IGL_INLINE void igl::copyleft::cgal::outer_hull(
const Eigen::PlainObjectBase<DerivedV> & V,
const Eigen::PlainObjectBase<DerivedF> & F,
Eigen::PlainObjectBase<DerivedG> & G,
Eigen::PlainObjectBase<DerivedJ> & J,
Eigen::PlainObjectBase<Derivedflip> & flip)
{
#ifdef IGL_OUTER_HULL_DEBUG
std::cerr << "Extracting outer hull" << std::endl;
#endif
using namespace Eigen;
using namespace std;
typedef typename DerivedF::Index Index;
Matrix<Index,DerivedF::RowsAtCompileTime,1> C;
typedef Matrix<typename DerivedV::Scalar,Dynamic,DerivedV::ColsAtCompileTime> MatrixXV;
//typedef Matrix<typename DerivedF::Scalar,Dynamic,DerivedF::ColsAtCompileTime> MatrixXF;
typedef Matrix<typename DerivedG::Scalar,Dynamic,DerivedG::ColsAtCompileTime> MatrixXG;
typedef Matrix<typename DerivedJ::Scalar,Dynamic,DerivedJ::ColsAtCompileTime> MatrixXJ;
const Index m = F.rows();
// UNUSED:
//const auto & duplicate_simplex = [&F](const int f, const int g)->bool
//{
// return
// (F(f,0) == F(g,0) && F(f,1) == F(g,1) && F(f,2) == F(g,2)) ||
// (F(f,1) == F(g,0) && F(f,2) == F(g,1) && F(f,0) == F(g,2)) ||
// (F(f,2) == F(g,0) && F(f,0) == F(g,1) && F(f,1) == F(g,2)) ||
// (F(f,0) == F(g,2) && F(f,1) == F(g,1) && F(f,2) == F(g,0)) ||
// (F(f,1) == F(g,2) && F(f,2) == F(g,1) && F(f,0) == F(g,0)) ||
// (F(f,2) == F(g,2) && F(f,0) == F(g,1) && F(f,1) == F(g,0));
//};
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"outer hull..."<<endl;
#endif
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"edge map..."<<endl;
#endif
typedef Matrix<typename DerivedF::Scalar,Dynamic,2> MatrixX2I;
typedef Matrix<typename DerivedF::Index,Dynamic,1> VectorXI;
//typedef Matrix<typename DerivedV::Scalar, 3, 1> Vector3F;
MatrixX2I E,uE;
VectorXI EMAP;
vector<vector<typename DerivedF::Index> > uE2E;
unique_edge_map(F,E,uE,EMAP,uE2E);
#ifdef IGL_OUTER_HULL_DEBUG
for (size_t ui=0; ui<uE.rows(); ui++) {
std::cout << ui << ": " << uE2E[ui].size() << " -- (";
for (size_t i=0; i<uE2E[ui].size(); i++) {
std::cout << uE2E[ui][i] << ", ";
}
std::cout << ")" << std::endl;
}
#endif
std::vector<std::vector<typename DerivedF::Index> > uE2oE;
std::vector<std::vector<bool> > uE2C;
order_facets_around_edges(V, F, uE, uE2E, uE2oE, uE2C);
uE2E = uE2oE;
VectorXI diIM(3*m);
for (auto ue : uE2E) {
for (size_t i=0; i<ue.size(); i++) {
auto fe = ue[i];
diIM[fe] = i;
}
}
vector<vector<vector<Index > > > TT,_1;
triangle_triangle_adjacency(E,EMAP,uE2E,false,TT,_1);
VectorXI counts;
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"facet components..."<<endl;
#endif
facet_components(TT,C,counts);
assert(C.maxCoeff()+1 == counts.rows());
const size_t ncc = counts.rows();
G.resize(0,F.cols());
J.resize(0,1);
flip.setConstant(m,1,false);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"reindex..."<<endl;
#endif
// H contains list of faces on outer hull;
vector<bool> FH(m,false);
vector<bool> EH(3*m,false);
vector<MatrixXG> vG(ncc);
vector<MatrixXJ> vJ(ncc);
vector<MatrixXJ> vIM(ncc);
//size_t face_count = 0;
for(size_t id = 0;id<ncc;id++)
{
vIM[id].resize(counts[id],1);
}
// current index into each IM
vector<size_t> g(ncc,0);
// place order of each face in its respective component
for(Index f = 0;f<m;f++)
{
vIM[C(f)](g[C(f)]++) = f;
}
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"barycenters..."<<endl;
#endif
// assumes that "resolve" has handled any coplanar cases correctly and nearly
// coplanar cases can be sorted based on barycenter.
MatrixXV BC;
barycenter(V,F,BC);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"loop over CCs (="<<ncc<<")..."<<endl;
#endif
for(Index id = 0;id<(Index)ncc;id++)
{
auto & IM = vIM[id];
// starting face that's guaranteed to be on the outer hull and in this
// component
int f;
bool f_flip;
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"outer facet..."<<endl;
#endif
igl::copyleft::cgal::outer_facet(V,F,IM,f,f_flip);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"outer facet: "<<f<<endl;
//cout << V.row(F(f, 0)) << std::endl;
//cout << V.row(F(f, 1)) << std::endl;
//cout << V.row(F(f, 2)) << std::endl;
#endif
int FHcount = 1;
FH[f] = true;
// Q contains list of face edges to continue traversing upong
queue<int> Q;
Q.push(f+0*m);
Q.push(f+1*m);
Q.push(f+2*m);
flip(f) = f_flip;
//std::cout << "face " << face_count++ << ": " << f << std::endl;
//std::cout << "f " << F.row(f).array()+1 << std::endl;
//cout<<"flip("<<f<<") = "<<(flip(f)?"true":"false")<<endl;
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"BFS..."<<endl;
#endif
while(!Q.empty())
{
// face-edge
const int e = Q.front();
Q.pop();
// face
const int f = e%m;
// corner
const int c = e/m;
#ifdef IGL_OUTER_HULL_DEBUG
std::cout << "edge: " << e << ", ue: " << EMAP(e) << std::endl;
std::cout << "face: " << f << std::endl;
std::cout << "corner: " << c << std::endl;
std::cout << "consistent: " << uE2C[EMAP(e)][diIM[e]] << std::endl;
#endif
// Should never see edge again...
if(EH[e] == true)
{
continue;
}
EH[e] = true;
// source of edge according to f
const int fs = flip(f)?F(f,(c+2)%3):F(f,(c+1)%3);
// destination of edge according to f
const int fd = flip(f)?F(f,(c+1)%3):F(f,(c+2)%3);
// edge valence
const size_t val = uE2E[EMAP(e)].size();
#ifdef IGL_OUTER_HULL_DEBUG
//std::cout << "vd: " << V.row(fd) << std::endl;
//std::cout << "vs: " << V.row(fs) << std::endl;
//std::cout << "edge: " << V.row(fd) - V.row(fs) << std::endl;
for (size_t i=0; i<val; i++) {
if (i == diIM(e)) {
std::cout << "* ";
} else {
std::cout << " ";
}
std::cout << i << ": "
<< " (e: " << uE2E[EMAP(e)][i] << ", f: "
<< uE2E[EMAP(e)][i] % m * (uE2C[EMAP(e)][i] ? 1:-1) << ")" << std::endl;
}
#endif
// is edge consistent with edge of face used for sorting
const int e_cons = (uE2C[EMAP(e)][diIM(e)] ? 1: -1);
int nfei = -1;
// Loop once around trying to find suitable next face
for(size_t step = 1; step<val+2;step++)
{
const int nfei_new = (diIM(e) + 2*val + e_cons*step*(flip(f)?-1:1))%val;
const int nf = uE2E[EMAP(e)][nfei_new] % m;
{
#ifdef IGL_OUTER_HULL_DEBUG
//cout<<"Next facet: "<<(f+1)<<" --> "<<(nf+1)<<", |"<<
// di[EMAP(e)][diIM(e)]<<" - "<<di[EMAP(e)][nfei_new]<<"| = "<<
// abs(di[EMAP(e)][diIM(e)] - di[EMAP(e)][nfei_new])
// <<endl;
#endif
// Only use this face if not already seen
if(!FH[nf])
{
nfei = nfei_new;
//} else {
// std::cout << "skipping face " << nfei_new << " because it is seen before"
// << std::endl;
}
break;
//} else {
// std::cout << di[EMAP(e)][diIM(e)].transpose() << std::endl;
// std::cout << di[EMAP(e)][diIM(nfei_new)].transpose() << std::endl;
// std::cout << "skipping face " << nfei_new << " with identical dihedral angle"
// << std::endl;
}
//#ifdef IGL_OUTER_HULL_DEBUG
// cout<<"Skipping co-planar facet: "<<(f+1)<<" --> "<<(nf+1)<<endl;
//#endif
}
int max_ne = -1;
if(nfei >= 0)
{
max_ne = uE2E[EMAP(e)][nfei];
}
if(max_ne>=0)
{
// face of neighbor
const int nf = max_ne%m;
#ifdef IGL_OUTER_HULL_DEBUG
if(!FH[nf])
{
// first time seeing face
cout<<(f+1)<<" --> "<<(nf+1)<<endl;
}
#endif
FH[nf] = true;
//std::cout << "face " << face_count++ << ": " << nf << std::endl;
//std::cout << "f " << F.row(nf).array()+1 << std::endl;
FHcount++;
// corner of neighbor
const int nc = max_ne/m;
const int nd = F(nf,(nc+2)%3);
const bool cons = (flip(f)?fd:fs) == nd;
flip(nf) = (cons ? flip(f) : !flip(f));
//cout<<"flip("<<nf<<") = "<<(flip(nf)?"true":"false")<<endl;
const int ne1 = nf+((nc+1)%3)*m;
const int ne2 = nf+((nc+2)%3)*m;
if(!EH[ne1])
{
Q.push(ne1);
}
if(!EH[ne2])
{
Q.push(ne2);
}
}
}
{
vG[id].resize(FHcount,3);
vJ[id].resize(FHcount,1);
//nG += FHcount;
size_t h = 0;
assert(counts(id) == IM.rows());
for(int i = 0;i<counts(id);i++)
{
const size_t f = IM(i);
//if(f_flip)
//{
// flip(f) = !flip(f);
//}
if(FH[f])
{
vG[id].row(h) = (flip(f)?F.row(f).reverse().eval():F.row(f));
vJ[id](h,0) = f;
h++;
}
}
assert((int)h == FHcount);
}
}
// Is A inside B? Assuming A and B are consistently oriented but closed and
// non-intersecting.
const auto & has_overlapping_bbox = [](
const Eigen::PlainObjectBase<DerivedV> & V,
const MatrixXG & A,
const MatrixXG & B)->bool
{
const auto & bounding_box = [](
const Eigen::PlainObjectBase<DerivedV> & V,
const MatrixXG & F)->
DerivedV
{
DerivedV BB(2,3);
BB<<
1e26,1e26,1e26,
-1e26,-1e26,-1e26;
const size_t m = F.rows();
for(size_t f = 0;f<m;f++)
{
for(size_t c = 0;c<3;c++)
{
const auto & vfc = V.row(F(f,c)).eval();
BB(0,0) = std::min(BB(0,0), vfc(0,0));
BB(0,1) = std::min(BB(0,1), vfc(0,1));
BB(0,2) = std::min(BB(0,2), vfc(0,2));
BB(1,0) = std::max(BB(1,0), vfc(0,0));
BB(1,1) = std::max(BB(1,1), vfc(0,1));
BB(1,2) = std::max(BB(1,2), vfc(0,2));
}
}
return BB;
};
// A lot of the time we're dealing with unrelated, distant components: cull
// them.
DerivedV ABB = bounding_box(V,A);
DerivedV BBB = bounding_box(V,B);
if( (BBB.row(0)-ABB.row(1)).maxCoeff()>0 ||
(ABB.row(0)-BBB.row(1)).maxCoeff()>0 )
{
// bounding boxes do not overlap
return false;
} else {
return true;
}
};
// Reject components which are completely inside other components
vector<bool> keep(ncc,true);
size_t nG = 0;
// This is O( ncc * ncc * m)
for(size_t id = 0;id<ncc;id++)
{
if (!keep[id]) continue;
std::vector<size_t> unresolved;
for(size_t oid = 0;oid<ncc;oid++)
{
if(id == oid || !keep[oid])
{
continue;
}
if (has_overlapping_bbox(V, vG[id], vG[oid])) {
unresolved.push_back(oid);
}
}
const size_t num_unresolved_components = unresolved.size();
DerivedV query_points(num_unresolved_components, 3);
for (size_t i=0; i<num_unresolved_components; i++) {
const size_t oid = unresolved[i];
DerivedF f = vG[oid].row(0);
query_points(i,0) = (V(f(0,0), 0) + V(f(0,1), 0) + V(f(0,2), 0))/3.0;
query_points(i,1) = (V(f(0,0), 1) + V(f(0,1), 1) + V(f(0,2), 1))/3.0;
query_points(i,2) = (V(f(0,0), 2) + V(f(0,1), 2) + V(f(0,2), 2))/3.0;
}
Eigen::VectorXi inside;
igl::copyleft::cgal::points_inside_component(V, vG[id], query_points, inside);
assert((size_t)inside.size() == num_unresolved_components);
for (size_t i=0; i<num_unresolved_components; i++) {
if (inside(i, 0)) {
const size_t oid = unresolved[i];
keep[oid] = false;
}
}
}
for (size_t id = 0; id<ncc; id++) {
if (keep[id]) {
nG += vJ[id].rows();
}
}
// collect G and J across components
G.resize(nG,3);
J.resize(nG,1);
{
size_t off = 0;
for(Index id = 0;id<(Index)ncc;id++)
{
if(keep[id])
{
assert(vG[id].rows() == vJ[id].rows());
G.block(off,0,vG[id].rows(),vG[id].cols()) = vG[id];
J.block(off,0,vJ[id].rows(),vJ[id].cols()) = vJ[id];
off += vG[id].rows();
}
}
}
}
IGL_INLINE void igl::outer_hull(
const Eigen::PlainObjectBase<DerivedV> & V,
const Eigen::PlainObjectBase<DerivedF> & F,
const Eigen::PlainObjectBase<DerivedN> & N,
Eigen::PlainObjectBase<DerivedG> & G,
Eigen::PlainObjectBase<DerivedJ> & J,
Eigen::PlainObjectBase<Derivedflip> & flip)
{
using namespace Eigen;
using namespace std;
using namespace igl;
typedef typename DerivedF::Index Index;
Matrix<Index,DerivedF::RowsAtCompileTime,1> C;
typedef Matrix<typename DerivedV::Scalar,Dynamic,DerivedV::ColsAtCompileTime> MatrixXV;
typedef Matrix<typename DerivedF::Scalar,Dynamic,DerivedF::ColsAtCompileTime> MatrixXF;
typedef Matrix<typename DerivedG::Scalar,Dynamic,DerivedG::ColsAtCompileTime> MatrixXG;
typedef Matrix<typename DerivedJ::Scalar,Dynamic,DerivedJ::ColsAtCompileTime> MatrixXJ;
typedef Matrix<typename DerivedN::Scalar,1,3> RowVector3N;
const Index m = F.rows();
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"outer hull..."<<endl;
#endif
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"edge map..."<<endl;
#endif
typedef Matrix<typename DerivedF::Scalar,Dynamic,2> MatrixX2I;
typedef Matrix<typename DerivedF::Index,Dynamic,1> VectorXI;
MatrixX2I E,uE;
VectorXI EMAP;
vector<vector<typename DerivedF::Index> > uE2E;
unique_edge_map(F,E,uE,EMAP,uE2E);
// TODO:
// uE --> face-edge index, sorted CCW around edge according to normal
// uE --> sorted order index
// uE --> bool, whether needed to flip face to make "consistent" with unique
// edge
VectorXI diIM(3*m);
VectorXI dicons(3*m);
vector<vector<typename DerivedV::Scalar> > di(uE2E.size());
// For each list of face-edges incide on a unique edge
for(size_t ui = 0;ui<(size_t)uE.rows();ui++)
{
// Base normal vector to orient against
const auto fe0 = uE2E[ui][0];
const RowVector3N & eVp = N.row(fe0%m);
di[ui].resize(uE2E[ui].size());
const typename DerivedF::Scalar d = F(fe0%m,((fe0/m)+2)%3);
const typename DerivedF::Scalar s = F(fe0%m,((fe0/m)+1)%3);
// Edge vector
const auto & eV = (V.row(d)-V.row(s)).normalized();
vector<bool> cons(uE2E[ui].size());
// Loop over incident face edges
for(size_t fei = 0;fei<uE2E[ui].size();fei++)
{
const auto & fe = uE2E[ui][fei];
const auto f = fe % m;
const auto c = fe / m;
// source should match destination to be consistent
cons[fei] = (d == F(f,(c+1)%3));
assert( cons[fei] || (d == F(f,(c+2)%3)));
assert(!cons[fei] || (s == F(f,(c+2)%3)));
assert(!cons[fei] || (d == F(f,(c+1)%3)));
// Angle between n and f
const RowVector3N & n = N.row(f);
di[ui][fei] = M_PI - atan2( eVp.cross(n).dot(eV), eVp.dot(n));
if(!cons[fei])
{
di[ui][fei] = di[ui][fei] + M_PI;
if(di[ui][fei]>2.*M_PI)
{
di[ui][fei] = di[ui][fei] - 2.*M_PI;
}
}
}
vector<size_t> IM;
igl::sort(di[ui],true,di[ui],IM);
// copy old list
vector<typename DerivedF::Index> temp = uE2E[ui];
for(size_t fei = 0;fei<uE2E[ui].size();fei++)
{
uE2E[ui][fei] = temp[IM[fei]];
const auto & fe = uE2E[ui][fei];
diIM(fe) = fei;
dicons(fe) = cons[IM[fei]];
}
}
vector<vector<vector<Index > > > TT,_1;
triangle_triangle_adjacency(E,EMAP,uE2E,false,TT,_1);
VectorXI counts;
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"facet components..."<<endl;
#endif
facet_components(TT,C,counts);
assert(C.maxCoeff()+1 == counts.rows());
const size_t ncc = counts.rows();
G.resize(0,F.cols());
J.resize(0,1);
flip.setConstant(m,1,false);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"reindex..."<<endl;
#endif
// H contains list of faces on outer hull;
vector<bool> FH(m,false);
vector<bool> EH(3*m,false);
vector<MatrixXG> vG(ncc);
vector<MatrixXJ> vJ(ncc);
vector<MatrixXJ> vIM(ncc);
for(size_t id = 0;id<ncc;id++)
{
vIM[id].resize(counts[id],1);
}
// current index into each IM
vector<size_t> g(ncc,0);
// place order of each face in its respective component
for(Index f = 0;f<m;f++)
{
vIM[C(f)](g[C(f)]++) = f;
}
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"barycenters..."<<endl;
#endif
// assumes that "resolve" has handled any coplanar cases correctly and nearly
// coplanar cases can be sorted based on barycenter.
MatrixXV BC;
barycenter(V,F,BC);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"loop over CCs (="<<ncc<<")..."<<endl;
#endif
for(Index id = 0;id<(Index)ncc;id++)
{
auto & IM = vIM[id];
// starting face that's guaranteed to be on the outer hull and in this
// component
int f;
bool f_flip;
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"outer facet..."<<endl;
#endif
outer_facet(V,F,N,IM,f,f_flip);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"outer facet: "<<f<<endl;
#endif
int FHcount = 0;
// Q contains list of face edges to continue traversing upong
queue<int> Q;
Q.push(f+0*m);
Q.push(f+1*m);
Q.push(f+2*m);
flip(f) = f_flip;
//cout<<"flip("<<f<<") = "<<(flip(f)?"true":"false")<<endl;
#ifdef IGL_OUTER_HULL_DEBUG
cout<<"BFS..."<<endl;
#endif
while(!Q.empty())
{
// face-edge
const int e = Q.front();
Q.pop();
// face
const int f = e%m;
// corner
const int c = e/m;
// Should never see edge again...
if(EH[e] == true)
{
continue;
}
EH[e] = true;
// first time seeing face
if(!FH[f])
{
FH[f] = true;
FHcount++;
}
// find overlapping face-edges
const auto & neighbors = uE2E[EMAP(e)];
// normal after possible flipping
const auto & fN = (flip(f)?-1.:1.)*N.row(f);
// source of edge according to f
const int fs = flip(f)?F(f,(c+2)%3):F(f,(c+1)%3);
// destination of edge according to f
const int fd = flip(f)?F(f,(c+1)%3):F(f,(c+2)%3);
// Edge vector according to f's (flipped) orientation.
const auto & eV = (V.row(fd)-V.row(fs)).normalized();
// edge valence
const size_t val = uE2E[EMAP(e)].size();
//#warning "EXPERIMENTAL, DO NOT USE"
//// THIS IS WRONG! The first face is---after sorting---no longer the face
//// used for orienting the sort.
//const auto ui = EMAP(e);
//const auto fe0 = uE2E[ui][0];
//const auto es = F(fe0%m,((fe0/m)+1)%3);
const int e_cons = (dicons(e) ? 1: -1);
const int nfei = (diIM(e) + val + e_cons*(flip(f)?-1:1))%val;
const int max_ne_2 = uE2E[EMAP(e)][nfei];
int max_ne = -1;
//// Loop over and find max dihedral angle
//typename DerivedV::Scalar max_di = -1;
//for(const auto & ne : neighbors)
//{
// const int nf = ne%m;
// if(nf == f)
// {
// continue;
// }
// // Corner of neighbor
// const int nc = ne/m;
// // Is neighbor oriented consistently with (flipped) f?
// //const int ns = F(nf,(nc+1)%3);
// const int nd = F(nf,(nc+2)%3);
// const bool cons = (flip(f)?fd:fs) == nd;
// // Normal after possibly flipping to match flip or orientation of f
// const auto & nN = (cons? (flip(f)?-1:1.) : (flip(f)?1.:-1.) )*N.row(nf);
// // Angle between n and f
// const auto & ndi = M_PI - atan2( fN.cross(nN).dot(eV), fN.dot(nN));
// if(ndi>=max_di)
// {
// max_ne = ne;
// max_di = ndi;
// }
//}
////cout<<(max_ne != max_ne_2)<<" =?= "<<e_cons<<endl;
//if(max_ne != max_ne_2)
//{
// cout<<(f+1)<<" ---> "<<(max_ne%m)+1<<" != "<<(max_ne_2%m)+1<<" ... "<<e_cons<<" "<<flip(f)<<endl;
// typename DerivedV::Scalar max_di = -1;
// for(size_t nei = 0;nei<neighbors.size();nei++)
// {
// const auto & ne = neighbors[nei];
// const int nf = ne%m;
// if(nf == f)
// {
// cout<<" "<<(ne%m)+1<<":\t"<<0<<"\t"<<di[EMAP[e]][nei]<<" "<<diIM(ne)<<endl;
// continue;
// }
// // Corner of neighbor
// const int nc = ne/m;
// // Is neighbor oriented consistently with (flipped) f?
// //const int ns = F(nf,(nc+1)%3);
// const int nd = F(nf,(nc+2)%3);
// const bool cons = (flip(f)?fd:fs) == nd;
// // Normal after possibly flipping to match flip or orientation of f
// const auto & nN = (cons? (flip(f)?-1:1.) : (flip(f)?1.:-1.) )*N.row(nf);
// // Angle between n and f
// const auto & ndi = M_PI - atan2( fN.cross(nN).dot(eV), fN.dot(nN));
// cout<<" "<<(ne%m)+1<<":\t"<<ndi<<"\t"<<di[EMAP[e]][nei]<<" "<<diIM(ne)<<endl;
// if(ndi>=max_di)
// {
// max_ne = ne;
// max_di = ndi;
// }
// }
//}
max_ne = max_ne_2;
if(max_ne>=0)
{
// face of neighbor
const int nf = max_ne%m;
// corner of neighbor
const int nc = max_ne/m;
const int nd = F(nf,(nc+2)%3);
const bool cons = (flip(f)?fd:fs) == nd;
flip(nf) = (cons ? flip(f) : !flip(f));
//cout<<"flip("<<nf<<") = "<<(flip(nf)?"true":"false")<<endl;
const int ne1 = nf+((nc+1)%3)*m;
const int ne2 = nf+((nc+2)%3)*m;
if(!EH[ne1])
{
Q.push(ne1);
}
if(!EH[ne2])
{
Q.push(ne2);
}
}
}
{
vG[id].resize(FHcount,3);
vJ[id].resize(FHcount,1);
//nG += FHcount;
size_t h = 0;
assert(counts(id) == IM.rows());
for(int i = 0;i<counts(id);i++)
{
const size_t f = IM(i);
//if(f_flip)
//{
// flip(f) = !flip(f);
//}
if(FH[f])
{
vG[id].row(h) = (flip(f)?F.row(f).reverse().eval():F.row(f));
vJ[id](h,0) = f;
h++;
}
}
assert((int)h == FHcount);
}
}
// Is A inside B? Assuming A and B are consistently oriented but closed and
// non-intersecting.
const auto & is_component_inside_other = [](
const Eigen::PlainObjectBase<DerivedV> & V,
const MatrixXV & BC,
const MatrixXG & A,
const MatrixXJ & AJ,
const MatrixXG & B)->bool
{
const auto & bounding_box = [](
const Eigen::PlainObjectBase<DerivedV> & V,
const MatrixXG & F)->
MatrixXV
{
MatrixXV BB(2,3);
BB<<
1e26,1e26,1e26,
-1e26,-1e26,-1e26;
const size_t m = F.rows();
for(size_t f = 0;f<m;f++)
{
for(size_t c = 0;c<3;c++)
{
const auto & vfc = V.row(F(f,c));
BB.row(0) = BB.row(0).array().min(vfc.array()).eval();
BB.row(1) = BB.row(1).array().max(vfc.array()).eval();
}
}
return BB;
};
// A lot of the time we're dealing with unrelated, distant components: cull
// them.
MatrixXV ABB = bounding_box(V,A);
MatrixXV BBB = bounding_box(V,B);
if( (BBB.row(0)-ABB.row(1)).maxCoeff()>0 ||
(ABB.row(0)-BBB.row(1)).maxCoeff()>0 )
{
// bounding boxes do not overlap
return false;
}
////////////////////////////////////////////////////////////////////////
// POTENTIAL ROBUSTNESS WEAK AREA
////////////////////////////////////////////////////////////////////////
//
// q could be so close (<~1e-16) to B that the winding number is not a robust way to
// determine inside/outsideness. We could try to find a _better_ q which is
// farther away, but couldn't they all be bad?
MatrixXV q = BC.row(AJ(0));
// In a perfect world, it's enough to test a single point.
double w;
// winding_number_3 expects colmajor
const typename DerivedV::Scalar * Vdata;
Vdata = V.data();
Matrix<
typename DerivedV::Scalar,
DerivedV::RowsAtCompileTime,
DerivedV::ColsAtCompileTime,
ColMajor> Vcol;
if(DerivedV::IsRowMajor)
{
// copy to convert to colmajor
Vcol = V;
Vdata = Vcol.data();
}
winding_number_3(
Vdata,V.rows(),
B.data(),B.rows(),
q.data(),1,&w);
return fabs(w)>0.5;
};
// Reject components which are completely inside other components
vector<bool> keep(ncc,true);
size_t nG = 0;
// This is O( ncc * ncc * m)
for(size_t id = 0;id<ncc;id++)
{
for(size_t oid = 0;oid<ncc;oid++)
{
if(id == oid)
{
continue;
}
const bool inside = is_component_inside_other(V,BC,vG[id],vJ[id],vG[oid]);
#ifdef IGL_OUTER_HULL_DEBUG
cout<<id<<" is inside "<<oid<<" ? "<<inside<<endl;
#endif
keep[id] = keep[id] && !inside;
}
if(keep[id])
{
nG += vJ[id].rows();
}
}
// collect G and J across components
G.resize(nG,3);
J.resize(nG,1);
{
size_t off = 0;
for(Index id = 0;id<(Index)ncc;id++)
{
if(keep[id])
{
assert(vG[id].rows() == vJ[id].rows());
G.block(off,0,vG[id].rows(),vG[id].cols()) = vG[id];
J.block(off,0,vJ[id].rows(),vJ[id].cols()) = vJ[id];
off += vG[id].rows();
}
}
}
}