Method RequestData

IO/Image/vtkVolume16Reader.cxx:144–208

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

//------------------------------------------------------------------------------
int vtkVolume16Reader::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  int first, last;
  int* dim;
  int dimensions[3];
  double Spacing[3];
  double origin[3];

  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  vtkDataObject* output_do = outInfo->Get(vtkDataObject::DATA_OBJECT());
  vtkImageData* output = this->AllocateOutputData(output_do, outInfo);
  vtkUnsignedShortArray* newScalars =
    vtkArrayDownCast<vtkUnsignedShortArray>(output->GetPointData()->GetScalars());

  // Validate instance variables
  if (this->FilePrefix == nullptr)
  {
    vtkErrorMacro(<< "FilePrefix is nullptr");
    return 1;
  }

  if (this->HeaderSize < 0)
  {
    vtkErrorMacro(<< "HeaderSize " << this->HeaderSize << " must be >= 0");
    return 1;
  }

  dim = this->DataDimensions;

  if (dim[0] <= 0 || dim[1] <= 0)
  {
    vtkErrorMacro(<< "x, y dimensions " << dim[0] << ", " << dim[1] << "must be greater than 0.");
    return 1;
  }

  if ((this->ImageRange[1] - this->ImageRange[0]) <= 0)
  {
    this->ReadImage(this->ImageRange[0], newScalars);
  }
  else
  {
    first = this->ImageRange[0];
    last = this->ImageRange[1];
    this->ReadVolume(first, last, newScalars);
  }

  // calculate dimensions of output from data dimensions and transform
  this->ComputeTransformedDimensions(dimensions);
  output->SetDimensions(dimensions);

  // calculate spacing of output from data spacing and transform
  this->ComputeTransformedSpacing(Spacing);

  // calculate origin of output from data origin and transform
  this->ComputeTransformedOrigin(origin);

  // adjust spacing and origin if spacing is negative