/// <summary>
/// construct EdgeSpan from a list of edges of mesh
/// </summary>
public static EdgeSpan FromEdges(DMesh3 mesh, IList <int> edges)
{
int[] Edges = new int[edges.Count];
for (int i = 0; i < Edges.Length; ++i)
{
Edges[i] = edges[i];
}
int[] Vertices = new int[Edges.Length + 1];
Index2i start_ev = mesh.GetEdgeV(Edges[0]);
Index2i prev_ev = start_ev;
if (Edges.Length > 1)
{
for (int i = 1; i < Edges.Length; ++i)
{
Index2i next_ev = mesh.GetEdgeV(Edges[i]);
Vertices[i] = IndexUtil.find_shared_edge_v(ref prev_ev, ref next_ev);
prev_ev = next_ev;
}
Vertices[0] = IndexUtil.find_edge_other_v(ref start_ev, Vertices[1]);
Vertices[Vertices.Length - 1] = IndexUtil.find_edge_other_v(prev_ev, Vertices[Vertices.Length - 2]);
}
else
{
Vertices[0] = start_ev[0]; Vertices[1] = start_ev[1];
}
return(new EdgeSpan(mesh, Vertices, Edges, false));
}
/// <summary>
/// construct EdgeLoop from a list of edges of mesh
/// </summary>
public static EdgeLoop FromEdges(DMesh3 mesh, IList <int> edges)
{
int[] Edges = new int[edges.Count];
for (int i = 0; i < Edges.Length; ++i)
{
Edges[i] = edges[i];
}
int[] Vertices = new int[Edges.Length];
Index2i start_ev = mesh.GetEdgeV(Edges[0]);
Index2i prev_ev = start_ev;
for (int i = 1; i < Edges.Length; ++i)
{
Index2i next_ev = mesh.GetEdgeV(Edges[i % Edges.Length]);
Vertices[i] = IndexUtil.find_shared_edge_v(ref prev_ev, ref next_ev);
prev_ev = next_ev;
}
Vertices[0] = IndexUtil.find_edge_other_v(ref start_ev, Vertices[1]);
return(new EdgeLoop(mesh, Vertices, Edges, false));
}
static List <int> walk_edge_span_forward(DMesh3 mesh, int start_edge, int start_pivot_v, HashSet <int> EdgeSet, out bool bClosedLoop)
{
bClosedLoop = false;
List <int> edgeSpan = new List <int>();
edgeSpan.Add(start_edge);
// we update this as we step
//int cur_edge = start_edge;
int cur_pivot_v = start_pivot_v;
int stop_pivot_v = IndexUtil.find_edge_other_v(mesh.GetEdgeV(start_edge), start_pivot_v);
Util.gDevAssert(stop_pivot_v != DMesh3.InvalidID);
bool done = false;
while (!done)
{
// find outgoing edge in set and connected to current pivot vtx
int next_edge = -1;
foreach (int nbr_edge in mesh.VtxEdgesItr(cur_pivot_v))
{
if (EdgeSet.Contains(nbr_edge))
{
next_edge = nbr_edge;
break;
}
}
// could not find - must be done span
if (next_edge == -1)
{
done = true;
break;
}
// figure out next pivot vtx (is 'other' from current pivot on next edge)
Index2i next_edge_v = mesh.GetEdgeV(next_edge);
if (next_edge_v.a == cur_pivot_v)
{
cur_pivot_v = next_edge_v.b;
}
else if (next_edge_v.b == cur_pivot_v)
{
cur_pivot_v = next_edge_v.a;
}
else
{
throw new Exception("walk_edge_span_forward: found valid next edge but not connected to previous vertex??");
}
edgeSpan.Add(next_edge);
EdgeSet.Remove(next_edge);
// if this happens, we closed a loop
if (cur_pivot_v == stop_pivot_v)
{
done = true;
bClosedLoop = true;
}
}
return(edgeSpan);
}
