void ElemCutter::find_intersection_points(const Elem &elem,
const std::vector<Real> &vertex_distance_func)
{
_intersection_pts.clear();
for (unsigned int e=0; e<elem.n_edges(); e++)
{
AutoPtr<Elem> edge (elem.build_edge(e));
// find the element nodes el0, el1 that map
unsigned int
el0 = elem.get_node_index(edge->get_node(0)),
el1 = elem.get_node_index(edge->get_node(1));
libmesh_assert (elem.is_vertex(el0));
libmesh_assert (elem.is_vertex(el1));
libmesh_assert_less (el0, vertex_distance_func.size());
libmesh_assert_less (el1, vertex_distance_func.size());
const Real
d0 = vertex_distance_func[el0],
d1 = vertex_distance_func[el1];
// if this egde has a 0 crossing
if (d0*d1 < 0.)
{
libmesh_assert_not_equal_to (d0, d1);
// then find d_star in [0,1], the
// distance from el0 to el1 where the 0 lives.
const Real d_star = d0 / (d0 - d1);
// Prevent adding nodes trivially close to existing
// nodes.
const Real endpoint_tol = 0.01;
if ( (d_star > endpoint_tol) &&
(d_star < (1.-endpoint_tol)) )
{
const Point x_star = (edge->point(0)*(1.-d_star) +
edge->point(1)*d_star);
std::cout << "adding cut point (d_star, x_star) = "
<< d_star << " , " << x_star << std::endl;
_intersection_pts.push_back (x_star);
}
}
}
}
//-----------------------------------------------------------------
// Mesh refinement methods
bool MeshRefinement::limit_level_mismatch_at_edge (const unsigned int max_mismatch)
{
// This function must be run on all processors at once
parallel_only();
bool flags_changed = false;
// Maps holding the maximum element level that touches an edge
std::map<std::pair<unsigned int, unsigned int>, unsigned char>
max_level_at_edge;
std::map<std::pair<unsigned int, unsigned int>, unsigned char>
max_p_level_at_edge;
// Loop over all the active elements & fill the maps
{
MeshBase::element_iterator elem_it = _mesh.active_elements_begin();
const MeshBase::element_iterator elem_end = _mesh.active_elements_end();
for (; elem_it != elem_end; ++elem_it)
{
const Elem* elem = *elem_it;
const unsigned char elem_level =
elem->level() + ((elem->refinement_flag() == Elem::REFINE) ? 1 : 0);
const unsigned char elem_p_level =
elem->p_level() + ((elem->p_refinement_flag() == Elem::REFINE) ? 1 : 0);
// Set the max_level at each edge
for (unsigned int n=0; n<elem->n_edges(); n++)
{
AutoPtr<Elem> edge = elem->build_edge(n);
unsigned int childnode0 = edge->node(0);
unsigned int childnode1 = edge->node(1);
if (childnode1 < childnode0)
std::swap(childnode0, childnode1);
for (const Elem *p = elem; p != NULL; p = p->parent())
{
AutoPtr<Elem> pedge = p->build_edge(n);
unsigned int node0 = pedge->node(0);
unsigned int node1 = pedge->node(1);
if (node1 < node0)
std::swap(node0, node1);
// If elem does not share this edge with its ancestor
// p, refinement levels of elements sharing p's edge
// are not restricted by refinement levels of elem.
// Furthermore, elem will not share this edge with any
// of p's ancestors, so we can safely break out of the
// for loop early.
if (node0 != childnode0 && node1 != childnode1)
break;
childnode0 = node0;
childnode1 = node1;
std::pair<unsigned int, unsigned int> edge_key =
std::make_pair(node0, node1);
if (max_level_at_edge.find(edge_key) ==
max_level_at_edge.end())
{
max_level_at_edge[edge_key] = elem_level;
max_p_level_at_edge[edge_key] = elem_p_level;
}
else
{
max_level_at_edge[edge_key] =
std::max (max_level_at_edge[edge_key], elem_level);
max_p_level_at_edge[edge_key] =
std::max (max_p_level_at_edge[edge_key], elem_p_level);
}
}
}
}
}
// Now loop over the active elements and flag the elements
// who violate the requested level mismatch
{
MeshBase::element_iterator elem_it = _mesh.active_elements_begin();
const MeshBase::element_iterator elem_end = _mesh.active_elements_end();
for (; elem_it != elem_end; ++elem_it)
{
Elem* elem = *elem_it;
const unsigned int elem_level = elem->level();
const unsigned int elem_p_level = elem->p_level();
// Skip the element if it is already fully flagged
if (elem->refinement_flag() == Elem::REFINE &&
elem->p_refinement_flag() == Elem::REFINE)
continue;
// Loop over the nodes, check for possible mismatch
for (unsigned int n=0; n<elem->n_edges(); n++)
{
AutoPtr<Elem> edge = elem->build_edge(n);
unsigned int node0 = edge->node(0);
unsigned int node1 = edge->node(1);
if (node1 < node0)
std::swap(node0, node1);
std::pair<unsigned int, unsigned int> edge_key =
std::make_pair(node0, node1);
// Flag the element for refinement if it violates
// the requested level mismatch
if ( (elem_level + max_mismatch) < max_level_at_edge[edge_key]
&& elem->refinement_flag() != Elem::REFINE)
{
elem->set_refinement_flag (Elem::REFINE);
flags_changed = true;
}
if ( (elem_p_level + max_mismatch) < max_p_level_at_edge[edge_key]
&& elem->p_refinement_flag() != Elem::REFINE)
{
elem->set_p_refinement_flag (Elem::REFINE);
flags_changed = true;
}
}
}
}
// If flags changed on any processor then they changed globally
CommWorld.max(flags_changed);
return flags_changed;
}