2011-05-18 110 views

回答

1

看一看:Core Location extensions for bearing and distance

随着初始行这些扩展和两个点,你应该能够获得支撑,加/减PI/2和发现点,这样两边:

double bearing = [bottomOfT bearingInRadiansTowardsLocation:topOfT]; 
CLLocation *left = [topOfT newLocationAtDistance:meters 
          alongBearingradians:bearing+M_PI/2]; 
CLLocation *right = [topOfT newLocationAtDistance:meters 
           alongBearingradians:bearing-M_PI/2];