From 74180ce5e2284414276dde344a9c1540e68baa93 Mon Sep 17 00:00:00 2001 From: Derek Gaston Date: Thu, 24 May 2012 10:41:16 -0600 Subject: [PATCH] preserve node ordering as much as possible --- src/mesh/serial_mesh.C | 87 ++++++++++++++++++++---------------------------- 1 files changed, 36 insertions(+), 51 deletions(-) diff --git a/src/mesh/serial_mesh.C b/src/mesh/serial_mesh.C index 8907ec5..bd50793 100644 --- a/src/mesh/serial_mesh.C +++ b/src/mesh/serial_mesh.C @@ -411,6 +411,9 @@ void SerialMesh::renumber_nodes_and_elements () unsigned int next_free_elem = 0; unsigned int next_free_node = 0; + // Will hold the set of nodes that are currently connected to elements + std::set connected_nodes; + // Loop over the elements. Note that there may // be NULLs in the _elements vector from the coarsening // process. Pack the elements in to a contiguous array @@ -431,33 +434,9 @@ void SerialMesh::renumber_nodes_and_elements () // Increment the element counter elem->set_id (next_free_elem++); - // Loop over this element's nodes. Number them, - // if they have not been numbered already. Also, - // position them in the _nodes vector so that they - // are packed contiguously from the beginning. + // Add this elements nodes to the connected list for (unsigned int n=0; nn_nodes(); n++) - if (elem->node(n) == next_free_node) // don't need to process - next_free_node++; // [(src == dst) below] - - else if (elem->node(n) > next_free_node) // need to process - { - // The source and destination indices - // for this node - const unsigned int src_idx = elem->node(n); - const unsigned int dst_idx = next_free_node++; - - // ensure we want to swap a valid nodes - libmesh_assert (_nodes[src_idx] != NULL); - - // Swap the source and destination nodes - std::swap(_nodes[src_idx], - _nodes[dst_idx] ); - - // Set proper indices where that makes sense - if (_nodes[src_idx] != NULL) - _nodes[src_idx]->set_id (src_idx); - _nodes[dst_idx]->set_id (dst_idx); - } + connected_nodes.insert(elem->get_node(n)); } // Erase any additional storage. These elements have been @@ -465,40 +444,46 @@ void SerialMesh::renumber_nodes_and_elements () // thus repeated and unnecessary. _elements.erase (out, end); } + - // Any nodes in the vector >= _nodes[next_free_node] - // are not connected to any elements and may be deleted - // if desired. - - // (This code block will erase the unused nodes) - // Now, delete the unused nodes + // Loop over the nodes. Note that there may + // be NULLs in the _nodes vector from the coarsening + // process. Pack the nodes in to a contiguous array + // and then trim any excess. { - std::vector::iterator nd = _nodes.begin(); + std::vector::iterator in = _nodes.begin(); + std::vector::iterator out = _nodes.begin(); const std::vector::iterator end = _nodes.end(); - std::advance (nd, next_free_node); - - for (std::vector::iterator it=nd; - it != end; ++it) + for (; in != end; ++in) + if (*in != NULL) { - // Mesh modification code might have already deleted some - // nodes - if (*it == NULL) - continue; - - // remove any boundary information associated with - // this node - this->boundary_info->remove (*it); - - // delete the node - delete *it; - *it = NULL; + // This is a reference so that if we change the pointer it will change in the vector + Node* & node = *in; + + // If this node is still connected to an elem, put it in the list + if(connected_nodes.find(node) != connected_nodes.end()) + { + *out = node; + ++out; + + // Increment the node counter + node->set_id (next_free_node++); + } + else // This node is orphaned, delete it! + { + this->boundary_info->remove (node); + + // delete the node + delete node; + node = NULL; + } } - _nodes.erase (nd, end); + // Erase any additional storage. Whatever was + _nodes.erase (out, end); } - libmesh_assert (next_free_elem == _elements.size()); libmesh_assert (next_free_node == _nodes.size()); -- 1.7.4.4