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//A class that follows a straight line through a Delaunay triangulation structure.
//Copyright (C) 2012 Utrecht University
//
// 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.
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0+
//
// Author(s): Thijs van Lankveld
#ifndef CGAL_TRIANGULATION_SEGMENT_TRAVERSER_3_H
#define CGAL_TRIANGULATION_SEGMENT_TRAVERSER_3_H
#include <CGAL/basic.h>
#include <iostream>
#include <list>
#include <set>
#include <map>
#include <utility>
#include <stack>
#include <CGAL/Unique_hash_map.h>
#include <CGAL/triangulation_assertions.h>
#include <CGAL/Triangulation_utils_3.h>
#include <CGAL/Triangulation_data_structure_3.h>
#include <CGAL/Triangulation_cell_base_3.h>
#include <CGAL/Triangulation_vertex_base_3.h>
#include <CGAL/Triangulation_simplex_3.h>
#include <CGAL/tuple.h>
// If defined, type casting is done statically,
// reducing type-safety overhead.
#define CGAL_TST_ASSUME_CORRECT_TYPES
namespace CGAL {
/*
add the following to Triangulation_segment_traverser_3.h to get a superclass of the Incrementer visitor.
template < class Tr, class Inc >
class Test_super_SCI;
namespace internal {
template < class Tr >
struct Test_incrementer: public Incrementer<Tr> {
typedef Incrementer<Tr> Base;
typedef Test_incrementer<Tr> Self;
typedef Test_super_SCI<Tr,Self> SCI;
Test_incrementer() {}
void increment( SCI& sci ) {
++sci._superclass;
sci.increment();
}
}; // struct Test_incrementer
} // namespace internal
template < class Tr_, class Inc = internal::Test_incrementer<Tr_> >
class Test_super_SCI: public Triangulation_segment_cell_iterator_3<Tr_,Inc> {
typedef Tr_ Tr;
typedef Triangulation_segment_cell_iterator_3<Tr,Inc> SCI;
int _superclass;
friend internal::Test_incrementer<Tr>;
public:
Test_super_SCI( const Tr& tr, const Point& s, const Point& t, Cell_handle hint = Cell_handle() )
: SCI(tr,s,t,hint), _superclass(0) {}
};
*/
template < class Tr, class Inc >
class Triangulation_segment_cell_iterator_3;
namespace internal {
template < class Tr >
struct Incrementer {
typedef Incrementer<Tr> Self;
typedef Triangulation_segment_cell_iterator_3<Tr,Self> SCI; // describes the type of iterator expected by the incrementer.
Incrementer() {}
void increment( SCI& sci ) { sci.walk_to_next(); }
}; // struct Incrementer
} // namespace internal
// provides an iterator over the cells intersected by a line segment.
/*
* The `Triangulation_segment_traverser_3` iterates over the cells
* of a `Triangulation_3` by following a straight line segment \f$ st \f$.
*
* This class is closely related to `Triangulation_3::locate(...)`.
* However, unlike this `locate(...)` method, all the cells traversed
* by the `Triangulation_segment_traverser_3` intersect the interior of the line
* segment \f$ st \f$.
*
* Traversal starts from a cell containing \f$ s \f$ and it ends in a cell containing
* \f$ t \f$.
* If \f$ st \f$ is coplanar with a facet or collinear with an edge, at most one of the
* incident cells is traversed.
* If \f$ st \f$ intersects an edge or vertex, at most two incident cells are traversed:
* the cells intersecting \f$ st \f$ strictly in their interior.
*
* If \f$ s \f$ lies on the convex hull, traversal starts in an incident cell inside
* the convex hull. Similarly, if \f$ t \f$ lies on the convex hull, traversal ends in
* an adjacent cell inside the convex hull.
*
* Both \f$ s \f$ and \f$ t \f$ may lie outside the convex hull of the triangulation,
* but they must lie within the affine hull of the triangulation. In either case, the
* finite facet of any infinite cells traversed must intersect \f$ st \f$.
*
* The traverser may be applied to any triangulation of dimension > 0.
* However, for triangulations of dimension 1, the functionality is somewhat trivial.
*
* The traverser becomes invalid whenever the triangulation is changed.
*
* \tparam Tr_ is the triangulation type to traverse.
*
* \cgalModels{ForwardIterator}
*
* \sa `Triangulation_3`
* \sa `Forward_circulator_base`
*/
template < class Tr_, class Inc = internal::Incrementer<Tr_> >
class Triangulation_segment_cell_iterator_3 {
typedef Tr_ Tr;
typedef typename Tr::Triangulation_data_structure Tds;
typedef typename Tr::Geom_traits Gt;
typedef Inc Incrementer;
public:
// \name Types
// \{
typedef Tr Triangulation; //< defines the triangulation type.
typedef Triangulation_segment_cell_iterator_3<Tr,Inc>
Segment_cell_iterator; //< defines the segment cell iterator type.
typedef typename Tr::Point Point; //< defines the point type.
typedef typename Tr::Segment Segment; //< defines the line segment type.
typedef typename Tr::Cell Cell; //< defines the type of a cell of the triangulation.
typedef typename Tr::Edge Edge; //< defines the type of an edge of the triangulation.
typedef typename Tr::Facet Facet; //< defines the type of a facet of the triangulation.
typedef typename Tr::Vertex_handle Vertex_handle; //< defines the type of a handle for a vertex in the triangulation.
typedef typename Tr::Cell_handle Cell_handle; //< defines the type of a handle for a cell in the triangulation.
typedef typename Tr::Locate_type Locate_type; //< defines the simplex type returned from location.
typedef CGAL::cpp11::tuple<Cell_handle,Locate_type,int,int>
Simplex; //< defines the simplex type.
typedef Cell value_type; //< defines the value type the iterator refers to.
typedef Cell& reference; //< defines the reference type of the iterator.
typedef Cell* pointer; //< defines the pointer type of the iterator.
typedef std::size_t size_type; //< defines the integral type that can hold the size of a sequence.
typedef std::ptrdiff_t difference_type; //< defines the signed integral type that can hold the distance between two iterators.
typedef std::forward_iterator_tag iterator_category; //< defines the iterator category.
// \}
// describes the iterator type when applied to another type of triangulation or incrementer.
template < class Tr2, class Inc2 >
struct Rebind { typedef Triangulation_segment_cell_iterator_3<Tr2,Inc2> Other; };
private:
typedef Segment_cell_iterator SCI;
friend internal::Incrementer<Tr>;
protected:
// \internal \name Protected Attributes
// \{
// \internal The triangulation to traverse.
const Tr& _tr;
// \}
// The source and target points of the traversal.
// These are also stored as vertices for cheaper equality computation.
Point _source;
Point _target;
Vertex_handle _s_vertex;
Vertex_handle _t_vertex;
// The current cell with its entry point and the previous cell with its
// exit point.
// Note that the current cell will be Cell_handle() after incrementing past
// the first cell containing the target.
Simplex _cur, _prev;
public:
// \name Constructors
// \{
// constructs an iterator.
/* \param tr the triangulation to iterate though. This triangulation must have dimension > 0.
* \param s the source vertex. This vertex must be initialized and cannot be the infinite vertex.
* \param t the target vertex. This vertex must be initialized and cannot be the infinite vertex.
* It cannot equal `s`.
*/
Triangulation_segment_cell_iterator_3( const Tr& tr, Vertex_handle s, Vertex_handle t );
// constructs an iterator.
/* \param tr the triangulation to iterate though. This triangulation must have dimension > 0.
* \param s the source vertex. This vertex must be initialized and cannot be the infinite vertex.
* \param t the target point. This point must be initialized and it cannot be be at the same location as `s`.
* If `tr` has dimension < 3, `t` must lie inside the affine hull of `tr`.
*/
Triangulation_segment_cell_iterator_3( const Tr& tr, Vertex_handle s, const Point& t );
// constructs an iterator.
/* \param tr the triangulation to iterate though. This triangulation must have dimension > 0.
* \param s the source point. This point must be initialized and it cannot be be at the same location as `t`.
* \param t the target vertex. This vertex must be initialized and cannot be the infinite vertex.
* If `tr` has dimension < 3, `s` must lie inside the affine hull of `tr`.
* \param hint the starting point to search for `s`.
*/
Triangulation_segment_cell_iterator_3( const Tr& tr, const Point& s, Vertex_handle t, Cell_handle hint = Cell_handle() );
// constructs an iterator.
/* \param tr the triangulation to iterate though. This triangulation must have dimension > 0.
* \param s the source point. This point must be initialized. If `tr` has dimension < 3, `s` must lie inside
* the affine hull of `tr`.
* \param t the target point. This point must be initialized and it cannot be be at the same location as `s`.
* If `tr` has dimension < 3, `t` must lie inside the affine hull of `tr`.
* \param hint the starting point to search for `s`.
*/
Triangulation_segment_cell_iterator_3( const Tr& tr, const Point& s, const Point& t, Cell_handle hint = Cell_handle() );
// constructs an iterator.
/* \param tr the triangulation to iterate though. This triangulation must have dimension > 0.
* \param S the segment to be traversed. If `tr` has dimension < 3, `S` must lie inside
* the affine hull of `tr`. `S` must not be degenerate, i.e. its source and target must not be equal.
* \param hint the starting point to search for `S`.
*/
Triangulation_segment_cell_iterator_3( const Tr& tr, const Segment& S, Cell_handle hint = Cell_handle() );
// \}
#ifndef CGAL_TST_ASSUME_CORRECT_TYPES
// The virtual destructor is mainly defined to indicate to the casting
// operators that this is a dynamic type.
virtual
#endif
~Triangulation_segment_cell_iterator_3() {}
private:
// private constructor that does not initialize the source and target.
Triangulation_segment_cell_iterator_3( const Tr& tr );
public:
// \name Accessors
// \{
const Tr& triangulation() const { return _tr; }
// gives the source point of the segment followed.
/* \return the source point.
*/
const Point& source() const { return _source; }
// gives the target point of the segment follwoed.
/* \return the target point.
*/
const Point& target() const { return _target; }
// gives the current cell.
/* By invariance, this cell is intersected by the segment
* between `source()` and `target()`.
* \return the current cell.
* \sa `handle()`.
*/
const Cell cell() const
{
using CGAL::cpp11::get;
return *get<0>(_cur);
}
// gives a handle to the current cell.
/* By invariance, this cell is intersected by the segment
* between `source()` and `target()`.
* \return a handle to the current cell.
* \sa `cell()`.
*/
Cell_handle handle()
{
using CGAL::cpp11::get;
return get<0>(_cur);
}
// gives the previous cell.
/* This cell is uninitialized until the iterator leaves the initial
* cell.
* By invariance, once initialized, this cell must be intersected by the segment
* between `source()` and `target()`.
* \return the previous cell.
* \sa `handle()`.
*/
Cell_handle previous() const
{
using CGAL::cpp11::get;
return get<0>(_prev);
}
// provides a dereference operator.
/* \return a pointer to the current cell.
*/
Cell* operator->()
{
using CGAL::cpp11::get;
return &*get<0>(_cur);
}
// provides an indirection operator.
/* \return the current cell.
*/
Cell& operator*()
{
using CGAL::cpp11::get;
return *get<0>(_cur);
}
// provides a conversion operator.
/* \return a handle to the current cell.
*/
operator const Cell_handle() const
{
using CGAL::cpp11::get;
return get<0>(_cur);
}
// provides a conversion operator.
/* \return the simplex through wich the current cell was entered.
*/
operator const Simplex() const { return _cur; }
// checks whether the iterator has reached the final cell, which contains the `target()`.
/* If the `target()` lies on a facet, edge, or vertex, the final cell is the cell containing
* the interior of the segment between `source()` and `target()`.
* \return true iff the current cell contains the `target()`.
*/
bool has_next() const
{
using CGAL::cpp11::get;
return get<0>(_cur) != Cell_handle();
}
// gives the simplex through which the current cell was entered.
/* For the first cell, containing the `source()` \f$ s \f$,
* this indicates the location of \f$ s \f$ in this cell.
*/
void entry( Locate_type& lt, int& li, int& lj ) const
{
using CGAL::cpp11::get;
lt = get<1>(_cur); li = get<2>(_cur); lj = get<3>(_cur);
}
// gives the simplex through which the previous cell was exited.
/* \pre the current cell is not the initial cell.
*/
void exit( Locate_type& lt, int& li, int& lj ) const
{
using CGAL::cpp11::get;
lt = get<1>(_prev); li = get<2>(_prev); lj = get<3>(_prev);
}
// gives the past-the-end iterator associated with this iterator.
SCI end() const;
// \}
public:
// \name Mutators
// \{
// provides the increment postfix operator.
/* After incrementing the iterator, the current cell intersects the segment
* between `source()` and `target()` closer to the `target()` than the previous cell.
* \sa `operator++(int)`.
* \pre The current cell does not contain the `target()`.
*/
SCI& operator++();
// provides the increment prefix operator.
/* After incrementing the iterator, the current cell intersects the segment
* between `source()` and `target()` closer to the `target()` than the previous cell.
* than the previous cell.
* \sa `operator++()`.
* \pre The current cell does not contain the `target()`.
*/
SCI operator++( int );
// iterates to the final cell, which contains the `target()`.
/* \return the final cell.
*/
Cell_handle complete();
// \}
public:
// \name Comparison
// \{
// compares this iterator with `sci`.
/* \param sci the other iterator.
* \return true iff the other iterator iterates the same triangulation along the same line segment
* and has the same current cell.
* \sa `operator!=( const SCI& t )`.
*/
bool operator==( const SCI& sci ) const;
// compares this iterator with `sci`.
/* \param sci the other iterator.
* \return `false` iff the other iterator iterates the same triangulation along the same line segment
* and has the same current cell.
* \sa `operator==( const SCI& t ) const`.
*/
bool operator!=( const SCI& sci ) const;
// compares the current cell with `ch`.
/* \param ch a handle to the other cell.
* \return true iff the current cell is the same as the one pointed to by `ch`.
* \sa `operator!=( const Cell_handle& ch ) const`.
* \sa `operator==( typename TriangulationTraits_3::Cell_handle ch, Triangulation_segment_cell_iterator_3<TriangulationTraits_3> t )`.
*/
bool operator==( const Cell_handle& ch ) const
{
using CGAL::cpp11::get;
return ch == get<0>(_cur);
}
// compares the current cell with `ch`.
/* \param ch a handle to the other cell.
* \return `false` iff the current cell is the same as the one pointed to by `ch`.
* \sa `operator==( const Cell_handle& ch )`.
* \sa `operator!=( typename TriangulationTraits_3::Cell_handle ch, Triangulation_segment_cell_iterator_3<TriangulationTraits_3> t )`.
*/
bool operator!=( const Cell_handle& ch ) const
{
using CGAL::cpp11::get;
return ch != get<0>(_cur);
}
// \}
bool operator==( Nullptr_t CGAL_triangulation_assertion_code(n) ) const;
bool operator!=( Nullptr_t n ) const;
protected:
// \internal \name Protected Member Functions
// \{
// walks to the next cell.
/* \sa `complete()`.
*/
void walk_to_next();
// increments the iterator.
/* This method may perform more actions based on the superclass.
* \sa `complete()`.
*/
void increment() {
typedef typename Incrementer::SCI Expected;
#ifdef CGAL_TST_ASSUME_CORRECT_TYPES
Expected& sci = static_cast<Expected&>( *this );
#else // CGAL_TST_ASSUME_CORRECT_TYPES
Expected& sci = dynamic_cast<Expected&>( *this );
#endif // CGAL_TST_ASSUME_CORRECT_TYPES
Incrementer().increment( sci );
}
// \}
private:
// at the end of the constructors, entry() is a vertex, edge or facet,
// we need to circulate/iterate over its incident cells to
// make sure that the current cell intersects the input query
void jump_to_intersecting_cell();
// walk_to_next(), if the triangulation is 3D.
void walk_to_next_3();
void walk_to_next_3_inf( int inf );
// walk_to_next(), if the triangulation is 2D.
void walk_to_next_2();
void walk_to_next_2_inf( int inf );
private:
inline int edgeIndex( int i, int j ) const {
CGAL_triangulation_precondition( i>=0 && i<=3 );
CGAL_triangulation_precondition( j>=0 && j<=3 );
CGAL_triangulation_precondition( i != j );
return ( i==0 || j==0 ) ? i+j-1 : i+j;
}
bool have_same_entry(const Simplex& s1, const Simplex& s2) const;
// Compute the orientation of a point compared to the oriented plane supporting a half-facet.
CGAL::Orientation orientation(const Facet& f, const Point& p) const;
bool coplanar(const Facet &f, const Point &p) const;
// Gives the edge incident to the same cell that is not incident to any of the input vertices.
Edge opposite_edge(Cell_handle c, int li, int lj) const;
Edge opposite_edge(const Edge& e) const;
}; // class Triangulation_segment_cell_iterator_3
// compares a handle to a cell to a traverser.
/* \param ch the handle to a cell.
* \param t the traverser.
* \return true iff the cell currently traversed by `t` is the same as the one pointed to by `ch`.
* \sa `operator!=( typename TriangulationTraits_3::Cell_handle ch, Triangulation_segment_cell_iterator_3<TriangulationTraits_3> t )`.
* \sa `Triangulation_segment_cell_iterator_3::operator==( const Cell_handle& ch )`.
*/
template < class Tr, class Inc >
inline bool operator==( typename Tr::Cell_handle ch, Triangulation_segment_cell_iterator_3<Tr,Inc> tci ) { return tci == ch; }
// compares a handle to a cell to a traverser.
/* \param ch the handle to a cell.
* \param t the traverser.
* \return `false` iff the cell currently traversed by `t` is the same as the one pointed to by `ch`.
* \sa `operator==( typename TriangulationTraits_3::Cell_handle ch, Triangulation_segment_cell_iterator_3<TriangulationTraits_3> t )`.
* \sa `Triangulation_segment_cell_iterator_3::operator!=( const Cell_handle& ch )`.
*/
template < class Tr, class Inc >
inline bool operator!=( typename Tr::Cell_handle ch, Triangulation_segment_cell_iterator_3<Tr,Inc> tci ) { return tci != ch; }
/********************************************************************/
/********************************************************************/
/********************************************************************/
template < class Tr_, class Inc = internal::Incrementer<Tr_> >
class Triangulation_segment_simplex_iterator_3
{
typedef Tr_ Tr;
typedef typename Tr::Triangulation_data_structure Tds;
typedef typename Tr::Geom_traits Gt;
typedef Inc Incrementer;
private:
typedef Triangulation_segment_simplex_iterator_3<Tr_, Inc> Simplex_iterator;
typedef Triangulation_segment_cell_iterator_3<Tr_, Inc> SCI;
private:
typedef typename SCI::Point Point;
typedef typename SCI::Segment Segment;
public:
// \{
typedef typename SCI::Vertex_handle Vertex_handle;//< defines the type of a handle for a vertex in the triangulation
typedef typename SCI::Cell_handle Cell_handle; //< defines the type of a handle for a cell in the triangulation.
typedef typename SCI::Cell Cell; //< defines the type of a handle for a cell in the triangulation.
typedef typename SCI::Triangulation::Edge Edge; //< defines the type of an edge in the triangulation.
typedef typename SCI::Triangulation::Facet Facet; //< defines the type of a facet in the triangulation.
typedef typename SCI::Locate_type Locate_type; //< defines the simplex type returned from location.
//typedef boost::variant<Vertex_handle, Edge, Facet, Cell_handle> Simplex_type; //types sorted by dimension
typedef CGAL::Triangulation_simplex_3<Tds> Simplex_type;
typedef Simplex_type value_type; //< defines the value type the iterator refers to.
typedef const Simplex_type& reference; //< defines the reference type of the iterator.
typedef const Simplex_type* pointer; //< defines the pointer type of the iterator.
typedef std::size_t size_type; //< defines the integral type that can hold the size of a sequence.
typedef std::ptrdiff_t difference_type; //< defines the signed integral type that can hold the distance between two iterators.
typedef std::forward_iterator_tag iterator_category; //< defines the iterator category.
// \}
private:
SCI _cell_iterator;
Simplex_type _curr_simplex;
public:
Triangulation_segment_simplex_iterator_3(const Tr& tr
, Vertex_handle s, Vertex_handle t)
: _cell_iterator(tr, s, t)
{ set_curr_simplex_to_entry(); }
Triangulation_segment_simplex_iterator_3(const Tr& tr
, Vertex_handle s, const Point& t)
: _cell_iterator(tr, s, t)
{ set_curr_simplex_to_entry(); }
Triangulation_segment_simplex_iterator_3(const Tr& tr
, const Point& s, Vertex_handle t, Cell_handle hint = Cell_handle())
: _cell_iterator(tr, s, t, hint)
{ set_curr_simplex_to_entry(); }
Triangulation_segment_simplex_iterator_3(const Tr& tr
, const Point& s, const Point& t, Cell_handle hint = Cell_handle())
: _cell_iterator(tr, s, t, hint)
{ set_curr_simplex_to_entry(); }
Triangulation_segment_simplex_iterator_3(const Tr& tr
, const Segment& seg, Cell_handle hint = Cell_handle())
: _cell_iterator(tr, seg, hint)
{ set_curr_simplex_to_entry(); }
bool operator==(const Simplex_iterator& sit) const
{
return sit._cell_iterator == _cell_iterator
&& sit._curr_simplex == _curr_simplex;
}
bool operator!=(const Simplex_iterator& sit) const
{
return sit._cell_iterator != _cell_iterator
|| sit._curr_simplex != _curr_simplex;
}
const Point& source() const { return _cell_iterator.source(); }
const Point& target() const { return _cell_iterator.target(); }
const Tr& triangulation() const { return _cell_iterator.triangulation(); }
private:
Triangulation_segment_simplex_iterator_3
(const SCI& sci)
: _cell_iterator(sci)
, _curr_simplex()
{}
private:
void set_curr_simplex_to_entry()
{
Locate_type lt;
int li, lj;
Cell_handle cell;
//check what is the entry type of _cell_iterator
if (Cell_handle(_cell_iterator) == Cell_handle())
{
//where did the segment get out from previous cell
cell = _cell_iterator.previous();
_cell_iterator.exit(lt, li, lj);
}
else
{
cell = Cell_handle(_cell_iterator);
_cell_iterator.entry(lt, li, lj);
}
switch (lt)
{
case Locate_type::VERTEX:
_curr_simplex = cell->vertex(li);
break;
case Locate_type::EDGE:
_curr_simplex = Edge(cell, li, lj);
break;
case Locate_type::FACET:
_curr_simplex = Facet(cell, li);
break;
//the 3 cases below correspond to the case when _cell_iterator
//is in its initial position: _cur is locate(source)
case Locate_type::CELL:
case Locate_type::OUTSIDE_CONVEX_HULL:
case Locate_type::OUTSIDE_AFFINE_HULL:
if (Cell_handle(_cell_iterator) == Cell_handle())
_curr_simplex = Simplex_type();
else
_curr_simplex = cell;
break;
default:
CGAL_assertion(false);
};
}
public:
Simplex_iterator end() const
{
Simplex_iterator sit(_cell_iterator.end());
return sit;
}
// provides the increment postfix operator.
Simplex_iterator& operator++()
{
CGAL_assertion(_curr_simplex.incident_cell() != Cell_handle());
Cell_handle ch = Cell_handle(_cell_iterator);
if (ch == Cell_handle())
{
_curr_simplex = Simplex_type();
return *this;
}
switch(_curr_simplex.dimension())
{
case 3 :/*Cell_handle*/
{
if (!cell_iterator_is_ahead())
++_cell_iterator;
set_curr_simplex_to_entry();
break;
}
case 2 :/*Facet*/
{
if (!cell_iterator_is_ahead())
{
//cell_iterator is not ahead. get_facet() is part of cell_iterator
//we cannot be in any of the degenerate cases, only detected by
//taking cell_iterator one step forward
CGAL_assertion(cell_has_facet(Cell_handle(_cell_iterator), get_facet()));
_curr_simplex = Cell_handle(_cell_iterator);
}
else
{
Cell_handle chnext = Cell_handle(_cell_iterator);
Locate_type ltnext;
int linext, ljnext;
_cell_iterator.entry(ltnext, linext, ljnext);
switch (ltnext)//entry simplex in next cell
{
case Locate_type::VERTEX:
{
//if the entry vertex is a vertex of current facet
int i;
if (triangulation().has_vertex(get_facet(), chnext->vertex(linext), i))
set_curr_simplex_to_entry();
else
_curr_simplex = chnext;
break;
}
case Locate_type::EDGE:
if (facet_has_edge(get_facet(), Edge(chnext, linext, ljnext)))
set_curr_simplex_to_entry();
else
_curr_simplex = chnext;
break;
case Locate_type::FACET:
_curr_simplex = chnext;
break;
default:
CGAL_assertion(false);
};
}//end else
break;
}
case 1:/*Edge*/
{
Locate_type lt;
int li, lj;
_cell_iterator.entry(lt, li, lj);
if (!cell_iterator_is_ahead())
++_cell_iterator;//cell_iterator needs to be ahead to detect degeneracies
Cell_handle chnext = Cell_handle(_cell_iterator);
Locate_type ltnext;
int linext, ljnext;
_cell_iterator.entry(ltnext, linext, ljnext);
switch (ltnext)//entry simplex in next cell
{
case Locate_type::VERTEX:
if (edge_has_vertex(get_edge(), chnext->vertex(linext)))
_curr_simplex = chnext->vertex(linext);
else
_curr_simplex = shared_facet(get_edge(), chnext->vertex(linext));
break;
case Locate_type::EDGE:
{
CGAL_assertion(_cell_iterator == _cell_iterator.end()
|| triangulation().is_infinite(chnext)
|| _curr_simplex != Simplex_type(Edge(chnext, linext, ljnext)));
if (_cell_iterator == _cell_iterator.end())
_curr_simplex = Simplex_type();
else if (triangulation().is_infinite(chnext)
&& _curr_simplex == Simplex_type(Edge(chnext, linext, ljnext)))
_curr_simplex = chnext;
else
_curr_simplex = shared_facet(get_edge(), Edge(chnext, linext, ljnext));
break;
}
case Locate_type::FACET:
_curr_simplex = Cell_handle(_cell_iterator);//query goes through the cell
break;
default:
CGAL_assertion(false);//should not happen
};
break;
}
case 0 :/*Vertex_handle*/
{
Cell_handle ch = Cell_handle(_cell_iterator);
if (cell_iterator_is_ahead())
{
_curr_simplex = ch;
std::cerr << "cell_iterator is ahead in vertex case (check to be done)"
<< std::endl;
}
else
{
++_cell_iterator;
Cell_handle chnext = Cell_handle(_cell_iterator);
//_cell_iterator is one step forward _curr_simplex
CGAL_assertion(ch != chnext);
Locate_type ltnext;
int linext, ljnext;
_cell_iterator.entry(ltnext, linext, ljnext);
switch (ltnext)
{
case Locate_type::VERTEX:
{
CGAL_assertion(_cell_iterator == _cell_iterator.end()
|| get_vertex() != chnext->vertex(linext)
|| triangulation().is_infinite(chnext));
if (_cell_iterator == _cell_iterator.end())
{
_curr_simplex = Simplex_type();
}
else
{
if (triangulation().is_infinite(chnext) && get_vertex() == chnext->vertex(linext))
_curr_simplex = chnext;
else
{
Cell_handle ec;
int ei, ej;
if (!triangulation().is_edge(get_vertex(), chnext->vertex(linext), ec, ei, ej))
CGAL_assertion(false);
_curr_simplex = Edge(ec, ei, ej);
}
}
break;
}
case Locate_type::EDGE:
{
//facet shared by get_vertex() and the edge
//none of ch and chnext is certainly shared by both endpoints
_curr_simplex = shared_facet(Edge(chnext, linext, ljnext), get_vertex());
break;
}
default ://FACET
CGAL_assertion(ltnext == Locate_type::FACET);
_curr_simplex = ch;
};
}
break;
}
default:
CGAL_assertion(false);
};
return *this;
}
// provides the increment prefix operator.
Simplex_iterator operator++(int)
{
Simplex_iterator tmp(*this);
++(*this);
return tmp;
}
// provides a dereference operator.
/* \return a pointer to the current cell.
*/
const Simplex_type* operator->() { return &_curr_simplex; }
// provides an indirection operator.
/* \return the current cell.
*/
const Simplex_type& operator*() { return _curr_simplex; }
// provides a conversion operator.
/* \return a handle to the current cell.
*/
operator const Cell_handle() const { return Cell_handle(_cell_iterator); }
bool is_vertex() const { return _curr_simplex.dimension() == 0; }
bool is_edge() const { return _curr_simplex.dimension() == 1; }
bool is_facet() const { return _curr_simplex.dimension() == 2; }
bool is_cell() const { return _curr_simplex.dimension() == 3; }
const Cell cell() const
{
return _cell_iterator.cell();
}
const Simplex_type& get_simplex() const { return _curr_simplex; }
Vertex_handle get_vertex() const
{
CGAL_assertion(is_vertex());
return Vertex_handle(_curr_simplex);
}
Edge get_edge() const
{
CGAL_assertion(is_edge());
return Edge(_curr_simplex);
}
Facet get_facet() const
{
CGAL_assertion(is_facet());
return Facet(_curr_simplex);
}
Cell_handle get_cell() const
{
CGAL_assertion(is_cell());
return Cell_handle(_curr_simplex);
}
public:
//returns true in any of the degenerate cases,
//i.e. when _curr_simplex has the following values successively
// edge / facet / edge
// edge / facet / vertex
// vertex / facet / edge
// vertex / edge / vertex
// TODO : rename this function
bool is_collinear() const
{
int curr_dim = _curr_simplex.dimension();
//this concerns only edges and facets
if (curr_dim == 1 || curr_dim == 2)
return cell_iterator_is_ahead();
//the degeneracy has been detected by moving cell_iterator forward
else
return false;
}
int simplex_dimension() const
{
return _curr_simplex.dimension();
}
private:
bool cell_iterator_is_ahead() const
{
Cell_handle ch = Cell_handle(_cell_iterator);
if(ch == Cell_handle())
return true;
switch (_curr_simplex.dimension())
{
case 0 ://vertex
return !ch->has_vertex(get_vertex());
case 1 ://edge
return !cell_has_edge(ch, get_edge());
case 2 ://facet
return !cell_has_facet(ch, get_facet());
case 3 ://cell
return ch != get_cell();
default:
CGAL_assertion(false);
}
//should not be reached
CGAL_assertion(false);
return false;
}
bool cell_has_edge(const Cell_handle ch, const Edge& e) const
{
Vertex_handle v1 = e.first->vertex(e.second);
Vertex_handle v2 = e.first->vertex(e.third);
return ch->has_vertex(v1) && ch->has_vertex(v2);
}
bool cell_has_facet(const Cell_handle c, const Facet& f) const
{
return f.first == c
|| f.first->neighbor(f.second) == c;
}
bool facet_has_edge(const Facet& f, const Edge& e) const
{
Vertex_handle v1 = e.first->vertex(e.second);
Vertex_handle v2 = e.first->vertex(e.third);
Cell_handle c = f.first;
const int fi = f.second;
unsigned int count = 0;
for (int i = 1; i < 4; ++i)
{
Vertex_handle vi = c->vertex((fi + i) % 4);
if (vi == v1 || vi == v2)
++count;
if (count == 2)
return true;
}
return false;
}
bool edge_has_vertex(const Edge& e, const Vertex_handle v) const
{
return e.first->vertex(e.second) == v
|| e.first->vertex(e.third) == v;
}
Vertex_handle shared_vertex(const Edge& e1, const Edge& e2) const
{
Vertex_handle v1a = e1.first->vertex(e1.second);
Vertex_handle v1b = e1.first->vertex(e1.third);
Vertex_handle v2a = e2.first->vertex(e2.second);
Vertex_handle v2b = e2.first->vertex(e2.third);
if (v1a == v2a || v1a == v2b)
return v1a;
else if (v1b == v2a || v1b == v2b)
return v1b;
std::cerr << "There is no vertex shared by e1 and e2" << std::endl;
CGAL_assertion(false);
return Vertex_handle();
}
Facet shared_facet(const Edge& e1, const Edge& e2) const
{
Vertex_handle v2a = e2.first->vertex(e2.second);
Vertex_handle v2b = e2.first->vertex(e2.third);
Vertex_handle sv = shared_vertex(e1, e2);
Vertex_handle nsv2 = (sv == v2a) ? v2b : v2a;
typename Tr::Facet_circulator circ
= triangulation().incident_facets(e1);
typename Tr::Facet_circulator end = circ;
do
{
Facet f = *circ;
for (int i = 1; i < 4; ++i)
{
if (nsv2 == f.first->vertex((f.second + i) % 4))
return f;
}
} while (++circ != end);
std::cerr << "There is no facet shared by e1 and e2" << std::endl;
CGAL_assertion(false);
return Facet(Cell_handle(), 0);
}
Facet shared_facet(const Edge& e, const Vertex_handle v) const
{
typename Tr::Facet_circulator circ
= triangulation().incident_facets(e);
typename Tr::Facet_circulator end = circ;
do
{
Facet f = *circ;
int i;
if (triangulation().has_vertex(f, v, i))
return f;
} while (++circ != end);
std::cerr << "There is no facet shared by e and v" << std::endl;
CGAL_assertion(false);
return Facet(Cell_handle(), 0);
}
Cell_handle shared_cell(const Edge& e, const Vertex_handle v) const
{
typename Tr::Cell_circulator circ
= triangulation().incident_cells(e);
typename Tr::Cell_circulator end = circ;
do
{
Cell_handle c = circ;
if (c->has_vertex(v))
return c;
} while (++circ != end);
std::cerr << "There is no cell shared by e and v" << std::endl;
CGAL_assertion(false);
return Cell_handle();
}
};//class Triangulation_segment_simplex_iterator_3
} // namespace CGAL
#include <CGAL/Triangulation_segment_traverser_3_impl.h>
#endif // CGAL_TRIANGULATION_SEGMENT_TRAVERSER_3_H
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