cgal/Operations_on_polyhedra/include/CGAL/Self_intersection_polyhedro...

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// Copyright (c) 2008 INRIA Sophia-Antipolis (France).
// Copyright (c) 2008-2013 GeometryFactory (France).
// 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) : Pierre Alliez, Laurent Rineau
// compute self-intersection of a CGAL triangle polyhedron mesh
// original code from Lutz Kettner
#ifndef CGAL_SELF_INTERSECTION_POLYHEDRON_3
#define CGAL_SELF_INTERSECTION_POLYHEDRON_3
#include <CGAL/box_intersection_d.h>
#include <CGAL/intersections.h>
#include <CGAL/Bbox_3.h>
#include <vector>
#include <exception>
#include <boost/function_output_iterator.hpp>
namespace CGAL {
namespace internal {
template <class Polyhedron, class Kernel, class OutputIterator>
struct Intersect_facets
{
// wrapper to check whether anything is inserted to output iterator
struct Output_iterator_with_bool
{
Output_iterator_with_bool(OutputIterator* out, bool* intersected)
: m_iterator(out), m_intersected(intersected) { }
template<class T>
void operator()(const T& t) {
*m_intersected = true;
*(*m_iterator)++ = t;
}
OutputIterator* m_iterator;
bool* m_intersected;
};
// typedefs
typedef typename Kernel::Segment_3 Segment;
typedef typename Kernel::Triangle_3 Triangle;
typedef typename Polyhedron::Facet_const_handle Facet_const_handle;
typedef typename Polyhedron::Halfedge_const_handle Halfedge_const_handle;
typedef typename CGAL::Box_intersection_d::Box_with_handle_d<double, 3, Facet_const_handle> Box;
// members
mutable OutputIterator m_iterator;
mutable bool m_intersected;
mutable boost::function_output_iterator<Output_iterator_with_bool> m_iterator_wrapper;
typename Kernel::Construct_segment_3 segment_functor;
typename Kernel::Construct_triangle_3 triangle_functor;
typename Kernel::Do_intersect_3 do_intersect_3_functor;
Intersect_facets(OutputIterator it, const Kernel& kernel)
:
m_iterator(it),
m_intersected(false),
m_iterator_wrapper(Output_iterator_with_bool(&m_iterator, &m_intersected)),
segment_functor(kernel.construct_segment_3_object()),
triangle_functor(kernel.construct_triangle_3_object()),
do_intersect_3_functor(kernel.do_intersect_3_object())
{ }
void operator()(const Box* b,
const Box* c) const
{
Halfedge_const_handle h = b->handle()->halfedge();
// check for shared egde --> no intersection
if(h->opposite()->facet() == c->handle() ||
h->next()->opposite()->facet() == c->handle() ||
h->next()->next()->opposite()->facet() == c->handle())
return;
// check for shared vertex --> maybe intersection, maybe not
Halfedge_const_handle g = c->handle()->halfedge();
Halfedge_const_handle v;
if(h->vertex() == g->vertex())
v = g;
if(h->vertex() == g->next()->vertex())
v = g->next();
if(h->vertex() == g->next()->next()->vertex())
v = g->next()->next();
if(v == Halfedge_const_handle())
{
h = h->next();
if(h->vertex() == g->vertex())
v = g;
if(h->vertex() == g->next()->vertex())
v = g->next();
if(h->vertex() == g->next()->next()->vertex())
v = g->next()->next();
if(v == Halfedge_const_handle())
{
h = h->next();
if(h->vertex() == g->vertex())
v = g;
if(h->vertex() == g->next()->vertex())
v = g->next();
if(h->vertex() == g->next()->next()->vertex())
v = g->next()->next();
}
}
if(v != Halfedge_const_handle())
{
// found shared vertex:
CGAL_assertion(h->vertex() == v->vertex());
// geometric check if the opposite segments intersect the triangles
Triangle t1 = triangle_functor( h->vertex()->point(), h->next()->vertex()->point(), h->next()->next()->vertex()->point());
Triangle t2 = triangle_functor( v->vertex()->point(), v->next()->vertex()->point(), v->next()->next()->vertex()->point());
Segment s1 = segment_functor( h->next()->vertex()->point(), h->next()->next()->vertex()->point());
Segment s2 = segment_functor( v->next()->vertex()->point(), v->next()->next()->vertex()->point());
if(do_intersect_3_functor(t1,s2))
{
*m_iterator_wrapper++ = std::make_pair(b->handle(), c->handle());
}
else if(do_intersect_3_functor(t2,s1))
{
*m_iterator_wrapper++ = std::make_pair(b->handle(), c->handle());
}
return;
}
// check for geometric intersection
Triangle t1 = triangle_functor( h->vertex()->point(), h->next()->vertex()->point(), h->next()->next()->vertex()->point());
Triangle t2 = triangle_functor( g->vertex()->point(), g->next()->vertex()->point(), g->next()->next()->vertex()->point());
if(do_intersect_3_functor(t1, t2))
{
*m_iterator_wrapper++ = std::make_pair(b->handle(), c->handle());
}
} // end operator ()
}; // end struct Intersect_facets
struct Throw_at_output {
class Throw_at_output_exception: public std::exception
{ };
template<class T>
void operator()(const T& /* t */) const {
throw Throw_at_output_exception();
}
};
}// namespace internal
////////////////////////////////////////////////////////////////////////////////////
/*
/// Geometric traits concept for the functions `self_intersect`
concept SelfIntersectionTraits{
/// @name Geometric Types
/// @{
/// 3D point type
typedef unspecified_type Point_3;
/// 3D triangle type
typedef unspecified_type Triangle_3;
/// 3D segment type
typedef unspecified_type Segment_3;
/// @}
/// @name Functors
/// @{
/// Functor constructing triangles. It provides `Triangle_3 operator() const(const Point_3&, const Point_3&, const Point_3&)
typedef unspecified_type Construct_triangle_3;
/// Functor constructing segments. It provides `Segment_3 operator() const(const Point_3&, const Point_3&)
typedef unspecified_type Construct_segment_3;
/// Functor testing intersections between triangles and segment. It provides `bool operator() const (const Triangle_3&, const Segment_3&)` and `bool operator() const (const Triangle_3&, const Triangle_3&)`
typedef unspecified_type Do_intersect_3;
/// @}
/// @name Functions
/// @{
Construct_triangle_3 construct_triangle_3_object() const;
Construct_segment_3 construct_segment_3_object() const;
Do_intersect_3 do_intersect_3_object() const;
/// @}
};
*/
////////////////////////////////////////////////////////////////////////////////////
/**
* Detects and reports self-intersections of a triangulated polyhedral surface
* @pre @a p.is_pure_triangle()
*
* @tparam GeomTraits a model of `SelfIntersectionTraits`
* @tparam Polyhedron a \cgal polyhedron
* @tparam OutputIterator Output iterator accepting objects of type `std::pair<Polyhedron::Facet_const_handle, Polyhedron::Facet_const_handle>`
*
* @param polyhedron polyhedron to be checked
* @param out all pairs of non-adjacent facets intersecting are put in it
*
* @return out
*
* \TODO Doc: move SelfIntersectionTraits concept to appropriate location.
*/
template <class GeomTraits, class Polyhedron, class OutputIterator>
std::pair<bool, OutputIterator>
self_intersect(const Polyhedron& polyhedron, OutputIterator out, const GeomTraits& geom_traits = GeomTraits())
{
CGAL_assertion(polyhedron.is_pure_triangle());
typedef typename Polyhedron::Facet_const_iterator Facet_const_iterator;
typedef typename Polyhedron::Facet_const_handle Facet_const_handle;
typedef typename CGAL::Box_intersection_d::Box_with_handle_d<double, 3, Facet_const_handle> Box;
// make one box per facet
std::vector<Box> boxes;
boxes.reserve(polyhedron.size_of_facets());
Facet_const_iterator f;
for(f = polyhedron.facets_begin();
f != polyhedron.facets_end();
f++)
boxes.push_back(Box( f->halfedge()->vertex()->point().bbox() +
f->halfedge()->next()->vertex()->point().bbox() +
f->halfedge()->next()->next()->vertex()->point().bbox(),
f));
// generate box pointers
std::vector<const Box*> box_ptr;
box_ptr.reserve(polyhedron.size_of_facets());
typename std::vector<Box>::iterator b;
for(b = boxes.begin();
b != boxes.end();
b++)
box_ptr.push_back(&*b);
// compute self-intersections filtered out by boxes
internal::Intersect_facets<Polyhedron,GeomTraits,OutputIterator> intersect_facets(out, geom_traits);
std::ptrdiff_t cutoff = 2000;
CGAL::box_self_intersection_d(box_ptr.begin(), box_ptr.end(),intersect_facets,cutoff);
return std::make_pair(intersect_facets.m_intersected, intersect_facets.m_iterator);
}
/**
* Checks if a polyhedron is self-intersecting
* @pre @a p.is_pure_triangle()
*
* @tparam GeomTraits a model of `SelfIntersectionTraits`
* @tparam Polyhedron a %CGAL polyhedron
*
* @param polyhedron polyhedron to be tested
*
* @return true if `polyhedron` is self-intersecting
*/
template <class GeomTraits, class Polyhedron>
bool self_intersect(const Polyhedron& polyhedron, const GeomTraits& geom_traits = GeomTraits())
{
try
{
typedef boost::function_output_iterator<internal::Throw_at_output> OutputIterator;
self_intersect<GeomTraits>(polyhedron, OutputIterator(), geom_traits);
}
catch( internal::Throw_at_output::Throw_at_output_exception& )
{ return true; }
return false;
}
}// namespace CGAL
#endif // CGAL_SELF_INTERSECTION_POLYHEDRON_3