Method RequestInformation

IO/Image/vtkImageReader.cxx:76–114

This method returns the largest data that can be generated. ------------------------------------------------------------------------------

// This method returns the largest data that can be generated.
//------------------------------------------------------------------------------
int vtkImageReader::RequestInformation(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  // call the old method to help with backwards compatibility
  this->ExecuteInformation();

  // get the info objects
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  outInfo->Set(vtkAlgorithm::CAN_PRODUCE_SUB_EXTENT(), 1);

  double spacing[3];
  int extent[6];
  double origin[3];

  // set the extent, if the VOI has not been set then default to
  // the DataExtent
  if (this->DataVOI[0] || this->DataVOI[1] || this->DataVOI[2] || this->DataVOI[3] ||
    this->DataVOI[4] || this->DataVOI[5])
  {
    this->ComputeTransformedExtent(this->DataVOI, extent);
  }
  else
  {
    this->ComputeTransformedExtent(this->DataExtent, extent);
  }
  outInfo->Set(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), extent, 6);

  // set the spacing
  this->ComputeTransformedSpacing(spacing);
  outInfo->Set(vtkDataObject::SPACING(), this->DataSpacing, 3);

  // set the origin.
  this->ComputeTransformedOrigin(origin);
  outInfo->Set(vtkDataObject::ORIGIN(), this->DataOrigin, 3);

  vtkDataObject::SetPointDataActiveScalarInfo(
    outInfo, this->DataScalarType, this->NumberOfScalarComponents);
  return 1;
}

//------------------------------------------------------------------------------
int vtkImageReader::OpenAndSeekFile(int dataExtent[6], int idx)