Method LoadFile

IO/OpenVDB/vtkOpenVDBReader.cxx:832–892

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

//------------------------------------------------------------------------
bool vtkOpenVDBReader::LoadFile()
{
  if (this->FileName == nullptr && this->Stream == nullptr)
  {
    vtkErrorMacro(<< "No file name or stream has been set.");
    return false;
  }

  this->Internals->ResetCurrentlyOpenedFile(this->FileName);

  this->DataCorrect = true;

  if (this->Stream)
  {
    // Encapsulate resource stream into an istream
    this->Stream->Seek(0, vtkResourceStream::SeekDirection::Begin);
    auto strbuf = this->Stream->ToStreambuf();
    std::istream buffer(strbuf.get());

    try
    {
      // Read the istream using OpenVDB
      this->Internals->GridsVdbMetadata = openvdb::io::Stream(buffer, false).getGrids();
    }
    catch (openvdb::IoError& e)
    {
      // happens when the strean is not a VDB file
      vtkErrorMacro("Error while loading grids from stream: " << e.what());
      return false;
    }
  }
  else
  {
    vtkOpenVDBReaderInternals::VdbFileContext resCtx = this->Internals->OpenFile(this->FileName);

    if (resCtx.File == nullptr)
    {
      return false;
    }

    // then try to read the metadata
    try
    {
      // it creates the pointers to the metadata of the grids
      this->Internals->GridsVdbMetadata = resCtx.File->readAllGridMetadata();
    }
    catch (openvdb::IoError& e)
    {
      vtkErrorMacro(<< "Error while loading metadata from " << this->FileName << ": " << e.what());
      resCtx.File = nullptr;
      resCtx.FileName = "";
      return false;
    }

    // if everything went well, copy it into CurrentlyOpenedFile
    this->Internals->CurrentlyOpenedFile.File = resCtx.File;
    this->Internals->CurrentlyOpenedFile.FileName = resCtx.FileName;
  }