Thanks a lot, man! Great job! I'll be posting a bug report soon about this.
EDIT: Could you explain what that "Self.isMirrored ? -1 : 1" part means?
EDIT2: This seems to only work on static objects. My object has an attack animation, so I have to constantly change the "OriginaWidth" and that seems to mess the calculation up pretty badly causing flickering. A static number does work and kinda does what I want and should be good enough for now.