Alright, still no idea how to use the Simple* APIs, I have in the meantime found a hint to the issue here, but this is the best I've managed to get:
(sorry, open original, forum compression is terrible)
The red and blue dots should be on the LEFT and RIGHT points of the rectangle (capture starts somewhere in the middle of the animation) and the rectangle is supposed to rotate around the RIGHT point.
Basically what I used is:
Code:
offset_x_fixed = offset_x * width / UIParent:GetWidth();
But you can see that's not 100% correct, it's still "wobbly"