private static RouteFeature[] ReadFeatures(string path)
{
var sf = Shapefile.OpenFile(path);
sf.Reproject(KnownCoordinateSystems.Geographic.World.WGS1984);
var features = new List <RouteFeature>();
var columns = GetColumns(sf);
foreach (var feature in sf.Features)
{
var f = new RouteFeature();
f.Data.Coordinates = feature.Coordinates.Select(t => new PointPosition
{
Latitude = t.Y,
Longitude = t.X
}).ToArray();
f.Data.Properties = GetAttributes(feature, columns);
features.Add(f);
}
return(features.ToArray());
}
private bool AreNeighbours(RouteFeature routeFeature, RouteFeature testRouteFeature)
{
if (routeFeature == testRouteFeature)
{
return(false);
}
var startPoint1 = routeFeature.Feature.Coordinates.First();
var endPoint1 = routeFeature.Feature.Coordinates.Last();
var startPoint2 = testRouteFeature.Feature.Coordinates.First();
var endPoint2 = testRouteFeature.Feature.Coordinates.Last();
if (Helpers.AreClose(startPoint1, startPoint2))
{
return(true);
}
if (Helpers.AreClose(startPoint1, endPoint2))
{
return(true);
}
if (Helpers.AreClose(endPoint1, startPoint2))
{
return(true);
}
if (Helpers.AreClose(endPoint1, endPoint2))
{
return(true);
}
return(false);
}
private double ApplySearchOptionsToGetLength(RouteFeature feature, List <RouteFeature> featuresToOverlap)
{
var featureLength = feature.Feature.Properties["length"];
if (_searchOptions == null)
{
return(featureLength);
}
var option = _searchOptions.PropertyImportance.FirstOrDefault(x =>
feature.Feature.Properties.Any(y => y.Key == x.Property && y.Value == x.Value));
if (option != null)
{
featureLength *= option.Importance;
}
if (featuresToOverlap != null && featuresToOverlap.Contains(feature))
{
featureLength *= _searchOptions.TrackOverlapImportance;
}
foreach (var propertyValueImportance in _searchOptions.PropertyValueImportance)
{
if (feature.Feature.Properties[propertyValueImportance.Property] <= propertyValueImportance.Threshold)
{
featureLength *= propertyValueImportance.Importance;
}
}
return(featureLength);
}
public static double CalcualteDistanceToFeature(RouteFeature feature, Coordinate coordinate)
{
var lineSegments = SplitFeatureIntoLineSegments(feature);
var distance = GetDistance(lineSegments.First(), coordinate);
foreach (var c in lineSegments.Skip(1))
{
var newDistance = GetDistance(c, coordinate);
if (newDistance < distance)
{
distance = newDistance;
}
}
return(distance);
}
public static Tuple <CustomPosition, CustomPosition>[] SplitFeatureIntoLineSegments(RouteFeature feature)
{
var coords = feature.Feature.Coordinates;
var lineSegments = new List <Tuple <CustomPosition, CustomPosition> >();
var lastPosition = coords.First();
foreach (var c in coords.Skip(1))
{
lineSegments.Add(new Tuple <CustomPosition, CustomPosition>(lastPosition, c));
lastPosition = c;
}
return(lineSegments.ToArray());
}
public List <RouteFeature> FindShortestPath(RouteFeature startFeature, RouteFeature endFeature, List <RouteFeature> featuresToOverlap)
{
var previous = new Dictionary <RouteFeature, RouteFeature>();
var distances = new Dictionary <RouteFeature, double>();
var nodes = new List <RouteFeature>();
List <RouteFeature> path = null;
foreach (var vertex in _routeFeatures)
{
if (vertex == startFeature)
{
distances[vertex] = ApplySearchOptionsToGetLength(startFeature, featuresToOverlap);
}
else
{
distances[vertex] = double.MaxValue;
}
nodes.Add(vertex);
}
while (nodes.Count != 0)
{
//Debug.WriteLine(nodes.Count());
nodes.Sort((x, y) => Math.Sign(distances[x] - distances[y]));
var smallest = nodes.First();
nodes.Remove(smallest);
if (smallest == endFeature)
{
path = new List <RouteFeature>();
while (previous.ContainsKey(smallest))
{
path.Add(smallest);
smallest = previous[smallest];
}
break;
}
if (distances[smallest] == double.MaxValue)
{
break;
}
foreach (var neighbor in smallest.Neighbours)
{
var alt = distances[smallest] + ApplySearchOptionsToGetLength(neighbor, featuresToOverlap);
if (alt < distances[neighbor])
{
distances[neighbor] = alt;
previous[neighbor] = smallest;
}
}
}
if (path == null) //no path
{
return(null);
}
path.Add(startFeature);
return(path);
}
