/// <summary>
///
/// </summary>
/// <param name="graph"></param>
/// <param name="settings"></param>
public SteinerFinder(HeGraphSim graph, SteinerFinderSettings settings = null)
{
_graph = graph;
_graph.Compact();
_settings = settings ?? new SteinerFinderSettings();
SetTerminalStatus();
}
/// <summary>
///
/// </summary>
void CollapseEdges()
{
var hedges = _graph.Halfedges;
double dmin = _settings.MinLength;
dmin *= dmin;
for (int i = 0; i < hedges.Count; i += 2)
{
var he0 = hedges[i];
var he1 = hedges[i + 1];
var v0 = he0.Start;
var v1 = he1.Start;
if (v0 == v1)
{
he0.Remove(); // remove if self loop
}
else if (he0.IsAtDegree2 && !v0.IsTerminal)
{
_graph.CollapseEdge(he0); // collapse degree 2
}
else if (he1.IsAtDegree2 && !v1.IsTerminal)
{
_graph.CollapseEdge(he1); // collapse degree 2
}
else
{
var p0 = v0.Position;
var p1 = v1.Position;
// collapse short edges
if (p0.SquareDistanceTo(p1) < dmin)
{
if (v0.IsTerminal)
{
if (!v1.IsTerminal)
{
_graph.CollapseEdge(he1);
}
}
else if (v1.IsTerminal)
{
if (!v0.IsTerminal)
{
_graph.CollapseEdge(he0);
}
}
else
{
_graph.CollapseEdge(he0);
}
}
}
}
/*
* // cleanup any multi-edges created during collapse
* hedges.RemoveMultiEdges();
*/
_graph.Compact();
}