/// <summary>
/// Creates a polyline by joining together the end of each polyline
/// with the beginning of the next polyline. This method assumes that
/// the first point of each polyline corresponds to the last point of
/// its predecessor, if any. It also assumes that no polyline is empty.
/// </summary>
/// <returns>The overall polyline.</returns>
/// <param name="polylines">List of polylines whose ends align.</param>
public static GeoPolyline Join(IEnumerable <GeoPolyline> polylines)
{
GeoPolyline first = polylines.First();
var rest = polylines.Skip(1);
return(new GeoPolyline(first.Points.Concat(
rest.SelectMany((line) => line.Points.Skip(1)))));
}
/// <summary>
/// Tests whether the rectangle is within a given distance of the polyline,
/// where the distance is given by the metric lat^2 + long^2 in WGS84
/// coordinates (so it doesn't correspond to real distance).
/// </summary>
/// <returns><c>true</c>, if rect is within distance, <c>false</c> otherwise.</returns>
/// <param name="geoRect">A valid geo rectangle.</param>
/// <param name="distance">Distance in units of sqrt(lat^2 + long^2).</param>
public bool RectWithinDistance(Rect geoRect, double distance)
{
if (!GeoRectUtils.IsValidGeoRect(geoRect))
{
throw new ArgumentException("Rectangle must be valid geo rectangle.");
}
// Try fast heuristics for longer polylines.
if (Points.Count >= 10)
{
Rect fattenedBounds = BoundingRect();
fattenedBounds.xMin -= distance;
fattenedBounds.yMin -= distance;
fattenedBounds.xMax += distance;
fattenedBounds.yMax += distance;
// Ensure rectangle is within geo bounds.
fattenedBounds.yMin = Math.Max(-90, fattenedBounds.yMin);
fattenedBounds.yMax = Math.Min(90, fattenedBounds.yMax);
// Quick test to rule out certain cases (good for long polylines)
if (!GeoRectUtils.Intersect(geoRect, fattenedBounds))
{
return(false);
}
GeoPolyline firstHalf = new GeoPolyline(this, 0, Points.Count / 2);
GeoPolyline secondHalf = new GeoPolyline(this, Points.Count / 2, Points.Count);
return(firstHalf.RectWithinDistance(geoRect, distance) ||
secondHalf.RectWithinDistance(geoRect, distance));
}
if (Points.Count >= 2)
{
return(Segments.Any(segment => GeoRectUtils.RectNearSegment(segment, geoRect, distance)));
}
if (Points.Count == 1)
{
// Perform a capsule test on a single point (this amounts to
// a circle test).
return(GeoRectUtils.RectNearSegment(new GeoSegment(Points[0], Points[0]), geoRect, distance));
}
return(true);
}
/// <summary>
/// Creates a new GeoPolyline that is a piece of a larger GeoPolyline.
/// This is a lightweight view into the larger polyline.
/// </summary>
/// <param name="original">Original polyline.</param>
/// <param name="startIdx">Index of first point that belongs to this polyline.</param>
/// <param name="endIdx">Index after the last point that belongs to this polyline.</param>
public GeoPolyline(GeoPolyline original, int startIdx, int endIdx)
{
Points = new ReadOnlySubList <GeoCoordinates>(original.Points, startIdx, endIdx - startIdx);
}
public RouteInfo(GeoPolyline overview, TimeSpan?time = null)
{
overviewPolyline = overview;
drivingTime = time;
}
