Question

鉴于移动设备在短时间内的实时位置数据，如何在这条路上进一步获得一对纬度/长对，比如2英里，甚至更好，5分钟的驾驶？

我发现我可以使用Google的Roads API来捕捉一条长/长对https://developers.google.com/maps/documentation/roads/snap的道路，但这只会让我分道扬..

这将在Android应用中。

Answer 1

如果路线表示为List<LatLng>，则此函数计算路线上的点，该点来自该路线distance的{{1}}米{（使用Google Maps API Utility Library}做一些计算）：

origin

以下是一些测试：

private LatLng extrapolate(List<LatLng> path, LatLng origin, float distance) {
    LatLng extrapolated = null;

    if (!PolyUtil.isLocationOnPath(origin, path, false, 1)) { // If the location is not on path non geodesic, 1 meter tolerance
        return null;
    }

    float accDistance = 0f;
    boolean foundStart = false;
    List<LatLng> segment = new ArrayList<>();

    for (int i = 0; i < path.size() - 1; i++) {
        LatLng segmentStart = path.get(i);
        LatLng segmentEnd = path.get(i + 1);

        segment.clear();
        segment.add(segmentStart);
        segment.add(segmentEnd);

        double currentDistance = 0d;

        if (!foundStart) {
            if (PolyUtil.isLocationOnPath(origin, segment, false, 1)) {
                foundStart = true;

                currentDistance = SphericalUtil.computeDistanceBetween(origin, segmentEnd);

                if (currentDistance > distance) {
                    double heading = SphericalUtil.computeHeading(origin, segmentEnd);
                    extrapolated = SphericalUtil.computeOffset(origin, distance - accDistance, heading);
                    break;
                }
            }
        } else {
            currentDistance = SphericalUtil.computeDistanceBetween(segmentStart, segmentEnd);

            if (currentDistance + accDistance > distance) {
                double heading = SphericalUtil.computeHeading(segmentStart, segmentEnd);
                extrapolated = SphericalUtil.computeOffset(segmentStart, distance - accDistance, heading);
                break;
            }
        }

        accDistance += currentDistance;
    }

    return extrapolated;
}

我怎样才能在道路上进一步推断？

1 个答案: