protected override void InternalCompute()
{
var visibilityGraph = new VisibilityGraph();
foreach (TVertex vertex in VisitedGraph.Vertices)
{
Point pos = _vertexPositions[vertex];
Size sz = _vertexSizes[vertex];
var rect = new Rect(new Point(pos.X - (sz.Width / 2), pos.Y - (sz.Height / 2)), sz);
rect.Inflate(_parameters.VertexMargin, _parameters.VertexMargin);
visibilityGraph.Obstacles.Add(new Obstacle(rect.TopLeft, rect.TopRight, rect.BottomRight, rect.BottomLeft));
}
foreach (TEdge edge in VisitedGraph.Edges)
{
visibilityGraph.SinglePoints.Add(_vertexPositions[edge.Source]);
visibilityGraph.SinglePoints.Add(_vertexPositions[edge.Target]);
}
var vertexPoints = new HashSet <PointVertex>(_vertexPositions.Select(kvp => new PointVertex(kvp.Value)));
visibilityGraph.Compute();
IUndirectedGraph <PointVertex, Edge <PointVertex> > graph = visibilityGraph.Graph;
var usedEdges = new HashSet <Edge <PointVertex> >();
foreach (TEdge edge in VisitedGraph.Edges)
{
var pos1 = new PointVertex(_vertexPositions[edge.Source]);
var pos2 = new PointVertex(_vertexPositions[edge.Target]);
TryFunc <PointVertex, IEnumerable <Edge <PointVertex> > > paths = graph.ShortestPathsDijkstra(e => GetWeight(vertexPoints, usedEdges, pos1, pos2, e), pos1);
IEnumerable <Edge <PointVertex> > path;
if (paths(pos2, out path))
{
var edgeRoute = new List <Point>();
bool first = true;
PointVertex point = pos1;
foreach (Edge <PointVertex> e in path)
{
if (!first)
{
edgeRoute.Add(point.Point);
}
usedEdges.Add(e);
point = e.GetOtherVertex(point);
first = false;
}
_edgeRoutes[edge] = edgeRoute.ToArray();
}
}
}
public static IEnumerable <TEdge> FindShortestPath <TVertex, TEdge>(
IUndirectedGraph <TVertex, TEdge> graph,
TVertex startVertex,
TVertex endVertex)
where TEdge : class, IEdge <TVertex>
{
Func <TEdge, double> edgeCost = e => 1; // constant cost
var tryGetPaths = graph.ShortestPathsDijkstra(edgeWeights: edgeCost, source: startVertex);
IEnumerable <TEdge> edgePath;
if (!tryGetPaths(endVertex, out edgePath))
{
return(Enumerable.Empty <TEdge>());
}
return(edgePath);
}
