// compute one cross point between 1-ring of c_vh and cutPlane
bool vertexTo(Vertex_handle &c_vh, Halfedge_handle &c_hh, Vertex_handle center,
Halfedge_vertex_circulator &optimal_start_spoke,
const Plane_3 &cutPlane, Polyhedron* mesh, std::list<Point_3> &cross_points,
int nthTarget)
{
bool result(false);
Halfedge_vertex_circulator hc;
if ( c_vh == center )
hc = optimal_start_spoke;
else
hc = c_vh->vertex_begin();
Halfedge_vertex_circulator end = hc;
CGAL_For_all(hc,end)
{
Vertex_handle lvh = hc->opposite()->vertex();
Vertex_handle rvh = hc->next()->vertex();
Point_3 lp = lvh->point();
Point_3 rp = rvh->point();
int il = cutPlane.oriented_side(lp);
int ir = cutPlane.oriented_side(rp);
int tmp = il*ir;
if ( tmp<0)//异侧
{
Halfedge_handle lrhh = hc->next()->next();
if (lrhh->tag()==nthTarget)//在找这次的target的过程中已经用过了
{
continue;
}
else
{
lrhh->tag(nthTarget);
lrhh->opposite()->tag(nthTarget);
}
if ( c_vh == center )
{
optimal_start_spoke = hc;// ++optimal_start_spoke;
}
Point_3 cp = compute_cross_point(cutPlane,lp,rp);
cross_points.push_back(cp);
c_hh = hc->next()->next()->opposite();
c_vh = 0;
result = true;
break;
}
else if(tmp>0)//同侧
{
continue;
}
if (ir)//lp is on the cut plane
{
if (lvh->tag()==nthTarget)//在找这次的target的过程中已经用过了
{
continue;
}
else
{
lvh->tag(nthTarget);
}
if ( c_vh == center)
{
optimal_start_spoke = hc;// ++optimal_start_spoke;
}
c_vh = lvh;
}
else
{
if (rvh->tag()==nthTarget)//在找这次的target的过程中已经用过了
{
continue;
}
else
{
rvh->tag(nthTarget);
}
if ( c_vh == center)
{
optimal_start_spoke = hc; ++optimal_start_spoke; //++optimal_start_spoke;
}
c_vh = rvh;
}
cross_points.push_back(c_vh->point());
c_hh = 0;
result = true;
break;
}
