bool Triangulator::RemoveAnyEdge(_Internal::_edge* e)
{
_Internal::_edge* bedge = NULL;
_Internal::_edge* hedge = NULL;
if(e->type == _Internal::Inside) e->type = _Internal::Hole; //after removal, a hole will be created.
for(int k=0; k<2; ++k)
{
if(e->faces[k])
{
for(int i=0; i<3; ++i)
{
if(bedge == NULL && e->faces[k]->edges[i]->type == _Internal::Boundary)
{
bedge = e->faces[k]->edges[i];
}
if(hedge == NULL && e->faces[k]->edges[i]->type == _Internal::Hole)
{
hedge = e->faces[k]->edges[i];
}
}
}
}
_Internal::_edge* dominant = e;
if(bedge)
{
dominant = bedge;
}
else if(hedge)
{
dominant = hedge;
}
for(int k=0; k<2; ++k)
{
_Internal::_triangle* tr = e->faces[k]; //a triangle to be removed
if(tr == NULL) continue;
//remove this triangle from three edges forming the triangle.
for(int i=0; i<3; ++i)
{
tr->edges[i]->type = dominant->type;
merge(dominant->node, tr->edges[i]->node);
tr->edges[i]->RemoveFace(tr);
}
vector<_Internal::_triangle*>::iterator itf = find(faces.begin(), faces.end(), tr);
assert(itf != faces.end());
faces.erase(itf);
deleted_faces.push_back(tr);
}
for(int i=0; i<edges.size(); ++i)
{
if(findset(dominant->node)==findset(edges[i]->node))
{
edges[i]->type = dominant->type;
}
}
_DeleteEdge(e);
return true;
}
bool Triangulator::RemoveIsolatedEdge(_Internal::_edge* e)
{
if(e->faces[0]==NULL && e->faces[1]==NULL)
{
_DeleteEdge(e);
return true;
}
else
{
return false;
}
}
bool Triangulator::RemoveSafeEdge(_Internal::_edge* e)
{
if(isSafe(e)) //only a boundary edge can be removed.
{
_Internal::_triangle* tr = e->faces[0]; //a triangle to be removed
for(int i=0; i<3; ++i)
{
tr->edges[i]->RemoveFace(tr);
tr->edges[i]->type == _Internal::Boundary;
}
_DeleteEdge(e);
vector<_Internal::_triangle*>::iterator it = find(faces.begin(), faces.end(), tr);
assert(it != faces.end());
faces.erase(it);
deleted_faces.push_back(tr);
//delete tr;
}
else
{
return false;
}
}
