Method UpdateWithDecimation

Rendering/HyperTreeGrid/vtkHyperTreeGridMapper.cxx:240–295

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vtkSmartPointer<vtkCompositeDataSet> vtkHyperTreeGridMapper::UpdateWithDecimation(
  vtkCompositeDataSet* cds, vtkRenderer* ren)
{
  bool useAdapt = this->UseAdaptiveDecimation;

  vtkNew<vtkAdaptiveDataSetSurfaceFilter> adaptiveGeometryFilter;
  vtkNew<vtkHyperTreeGridGeometry> geometryFilter;
  vtkNew<vtkDataSetSurfaceFilter> surfaceFilter;

  adaptiveGeometryFilter->SetRenderer(ren);

  auto outputComposite = vtkSmartPointer<vtkCompositeDataSet>::Take(cds->NewInstance());
  outputComposite->CopyStructure(cds);

  auto iter = vtkSmartPointer<vtkCompositeDataIterator>::Take(cds->NewIterator());
  iter->SkipEmptyNodesOn();
  for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
  {
    vtkDataObject* leaf = iter->GetCurrentDataObject();
    if (auto* htg = vtkHyperTreeGrid::SafeDownCast(leaf))
    {
      if (useAdapt)
      {
        // use adaptive decimation
        adaptiveGeometryFilter->SetInputDataObject(htg);
        adaptiveGeometryFilter->Update();
        vtkDataObject* outputDS = adaptiveGeometryFilter->GetOutputDataObject(0);
        auto newBlock = vtkSmartPointer<vtkDataObject>::Take(outputDS->NewInstance());
        newBlock->ShallowCopy(outputDS);
        outputComposite->SetDataSet(iter.Get(), newBlock);
      }
      else
      {
        // simply transform to polydata
        geometryFilter->SetInputDataObject(htg);
        geometryFilter->Update();
        vtkDataObject* outputDS = geometryFilter->GetOutputDataObject(0);
        auto newBlock = vtkSmartPointer<vtkDataObject>::Take(outputDS->NewInstance());
        newBlock->ShallowCopy(outputDS);
        outputComposite->SetDataSet(iter.Get(), newBlock);
      }
    }
    else if (auto* ds = vtkDataSet::SafeDownCast(leaf))
    {
      // other cases
      surfaceFilter->SetInputDataObject(ds);
      surfaceFilter->Update();
      vtkDataObject* outputDS = surfaceFilter->GetOutputDataObject(0);
      auto newBlock = vtkSmartPointer<vtkDataObject>::Take(outputDS->NewInstance());
      newBlock->ShallowCopy(outputDS);
      outputComposite->SetDataSet(iter.Get(), newBlock);
    }
  }

  return outputComposite;
}

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