/// <summary>
/// Decompose graph into simple polylines and polygons.
/// </summary>
public static Curves ExtractCurves(DGraph3 graph)
{
Curves c = new Curves();
c.Loops = new List <DCurve3>();
c.Paths = new List <DCurve3>();
HashSet <int> used = new HashSet <int>();
// find boundary and junction vertices
HashSet <int> boundaries = new HashSet <int>();
HashSet <int> junctions = new HashSet <int>();
foreach (int vid in graph.VertexIndices())
{
if (graph.IsBoundaryVertex(vid))
{
boundaries.Add(vid);
}
if (graph.IsJunctionVertex(vid))
{
junctions.Add(vid);
}
}
// walk paths from boundary vertices
foreach (int start_vid in boundaries)
{
int vid = start_vid;
int eid = graph.GetVtxEdges(vid)[0];
if (used.Contains(eid))
{
continue;
}
DCurve3 path = new DCurve3()
{
Closed = false
};
path.AppendVertex(graph.GetVertex(vid));
while (true)
{
used.Add(eid);
Index2i next = NextEdgeAndVtx(eid, vid, graph);
eid = next.a;
vid = next.b;
path.AppendVertex(graph.GetVertex(vid));
if (boundaries.Contains(vid) || junctions.Contains(vid))
{
break; // done!
}
}
c.Paths.Add(path);
}
// ok we should be done w/ boundary verts now...
boundaries.Clear();
foreach (int start_vid in junctions)
{
foreach (int outgoing_eid in graph.VtxEdgesItr(start_vid))
{
if (used.Contains(outgoing_eid))
{
continue;
}
int vid = start_vid;
int eid = outgoing_eid;
DCurve3 path = new DCurve3()
{
Closed = false
};
path.AppendVertex(graph.GetVertex(vid));
while (true)
{
used.Add(eid);
Index2i next = NextEdgeAndVtx(eid, vid, graph);
eid = next.a;
vid = next.b;
path.AppendVertex(graph.GetVertex(vid));
if (eid == int.MaxValue || junctions.Contains(vid))
{
break; // done!
}
}
// we could end up back at our start junction vertex!
if (vid == start_vid)
{
path.RemoveVertex(path.VertexCount - 1);
path.Closed = true;
c.Loops.Add(path);
// need to mark incoming edge as used...but is it valid now?
//Util.gDevAssert(eid != int.MaxValue);
if (eid != int.MaxValue)
{
used.Add(eid);
}
}
else
{
c.Paths.Add(path);
}
}
}
// all that should be left are continuous loops...
foreach (int start_eid in graph.EdgeIndices())
{
if (used.Contains(start_eid))
{
continue;
}
int eid = start_eid;
Index2i ev = graph.GetEdgeV(eid);
int vid = ev.a;
DCurve3 poly = new DCurve3()
{
Closed = true
};
poly.AppendVertex(graph.GetVertex(vid));
while (true)
{
used.Add(eid);
Index2i next = NextEdgeAndVtx(eid, vid, graph);
eid = next.a;
vid = next.b;
poly.AppendVertex(graph.GetVertex(vid));
if (eid == int.MaxValue || junctions.Contains(vid))
{
throw new Exception("how did this happen??");
}
if (used.Contains(eid))
{
break;
}
}
poly.RemoveVertex(poly.VertexCount - 1);
c.Loops.Add(poly);
}
return(c);
}
/// <summary>
/// Decompose graph into simple polylines and polygons.
/// </summary>
public static Curves ExtractCurves(DGraph3 graph,
bool bWantLoopIndices = false,
Func <int, bool> CurveOrientationF = null)
{
var c = new Curves();
c.Loops = new List <DCurve3>();
c.Paths = new List <DCurve3>();
if (bWantLoopIndices)
{
c.LoopEdges = new List <List <int> >();
c.PathEdges = new List <List <int> >();
}
var used = new HashSet <int>();
// find boundary and junction vertices
var boundaries = new HashSet <int>();
var junctions = new HashSet <int>();
foreach (int vid in graph.VertexIndices())
{
if (graph.IsBoundaryVertex(vid))
{
boundaries.Add(vid);
}
if (graph.IsJunctionVertex(vid))
{
junctions.Add(vid);
}
}
// walk paths from boundary vertices
foreach (int start_vid in boundaries)
{
int vid = start_vid;
int eid = graph.GetVtxEdges(vid)[0];
if (used.Contains(eid))
{
continue;
}
bool reverse = (CurveOrientationF != null) ? CurveOrientationF(eid) : false;
var path = new DCurve3()
{
Closed = false
};
List <int> pathE = (bWantLoopIndices) ? new List <int>() : null;
path.AppendVertex(graph.GetVertex(vid));
if (pathE != null)
{
pathE.Add(eid);
}
while (true)
{
used.Add(eid);
Index2i next = NextEdgeAndVtx(eid, vid, graph);
eid = next.a;
vid = next.b;
path.AppendVertex(graph.GetVertex(vid));
if (boundaries.Contains(vid) || junctions.Contains(vid))
{
break; // done!
}
if (pathE != null)
{
pathE.Add(eid);
}
}
if (reverse)
{
path.Reverse();
}
c.Paths.Add(path);
if (pathE != null)
{
Util.gDevAssert(pathE.Count == path.VertexCount - 1);
if (reverse)
{
pathE.Reverse();
}
c.PathEdges.Add(pathE);
}
}
// ok we should be done w/ boundary verts now...
//boundaries.Clear();
c.BoundaryV = boundaries;
foreach (int start_vid in junctions)
{
foreach (int outgoing_eid in graph.VtxEdgesItr(start_vid))
{
if (used.Contains(outgoing_eid))
{
continue;
}
int vid = start_vid;
int eid = outgoing_eid;
bool reverse = (CurveOrientationF != null) ? CurveOrientationF(eid) : false;
var path = new DCurve3()
{
Closed = false
};
List <int> pathE = (bWantLoopIndices) ? new List <int>() : null;
path.AppendVertex(graph.GetVertex(vid));
if (pathE != null)
{
pathE.Add(eid);
}
while (true)
{
used.Add(eid);
Index2i next = NextEdgeAndVtx(eid, vid, graph);
eid = next.a;
vid = next.b;
path.AppendVertex(graph.GetVertex(vid));
if (eid == int.MaxValue || junctions.Contains(vid))
{
break; // done!
}
if (pathE != null)
{
pathE.Add(eid);
}
}
// we could end up back at our start junction vertex!
if (vid == start_vid)
{
path.RemoveVertex(path.VertexCount - 1);
path.Closed = true;
if (reverse)
{
path.Reverse();
}
c.Loops.Add(path);
if (pathE != null)
{
Util.gDevAssert(pathE.Count == path.VertexCount);
if (reverse)
{
pathE.Reverse();
}
c.LoopEdges.Add(pathE);
}
// need to mark incoming edge as used...but is it valid now?
//Util.gDevAssert(eid != int.MaxValue);
if (eid != int.MaxValue)
{
used.Add(eid);
}
}
else
{
if (reverse)
{
path.Reverse();
}
c.Paths.Add(path);
if (pathE != null)
{
Util.gDevAssert(pathE.Count == path.VertexCount - 1);
if (reverse)
{
pathE.Reverse();
}
c.PathEdges.Add(pathE);
}
}
}
}
c.JunctionV = junctions;
// all that should be left are continuous loops...
foreach (int start_eid in graph.EdgeIndices())
{
if (used.Contains(start_eid))
{
continue;
}
int eid = start_eid;
Index2i ev = graph.GetEdgeV(eid);
int vid = ev.a;
bool reverse = (CurveOrientationF != null) ? CurveOrientationF(eid) : false;
var poly = new DCurve3()
{
Closed = true
};
List <int> polyE = (bWantLoopIndices) ? new List <int>() : null;
poly.AppendVertex(graph.GetVertex(vid));
if (polyE != null)
{
polyE.Add(eid);
}
while (true)
{
used.Add(eid);
Index2i next = NextEdgeAndVtx(eid, vid, graph);
eid = next.a;
vid = next.b;
poly.AppendVertex(graph.GetVertex(vid));
if (polyE != null)
{
polyE.Add(eid);
}
if (eid == int.MaxValue || junctions.Contains(vid))
{
throw new Exception("how did this happen??");
}
if (used.Contains(eid))
{
break;
}
}
poly.RemoveVertex(poly.VertexCount - 1);
if (reverse)
{
poly.Reverse();
}
c.Loops.Add(poly);
if (polyE != null)
{
polyE.RemoveAt(polyE.Count - 1);
Util.gDevAssert(polyE.Count == poly.VertexCount);
if (reverse)
{
polyE.Reverse();
}
c.LoopEdges.Add(polyE);
}
}
return(c);
}
