So I want to rotate a group of points, and so far I've used this formula:

x′=xcosθ−ysinθ

y′=ycosθ+xsinθ

x′,y′=new rotated coordinates

x,y=old coordinates of point I want to rotate

θ=angle

And I know that in order to rotate around a center point rather than the origin, I need to subtract the center point from the point I want to rotate, do the math, then add it again. But because Axe doesn't have negative numbers, (unless somehow I completely missed that, though I highly doubt that's the case) it instead looping back to the highest number, I think that messes with the math.

How did anyone else do it?