Question

我正在尝试从GeoPoints集合中找到边界框，但它没有正确缩放。我正在粘贴我用来找到下面的边界框的功能

private BoundingBox createBoundingBox(final ArrayList<LatLng> list){
        double minLatitude = 90, minLongitiude = 180, maxLatitude = -90, maxLongitude = -180;
        double currentLat, currentLng;
        for(LatLng location : list){
            currentLat    = location.getLatitude();
            currentLng    = location.getLongitude();
            minLatitude   = Math.max(minLatitude, currentLat);
            minLongitiude = Math.max(minLongitiude, currentLng);
            maxLatitude   = Math.min(maxLatitude, currentLat);
            maxLongitude  = Math.min(maxLongitude, currentLng);
        }
       return new BoundingBox(minLatitude, minLongitiude, maxLatitude - minLatitude,
               maxLongitude - minLongitiude);
}

有谁能告诉我这里我做错了什么。地图缩放级别仍为0。

Answer 1

看起来你走的是正确的道路，但你的默认分钟和最大值会造成一些麻烦。试试以下内容：

public BoundingBox findBoundingBoxForGivenLocations(ArrayList<LatLng> coordinates)
{
    double west = 0.0;
    double east = 0.0;
    double north = 0.0;
    double south = 0.0;

    for (int lc = 0; lc < coordinates.size(); lc++)
    {
        LatLng loc = coordinates.get(lc);
        if (lc == 0)
        {
            north = loc.getLatitude();
            south = loc.getLatitude();
            west = loc.getLongitude();
            east = loc.getLongitude();
        }
        else
        {
            if (loc.getLatitude() > north)
            {
                north = loc.getLatitude();
            }
            else if (loc.getLatitude() < south)
            {
                south = loc.getLatitude();
            }
            if (loc.getLongitude() < west)
            {
                west = loc.getLongitude();
            }
            else if (loc.getLongitude() > east)
            {
                east = loc.getLongitude();
            }
        }
    }

    // OPTIONAL - Add some extra "padding" for better map display
    double padding = 0.01;
    north = north + padding;
    south = south - padding;
    west = west - padding;
    east = east + padding;

    return new BoundingBox(north, east, south, west);
}

Answer 2

这里@Brad Leege's answer进行了一些小的改进，已移植到Kotlin：

fun findEnclosingBoundingBox(coordinates: ArrayList<LatLng>): BoundingBox {
    var west = GeometryConstants.MAX_LONGITUDE
    var east = GeometryConstants.MIN_LONGITUDE
    var north = GeometryConstants.MIN_LATITUDE
    var south = GeometryConstants.MAX_LATITUDE

    coordinates.forEach { loc ->
        north = Math.max(loc.latitude, north)
        south = Math.min(loc.latitude, south)
        west = Math.min(loc.longitude, west)
        east = Math.min(loc.longitude, east)
    }

    // Add some extra "padding"
    val padding = 0.01
    north += padding
    south -= padding
    west -= padding
    east += padding

    return BoundingBox.fromLngLats(west, south, east, north)
}

Answer 3

科特林溶液。对@Pulkit Goyal的改进

private fun zoomToMultipleGeoCoordinates(boundingList: List<GeoCoordinates>, isPaddingRequired: Boolean) {
    var north = Double.MIN_VALUE
    var south = Double.MAX_VALUE
    var east = Double.MIN_VALUE
    var west = Double.MAX_VALUE

    boundingList.forEach { loc ->
        north = loc.latitude.coerceAtLeast(north)
        south = loc.latitude.coerceAtMost(south)
        west = loc.longitude.coerceAtMost(west)
        east = loc.longitude.coerceAtLeast(east)
    }

    if (isPaddingRequired) {
        val padding = 0.01
        north += padding
        south -= padding
        west -= padding
        east += padding
    }
 return BoundingBox.fromLngLats(west, south, east, north)
}

从一组Geopoints Mapbox中找到边界框

3 个答案: