Method ExecuteDataWithInformation

IO/Image/vtkMRCReader.cxx:342–397

}

void vtkMRCReader::ExecuteDataWithInformation(
  vtkDataObject* vtkNotUsed(output), vtkInformation* outInfo)
{
  vtkIdType outInc[3];
  vtkIdType inOffsets[3];
  int* outExt;
  int modifiedOutExt[6];
  int* execExt = outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT());
  vtkImageData* data = vtkImageData::GetData(outInfo);
  this->AllocateOutputData(data, outInfo, execExt);

  if (data->GetNumberOfPoints() <= 0)
  {
    return;
  }
  outExt = data->GetExtent();
  // this should result in the bottom corner of the image having extent
  // 0,0,0 which makes the 'where in the file is this extent' math easier
  modifiedOutExt[0] = outExt[0] - this->Internals->header.nxstart;
  modifiedOutExt[1] = outExt[1] - this->Internals->header.nxstart;
  modifiedOutExt[2] = outExt[2] - this->Internals->header.nystart;
  modifiedOutExt[3] = outExt[3] - this->Internals->header.nystart;
  modifiedOutExt[4] = outExt[4] - this->Internals->header.nzstart;
  modifiedOutExt[5] = outExt[5] - this->Internals->header.nzstart;
  data->GetContinuousIncrements(outExt, outInc[0], outInc[1], outInc[2]);
  void* outPtr = data->GetScalarPointer(outExt[0], outExt[2], outExt[4]);

  if (!this->Internals->stream)
  {
    return;
  }
  // data start position is 1024 (the header size) plus the extended header size
  vtkIdType dataStartPos = 1024 + this->Internals->header.next;
  this->Internals->stream->seekg(dataStartPos, vtksys::ifstream::beg);

  int vtkType = getFileDataType(this->Internals->header.mode);
  int numComponents = getFileDataNumComponents(this->Internals->header.mode);
  inOffsets[0] = numComponents;
  inOffsets[1] = this->Internals->header.nx * numComponents;
  inOffsets[2] = this->Internals->header.ny * this->Internals->header.nx * numComponents;

  // This is what the big-endian MRC files are supposed to look like.  I don't have one to
  // test with though.  However, if it does not look like that, assume it is little endian.
  // There are some non-conformant programs that don't correctly fill in this field, and
  // assuming little endian is safer.
  bool fileIsLittleEndian = (this->Internals->header.stamp[0] != ((char)17));

  ByteSwapFunction byteSwapFunction = getByteSwapFunction(vtkType, fileIsLittleEndian);
  switch (vtkType)
  {
    vtkTemplateMacro(readData<VTK_TT>(numComponents, modifiedOutExt, outInc, inOffsets,
      static_cast<VTK_TT*>(outPtr), *this->Internals->stream, dataStartPos, byteSwapFunction));
    default:
      vtkErrorMacro("Unknown data type");
  }
}
VTK_ABI_NAMESPACE_END