Line of sight distance?

I'm looking for a way to display line of sight distance from either, a) my current position or b) a dropped waypoint, that takes into account the topography. I'd use it for determining what, if any, repeaters would be within useful range when planning trips, but I could see it being useful for planning out when to take bearings based on what prominent features one could see from a given point. I've played around and couldn't find anything. Has anyone figured this out? Devs, any odds of adding this functionality?