/// <summary>
///
/// </summary>
/// <typeparam name="UV"></typeparam>
/// <typeparam name="UE"></typeparam>
/// <param name="graph"></param>
/// <param name="componentIndex"></param>
/// <param name="edgeIndex"></param>
/// <param name="setVertex"></param>
/// <param name="setHedge"></param>
/// <returns></returns>
public TG[] CreateConnectedComponents <UV, UE>(HeGraph <UV, UE> graph, Property <UE, int> componentIndex, Property <UE, int> edgeIndex, Action <TV, UV> setVertex = null, Action <TE, UE> setHedge = null)
where UV : HeGraph <UV, UE> .Vertex
where UE : HeGraph <UV, UE> .Halfedge
{
var vertices = graph.Vertices;
var hedges = graph.Halfedges;
int ncomp = graph.GetEdgeComponentIndices(componentIndex.Set);
var comps = new TG[ncomp];
// initialize components
for (int i = 0; i < comps.Length; i++)
{
comps[i] = Create();
}
// create component halfedges
for (int i = 0; i < hedges.Count; i += 2)
{
var heA = hedges[i];
if (heA.IsUnused)
{
continue;
}
var comp = comps[componentIndex.Get(heA)];
var heB = comp.AddEdge();
edgeIndex.Set(heA, heB.Index >> 1);
}
// set component halfedge->halfedge refs
for (int i = 0; i < hedges.Count; i++)
{
var heA0 = hedges[i];
if (heA0.IsUnused)
{
continue;
}
// the component to which heA0 was copied
var compHedges = comps[componentIndex.Get(heA0)].Halfedges;
var heA1 = heA0.NextAtStart;
// set refs
var heB0 = compHedges[(edgeIndex.Get(heA0) << 1) + (i & 1)];
var heB1 = compHedges[(edgeIndex.Get(heA1) << 1) + (heA1.Index & 1)];
heB0.MakeConsecutive(heB1);
// transfer attributes
setHedge?.Invoke(heB0, heA0);
}
// create component vertices
for (int i = 0; i < vertices.Count; i++)
{
var vA = vertices[i];
if (vA.IsUnused)
{
continue;
}
var heA = vA.First;
var comp = comps[componentIndex.Get(heA)];
var heB = comp.Halfedges[(edgeIndex.Get(heA) << 1) + (heA.Index & 1)];
// set vertex refs
var vB = comp.AddVertex();
vB.First = heB;
foreach (var he in heB.CirculateStart)
{
he.Start = vB;
}
// transfer attributes
setVertex?.Invoke(vB, vA);
}
return(comps);
}
