/// <summary>
/// Returns a topologically sorted version of the given graph.
/// </summary>
/// <param name="graph"></param>
/// <returns></returns>
public static IDynamicGraph <CHEdgeData> SortGraph(IDynamicGraph <CHEdgeData> graph)
{
// also add all downward edges.
graph.AddDownwardEdges();
// sort the topologically ordered vertices into bins representing a certain height range.
List <uint>[] heightBins = new List <uint> [1000];
foreach (var vertexDepth in new CHDepthFirstEnumerator(graph))
{ // enumerates all vertixes depth-first.
int binIdx = (int)(vertexDepth.Depth / HeightBinSize);
if (heightBins.Length < binIdx)
{ // resize bin array if needed.
Array.Resize(ref heightBins, System.Math.Max(heightBins.Length + 1000, binIdx + 1));
}
// add to the current bin.
List <uint> bin = heightBins[binIdx];
if (bin == null)
{ // create new bin.
bin = new List <uint>();
heightBins[binIdx] = bin;
}
bin.Add(vertexDepth.VertexId);
}
// temp test.
MemoryDynamicGraph <CHEdgeData> sortedGraph = new MemoryDynamicGraph <CHEdgeData>();
Dictionary <uint, uint> currentBinIds = new Dictionary <uint, uint>();
uint newVertexId;
for (int idx = 0; idx < heightBins.Length; idx++)
{
List <uint> bin = heightBins[idx];
if (bin != null)
{ // translate ids.
// fill current bin ids and add vertices to the new graph.
foreach (uint binVertexId in bin)
{
float latitude, longitude;
graph.GetVertex(binVertexId, out latitude, out longitude);
newVertexId = sortedGraph.AddVertex(latitude, longitude);
currentBinIds.Add(binVertexId, newVertexId); // add to the current bin index.
}
}
}
// rebuild the CH graph based on the new ordering and build the CHRegions.
newVertexId = 0;
for (int idx = 0; idx < heightBins.Length; idx++)
{
List <uint> bin = heightBins[idx];
if (bin != null)
{ // translate ids.
// fill current bin ids and add vertices to the new graph.
//foreach (uint binVertexId in bin)
//{
// float latitude, longitude;
// graph.GetVertex(binVertexId, out latitude, out longitude);
// newVertexId = sortedGraph.AddVertex(latitude, longitude);
// currentBinIds.Add(binVertexId, newVertexId); // add to the current bin index.
//}
foreach (uint binVertexId in bin)
{
currentBinIds.TryGetValue(binVertexId, out newVertexId);
// get the higher arcs and convert their ids.
KeyValuePair <uint, CHEdgeData>[] arcs = graph.GetArcsHigher(binVertexId);
foreach (KeyValuePair <uint, CHEdgeData> arc in arcs)
{
// get target vertex.
uint nextVertexArcId = CHEdgeDataDataSourceSerializer.SearchVertex(arc.Key, currentBinIds, heightBins);
// convert edge.
CHEdgeData newEdge = new CHEdgeData();
newEdge.Direction = arc.Value.Direction;
if (arc.Value.HasContractedVertex)
{ // contracted info.
newEdge.ContractedVertexId = CHEdgeDataDataSourceSerializer.SearchVertex(arc.Value.ContractedVertexId, currentBinIds, heightBins);
}
else
{ // no contracted info.
newEdge.ContractedVertexId = 0;
}
newEdge.Tags = arc.Value.Tags;
newEdge.Weight = arc.Value.Weight;
sortedGraph.AddArc(newVertexId, nextVertexArcId, newEdge, null);
}
}
}
}
return(sortedGraph);
}