cutFaceImage method Null safety

Implementation

Uint8List cutFaceImage(ImageFormatCode imageFormat, FaceCutType cutType) {
    final exception = _getException();
    Pointer<Int32> widthPtr = malloc.allocate(sizeOf<Pointer<Int32>>());
    Pointer<Int32> heightPtr = malloc.allocate(sizeOf<Pointer<Int32>>());

    PointerBuffer<Uint8> buffer = PointerBuffer<Uint8>.empty(sizeOf<Uint8>());

    if(widthPtr.address == nullptr.address || heightPtr.address == nullptr.address)
      throw Exception("RawSample.cutFaceImage: Failed to allocate a ${sizeOf<Pointer<Int32>>()} bytes");

    final get = _dll_handle.lookupFunction<_RScutFaceImage_c, _RScutFaceImage_dart>
      (_c_namespace + 'RawSample_cutFaceImage');

    get(
        this._impl,
        buffer.ptr.cast(),
        Pointer.fromFunction(WrapBytesWrite.writeByteListFunc),
        widthPtr,
        heightPtr,
        imageFormat.index,
        -1,
        cutType.index,
        exception);

    checkException(exception, _dll_handle);

    // int width = widthPtr.value;
    // int height = heightPtr.value;

    Uint8List list = buffer.dataPtr<Uint8>().asTypedList(buffer.length);
    Uint8List outData = Uint8List.fromList(list);

    buffer.dispose();

    malloc.free(widthPtr);
    malloc.free(heightPtr);

    return outData;
  }