cgal/Packages/Spatial_searching/include/CGAL/Splitting_rules.h

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// ======================================================================
//
// Copyright (c) 2001 The CGAL Consortium
//
// This software and related documentation is part of an INTERNAL release
// of the Computational Geometry Algorithms Library (CGAL). It is not
// intended for general use.
//
// ----------------------------------------------------------------------
//
// release :
// release_date :
//
// file : include/CGAL/Splitting_rules.h
// package : APSPAS
// revision : 1.0
// revision_date : 2001/06/12
// maintainer : Hans Tangelder (<hanst@cs.uu.nl>)
//
// ======================================================================
// Defines rules used for constructing a split node. That is, it implements, in several ways, the concept
// Boxtree_splitter<NT>.
#ifndef CGAL_SPLITTING_RULES_H
#define CGAL_SPLITTING_RULES_H
#include <CGAL/Points_container.h>
#include <CGAL/Plane_separator.h>
namespace CGAL {
enum Split_rule {MEDIAN_OF_MAX_SPREAD, MEDIAN_OF_BOX,
MIDPOINT_OF_MAX_SPREAD, MIDPOINT_OF_BOX, FAIR, SLIDING_MIDPOINT, SLIDING_FAIR};
enum Shrink_rule {NONE, SIMPLE, CENTROID};
template <class P>
class Splitter {
public:
typedef typename P::FT NT;
// virtual void rule(Points_container<P>& c, Plane_separator<NT>* sep) {}
};
template <class P>
class Median_Of_Max_Spread : public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c) {
Plane_separator<NT>* sep =
new Plane_separator<NT>(c.max_tight_span_coord(),0.0);
sep->set_cutting_val(c.median(sep->cutting_dimension()));
return sep;
}
};
template <class P>
class Fair : public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c, NT Aspect_ratio) {
// find legal cut with max spread
Plane_separator<NT>* sep =
new Plane_separator<NT>(c.max_tight_span_coord_balanced(Aspect_ratio),0.0);
sep->set_cutting_val(c.balanced_fair(sep->cutting_dimension(),Aspect_ratio));
return sep;
}
};
template <class P>
class Sliding_Fair : public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c, NT Aspect_ratio) {
// find legal cut with max spread
Plane_separator<NT>* sep =
new Plane_separator<NT>(c.max_tight_span_coord_balanced(Aspect_ratio),0.0);
sep->set_cutting_val(c.balanced_sliding_fair(sep->cutting_dimension(),Aspect_ratio));
return sep;
}
};
template <class P>
class Sliding_MidPoint: public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c)
{
Plane_separator<NT>* sep = new Plane_separator<NT>(c.max_span_coord(),
(c.max_span_upper() + c.max_span_lower())/2.0);
NT max_span_lower = c.tight_bounding_box().lower(c.max_span_coord());
NT max_span_upper = c.tight_bounding_box().upper(c.max_span_coord());
if (max_span_upper <= sep->cutting_value()) {
sep->set_cutting_val(max_span_upper);
}
if (max_span_lower >= sep->cutting_value()) {
sep->set_cutting_val(max_span_lower);
}
return sep;
}
};
template <class P>
class Median_Of_Box : public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c)
{
Plane_separator<NT>* sep = new Plane_separator<NT>(c.max_span_coord(),0.0);
sep->set_cutting_val(c.median(sep->cutting_dimension()));
return sep;
}
};
template <class P>
class MidPoint_Of_Max_Spread : public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c)
{
Plane_separator<NT>* sep = new Plane_separator<NT>(c.max_tight_span_coord(),
(c.max_tight_span_upper() + c.max_tight_span_lower())/2.0);
return sep;
}
};
template <class P>
class MidPoint_Of_Box: public Splitter<P> {
public:
typedef typename P::FT NT;
Plane_separator<NT>* rule(Points_container<P>& c)
{
Plane_separator<NT>* sep = new Plane_separator<NT>(c.max_span_coord(),
(c.max_span_upper() + c.max_span_lower())/2.0);
return sep;
}
};
} // namespace CGAL
#endif // CGAL_SPLITTING_RULES_H