/// <summary>
/// Calculates the closest point on the route relative to the given coordinate.
/// </summary>
/// <returns></returns>
public bool ProjectOn(GeoCoordinate coordinates, out GeoCoordinate projectedCoordinates, out int entryIndex, out Meter distanceFromStart, out Second timeFromStart)
{
double distance = double.MaxValue;
distanceFromStart = 0;
timeFromStart = 0;
double currentDistanceFromStart = 0;
projectedCoordinates = null;
entryIndex = -1;
// loop over all points and try to project onto the line segments.
GeoCoordinate projected;
double currentDistance;
var points = this.GetPoints();
for (int idx = 0; idx < points.Count - 1; idx++)
{
var line = new GeoCoordinateLine(points[idx], points[idx + 1], true, true);
var projectedPoint = line.ProjectOn(coordinates);
if (projectedPoint != null)
{ // there was a projected point.
projected = new GeoCoordinate(projectedPoint[1], projectedPoint[0]);
currentDistance = coordinates.Distance(projected);
if (currentDistance < distance)
{ // this point is closer.
projectedCoordinates = projected;
entryIndex = idx;
distance = currentDistance;
// calculate distance/time.
double localDistance = projected.DistanceReal(points[idx]).Value;
distanceFromStart = currentDistanceFromStart + localDistance;
if(this.HasTimes && idx > 0)
{ // there should be proper timing information.
double timeToSegment = this.Segments[idx].Time;
double timeToNextSegment = this.Segments[idx + 1].Time;
timeFromStart = timeToSegment + ((timeToNextSegment - timeToSegment) * (localDistance / line.LengthReal.Value));
}
}
}
// check first point.
projected = points[idx];
currentDistance = coordinates.Distance(projected);
if (currentDistance < distance)
{ // this point is closer.
projectedCoordinates = projected;
entryIndex = idx;
distance = currentDistance;
distanceFromStart = currentDistanceFromStart;
if (this.HasTimes)
{ // there should be proper timing information.
timeFromStart = this.Segments[idx].Time;
}
}
// update distance from start.
currentDistanceFromStart = currentDistanceFromStart + points[idx].DistanceReal(points[idx + 1]).Value;
}
// check last point.
projected = points[points.Count - 1];
currentDistance = coordinates.Distance(projected);
if (currentDistance < distance)
{ // this point is closer.
projectedCoordinates = projected;
entryIndex = points.Count - 1;
distance = currentDistance;
distanceFromStart = currentDistanceFromStart;
if (this.HasTimes)
{ // there should be proper timing information.
timeFromStart = this.Segments[points.Count - 1].Time;
}
}
return true;
}
/// <summary>
/// Project on route and return the next entry index and coordinate.
/// </summary>
/// <param name="route"></param>
/// <param name="coordinates"></param>
/// <returns></returns>
private KeyValuePair<int, GeoCoordinate> ProjectOn(Route route, GeoCoordinate coordinates)
{
double distance = double.MaxValue;
GeoCoordinate closest = null;
int closestIdx = -1;
List<GeoCoordinate> points = route.GetPoints();
for (int idx = 0; idx < points.Count - 1; idx++)
{
GeoCoordinateLine line = new GeoCoordinateLine(points[idx], points[idx + 1], true, true);
PointF2D projectedPoint = line.ProjectOn(coordinates);
GeoCoordinate projected;
double currentDistance;
if (projectedPoint != null) {
projected = new GeoCoordinate(projectedPoint[1], projectedPoint[0]);
currentDistance = coordinates.Distance(projected);
if (currentDistance < distance)
{
closest = projected;
closestIdx = idx + 1;
distance = currentDistance;
}
}
projected = points[idx];
currentDistance = coordinates.Distance(projected);
if (currentDistance < distance)
{
closest = projected;
closestIdx = idx;
distance = currentDistance;
}
}
return new KeyValuePair<int,GeoCoordinate>(closestIdx, closest);
}
/// <summary>
/// Calculates the closest point on the route.
/// </summary>
/// <param name="coordinates"></param>
/// <returns></returns>
public GeoCoordinate ProjectOn(GeoCoordinate coordinates)
{
double distance = double.MaxValue;
GeoCoordinate closests = null;
List<GeoCoordinate> points = this.GetPoints();
for (int idx = 0; idx < points.Count - 1; idx++)
{
GeoCoordinateLine line = new GeoCoordinateLine(points[idx], points[idx + 1]);
PointF2D projectedPoint = line.ProjectOn(coordinates);
GeoCoordinate projected = new GeoCoordinate(projectedPoint[1], projectedPoint[0]);
double currentDistance = coordinates.Distance(projected);
if (currentDistance < distance)
{
closests = projected;
distance = currentDistance;
}
}
return closests;
}