private static bool RemoveLongestEdge(Tiling gPlanar, List <Vertex> face) { double longestLength = -1, length; Vertex initialVertex = null, oldVertex = null; Vertex removeA = null, removeB = null; foreach (Vertex boundaryVertex in face) { if (oldVertex == null) { initialVertex = oldVertex = boundaryVertex; continue; } length = gPlanar.GetEucledianDist(boundaryVertex.Id, oldVertex.Id); if (longestLength < length) { removeA = oldVertex; removeB = boundaryVertex; longestLength = length; } oldVertex = boundaryVertex; } length = gPlanar.GetEucledianDist(oldVertex.Id, initialVertex.Id); if (longestLength < length) { removeA = initialVertex; removeB = oldVertex; longestLength = length; } //Console.WriteLine("Removing an edge of length "+ longestLength); //remove the longest edge return(gPlanar.RemoveEdge(removeA.Id, removeB.Id)); }
public static void MsaglShortcutShortEdges(Tiling g, Dictionary <int, Node> idToNodes, LgLayoutSettings _lgLayoutSettings) { int unit = (int)_lgLayoutSettings.NodeSeparation; int shortcutcount = 1; int iteration = 10; //Console.WriteLine(); //Console.WriteLine("Minimize the number of railes for quick interaction? (Y/N)"); //string input = Console.ReadLine(); if (_lgLayoutSettings.hugeGraph) { iteration = 1; unit *= 5; } while (shortcutcount > 0 && iteration > 0) { iteration--; //for all vertices that are not real vertices for (int index = g.N; index < g.NumOfnodesBeforeDetour; index++) { //current vertex is w Vertex w = g.VList[index]; //for each neighbor of w for (int k = 0; k < g.DegList[w.Id]; k++) { Vertex neighbor = g.VList[g.EList[w.Id, k].NodeId]; //if neighbor is a real vertex then continue if (neighbor.Id < g.N) { continue; } //else check whether the edge is short double l = g.GetEucledianDist(w.Id, neighbor.Id); //if the length is short engough then short-cut if (l < unit) { //shortcut this edge //take all the neighbors of the 'neighbor' into the modification list List <int> modificationList = new List <int>(); for (int j = 0; j < g.DegList[neighbor.Id]; j++) { int id = g.EList[neighbor.Id, j].NodeId; if (id != w.Id) { modificationList.Add(id); } } //check whether it is safe to modify the graph bool safetomodify = true; if (g.DegList[w.Id] + modificationList.Count >= g.maxDeg) { continue; } foreach (var x in modificationList) { if (g.DegList[x] + 1 >= g.maxDeg) { safetomodify = false; } } foreach (var x in modificationList) { if (g.Crossings(w.Id, x)) { safetomodify = false; } } if (!safetomodify) { continue; } //add edges between w and the neighbor's neighbor foreach (var x in modificationList) { g.AddEdge(w.Id, x); } g.RemoveEdge(w.Id, neighbor.Id); shortcutcount++; } } } unit *= 2; } Console.WriteLine("Shortcut made for " + shortcutcount + " edges"); }