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Giles Bathgate 2025-12-03 14:01:24 +01:00 committed by GitHub
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1 changed files with 85 additions and 28 deletions

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@ -20,6 +20,7 @@
#include <CGAL/Handle_for.h>
#include <CGAL/Nef_S2/Sphere_point.h>
#include <CGAL/Nef_S2/Sphere_circle.h>
#include <memory>
#include <vector>
namespace CGAL {
@ -201,11 +202,7 @@ bool is_short() const
bool is_long() const
/*{\Mop a segment is long iff it is longer than a halfcircle.}*/
{ return R().orientation_3_object()(CGAL::ORIGIN,
source(),
target(),
orthogonal_pole())
== CGAL::NEGATIVE; }
{ return is_long(orthogonal_pole()); }
bool is_degenerate() const { return source() == target(); }
/*{\Mop return true iff |\Mvar| is degenerate.}*/
@ -231,23 +228,51 @@ bool operator!=(const Sphere_segment<R>& so) const
private:
Point_3 orthogonal_pole() const
template <typename R>
friend bool do_intersect_internally(const Sphere_segment<R>& s1,
const Sphere_segment<R>& s2,
Sphere_point<R>& p);
template <typename R>
friend bool do_intersect_internally(const Sphere_circle<R>& c1,
const Sphere_segment<R>& s2,
Sphere_point<R>& p);
Sphere_point<R> orthogonal_pole() const
{ return CGAL::ORIGIN + sphere_circle().orthogonal_vector(); }
CGAL::Orientation source_orientation(const CGAL::Sphere_point<R>& p) const
inline CGAL::Orientation source_orientation(const CGAL::Sphere_point<R>& p,
const CGAL::Sphere_point<R>& pole) const
{ return R().orientation_3_object()(CGAL::ORIGIN,
orthogonal_pole(),
pole,
source(),
p);
}
CGAL::Orientation target_orientation(const CGAL::Sphere_point<R>& p) const
inline CGAL::Orientation target_orientation(const CGAL::Sphere_point<R>& p,
const CGAL::Sphere_point<R>& pole) const
{ return R().orientation_3_object()(CGAL::ORIGIN,
target(),
orthogonal_pole(),
pole,
p);
}
bool is_long(const Sphere_point<R>& pole) const
{ return R().orientation_3_object()(CGAL::ORIGIN,
source(),
target(),
pole)
== CGAL::NEGATIVE; }
bool has_in_relative_interior(const CGAL::Sphere_point<R>& p,
const CGAL::Sphere_point<R>& pole,
bool long_segment,
bool check_has_on = true) const;
bool has_in_relative_interior(const CGAL::Sphere_point<R>& p,
std::unique_ptr<CGAL::Sphere_point<R>>& pole,
std::unique_ptr<bool>& long_segment,
bool check_has_on = true) const;
};
template <typename R>
@ -305,35 +330,59 @@ template <typename R>
bool Sphere_segment<R>::
has_on(const CGAL::Sphere_point<R>& p) const
{ if ( !sphere_circle().has_on(p) ) return false;
if ( !is_long() ) {
return source_orientation(p) != CGAL::NEGATIVE &&
target_orientation(p) != CGAL::NEGATIVE;
const Sphere_point<R>& pole = orthogonal_pole();
if ( !is_long(pole) ) {
return source_orientation(p, pole) != CGAL::NEGATIVE &&
target_orientation(p, pole) != CGAL::NEGATIVE;
} else {
return source_orientation(p) != CGAL::NEGATIVE ||
target_orientation(p) != CGAL::NEGATIVE;
return source_orientation(p, pole) != CGAL::NEGATIVE ||
target_orientation(p, pole) != CGAL::NEGATIVE;
}
}
template <typename R>
bool Sphere_segment<R>::
has_on_after_intersection(const CGAL::Sphere_point<R>& p) const
{ return source_orientation(p) != CGAL::NEGATIVE &&
target_orientation(p) != CGAL::NEGATIVE;
{ const Sphere_point<R>& pole = orthogonal_pole();
return source_orientation(p, pole) != CGAL::NEGATIVE &&
target_orientation(p, pole) != CGAL::NEGATIVE;
}
template <typename R>
bool Sphere_segment<R>::
has_in_relative_interior(const CGAL::Sphere_point<R>& p, bool check_has_on) const
{ if (check_has_on &&( !sphere_circle().has_on(p) ) ) return false;
if ( !is_long() ) {
return source_orientation(p) == CGAL::POSITIVE &&
target_orientation(p) == CGAL::POSITIVE;
const Sphere_point<R>& pole = orthogonal_pole();
return has_in_relative_interior(p, pole, is_long(pole), false);
}
template <typename R>
bool Sphere_segment<R>::
has_in_relative_interior(const CGAL::Sphere_point<R>& p,
const CGAL::Sphere_point<R>& pole,
bool long_segment,
bool check_has_on) const
{ if (check_has_on &&( !sphere_circle().has_on(p) ) ) return false;
if (!long_segment) {
return source_orientation(p, pole) == CGAL::POSITIVE &&
target_orientation(p, pole) == CGAL::POSITIVE;
} else {
return source_orientation(p) == CGAL::POSITIVE ||
target_orientation(p) == CGAL::POSITIVE;
return source_orientation(p, pole) == CGAL::POSITIVE ||
target_orientation(p, pole) == CGAL::POSITIVE;
}
}
template <typename R>
bool Sphere_segment<R>::
has_in_relative_interior(const CGAL::Sphere_point<R>& p,
std::unique_ptr<CGAL::Sphere_point<R>>& pole,
std::unique_ptr<bool>& long_segment,
bool check_has_on) const
{ if (check_has_on &&( !sphere_circle().has_on(p) ) ) return false;
if(!pole) pole = std::make_unique<CGAL::Sphere_point<R>>(orthogonal_pole());
if(!long_segment) long_segment = std::make_unique<bool>(is_long(*pole));
return has_in_relative_interior(p, *pole, *long_segment, false);
}
/* Intersection of two sphere segments. It does not work if the two
@ -358,11 +407,15 @@ bool do_intersect_internally(const Sphere_segment<R>& s1,
if ( equal_as_sets(s1.sphere_circle(),s2.sphere_circle()) )
return false;
p = CGAL::intersection(s1.sphere_circle(),s2.sphere_circle());
if ( s1.has_in_relative_interior(p, false) &&
s2.has_in_relative_interior(p, false) ) return true;
std::unique_ptr<Sphere_point<R>> s1_pole,s2_pole;
std::unique_ptr<bool> s1_long,s2_long;
if ( s1.has_in_relative_interior(p, s1_pole, s1_long, false) &&
s2.has_in_relative_interior(p, s2_pole, s2_long, false) ) return true;
p = p.antipode();
if ( s1.has_in_relative_interior(p, false) &&
s2.has_in_relative_interior(p, false) ) return true;
if ( s1.has_in_relative_interior(p, s1_pole, s1_long, false) &&
s2.has_in_relative_interior(p, s2_pole, s2_long, false) ) return true;
return false;
}
@ -375,9 +428,13 @@ bool do_intersect_internally(const Sphere_circle<R>& c1,
if ( equal_as_sets(c1,s2.sphere_circle()) )
return false;
p = CGAL::intersection(c1,s2.sphere_circle());
if ( s2.has_in_relative_interior(p, false) ) return true;
const Sphere_point<R>& s2_pole = s2.orthogonal_pole();
bool s2_long = s2.is_long(s2_pole);
if ( s2.has_in_relative_interior(p, s2_pole, s2_long, false) ) return true;
p = p.antipode();
if ( s2.has_in_relative_interior(p, false) ) return true;
if ( s2.has_in_relative_interior(p, s2_pole, s2_long, false) ) return true;
return false;
}