Method ThreadedRequestData

Imaging/General/vtkImageGradient.cxx:279–322

------------------------------------------------------------------------------ This method contains a switch statement that calls the correct templated function for the input data type. This method does handle boundary conditions.

// templated function for the input data type.  This method does handle
// boundary conditions.
void vtkImageGradient::ThreadedRequestData(vtkInformation*, vtkInformationVector** inputVector,
  vtkInformationVector*, vtkImageData*** inData, vtkImageData** outData, int outExt[6],
  int threadId)
{
  // Get the input and output data objects.
  vtkImageData* input = inData[0][0];
  vtkImageData* output = outData[0];

  // The output scalar type must be double to store proper gradients.
  auto outScalars =
    vtkAOSDataArrayTemplate<double>::FastDownCast(output->GetPointData()->GetScalars());
  if (!outScalars)
  {
    vtkErrorMacro("Execute: output ScalarType must be double.");
    return;
  }

  vtkDataArray* inputArray = this->GetInputArrayToProcess(0, inputVector);
  if (!inputArray)
  {
    vtkErrorMacro("No input array was found. Cannot execute");
    return;
  }

  // Gradient makes sense only with one input component.  This is not
  // a Jacobian filter.
  if (inputArray->GetNumberOfComponents() != 1)
  {
    vtkErrorMacro("Execute: input has more than one component. "
                  "The input to gradient should be a single component image. "
                  "Think about it. If you insist on using a color image then "
                  "run it though RGBToHSV then ExtractComponents to get the V "
                  "components. That's probably what you want anyhow.");
    return;
  }

  double* scalarsPtr = outScalars->GetPointer(output->GetValueIndexForExtent(outScalars, outExt));
  vtkImageGradientFunctor functor;
  if (!vtkArrayDispatch::Dispatch::Execute(
        inputArray, functor, this, input, output, scalarsPtr, outExt, threadId))
  {
    functor(inputArray, this, input, output, scalarsPtr, outExt, threadId);
  }
}
VTK_ABI_NAMESPACE_END