Method RequestData

Filters/General/vtkTimeSourceExample.cxx:165–321

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//------------------------------------------------------------------------------
int vtkTimeSourceExample::RequestData(vtkInformation* vtkNotUsed(reqInfo),
  vtkInformationVector** vtkNotUsed(inVector), vtkInformationVector* outVector)
{
  vtkInformation* outInfo = outVector->GetInformationObject(0);
  vtkUnstructuredGrid* output =
    vtkUnstructuredGrid::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));
  if (!output)
  {
    return 0;
  }

  // determine what time is being asked for
  double reqTime = 0.0;
  // int reqNTS = 0;
  double reqTS(0);
  if (outInfo->Has(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP()))
  {
    // reqNTS = outInfo->Length
    //  (vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());
    reqTS = outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());

    // TODO: produce multiblock output when multiple time steps are asked for
    // for now just answer the first one
    reqTime = reqTS;
  }

  // if analytic compute the value at that time
  // if discrete look up the nearest time and value from the table
  double time = reqTime;
  double value = 0.0;
  this->LookupTimeAndValue(time, value);

  output->Initialize();
  output->GetInformation()->Set(vtkDataObject::DATA_TIME_STEP(), time);

  // figure out the world space position of the output
  double x = this->XFunction(time);
  double y = this->YFunction(time);

  // figure out the number of cells in the output
  int numCells = this->NumCellsFunction(time);

  // compute values for each point and cell to test with
  vtkDoubleArray* pd = vtkDoubleArray::New();
  pd->SetNumberOfComponents(1);
  pd->SetName("Point Value");
  output->GetPointData()->AddArray(pd);
  vtkIdTypeArray* id = vtkIdTypeArray::New();
  id->SetNumberOfComponents(1);
  id->SetName("Point Label");
  output->GetPointData()->AddArray(id);
  output->GetPointData()->SetGlobalIds(id);
  vtkDoubleArray* xd = vtkDoubleArray::New();
  xd->SetNumberOfComponents(1);
  xd->SetName("Point X");
  output->GetPointData()->AddArray(xd);
  vtkDoubleArray* yd = vtkDoubleArray::New();
  yd->SetNumberOfComponents(1);