polyline_generator.py 文件源码

def get_alt(self, at_point=None):
        if at_point is None:
            at_point = self._last_pos
        if self._elevation_at_point:
            elevations = sorted([(great_circle(at_point, k).meters, v, k) for k, v in self._elevation_at_point.items()])

            if len(elevations) == 1:
                return elevations[0][1]
            else:
                (distance_to_p1, ep1, p1), (distance_to_p2, ep2, p2) = elevations[:2]
                distance_p1_p2 = great_circle(p1, p2).meters
                return self._get_relative_hight(ep1, ep2, distance_p1_p2, distance_to_p1, distance_to_p2)
        else:
            return None