Function Deserialize_vtkFieldData

Common/DataModel/vtkFieldDataSerDesHelper.cxx:56–115

----------------------------------------------------------------------------

  //----------------------------------------------------------------------------
  static void Deserialize_vtkFieldData(
    const nlohmann::json& state, vtkObjectBase* object, vtkDeserializer* deserializer)
  {
    using nlohmann::json;
    if (auto* fd = vtkFieldData::SafeDownCast(object))
    {
      if (auto superDeserializer = deserializer->GetHandler(typeid(vtkFieldData::Superclass)))
      {
        superDeserializer(state, object, deserializer);
      }
      auto* context = deserializer->GetContext();
      const auto& stateOfArrays = state["Arrays"];
      // vector used to keep existing arrays alive so that fd->RemoveArray doesn't destroy the
      // vtkAbstractArray object.
      std::vector<vtkSmartPointer<vtkAbstractArray>> arrays;
      for (auto& stateOfarray : stateOfArrays)
      {
        const auto identifier = stateOfarray["Id"].get<vtkTypeUInt32>();
        auto subObject = context->GetObjectAtId(identifier);
        deserializer->DeserializeJSON(identifier, subObject);
        if (auto* array = vtkAbstractArray::SafeDownCast(subObject))
        {
          arrays.emplace_back(array);
        }
      }
      // Now remove arrays from the collection.
      // If arrays already existed before entering this function, it does not invoke
      // destructor on the vtkAbstractArray because a reference is held by the vector of arrays.
      if (static_cast<std::size_t>(fd->GetNumberOfArrays()) != arrays.size())
      {
        while (fd->GetNumberOfArrays() > 0)
        {
          auto* array = fd->GetAbstractArray(0);
          context->UnRegisterObject(context->GetId(array));
          fd->RemoveArray(0);
        }
        for (const auto& array : arrays)
        {
          fd->AddArray(array);
        }
      }
      else
      {
        int i = 0;
        for (const auto& array : arrays)
        {
          // vtkFieldData::SetArray only marks the vtkFieldData as modified if the array is
          // different from the one already present in the vtkFieldData. This is important because
          // the vtkFieldData::MTime affects the MTime of a vtkPolyData object. We need to be very
          // careful here because unnecessary modification of the vtkFieldData::MTime will cause the
          // vtkPolyData to be marked as modified and, in turn, will force a mapper to upload the
          // data again.
          fd->SetArray(i, array);
          ++i;
        }
      }
      VTK_DESERIALIZE_VALUE_FROM_STATE(NumberOfTuples, int, state, fd);
      VTK_DESERIALIZE_VALUE_FROM_STATE(GhostsToSkip, int, state, fd);