Here is some code:
struct K : CGAL::Exact_predicates_inexact_constructions_kernel {};
typedef CGAL::Triangulation_vertex_base_2<K> Vb;
typedef CGAL::Constrained_triangulation_face_base_2<K> Fb;
typedef CGAL::Triangulation_data_structure_2<Vb,Fb> TDS;
typedef CGAL::Exact_predicates_tag Itag;
typedef CGAL::Constrained_triangulation_2<K, TDS, Itag> CT;
typedef CT::Point Point;
for (CT::Finite_edges_iterator eit = ct.finite_edges_begin();
eit != ct.finite_edges_end(); ++eit){
// TODO: list vertex co-ordin开发者_StackOverflow中文版ates here
}
From the manual:
"The edges are not explicitly represented, they are only implicitly represented through the adjacency relations of two faces. Each edge has two implicit representations: the edge of a face f which is opposed to the vertex indexed i, can be represented as well as an edge of the neighbor(i) of f."
That's fine by me... but how do I get the end vertices of the edge using a CT::Finite_edges_iterator
in the code given above?
Update: I managed to come up with this solution:
Segment s = ct.segment(eit);
const Point& p1 = s.point(0);
const Point& p2 = s.point(1);
I am still looking for a better way to do this.
I managed to come up with this solution:
Segment s = ct.segment(eit);
const Point& p1 = s.point(0);
const Point& p2 = s.point(1);
I am still looking for a better way to do this.
I have using something like
Triangulation::Vertex_handle fVertex = eit->first->vertex(Triangulation::ccw(eit->second));
Triangulation::Vertex_handle sVertex = eit->first->vertex(Triangulation::cw(eit->second));
The edges provide the indices of the vertices on the face. The face of a triangulation has only 3 vertices in CGAL. Edges are a triplet; (face, i, j). You can get the i-th (either 0, 1, or 2) vertex of a face using the vertex(i) method.. So, to get the vertices, use:
v1 = eit->first->vertex(eit->second);
v2 = eit->first->vertex(eit->third);
精彩评论