Comment 3 for bug 171797

@~suv while all this is very useful (i feel like i learned something), i'm pretty sure that these tips can't emulate mirroring over *any* axis. say, for example, i want to mirror across an axis that is drawn but is neither horizontal nor vertical and whose angle i don't know. the only way i can think of doing that now is to restrict my drawings at special angles (like 45deg) from the beginning. is there a way to rotate a drawing such that a given line becomes horizontal (without knowing the angle of the line)?