Having difficulty calculating the ~90 degree spread between corners. Radar still borked.
Added lambdas for gun, body, and radar rotation. Fixed re-cornering bug (wasn't setting new current corner).  Fixed painting but (sin and cos switched, calculating inverted triangle).
Merge branch 'radar'

* radar:
  Added lambdas for gun, body, and radar rotation. Fixed re-cornering bug (wasn't setting new current corner).  Fixed painting but (sin and cos switched, calculating inverted triangle).
  Having difficulty calculating the ~90 degree spread between corners. Radar still borked.