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// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// You can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
//
//
// Author(s) : Susan Hert <hert@mpi-sb.mpg.de>
// : Amol Prakash <prakash@mpi-sb.mpg.de>
// : Andreas Fabri
#ifndef CGAL_CONVEX_HULL_3_H
#define CGAL_CONVEX_HULL_3_H
#include <CGAL/basic.h>
#include <CGAL/algorithm.h>
#include <CGAL/convex_hull_2.h>
#include <CGAL/Polyhedron_incremental_builder_3.h>
#include <CGAL/Projection_traits_xy_3.h>
#include <CGAL/Projection_traits_xz_3.h>
#include <CGAL/Projection_traits_yz_3.h>
#include <CGAL/Convex_hull_traits_3.h>
#include <CGAL/Convex_hull_2/ch_assertions.h>
#include <CGAL/Triangulation_data_structure_2.h>
#include <CGAL/Triangulation_vertex_base_with_info_2.h>
#include <CGAL/Cartesian_converter.h>
#include <CGAL/Simple_cartesian.h>
#include <iostream>
#include <algorithm>
#include <utility>
#include <list>
#include <map>
#include <vector>
#include <boost/bind.hpp>
#include <boost/next_prior.hpp>
#include <boost/type_traits/is_floating_point.hpp>
#include <CGAL/internal/Exact_type_selector.h>
#ifndef CGAL_CH_NO_POSTCONDITIONS
#include <CGAL/convexity_check_3.h>
#endif // CGAL_CH_NO_POSTCONDITIONS
namespace CGAL {
namespace internal{ namespace Convex_hull_3{
//struct to select the default traits class for computing convex hull
template< class Point_3,
class Is_floating_point=typename boost::is_floating_point<typename Kernel_traits<Point_3>::Kernel::FT>::type,
class Has_filtered_predicates_tag=typename Kernel_traits<Point_3>::Kernel::Has_filtered_predicates_tag >
struct Default_traits_for_Chull_3{
typedef typename Kernel_traits<Point_3>::Kernel type;
};
//FT is a floating point type and Kernel is a filtered kernel
template <class Point_3>
struct Default_traits_for_Chull_3<Point_3,boost::true_type,Tag_true>{
typedef Convex_hull_traits_3< typename Kernel_traits<Point_3>::Kernel > type;
};
template <class Traits>
struct Default_polyhedron_for_Chull_3{
typedef CGAL::Polyhedron_3<Traits> type;
};
template <class K>
struct Default_polyhedron_for_Chull_3<Convex_hull_traits_3<K> >{
typedef typename Convex_hull_traits_3<K>::Polyhedron_3 type;
};
//utility class to select the right version of internal predicate Is_on_positive_side_of_plane_3
template <class Traits,
class Is_floating_point=
typename boost::is_floating_point<typename Kernel_traits<typename Traits::Point_3>::Kernel::FT>::type,
class Has_filtered_predicates_tag=typename Kernel_traits<typename Traits::Point_3>::Kernel::Has_filtered_predicates_tag,
class Has_cartesian_tag=typename Kernel_traits<typename Traits::Point_3>::Kernel::Kernel_tag >
struct Use_advanced_filtering{
typedef CGAL::Tag_false type;
};
template <class Traits>
struct Use_advanced_filtering<Traits,boost::true_type,Tag_true,Cartesian_tag>{
typedef typename Kernel_traits<typename Traits::Point_3>::Kernel K;
typedef CGAL::Boolean_tag<K::Has_static_filters> type;
};
//Predicates internally used
template <class Traits,class Tag_use_advanced_filtering=typename Use_advanced_filtering<Traits>::type >
class Is_on_positive_side_of_plane_3{
typedef typename Traits::Point_3 Point_3;
typename Traits::Plane_3 plane;
typename Traits::Has_on_positive_side_3 has_on_positive_side;
public:
typedef Protect_FPU_rounding<false> Protector;
Is_on_positive_side_of_plane_3(const Traits& traits,const Point_3& p,const Point_3& q,const Point_3& r)
:plane(traits.construct_plane_3_object()(p,q,r)),has_on_positive_side(traits.has_on_positive_side_3_object()) {}
bool operator() (const Point_3& s) const
{
return has_on_positive_side(plane,s);
}
};
//This predicate uses copy of the code from the statically filtered version of
//Orientation_3. The rational is that the plane is a member of the functor
//so optimization are done to avoid doing several time operations on the plane.
//The main operator() first tries the static version of the predicate, then uses
//interval arithmetic (the protector must be created before using this predicate)
//and in case of failure, exact arithmetic is used.
template <class Kernel>
class Is_on_positive_side_of_plane_3<Convex_hull_traits_3<Kernel>,Tag_true>{
typedef Simple_cartesian<CGAL::internal::Exact_type_selector<double>::Type> PK;
typedef Simple_cartesian<Interval_nt_advanced > CK;
typedef Convex_hull_traits_3<Kernel> Traits;
typedef typename Traits::Point_3 Point_3;
Cartesian_converter<Kernel,CK> to_CK;
Cartesian_converter<Kernel,PK> to_PK;
const Point_3& p,q,r;
mutable typename CK::Plane_3* ck_plane;
mutable typename PK::Plane_3* pk_plane;
double m10,m20,m21,Maxx,Maxy,Maxz;
static const int STATIC_FILTER_FAILURE = 555;
//this function is a made from the statically filtered version of Orientation_3
int static_filtered(double psx,double psy, double psz) const{
// Then semi-static filter.
double apsx = CGAL::abs(psx);
double apsy = CGAL::abs(psy);
double apsz = CGAL::abs(psz);
double maxx = (Maxx < apsx)? apsx : Maxx;
double maxy = (Maxy < apsy)? apsy : Maxy;
double maxz = (Maxz < apsz)? apsz : Maxz;
double det = psx*m10 - m20*psy + m21*psz;
// Sort maxx < maxy < maxz.
if (maxx > maxz)
std::swap(maxx, maxz);
if (maxy > maxz)
std::swap(maxy, maxz);
else if (maxy < maxx)
std::swap(maxx, maxy);
// Protect against underflow in the computation of eps.
if (maxx < 1e-97) /* cbrt(min_double/eps) */ {
if (maxx == 0)
return 0;
}
// Protect against overflow in the computation of det.
else if (maxz < 1e102) /* cbrt(max_double [hadamard]/4) */ {
double eps = 5.1107127829973299e-15 * maxx * maxy * maxz;
if (det > eps) return 1;
if (det < -eps) return -1;
}
return STATIC_FILTER_FAILURE;
}
public:
typedef typename Interval_nt_advanced::Protector Protector;
Is_on_positive_side_of_plane_3(const Traits&,const Point_3& p_,const Point_3& q_,const Point_3& r_)
:p(p_),q(q_),r(r_),ck_plane(NULL),pk_plane(NULL)
{
double pqx = q.x() - p.x();
double pqy = q.y() - p.y();
double pqz = q.z() - p.z();
double prx = r.x() - p.x();
double pry = r.y() - p.y();
double prz = r.z() - p.z();
m10 = pqy*prz - pry*pqz;
m20 = pqx*prz - prx*pqz;
m21 = pqx*pry - prx*pqy;
double aprx = CGAL::abs(prx);
double apry = CGAL::abs(pry);
double aprz = CGAL::abs(prz);
Maxx = CGAL::abs(pqx);
if (Maxx < aprx) Maxx = aprx;
Maxy = CGAL::abs(pqy);
if (Maxy < apry) Maxy = apry;
Maxz = CGAL::abs(pqz);
if (Maxz < aprz) Maxz = aprz;
}
~Is_on_positive_side_of_plane_3(){
if (ck_plane!=NULL) delete ck_plane;
if (pk_plane!=NULL) delete pk_plane;
}
bool operator() (const Point_3& s) const
{
double psx = s.x() - p.x();
double psy = s.y() - p.y();
double psz = s.z() - p.z();
int static_res = static_filtered(psx,psy,psz);
if (static_res != STATIC_FILTER_FAILURE)
return static_res == 1;
try{
if (ck_plane==NULL)
ck_plane=new typename CK::Plane_3(to_CK(p),to_CK(q),to_CK(r));
return ck_plane->has_on_positive_side(to_CK(s));
}
catch (Uncertain_conversion_exception){
if (pk_plane==NULL)
pk_plane=new typename PK::Plane_3(to_PK(p),to_PK(q),to_PK(r));
return pk_plane->has_on_positive_side(to_PK(s));
}
}
};
template<class HDS, class ForwardIterator>
class Build_coplanar_poly : public Modifier_base<HDS> {
public:
Build_coplanar_poly(ForwardIterator i, ForwardIterator j)
{
start = i;
end = j;
}
void operator()( HDS& hds) {
Polyhedron_incremental_builder_3<HDS> B(hds,true);
ForwardIterator iter = start;
int count = 0;
while (iter != end)
{
count++;
iter++;
}
B.begin_surface(count, 1, 2*count);
iter = start;
while (iter != end)
{
B.add_vertex(*iter);
iter++;
}
iter = start;
B.begin_facet();
int p = 0;
while (p < count)
{
B.add_vertex_to_facet(p);
p++;
}
B.end_facet();
B.end_surface();
}
private:
ForwardIterator start;
ForwardIterator end;
};
template <class InputIterator, class Plane_3, class Polyhedron_3, class Traits>
void coplanar_3_hull(InputIterator first, InputIterator beyond,
Plane_3 plane, Polyhedron_3& P, const Traits& traits)
{
typedef typename Traits::Point_3 Point_3;
typedef typename Kernel_traits<Point_3>::Kernel R;
typedef typename Traits::Vector_3 Vector_3;
typedef Max_coordinate_3<Vector_3> Max_coordinate_3;
typedef Polyhedron_3 Polyhedron;
std::list<Point_3> CH_2;
typedef typename std::list<Point_3>::iterator CH_2_iterator;
typedef typename Traits::Construct_orthogonal_vector_3
Construct_normal_vec;
Max_coordinate_3 max_coordinate;
Construct_normal_vec c_normal =
traits.construct_orthogonal_vector_3_object();
Vector_3 normal = c_normal(plane);
int max_coord = max_coordinate(normal);
switch (max_coord)
{
case 0:
{
convex_hull_points_2(first, beyond, std::back_inserter(CH_2),
Projection_traits_yz_3<R>());
break;
}
case 1:
{
convex_hull_points_2(first, beyond, std::back_inserter(CH_2),
Projection_traits_xz_3<R>());
break;
}
case 2:
{
convex_hull_points_2(first, beyond, std::back_inserter(CH_2),
Projection_traits_xy_3<R>());
break;
}
default:
break;
}
typedef typename Polyhedron::Halfedge_data_structure HDS;
Build_coplanar_poly<HDS,CH_2_iterator> poly(CH_2.begin(),CH_2.end());
P.delegate(poly);
}
//
// visible is the set of facets visible from point and reachable from
// start_facet.
//
template <class TDS_2, class Traits>
void
find_visible_set(TDS_2& tds,
const typename Traits::Point_3& point,
typename TDS_2::Face_handle start,
std::list<typename TDS_2::Face_handle>& visible,
std::map<typename TDS_2::Vertex_handle, typename TDS_2::Edge>& outside,
const Traits& traits)
{
typedef typename Traits::Plane_3 Plane_3;
typedef typename TDS_2::Face_handle Face_handle;
typedef typename TDS_2::Vertex_handle Vertex_handle;
typename Traits::Has_on_positive_side_3 has_on_positive_side =
traits.has_on_positive_side_3_object();
std::vector<Vertex_handle> vertices;
vertices.reserve(10);
int VISITED=1, BORDER=2;
visible.clear();
typename std::list<Face_handle>::iterator vis_it;
visible.push_back(start);
start->info() = VISITED;
vertices.push_back(start->vertex(0));
vertices.push_back(start->vertex(1));
vertices.push_back(start->vertex(2));
start->vertex(0)->info() = start->vertex(1)->info() = start->vertex(2)->info() = VISITED;
for (vis_it = visible.begin(); vis_it != visible.end(); vis_it++)
{
// check all the neighbors of the current face to see if they have
// already been visited or not and if not whether they are visible
// or not.
for(int i=0; i < 3; i++) {
// the facet on the other side of the current halfedge
Face_handle f = (*vis_it)->neighbor(i);
// if haven't already seen this facet
if (f->info() == 0) {
f->info() = VISITED;
Plane_3 plane(f->vertex(0)->point(),f->vertex(1)->point(),f->vertex(2)->point());
int ind = f->index(*vis_it);
if ( has_on_positive_side(plane, point) ){ // is visible
visible.push_back(f);
Vertex_handle vh = f->vertex(ind);
if(vh->info() == 0){ vertices.push_back(vh); vh->info() = VISITED;}
} else {
f->info() = BORDER;
f->vertex(TDS_2::cw(ind))->info() = BORDER;
f->vertex(TDS_2::ccw(ind))->info() = BORDER;
outside.insert(std::make_pair(f->vertex(TDS_2::cw(ind)),
typename TDS_2::Edge(f,ind)));
}
} else if(f->info() == BORDER) {
int ind = f->index(*vis_it);
f->vertex(TDS_2::cw(ind))->info() = BORDER;
f->vertex(TDS_2::ccw(ind))->info() = BORDER;
outside.insert(std::make_pair(f->vertex(TDS_2::cw(ind)),
typename TDS_2::Edge(f,ind)));
}
}
}
for(typename std::vector<Vertex_handle>::iterator vit = vertices.begin();
vit != vertices.end();
++vit){
if((*vit)->info() != BORDER){
tds.delete_vertex(*vit);
} else {
(*vit)->info() = 0;
}
}
}
// using a third template parameter for the point instead of getting it from
// the traits class as it should be is required by M$VC6
template <class Face_handle, class Traits, class Point>
typename std::list<Point>::iterator
farthest_outside_point(Face_handle f, std::list<Point>& outside_set,
const Traits& traits)
{
typedef typename std::list<Point>::iterator Outside_set_iterator;
CGAL_ch_assertion(!outside_set.empty());
typename Traits::Plane_3 plane(f->vertex(0)->point(),f->vertex(1)->point(),f->vertex(2)->point());
typename Traits::Less_signed_distance_to_plane_3 less_dist_to_plane =
traits.less_signed_distance_to_plane_3_object();
Outside_set_iterator farthest_it =
std::max_element(outside_set.begin(),
outside_set.end(),
boost::bind(less_dist_to_plane, plane, _1, _2));
return farthest_it;
}
template <class Face_handle, class Traits, class Point>
void
partition_outside_sets(const std::list<Face_handle>& new_facets,
std::list<Point>& vis_outside_set,
std::list<Face_handle>& pending_facets,
const Traits& traits)
{
typename std::list<Face_handle>::const_iterator f_list_it;
typename std::list<Point>::iterator point_it, to_splice;
// walk through all the new facets and check each unassigned outside point
// to see if it belongs to the outside set of this new facet.
for (f_list_it = new_facets.begin(); (f_list_it != new_facets.end()) && (! vis_outside_set.empty());
++f_list_it)
{
Face_handle f = *f_list_it;
Is_on_positive_side_of_plane_3<Traits> is_on_positive_side(
traits,f->vertex(0)->point(),f->vertex(1)->point(),f->vertex(2)->point());
std::list<Point>& point_list = f->points;
for (point_it = vis_outside_set.begin();point_it != vis_outside_set.end();){
if( is_on_positive_side(*point_it) ) {
to_splice = point_it;
++point_it;
point_list.splice(point_list.end(), vis_outside_set, to_splice);
} else {
++point_it;
}
}
if(! point_list.empty()){
pending_facets.push_back(f);
f->it = boost::prior(pending_facets.end());
} else {
f->it = pending_facets.end();
}
}
for (; f_list_it != new_facets.end();++f_list_it)
(*f_list_it)->it = pending_facets.end();
}
template <class TDS_2, class Traits>
void
ch_quickhull_3_scan(TDS_2& tds,
std::list<typename TDS_2::Face_handle>& pending_facets,
const Traits& traits)
{
typedef typename TDS_2::Edge Edge;
typedef typename TDS_2::Face_handle Face_handle;
typedef typename TDS_2::Vertex_handle Vertex_handle;
typedef typename Traits::Point_3 Point_3;
typedef std::list<Point_3> Outside_set;
typedef typename std::list<Point_3>::iterator Outside_set_iterator;
typedef std::map<typename TDS_2::Vertex_handle, typename TDS_2::Edge> Border_edges;
std::list<Face_handle> visible_set;
typename std::list<Face_handle>::iterator vis_set_it;
Outside_set vis_outside_set;
Border_edges border;
while (!pending_facets.empty())
{
vis_outside_set.clear();
Face_handle f_handle = pending_facets.front();
Outside_set_iterator farthest_pt_it = farthest_outside_point(f_handle, f_handle->points, traits);
Point_3 farthest_pt = *farthest_pt_it;
f_handle->points.erase(farthest_pt_it);
find_visible_set(tds, farthest_pt, f_handle, visible_set, border, traits);
// for each visible facet
for (vis_set_it = visible_set.begin(); vis_set_it != visible_set.end();
vis_set_it++)
{
// add its outside set to the global outside set list
std::list<Point_3>& point_list = (*vis_set_it)->points;
if(! point_list.empty()){
vis_outside_set.splice(vis_outside_set.end(), point_list, point_list.begin(), point_list.end());
}
if((*vis_set_it)->it != pending_facets.end()){
pending_facets.erase((*vis_set_it)->it);
}
(*vis_set_it)->info() = 0;
}
std::vector<Edge> edges;
edges.reserve(border.size());
typename Border_edges::iterator it = border.begin();
Edge e = it->second;
e.first->info() = 0;
edges.push_back(e);
border.erase(it);
while(! border.empty()){
it = border.find(e.first->vertex(TDS_2::ccw(e.second)));
assert(it != border.end());
e = it->second;
e.first->info() = 0;
edges.push_back(e);
border.erase(it);
}
// If we want to reuse the faces we must only pass |edges| many, and call delete_face for the others.
// Also create facets if necessary
std::ptrdiff_t diff = visible_set.size() - edges.size();
if(diff < 0){
for(int i = 0; i<-diff;i++){
visible_set.push_back(tds.create_face());
}
} else {
for(int i = 0; i<diff;i++){
tds.delete_face(visible_set.back());
visible_set.pop_back();
}
}
Vertex_handle vh = tds.star_hole(edges.begin(), edges.end(), visible_set.begin(), visible_set.end());
vh->point() = farthest_pt;
vh->info() = 0;
// now partition the set of outside set points among the new facets.
partition_outside_sets(visible_set, vis_outside_set,
pending_facets, traits);
}
}
template <class TDS_2, class Traits>
void non_coplanar_quickhull_3(std::list<typename Traits::Point_3>& points,
TDS_2& tds, const Traits& traits)
{
typedef typename Traits::Point_3 Point_3;
typedef typename TDS_2::Face_handle Face_handle;
typedef typename TDS_2::Face_iterator Face_iterator;
typedef typename std::list<Point_3>::iterator P3_iterator;
std::list<Face_handle> pending_facets;
typename Is_on_positive_side_of_plane_3<Traits>::Protector p;
// for each facet, look at each unassigned point and decide if it belongs
// to the outside set of this facet.
for(Face_iterator fit = tds.faces_begin(); fit != tds.faces_end(); ++fit){
Is_on_positive_side_of_plane_3<Traits> is_on_positive_side(
traits,fit->vertex(0)->point(),fit->vertex(1)->point(),fit->vertex(2)->point() );
for (P3_iterator point_it = points.begin() ; point_it != points.end(); )
{
if( is_on_positive_side(*point_it) ) {
P3_iterator to_splice = point_it;
++point_it;
fit->points.splice(fit->points.end(), points, to_splice);
} else {
++point_it;
}
}
}
// add all the facets with non-empty outside sets to the set of facets for
// further consideration
for(Face_iterator fit = tds.faces_begin(); fit != tds.faces_end(); ++fit){
if (! fit->points.empty()){
pending_facets.push_back(fit);
fit->it = boost::prior(pending_facets.end());
} else {
fit->it = pending_facets.end();
}
}
ch_quickhull_3_scan(tds, pending_facets, traits);
//std::cout << "|V(tds)| = " << tds.number_of_vertices() << std::endl;
// CGAL_ch_expensive_postcondition(all_points_inside(points.begin(),
// points.end(),P,traits));
// CGAL_ch_postcondition(is_strongly_convex_3(P, traits));
}
namespace internal{
template <class HDS,class TDS>
class Build_convex_hull_from_TDS_2 : public CGAL::Modifier_base<HDS> {
typedef std::map<typename TDS::Vertex_handle,unsigned> Vertex_map;
const TDS& t;
template <class Builder>
static unsigned get_vertex_index( Vertex_map& vertex_map,
typename TDS::Vertex_handle vh,
Builder& builder,
unsigned& vindex)
{
std::pair<typename Vertex_map::iterator,bool>
res=vertex_map.insert(std::make_pair(vh,vindex));
if (res.second){
builder.add_vertex(vh->point());
++vindex;
}
return res.first->second;
}
public:
Build_convex_hull_from_TDS_2(const TDS& t_):t(t_)
{
CGAL_assertion(t.dimension()==2);
}
void operator()( HDS& hds) {
// Postcondition: `hds' is a valid polyhedral surface.
CGAL::Polyhedron_incremental_builder_3<HDS> B( hds, true);
Vertex_map vertex_map;
//start the surface
B.begin_surface( t.number_of_vertices(), t.number_of_faces());
unsigned vindex=0;
for (typename TDS::Face_iterator it=t.faces_begin();it!=t.faces_end();++it)
{
unsigned i0=get_vertex_index(vertex_map,it->vertex(0),B,vindex);
unsigned i1=get_vertex_index(vertex_map,it->vertex(1),B,vindex);
unsigned i2=get_vertex_index(vertex_map,it->vertex(2),B,vindex);
B.begin_facet();
B.add_vertex_to_facet( i0 );
B.add_vertex_to_facet( i1 );
B.add_vertex_to_facet( i2 );
B.end_facet();
}
B.end_surface();
}
};
} //namespace internal
template <class InputIterator, class Polyhedron_3, class Traits>
void
ch_quickhull_polyhedron_3(std::list<typename Traits::Point_3>& points,
InputIterator point1_it, InputIterator point2_it,
InputIterator point3_it, Polyhedron_3& P,
const Traits& traits)
{
typedef typename Traits::Point_3 Point_3;
typedef typename Traits::Plane_3 Plane_3;
typedef typename std::list<Point_3>::iterator P3_iterator;
typedef typename Kernel_traits<typename Traits::Point_3>::Kernel R;
typedef Triangulation_data_structure_2<
Triangulation_vertex_base_with_info_2<int, GT3_for_CH3<R> >,
Convex_hull_face_base_2<int, R> > Tds;
typedef typename Tds::Vertex_handle Vertex_handle;
typedef typename Tds::Face_handle Face_handle;
// found three points that are not collinear, so construct the plane defined
// by these points and then find a point that has maximum distance from this
// plane.
typename Traits::Construct_plane_3 construct_plane =
traits.construct_plane_3_object();
Plane_3 plane = construct_plane(*point3_it, *point2_it, *point1_it);
typedef typename Traits::Less_signed_distance_to_plane_3 Dist_compare;
Dist_compare compare_dist = traits.less_signed_distance_to_plane_3_object();
typename Traits::Coplanar_3 coplanar = traits.coplanar_3_object();
// find both min and max here since using signed distance. If all points
// are on the negative side of the plane, the max element will be on the
// plane.
std::pair<P3_iterator, P3_iterator> min_max;
min_max = CGAL::min_max_element(points.begin(), points.end(),
boost::bind(compare_dist, plane, _1, _2),
boost::bind(compare_dist, plane, _1, _2));
P3_iterator max_it;
if (coplanar(*point1_it, *point2_it, *point3_it, *min_max.second))
{
max_it = min_max.first;
// want the orientation of the points defining the plane to be positive
// so have to reorder these points if all points were on negative side
// of plane
std::swap(*point1_it, *point3_it);
}
else
max_it = min_max.second;
// if the maximum distance point is on the plane then all are coplanar
if (coplanar(*point1_it, *point2_it, *point3_it, *max_it)) {
coplanar_3_hull(points.begin(), points.end(), plane, P, traits);
} else {
Tds tds;
Vertex_handle v0 = tds.create_vertex(); v0->set_point(*point1_it);
Vertex_handle v1 = tds.create_vertex(); v1->set_point(*point2_it);
Vertex_handle v2 = tds.create_vertex(); v2->set_point(*point3_it);
Vertex_handle v3 = tds.create_vertex(); v3->set_point(*max_it);
v0->info() = v1->info() = v2->info() = v3->info() = 0;
Face_handle f0 = tds.create_face(v0,v1,v2);
Face_handle f1 = tds.create_face(v3,v1,v0);
Face_handle f2 = tds.create_face(v3,v2,v1);
Face_handle f3 = tds.create_face(v3,v0,v2);
tds.set_dimension(2);
f0->set_neighbors(f2, f3, f1);
f1->set_neighbors(f0, f3, f2);
f2->set_neighbors(f0, f1, f3);
f3->set_neighbors(f0, f2, f1);
points.erase(point1_it);
points.erase(point2_it);
points.erase(point3_it);
points.erase(max_it);
if (!points.empty()){
non_coplanar_quickhull_3(points, tds, traits);
internal::Build_convex_hull_from_TDS_2<typename Polyhedron_3::HalfedgeDS,Tds> builder(tds);
P.delegate(builder);
}
else
P.make_tetrahedron(v0->point(),v1->point(),v2->point(),v3->point());
}
}
} } //namespace internal::Convex_hull_3
template <class InputIterator, class Traits>
void
convex_hull_3(InputIterator first, InputIterator beyond,
Object& ch_object, const Traits& traits)
{
typedef typename Traits::Point_3 Point_3;
typedef std::list<Point_3> Point_3_list;
typedef typename Point_3_list::iterator P3_iterator;
typedef std::pair<P3_iterator,P3_iterator> P3_iterator_pair;
if (first == beyond) // No point
return;
// If the first and last point are equal the collinearity test some lines below will always be true.
Point_3_list points(first, beyond);
std::size_t size = points.size();
while((size > 1) && (points.front() == points.back())){
points.pop_back();
--size;
}
if ( size == 1 ) // 1 point
{
ch_object = make_object(*points.begin());
return;
}
else if ( size == 2 ) // 2 points
{
typedef typename Traits::Segment_3 Segment_3;
typename Traits::Construct_segment_3 construct_segment =
traits.construct_segment_3_object();
Segment_3 seg = construct_segment(*points.begin(), *(++points.begin()));
ch_object = make_object(seg);
return;
}
else if ( size == 3 ) // 3 points
{
typedef typename Traits::Triangle_3 Triangle_3;
typename Traits::Construct_triangle_3 construct_triangle =
traits.construct_triangle_3_object();
Triangle_3 tri = construct_triangle(*(points.begin()),
*(++points.begin()),
*(--points.end()));
ch_object = make_object(tri);
return;
}
// at least 4 points
typename Traits::Collinear_3 collinear = traits.collinear_3_object();
P3_iterator point1_it = points.begin();
P3_iterator point2_it = points.begin();
point2_it++;
P3_iterator point3_it = points.end();
point3_it--;
// find three that are not collinear
while (point2_it != points.end() &&
collinear(*point1_it,*point2_it,*point3_it))
point2_it++;
// all are collinear, so the answer is a segment
if (point2_it == points.end())
{
typedef typename Traits::Less_distance_to_point_3 Less_dist;
Less_dist less_dist = traits.less_distance_to_point_3_object();
P3_iterator_pair endpoints =
min_max_element(points.begin(), points.end(),
boost::bind(less_dist, *points.begin(), _1, _2),
boost::bind(less_dist, *points.begin(), _1, _2));
typename Traits::Construct_segment_3 construct_segment =
traits.construct_segment_3_object();
typedef typename Traits::Segment_3 Segment_3;
Segment_3 seg = construct_segment(*endpoints.first, *endpoints.second);
ch_object = make_object(seg);
return;
}
// result will be a polyhedron
typename internal::Convex_hull_3::Default_polyhedron_for_Chull_3<Traits>::type P;
P3_iterator minx, maxx, miny, it;
minx = maxx = miny = it = points.begin();
++it;
for(; it != points.end(); ++it){
if(it->x() < minx->x()) minx = it;
if(it->x() > maxx->x()) maxx = it;
if(it->y() < miny->y()) miny = it;
}
if(! collinear(*minx, *maxx, *miny) ){
internal::Convex_hull_3::ch_quickhull_polyhedron_3(points, minx, maxx, miny, P, traits);
} else {
internal::Convex_hull_3::ch_quickhull_polyhedron_3(points, point1_it, point2_it, point3_it, P, traits);
}
CGAL_assertion(P.size_of_vertices()>=3);
if (boost::next(P.vertices_begin(),3) == P.vertices_end()){
typedef typename Traits::Triangle_3 Triangle_3;
typename Traits::Construct_triangle_3 construct_triangle =
traits.construct_triangle_3_object();
Triangle_3 tri = construct_triangle(P.halfedges_begin()->vertex()->point(),
P.halfedges_begin()->next()->vertex()->point(),
P.halfedges_begin()->opposite()->vertex()->point());
ch_object = make_object(tri);
}
else
ch_object = make_object(P);
}
template <class InputIterator>
void convex_hull_3(InputIterator first, InputIterator beyond,
Object& ch_object)
{
typedef typename std::iterator_traits<InputIterator>::value_type Point_3;
typedef typename internal::Convex_hull_3::Default_traits_for_Chull_3<Point_3>::type Traits;
convex_hull_3(first, beyond, ch_object, Traits());
}
template <class InputIterator, class Polyhedron_3, class Traits>
void convex_hull_3(InputIterator first, InputIterator beyond,
Polyhedron_3& polyhedron, const Traits& traits)
{
typedef typename Traits::Point_3 Point_3;
typedef std::list<Point_3> Point_3_list;
typedef typename Point_3_list::iterator P3_iterator;
Point_3_list points(first, beyond);
CGAL_ch_precondition(points.size() > 3);
// at least 4 points
typename Traits::Collinear_3 collinear = traits.collinear_3_object();
typename Traits::Equal_3 equal = traits.equal_3_object();
P3_iterator point1_it = points.begin();
P3_iterator point2_it = points.begin();
point2_it++;
// find three that are not collinear
while (point2_it != points.end() && equal(*point1_it,*point2_it))
++point2_it;
CGAL_ch_precondition_msg(point2_it != points.end(),
"All points are equal; cannot construct polyhedron.");
P3_iterator point3_it = point2_it;
++point3_it;
CGAL_ch_precondition_msg(point3_it != points.end(),
"Only two points with different coordinates; cannot construct polyhedron.");
while (point3_it != points.end() && collinear(*point1_it,*point2_it,*point3_it))
++point3_it;
CGAL_ch_precondition_msg(point3_it != points.end(),
"All points are collinear; cannot construct polyhedron.");
polyhedron.clear();
// result will be a polyhedron
internal::Convex_hull_3::ch_quickhull_polyhedron_3(points, point1_it, point2_it, point3_it,
polyhedron, traits);
}
template <class InputIterator, class Polyhedron_3>
void convex_hull_3(InputIterator first, InputIterator beyond,
Polyhedron_3& polyhedron)
{
typedef typename std::iterator_traits<InputIterator>::value_type Point_3;
typedef typename internal::Convex_hull_3::Default_traits_for_Chull_3<Point_3>::type Traits;
convex_hull_3(first, beyond, polyhedron, Traits());
}
} // namespace CGAL
#endif // CGAL_CONVEX_HULL_3_H
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