Rect contains question (regarding negative x,y values)

Hello. I know this is easy, and I should probably know this, but I have a rect defined that is centered at 0,0. So the extents of the rect are -512, 384, 512, -384.

I want to take a mouse position and determine if the position is contained with the rect. What is the best way to do this?

I could shift the values up so that the min x and y are positive, then do a Rect.contains() with the shifted mouse position. Or is there some easy matrix math that can accomplish this?

Thanks.