Beispiel #1
0
        /// <summary>
        /// Case 2: edge origin lies outside the domain.
        /// </summary>
        private void HandleCase2(HalfEdge edge, TVertex v1, TVertex v2)
        {
            // The vertices of the infinite edge.
            var p1 = (Point)edge.origin;
            var p2 = (Point)edge.twin.origin;

            // The two edges leaving p1, pointing into the mesh.
            var e1 = edge.twin.next;
            var e2 = e1.twin.next;

            // Find the two intersections with boundary edge.
            IntersectionHelper.IntersectSegments(v1, v2, e1.origin, e1.twin.origin, ref p2);
            IntersectionHelper.IntersectSegments(v1, v2, e2.origin, e2.twin.origin, ref p1);

            // The infinite edge will now lie on the boundary. Update pointers:
            e1.twin.next   = edge.twin;
            edge.twin.next = e2;
            edge.twin.face = e2.face;

            e1.origin = edge.twin.origin;

            edge.twin.twin = null;
            edge.twin      = null;

            // Close the cell.
            var gen = factory.CreateVertex(v1.x, v1.y);
            var he  = factory.CreateHalfEdge(gen, edge.face);

            edge.next = he;
            he.next   = edge.face.edge;

            // Let the face edge point to the edge leaving at generator.
            edge.face.edge = he;

            base.edges.Add(he);

            he.id = base.edges.Count;

            gen.id = offset++;
            base.vertices.Add(gen);
        }
Beispiel #2
0
        /// <summary>
        /// Case 1: edge origin lies inside the domain.
        /// </summary>
        private void HandleCase1(HalfEdge edge, TVertex v1, TVertex v2)
        {
            //int mark = GetBoundaryMark(v1);

            // The infinite vertex.
            var v = (Point)edge.twin.origin;

            // The half-edge is the bisector of v1 and v2, so the projection onto the
            // boundary segment is actually its midpoint.
            v.x = (v1.x + v2.x) / 2.0;
            v.y = (v1.y + v2.y) / 2.0;

            // Close the cell connected to edge.
            var gen = factory.CreateVertex(v1.x, v1.y);

            var h1 = factory.CreateHalfEdge(edge.twin.origin, edge.face);
            var h2 = factory.CreateHalfEdge(gen, edge.face);

            edge.next = h1;
            h1.next   = h2;
            h2.next   = edge.face.edge;

            gen.leaving = h2;

            // Let the face edge point to the edge leaving at generator.
            edge.face.edge = h2;

            base.edges.Add(h1);
            base.edges.Add(h2);

            int count = base.edges.Count;

            h1.id = count;
            h2.id = count + 1;

            gen.id = offset++;
            base.vertices.Add(gen);
        }