songsenand
/
cgal
mirror of https://github.com/CGAL/cgal
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #4187 from sgiraudot/Spatial_searching-Search_traits_adapter_without_lvalue_pmap-GF 

Spatial Searching: Search Traits Adapter without lvalue point map
This commit is contained in:
Sebastien Loriot 2019-08-29 07:31:25 +02:00 committed by GitHub
parent c003bf8f4d 33cc6f0483
commit ce82120d61
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 126 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Spatial_searching/doc/Spatial_searching/CGAL/Search_traits_adapter.h
View File

@ -11,7 +11,7 @@ in a nearest neighbor search algorithm, this class must be used as distance.
\tparam Key is a type that is associated to a point of type `Base_distance::Point_d`.
\tparam PointPropertyMap is a model of `LvaluePropertyMap`
\tparam PointPropertyMap is a model of `ReadablePropertyMap`
with `Key` as key type and `Base_distance::Point_d` as value type.
\tparam Base_distance is a model of either `GeneralDistance` or `OrthogonalDistance`.

131
Spatial_searching/include/CGAL/Search_traits_adapter.h
View File

@ -34,6 +34,7 @@
#include <boost/mpl/has_xxx.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/iterator/iterator_facade.hpp>
namespace CGAL{
@ -78,9 +79,6 @@ template <class Point_with_info,class PointPropertyMap,class Base_traits>
class Search_traits_adapter : public Base_traits{
PointPropertyMap ppmap;
CGAL_static_assertion( ( boost::is_same< boost::lvalue_property_map_tag,
typename boost::property_traits<PointPropertyMap>::category
>::value ) );
public:
typedef Base_traits Base;
typedef typename internal::Get_iso_box_d<Base>::type Iso_box_d;
@ -89,17 +87,19 @@ public:
const Base_traits& base=Base_traits()
):Base_traits(base),ppmap(ppmap_){}
typedef typename Base_traits::Cartesian_const_iterator_d Cartesian_const_iterator_d;
typedef Point_with_info Point_d;
typedef typename Base_traits::FT FT;
typedef typename Base_traits::Dimension Dimension;
struct Construct_cartesian_const_iterator_d: public Base_traits::Construct_cartesian_const_iterator_d{
// Default if point map is lvalue: use Construct_cartesian_const_iterator_d
struct Construct_cartesian_const_iterator_d_lvalue: public Base_traits::Construct_cartesian_const_iterator_d{
PointPropertyMap ppmap;
typedef typename Base_traits::Construct_cartesian_const_iterator_d Base;
Construct_cartesian_const_iterator_d(const typename Base_traits::Construct_cartesian_const_iterator_d& base, const PointPropertyMap& ppmap_)
Construct_cartesian_const_iterator_d_lvalue
(const typename Base_traits::Construct_cartesian_const_iterator_d& base, const PointPropertyMap& ppmap_)
:Base_traits::Construct_cartesian_const_iterator_d(base), ppmap(ppmap_){}
typename Base_traits::Cartesian_const_iterator_d operator()(const Point_with_info& p) const
@ -132,6 +132,125 @@ public:
{ return Base::operator() (p,0); }
};
// If point map is not lvalue, use this work-around that stores a
// Point object in a shared pointer to avoid iterating on a temp
// object
class No_lvalue_iterator
: public boost::iterator_facade<No_lvalue_iterator,
typename std::iterator_traits<typename Base::Cartesian_const_iterator_d>::value_type,
std::random_access_iterator_tag
>
{
typedef boost::iterator_facade<No_lvalue_iterator,
typename std::iterator_traits<typename Base::Cartesian_const_iterator_d>::value_type,
std::random_access_iterator_tag
> Facade;
typedef typename std::iterator_traits<typename Base::Cartesian_const_iterator_d>::value_type
Dereference_type;
typedef typename boost::property_traits<PointPropertyMap>::value_type
Point;
boost::shared_ptr<Point> point;
std::size_t idx;
public:
No_lvalue_iterator() : point(NULL), idx(0) { }
No_lvalue_iterator(const Point& point, std::size_t idx = 0) : point(new Point(point)), idx(idx) { }
private:
friend class boost::iterator_core_access;
void increment()
{
++idx;
CGAL_assertion(point != boost::shared_ptr<Point>());
}
void decrement()
{
--idx;
CGAL_assertion(point != boost::shared_ptr<Point>());
}
void advance(std::ptrdiff_t n)
{
idx += n;
CGAL_assertion(point != boost::shared_ptr<Point>());
}
std::ptrdiff_t distance_to(const No_lvalue_iterator& other) const
{
return other.idx - this->idx;
}
bool equal(const No_lvalue_iterator& other) const
{
return this->idx == other.idx;
}
Dereference_type&
dereference() const { return const_cast<Dereference_type&>((*point)[idx]); }
};
// Alternative Construct_cartesian_const_iterator_d if the point map
// is not lvalue (generates No_lvalue_iterator objects)
struct Construct_cartesian_const_iterator_d_no_lvalue {
typedef No_lvalue_iterator result_type;
PointPropertyMap ppmap;
Construct_cartesian_const_iterator_d_no_lvalue
(const typename Base_traits::Construct_cartesian_const_iterator_d&, const PointPropertyMap& ppmap_)
: ppmap(ppmap_) { }
No_lvalue_iterator operator()(const Point_with_info& p) const
{ return No_lvalue_iterator(get(ppmap, p)); }
No_lvalue_iterator operator()(const Point_with_info& p, int) const
{ return No_lvalue_iterator(get(ppmap, p),0); }
// These 2 additional operators forward the call to Base_traits.
// This is needed because of an undocumented requirement of
// Orthogonal_k_neighbor_search and Orthogonal_incremental_neighbor_search:
// Traits::Construct_cartesian_const_iterator should be callable
// on the query point type. If the query point type is the same as
// Point_with_info, we disable it.
template <typename Point> // boost::disable_if requires a template argument to work
No_lvalue_iterator operator()(const Point& p,
typename boost::disable_if<
boost::is_same<Point_with_info,
Point> >::type* = 0
) const
{ return No_lvalue_iterator(p); }
template <typename Point> // boost::disable_if requires a template argument to work
No_lvalue_iterator operator()(const Point& p, int,
typename boost::disable_if<
boost::is_same<Point_with_info,
Point> >::type* = 0
) const
{ return No_lvalue_iterator(p,0); }
};
// Select type of iterator + construct class depending on whether
// point map is lvalue or not
typedef typename boost::mpl::if_
<boost::is_same
<boost::lvalue_property_map_tag,
typename boost::property_traits<PointPropertyMap>::category >,
typename Base::Cartesian_const_iterator_d,
No_lvalue_iterator>::type
Cartesian_const_iterator_d;
typedef typename boost::mpl::if_
<boost::is_same
<boost::lvalue_property_map_tag,
typename boost::property_traits<PointPropertyMap>::category >,
Construct_cartesian_const_iterator_d_lvalue,
Construct_cartesian_const_iterator_d_no_lvalue>::type
Construct_cartesian_const_iterator_d;
struct Construct_iso_box_d: public Base::Construct_iso_box_d{
PointPropertyMap ppmap;
typedef typename Base_traits::FT FT; // needed for VC++, because otherwise it is taken from the private typedef of the base class