Function vtkMINCImageReaderExecuteChunk

IO/MINC/vtkMINCImageReader.cxx:928–1024

//------------------------------------------------------------------------------
template <class T1, class T2>
void vtkMINCImageReaderExecuteChunk(T1* outPtr, T2* buffer, double slope, double intercept,
  int ncid, int varid, int ndims, size_t* start, size_t* count, vtkIdType* permutedInc)
{
  // Read the chunk of data from the MINC file.
  vtkMINCImageReaderReadChunk(ncid, varid, start, count, buffer);

  // Create space to save values during the copy loop.
  T1* saveOutPtr[VTK_MINC_MAX_DIMS];
  size_t index[VTK_MINC_MAX_DIMS];
  int idim = 0;
  for (idim = 0; idim < ndims; idim++)
  {
    index[idim] = 0;
    saveOutPtr[idim] = outPtr;
  }

  // See if there is a range of dimensions over which the
  // the MINC data and VTK data will be contiguous.  The
  // lastdim is the dimension after which all dimensions
  // are contiguous between the MINC file and the output.
  int lastdim = ndims - 1;
  int ncontiguous = 1;
  vtkIdType dimprod = 1;
  for (idim = ndims; idim > 0;)
  {
    idim--;

    lastdim = idim;
    ncontiguous = dimprod;

    if (dimprod != permutedInc[idim])
    {
      break;
    }

    dimprod *= static_cast<vtkIdType>(count[idim]);
  }

  // Save the count and permuted increment of this dimension.
  size_t lastdimcount = count[lastdim];
  size_t lastdimindex = 0;
  vtkIdType lastdimInc = permutedInc[lastdim];
  T1* lastdimOutPtr = saveOutPtr[lastdim];

  // Loop over all contiguous sections of the image.
  for (;;)
  {
    // Loop through one contiguous section
    vtkIdType k = ncontiguous;
    do
    {
      // Use special function for type conversion.
      vtkMINCImageReaderConvert((*buffer++) * slope + intercept, *outPtr++);
    } while (--k);

    lastdimindex++;
    lastdimOutPtr += lastdimInc;
    outPtr = lastdimOutPtr;