/// <summary>
/// Imports a road graph.
/// </summary>
/// <param name="name">The name of the map used as prefix for the Verices and Edges file in the map folder.</param>
/// <returns>A map with roads and intersections representing the road graph.</returns>
public Map ReadMap(string name)
{
Map map = new Map(name);
string[] vertLines = File.ReadAllLines($"../../../Maps/{name}Vertices.txt");
string[] edgeLines = File.ReadAllLines($"../../../Maps/{name}Edges.txt");
Dictionary <int, Vector3> vertices = new Dictionary <int, Vector3>(); // mapping of vertexID to position/vertex
List <(Vector3, Vector3, bool)> edges = new List <(Vector3, Vector3, bool)>(); // an edge is represented by start and end position/vertex and a boolean for directedness.
Dictionary <Vector3, List <(Vector3, Vector3, bool)> > adjactentEdges = new Dictionary <Vector3, List <(Vector3, Vector3, bool)> >(); //mapping of vertex to all its adjacent edges
for (int i = 0; i < vertLines.Length; i++) // import vertices
{
string[] vars = vertLines[i].Split(',');
Vector3 pos = new Vector3(float.Parse(vars[1], CultureInfo.InvariantCulture), 0, float.Parse(vars[2], CultureInfo.InvariantCulture));
vertices.Add(int.Parse(vars[0]), pos);
adjactentEdges[pos] = new List <(Vector3, Vector3, bool)>();
}
for (int i = 0; i < edgeLines.Length; i++) //import edges and keep track of degrees so that intersections can be determined
{
string[] vars = edgeLines[i].Split(',');
Vector3 start = vertices[int.Parse(vars[1])];
Vector3 end = vertices[int.Parse(vars[2])];
bool dir = vars.Length == 4 ? vars[3] == "1" : false; //if the map has directedness info then use it, otherwise everything is undirected
adjactentEdges[start].Add((start, end, dir));
adjactentEdges[end].Add((start, end, dir));
edges.Add((start, end, dir));
}
foreach (Vector3 pos in vertices.Values) // make intersections for all the qualified vertices
{
List <(Vector3, Vector3, bool)> adjacents = adjactentEdges[pos];
if (adjacents.Count == 1 || adjacents.Count > 2) //if degree is 1 or larger than 2 a vertex is always an intersection.
{
Intersection i = new Intersection(pos, adjacents.Count(x => !x.Item3 || x.Item1 == pos)); //count amount of outgoing edges.
map.intersections.Add(i);
adjacents.RemoveAll(x => x.Item2 == pos); //remove adjacent edges where our new intersection is the end vertex.
}
else if (adjacents.Count == 2) // degree 2 vertices are intersections if the edges have different directedness, or are both outgoing or incoming.
{
if (adjacents[0].Item3 != adjacents[1].Item3 || adjacents.Count(x => x.Item1 == pos) == 2 || adjacents.Count(x => x.Item2 == pos) == 2)
{
Intersection i = new Intersection(pos, adjacents.Count(x => !x.Item3 || x.Item1 == pos));
map.intersections.Add(i);
adjacents.RemoveAll(x => x.Item2 == pos);
}
}
}
foreach (Intersection intersection in map.intersections.FindAll(x => x.outgoing != null)) // make the roads for intersections that had outgoing edges.
{
List <(Vector3, Vector3, bool)> outEdges = adjactentEdges[intersection.position];
for (int i = 0; i < outEdges.Count; i++)
{
Road road = new Road();
road.directed = outEdges[i].Item3;
road.start = intersection;
road.roadPoints.Add(outEdges[i].Item1);
road.roadPoints.Add(outEdges[i].Item2);
Vector3 lastPoint = road.roadPoints[road.roadPoints.Count - 1]; //the last roadpoint found until now.
while (!map.intersections.Exists(x => x.position == lastPoint)) //while there is no intersection equal to the last point in the road, we expand the road.
{
(Vector3, Vector3, bool)next = adjactentEdges[lastPoint].Find(x => x.Item1 == lastPoint);
road.roadPoints.Add(next.Item2);
lastPoint = road.roadPoints[road.roadPoints.Count - 1];
}
road.end = map.intersections.Find(x => x.position == lastPoint);
road.CalculateLength();
road.start.outgoing.Add(road);
if (!road.directed)
{
road.end.outgoing.Add(road);
}
map.roads.Add(road);
}
}
foreach (Road road in map.roads) //initialization of data used to keep track of road coverage of trajectory generation for the purpose of pruning the map.
{
for (int i = 0; i < road.roadPoints.Count; i++)
{
road.popularities.Add(0);
}
}
map.Refresh();
return(map);
}
/// <summary>
/// Helpermethod to Prune a road perfectly based on its popularities.
/// </summary>
/// <param name="map">map we are pruning</param>
/// <param name="road">road we would like to prune in it</param>
/// <param name="unusedRoads">Roads that will be deleted by PruneRoad method.</param>
/// <param name="newRoads">Roads that will be made by pruneRoad method.</param>
public void PruneEdges(Map map, Road road, List <Road> unusedRoads, List <Road> newRoads)
{
int startChain = -1; //at which index does are start road end
int tailChain = road.popularities.Count; //at which index does our end road end
while (startChain + 1 < road.popularities.Count && road.popularities[startChain + 1] > 0)
{
startChain++;
}
while (tailChain - 1 >= 0 && road.popularities[tailChain - 1] > 0)
{
tailChain--;
}
if (startChain == road.popularities.Count - 1)
{
return; //road is completely traveled by trajectories
}
if (startChain < 1) // road has no start
{
//do nothing
}
else //road has a start
{
Road startRoad = new Road();
Intersection startRoadEnd = new Intersection(road.roadPoints[road.roadPoints.Count - 1], road.directed ? 0 : 1);
startRoad.start = road.start;
for (int j = 0; j <= startChain; j++)
{
startRoad.roadPoints.Add(road.roadPoints[j]);
startRoad.popularities.Add(road.popularities[j]);
}
startRoad.end = startRoadEnd;
startRoad.directed = road.directed;
startRoad.traversed = road.traversed;
startRoad.CalculateLength();
startRoad.start.outgoing.Add(startRoad);
if (!startRoad.directed)
{
startRoad.end.outgoing.Add(startRoad);
}
newRoads.Add(startRoad);
map.intersections.Add(startRoadEnd);
}
if (tailChain > road.roadPoints.Count - 2) // road has no tail
{
//do nothing
}
else //road has a tail
{
Road tailRoad = new Road();
Intersection tailRoadStart = new Intersection(road.roadPoints[tailChain], 1);
tailRoad.start = tailRoadStart;
for (int j = tailChain; j < road.roadPoints.Count; j++)
{
tailRoad.roadPoints.Add(road.roadPoints[j]);
tailRoad.popularities.Add(road.popularities[j]);
}
tailRoad.end = road.end;
tailRoad.directed = road.directed;
tailRoad.traversed = road.traversed;
tailRoad.CalculateLength();
tailRoad.start.outgoing.Add(tailRoad);
if (!tailRoad.directed)
{
tailRoad.end.outgoing.Add(tailRoad);
}
newRoads.Add(tailRoad);
map.intersections.Add(tailRoadStart);
}
unusedRoads.Add(road);
}