DEdgeHandle

DEdgeHandle is a directed edge handle. A normal EdgeHandle identifies an undirected edge. A DEdgeHandle identifies one of its two orientations.

Dynamic fill-in uses directed edges because add_face(e0, e1, e2) needs a consistent triangle winding.

DEdgeHandle e0 = cavity.add_edge(v0, v1);
DEdgeHandle e1 = cavity.add_edge(v1, v2);
DEdgeHandle e2 = cavity.add_edge(v2, v0);

FaceHandle f = cavity.add_face(e0, e1, e2);

You usually get a DEdgeHandle from CavityManager:

DEdgeHandle boundary = cavity.get_cavity_edge(c, i);
DEdgeHandle created  = cavity.add_edge(src, dst);

The boundary edges returned by get_cavity_edge(...) are ordered around the cavity. The edges returned by add_edge(...) are oriented from the first vertex argument to the second.

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Flipping Direction

Use get_flip_dedge() when the next face needs the same underlying edge in the opposite direction.

DEdgeHandle e0 = cavity.add_edge(new_v, boundary_v0);
DEdgeHandle e1 = cavity.add_edge(boundary_v1, new_v);

FaceHandle f0 = cavity.add_face(e0, boundary_edge, e1);

// The next triangle reuses the shared edge in the opposite direction.
DEdgeHandle next_e0 = e1.get_flip_dedge();

DEdgeHandle get_flip_dedge() const

Returns the same undirected edge with the direction bit flipped.

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Using Edge Attributes

Attributes live on undirected edges, so convert to EdgeHandle before indexing an edge attribute.

DEdgeHandle de = cavity.add_edge(v0, v1);

if (de.is_valid()) {
    EdgeHandle e = de.get_edge_handle();
    edge_status(e) = 1;
}

EdgeHandle get_edge_handle() const

Returns the undirected edge handle.

bool is_valid() const

Returns whether the handle points to a real edge.

uint32_t patch_id() const

Patch id of the underlying edge.

uint16_t local_id() const

Local id of the underlying undirected edge. A directed edge and its flipped version share the same local_id().

uint64_t unique_id() const

Packed id including the direction bit.