Function vtkImageHistogramExecuteInt

Imaging/Statistics/vtkImageHistogram.cxx:407–444

//------------------------------------------------------------------------------
template <class T>
void vtkImageHistogramExecuteInt(vtkImageHistogram* self, vtkImageData* inData,
  vtkImageStencilData* stencil, T* inPtr, int extent[6], vtkIdType* outPtr, int component,
  int threadId)
{
  vtkImageStencilIterator<T> inIter(inData, stencil, extent, ((threadId == 0) ? self : nullptr));

  // set up components
  int nc = inData->GetNumberOfScalarComponents();
  int c = component;
  if (c < 0)
  {
    nc = 1;
    c = 0;
  }

  // iterate over all spans in the stencil
  while (!inIter.IsAtEnd())
  {
    if (inIter.IsInStencil())
    {
      inPtr = inIter.BeginSpan();
      T* inPtrEnd = inIter.EndSpan();

      // iterate over all voxels in the span
      if (inPtr != inPtrEnd)
      {
        int n = static_cast<int>((inPtrEnd - inPtr) / nc);
        inPtr += c;
        do
        {
          outPtr[*inPtr]++;
          inPtr += nc;
        } while (--n);
      }
    }
    inIter.NextSpan();
  }
}

// no-op version for float
void vtkImageHistogramExecuteInt(