
    return dsIndices;
  }
  else if (!isHierarchy && !leaf_nodes_only)
  {
    // convert partitioned dataset index to composite index.