Type Definition ul_sys::ULFileSystemOpenFileCallback

type ULFileSystemOpenFileCallback = Option<unsafe extern "C" fn(path: ULString, open_for_writing: bool) -> ULFileHandle>;

The callback invoked when the FileSystem wants to open a file path for reading or writing. Return file handle on success, or ULInvalidFileHandle on failure.

@NOTE: As of this writing (v1.2), this function is only used for reading.