Question about an old Mod

[Maldelic]

Iriel, I wish to ask you a question about StatRings.

I am trying to create a non-HUD unitframes mod just for vanity's purpose. It is not meant to be to customizable at first. The textures are all preloaded/sized. The predicament I am in is that there doesn't seem to be a single person who can tell me how to make a frame fill/texture draw along a curve. I have looked at the statrings code and found mention of math.angle, but I am unsure of the basic procedure.

Could you explain how to make a curved fill-bar? It needs to be able to do a 3/4 circle.