I just noticed that UnitAura (and the likes) returns a unit token instead of a boolean for "isMine" in 3.1 (confirmation). Notice that it returns "npc" for anything that is not in the party/raid and do not have a valid unit (like "target" or "focus").
You can add an 180 offset (not 90) and you'll get a 0-360 range where north is south
(I already mentioned on my first post that GetPlayerFacing() returns 1-180, -179-0 going ccw)
Adding an offset (even 180 which is the correct one) still doesn't make GetFacing() equivalent to GetPlayerFacing()*math.pi/180 for addon purposes.
(especially if you want to do minimal edits to existing code)
Those values you picked up on the ui and macros forums are indicative (examples to make it plain),
they don't mean Blizz rotated anything by 90 degrees.
They could just as well have said that SE = - 135 (which it is) would you add 135 then?
I apologize- I misunderstood. I had assumed that the intent was to get a typical 0->2pi measure, counterclockwise from East (and yes, what I posted above would've given negative values in the 4th quadrant, but they'd refer to the correct angles). Testing on live, though, you want 0 to -2pi ccw from North?
local radians = (-math.pi/180) * (GetPlayerFacing()+ (GetPlayerFacing() < 0 and 360 or 0))