问检查经度/纬度坐标是否驻留在嵌入式设备中的复杂多边形中？

EN

public bool Contains(GeoLocation location)
{
    if (!Bounds.Contains(location))
        return false;

    var lastPoint = _vertices[_vertices.Length - 1];
    var isInside = false;
    var x = location.Longitude;
    foreach (var point in _vertices)
    {
        var x1 = lastPoint.Longitude;
        var x2 = point.Longitude;
        var dx = x2 - x1;

        if (Math.Abs(dx) > 180.0)
        {
            // we have, most likely, just jumped the dateline (could do further validation to this effect if needed).  normalise the numbers.
            if (x > 0)
            {
                while (x1 < 0)
                    x1 += 360;
                while (x2 < 0)
                    x2 += 360;
            }
            else
            {
                while (x1 > 0)
                    x1 -= 360;
                while (x2 > 0)
                    x2 -= 360;
            }
            dx = x2 - x1;
        }

        if ((x1 <= x && x2 > x) || (x1 >= x && x2 < x))
        {
            var grad = (point.Latitude - lastPoint.Latitude) / dx;
            var intersectAtLat = lastPoint.Latitude + ((x - x1) * grad);

            if (intersectAtLat > location.Latitude)
                isInside = !isInside;
        }
        lastPoint = point;
    }

    return isInside;
}