Method Trace

Filters/ParallelFlowPaths/vtkPStreamTracer.cxx:1714–1784

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

//------------------------------------------------------------------------------
void vtkPStreamTracer::Trace(vtkDataSet* input, int vecType, const char* vecName,
  PStreamTracerPoint* point, vtkSmartPointer<vtkPolyData>& traceOut,
  vtkAbstractInterpolatedVelocityField* func, int maxCellSize)
{
  double* seedSource = point->GetSeed();
  int direction = point->GetDirection();

  this->Utils->InitializeVelocityFunction(point, func);

  vtkSmartPointer<vtkFloatArray> seeds = vtkSmartPointer<vtkFloatArray>::New();
  seeds->SetNumberOfComponents(3);
  seeds->InsertNextTuple(seedSource);

  vtkNew<vtkIdList> seedIds;
  seedIds->InsertNextId(0);

  vtkNew<vtkIntArray> integrationDirections;
  integrationDirections->InsertNextValue(direction);
  traceOut = vtkSmartPointer<vtkPolyData>::New();

  double propagation = point->GetPropagation();
  vtkIdType numSteps = point->GetNumSteps();
  double integrationTime = point->GetIntegrationTime();

  vtkStreamTracer::Integrate(input->GetPointData(), traceOut, seeds, seedIds, integrationDirections,
    func, maxCellSize, vecType, vecName, propagation, numSteps, integrationTime,
    this->CustomTerminationCallback, this->CustomTerminationClientData,
    this->CustomReasonForTermination);

  AssertGe(propagation, point->GetPropagation());
  AssertGe(numSteps, point->GetNumSteps());

  point->SetPropagation(propagation);
  point->SetNumSteps(numSteps);
  point->SetIntegrationTime(integrationTime);

  if (this->GenerateNormalsInIntegrate)
  {
    this->GenerateNormals(traceOut, point->GetNormal(), vecName);
  }

  if (traceOut->GetNumberOfPoints() > 0)
  {
    // If a point was produced, but no streamline, create arrays
    // which are used to communicate about streamline traversal.
    if (traceOut->GetLines()->GetNumberOfCells() == 0)
    {
      PRINT("Fix Single Point Path")
      AssertEq(traceOut->GetNumberOfPoints(), 1); // fix it
      vtkNew<vtkCellArray> newCells;
      vtkIdType cells[2] = { 0, 0 };
      newCells->InsertNextCell(2, cells);
      traceOut->SetLines(newCells);

      // Don't forget to add the ReasonForTermination cell array.
      vtkNew<vtkIntArray> retVals;
      retVals->SetName("ReasonForTermination");
      retVals->SetNumberOfTuples(1);