/// <summary>
/// Remove vertices that are colinear w/ their two neighbours, within angle tolerance
/// </summary>
public void CollapseFlatVertices(double fMaxDeviationDeg = 5)
{
bool done = false;
int max_passes = 200;
int pass_count = 0;
while (done == false && pass_count++ < max_passes)
{
done = true;
// [RMS] do modulo-indexing here to avoid pathological cases where we do things like
// continually collapse a short edge adjacent to a long edge (which will result in crazy over-collapse)
int N = Graph.MaxVertexID;
const int nPrime = 31337; // any prime will do...
int cur_vid = 0;
do
{
int vid = cur_vid;
cur_vid = (cur_vid + nPrime) % N;
if (!Graph.IsVertex(vid))
{
continue;
}
if (Graph.GetVtxEdgeCount(vid) != 2)
{
continue;
}
double open = Math.Abs(Graph.OpeningAngle(vid));
if (open < 180 - fMaxDeviationDeg)
{
continue;
}
var edges = Graph.GetVtxEdges(vid);
int eid = edges.First();
int eid2 = edges.Last();
if (FixedEdgeFilterF(eid) || FixedEdgeFilterF(eid2))
{
continue;
}
Index2i ev = Graph.GetEdgeV(eid);
int other_v = (ev.a == vid) ? ev.b : ev.a;
DGraph2.EdgeCollapseInfo collapseInfo;
MeshResult result = Graph.CollapseEdge(other_v, vid, out collapseInfo);
if (result == MeshResult.Ok)
{
done = false;
}
else
{
throw new Exception("DGraph2Resampler.CollapseFlatVertices: failed!");
}
} while (cur_vid != 0);
}
}
/// <summary>
/// If we are at edge eid, which as one vertex prev_vid, find 'other' vertex, and other edge connected to that vertex,
/// and return pair [next_edge, shared_vtx]
/// Returns [int.MaxValue, shared_vtx] if shared_vtx is not valence=2 (ie stops at boundaries and complex junctions)
/// </summary>
public static Index2i NextEdgeAndVtx(int eid, int prev_vid, DGraph2 graph)
{
Index2i ev = graph.GetEdgeV(eid);
if (ev.a == DGraph2.InvalidID)
{
return(Index2i.Max);
}
int next_vid = (ev.a == prev_vid) ? ev.b : ev.a;
if (graph.GetVtxEdgeCount(next_vid) != 2)
{
return(new Index2i(int.MaxValue, next_vid));
}
foreach (int next_eid in graph.VtxEdgesItr(next_vid))
{
if (next_eid != eid)
{
return(new Index2i(next_eid, next_vid));
}
}
return(Index2i.Max);
}
