Method RequestUpdateExtent

Filters/Extraction/vtkExtractRectilinearGrid.cxx:41–98

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

//------------------------------------------------------------------------------
int vtkExtractRectilinearGrid::RequestUpdateExtent(
  vtkInformation*, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (!this->Internal->IsValid())
  {
    return 0;
  }

  int i;
  // get the info objects
  vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);

  bool emptyExtent = false;
  int uExt[6];
  for (i = 0; i < 3; i++)
  {
    if (this->Internal->GetSize(i) < 1)
    {
      uExt[0] = uExt[2] = uExt[4] = 0;
      uExt[1] = uExt[3] = uExt[5] = -1;
      emptyExtent = true;
      break;
    }
  }

  if (!emptyExtent)
  {
    // Find input update extent based on requested output
    // extent
    int oUExt[6];
    outputVector->GetInformationObject(0)->Get(
      vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(), oUExt);
    int oWExt[6]; // For parallel partition this will be different.
    this->Internal->GetOutputWholeExtent(oWExt);
    for (i = 0; i < 3; i++)
    {
      int idx = oUExt[2 * i] - oWExt[2 * i]; // Extent value to index
      if (idx < 0 || idx >= this->Internal->GetSize(i))
      {
        vtkWarningMacro("Requested extent outside whole extent.");
        idx = 0;
      }
      uExt[2 * i] = this->Internal->GetMappedExtentValueFromIndex(i, idx);
      int jdx = oUExt[2 * i + 1] - oWExt[2 * i]; // Extent value to index
      if (jdx < idx || jdx >= this->Internal->GetSize(i))
      {
        vtkWarningMacro("Requested extent outside whole extent.");
        jdx = 0;
      }
      uExt[2 * i + 1] = this->Internal->GetMappedExtentValueFromIndex(i, jdx);
    }
  }
  inInfo->Set(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(), uExt, 6);
  // We can handle anything.
  inInfo->Set(vtkStreamingDemandDrivenPipeline::EXACT_EXTENT(), 0);

  return 1;
}