Method CreateSamplingPolyLine

Filters/ParallelDIY2/vtkProbeLineFilter.cxx:962–1018

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

//------------------------------------------------------------------------------
vtkSmartPointer<vtkPolyData> vtkProbeLineFilter::CreateSamplingPolyLine(
  vtkPoints* points, vtkIdList* pointIds, vtkDataObject* input, double tolerance) const
{
  std::vector<vtkSmartPointer<vtkPolyData>> polylines;
  double previousLength = 0.0;
  vtkSmartPointer<vtkDataSetAttributes> defaultPD;

  for (vtkIdType i = 0; i < pointIds->GetNumberOfIds() - 1; ++i)
  {
    const vtkVector3d p1(points->GetPoint(pointIds->GetId(i)));
    const vtkVector3d p2(points->GetPoint(pointIds->GetId(i + 1)));
    vtkSmartPointer<vtkPolyData> current = (this->SamplingPattern == SAMPLE_LINE_UNIFORMLY)
      ? this->SampleLineUniformly(p1, p2, input, tolerance)
      : this->SampleLineAtEachCell(p1, p2, input, tolerance);

    if (!defaultPD)
    {
      defaultPD = current->GetPointData();
    }

    vtkDataArray* arclength = current->GetPointData()->GetArray("arc_length");
    if (arclength && current->GetNumberOfCells() == 1 && current->GetNumberOfPoints() > 1)
    {
      if (previousLength != 0.0)
      {
        auto range = vtk::DataArrayValueRange<1>(arclength);
        vtkSMPTools::Transform(range.begin(), range.end(), range.begin(),
          [previousLength](double x) { return x + previousLength; });
      }
      previousLength = arclength->GetTuple1(arclength->GetNumberOfValues() - 1);
      polylines.emplace_back(current);
    }
  }

  if (polylines.empty())
  {
    auto res = vtkSmartPointer<vtkPolyData>::New();
    res->GetPointData()->ShallowCopy(defaultPD);
    return res;
  }
  else if (polylines.size() == 1)
  {
    return polylines[0];
  }
  else
  {
    vtkNew<vtkAppendDataSets> appender;
    for (const auto& pl : polylines)
    {
      appender->AddInputData(0, pl);
    }
    appender->SetOutputDataSetType(VTK_POLY_DATA);
    appender->SetMergePoints(false);
    appender->Update();
    return appender->GetPolyDataOutput();
  }
}