Compute Carry for PiTrac's own GUI

[jamespilgrim]

If the system isn't connected to a golf sim, it should still be able to do a reasonable job computing the carry yardage for a shot. Need to add to PiTrac whatever open-source physics algorithm there is and compute the carry before sending out data. Should probably NOT send carry to any golf-sims, as we assume they will do a better job themselves (plus the sim should be internally consistent and doesn't need PiTrac's help).

This would be a good issue to resolve for someone who doesn't have a physical PiTrac, but wants to dive into the code in Visual Studio on a Windows or Mac PC. See "TBD" comments in gs_results.cpp.

[ManBearPigWolf]

I like this idea. Just like how on a GCquad, there's a small display that shows the data from the last strike regardless of whether it's connected to a sim or not. It'd be a cool feature to implement.