void TriMesh::buildConnectivity() {
// skip
// Use the algorithm from the lecture to categorize the edges into inner, boundary or non-manifold
// Set the twin edge appropriately to the category of the current edge
// For each node take its leading halfedge and rewind (using getVtxRingPrev) until:
// - We get the one that we started with (no need to do anything)
// - We get NULL - then the previous choice should be used as the nodes leading halfedge
// unskip
std::vector<SortElement> helper = std::vector<SortElement>();
for(int i = 0; i < m_halfedges.size(); i++){
helper.push_back(m_halfedges[i]);
}
std::sort(helper.begin(), helper.end());
int i,j;
//Loop through all edges
for(j=0; j<helper.size(); j++){
//Find i so that i and i+1 are different edges
for(i=j; i<helper.size()-1; i++){
if(helper[i].m_a != helper[i+1].m_a || helper[i].m_b != helper[i+1].m_b){
break;
}
}
if(i==j){
helper[j].m_he->m_twin_ = NULL;
// helper[j] points to a boundary edge
}
else if (i==j+1){
helper[i].m_he->m_twin_ = helper[j].m_he;
helper[j].m_he->m_twin_ = helper[i].m_he;
// connect the triangles of helper[i] and helper[j]
}
else{
std::cout << "Non-manifold mesh!" << std::endl;
}
j = i;
}
for (int i = 0; i < m_nodes.size(); i++){
HalfEdge* beginLead = m_nodes[i].getLeadingHalfEdge();
HalfEdge* tempLead = m_nodes[i].getLeadingHalfEdge();
while(true){
HalfEdge* rewindHe = tempLead->getVtxRingPrev();
if (rewindHe == NULL){
m_nodes[i].m_he_ = tempLead;
break;
}
else if (rewindHe == beginLead)
break;
tempLead = rewindHe;
}
}
}
