Method follow_interior

site-packages/matplotlib/tri/_tri.cpp:898–939

}

void TriContourGenerator::follow_interior(ContourLine& contour_line,
                                          TriEdge& tri_edge,
                                          bool end_on_boundary,
                                          const double& level,
                                          bool on_upper)
{
    int& tri = tri_edge.tri;
    int& edge = tri_edge.edge;

    // Initial point.
    contour_line.push_back(edge_interp(tri, edge, level));

    while (true) {
        int visited_index = tri;
        if (on_upper)
            visited_index += _triangulation.get_ntri();

        // Check for end not on boundary.
        if (!end_on_boundary && _interior_visited[visited_index])
            break;  // Reached start point, so return.

        // Determine edge by which to leave this triangle.
        edge = get_exit_edge(tri, level, on_upper);
        assert(edge >= 0 && edge < 3 && "Invalid exit edge");

        _interior_visited[visited_index] = true;

        // Append new point to point set.
        assert(edge >= 0 && edge < 3 && "Invalid triangle edge");
        contour_line.push_back(edge_interp(tri, edge, level));

        // Move to next triangle.
        TriEdge next_tri_edge = _triangulation.get_neighbor_edge(tri,edge);

        // Check if ending on a boundary.
        if (end_on_boundary && next_tri_edge.tri == -1)
            break;

        tri_edge = next_tri_edge;
        assert(tri_edge.tri != -1 && "Invalid triangle for internal loop");
    }
}

const TriContourGenerator::Boundaries& TriContourGenerator::get_boundaries() const
{