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Constructing a Circle_3 passing through three points p, q, r

This commit is contained in:
Pedro Machado Manhaes de Castro 2008-07-17 14:08:50 +00:00
parent 56c402b0fe
commit e8663963f2
4 changed files with 59 additions and 3 deletions
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21
Cartesian_kernel/include/CGAL/Cartesian/Circle_3.h
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@ -88,7 +88,8 @@ public:
base = Rep(circle.diametral_sphere(), circle.supporting_plane());
else {
assign(point, obj);
CircleC3(point, FT(0), Vector_3(FT(1),FT(0),FT(0)));
CircleC3 circle = CircleC3(point, FT(0), Vector_3(FT(1),FT(0),FT(0)));
base = Rep(circle.diametral_sphere(), circle.supporting_plane());
}
}
@ -104,10 +105,26 @@ public:
base = Rep(circle.diametral_sphere(), circle.supporting_plane());
else {
assign(point, obj);
CircleC3(point, FT(0), Vector_3(FT(1),FT(0),FT(0)));
CircleC3 circle = CircleC3(point, FT(0), Vector_3(FT(1),FT(0),FT(0)));
base = Rep(circle.diametral_sphere(), circle.supporting_plane());
}
}
CircleC3(const Point_3 &p, const Point_3 &q, const Point_3 &r) {
// p, q, r are not collinear
CGAL_kernel_precondition(!R().collinear_3_object()(p, q, r));
Plane_3 p1 = R().construct_plane_3_object()(p, q, r);
Plane_3 p2 = R().construct_bisector_3_object()(p, q);
Plane_3 p3 = R().construct_bisector_3_object()(p, r);
Object obj = R().intersect_3_object()(p1, p2, p3);
// must be a point, otherwise they are collinear
Point_3 center;
assign(center, obj);
FT sqr = R().compute_squared_distance_3_object()(center, r);
Sphere_3 s = R().construct_sphere_3_object()(center, sqr);
base = Rep(s, p1);
}
const Plane_3& supporting_plane() const
{
return get(base).second;

3
Kernel_23/include/CGAL/Circle_3.h
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@ -100,6 +100,9 @@ public:
Circle_3(const Plane_3& p, const Sphere_3& s)
: Rep(typename R::Construct_circle_3()(p,s)) {}
Circle_3(const Point_3& p1, const Point_3& p2, const Point_3& p3)
: Rep(typename R::Construct_circle_3()(p1,p2,p3)) {}
Circle_3(const Rep& r)
: Rep(r) {}

9
Kernel_23/include/CGAL/Kernel/function_objects.h
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@ -810,6 +810,11 @@ namespace CommonKernelFunctors {
const Sphere_3& s, int a) const
{ return Rep(p, s, a); }
Rep
operator() (Return_base_tag, const Point_3& p1,
const Point_3& p2, const Point_3& p3) const
{ return Rep(p1, p2, p3); }
Circle_3
operator()(const Point_3& p, const FT& sr,
const Plane_3& plane) const
@ -844,6 +849,10 @@ namespace CommonKernelFunctors {
Circle_3
operator() (const Sphere_3& s, const Plane_3& p, int a) const
{ return this->operator()(Return_base_tag(), p, s, a); }
Circle_3
operator()( const Point_3& p1, const Point_3& p2, const Point_3& p3) const
{ return this->operator()(Return_base_tag(), p1, p2, p3); }
};

27
Kernel_23/test/Kernel_23/include/CGAL/_test_cls_circle_3.h
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@ -82,9 +82,13 @@ void _test_circle_construct(const K &k) {
typedef typename K::Vector_3 Vector_3;
typedef typename K::Equal_3 Equal_3;
typedef typename K::Construct_circle_3 Construct_circle_3;
typedef typename K::Compute_squared_distance_3 Compute_squared_distance_3;
typedef typename K::Collinear_3 Collinear_3;
Equal_3 theEqual_3 = k.equal_3_object();
Construct_circle_3 theConstruct_circle_3 = k.construct_circle_3_object();
Compute_squared_distance_3 squared_distance = k.compute_squared_distance_3_object();
Collinear_3 collinear = k.collinear_3_object();
CGAL::Random generatorOfgenerator;
int random_seed = generatorOfgenerator.get_int(0, 123456);
@ -140,6 +144,29 @@ void _test_circle_construct(const K &k) {
assert(theEqual_3(circle,circle3));
}
Point_3 p1, p2, p3;
p1 = Point_3(1,0,0);
p2 = Point_3(0,1,0);
p3 = Point_3(0,0,1);
Circle_3 c = theConstruct_circle_3(p1, p2, p3);
FT r1 = squared_distance(c.center(), p1);
FT r2 = squared_distance(c.center(), p2);
FT r3 = squared_distance(c.center(), p3);
assert(r1 == r2);
assert(r2 == r3);
assert(r3 == c.squared_radius());
p1 = Point_3(1.3,0.2,0.1);
p2 = Point_3(0.57,1.23,3.0);
p3 = Point_3(9,1.2,1.3);
c = theConstruct_circle_3(p1, p2, p3);
r1 = squared_distance(c.center(), p1);
r2 = squared_distance(c.center(), p2);
r3 = squared_distance(c.center(), p3);
assert(r1 == r2);
assert(r2 == r3);
assert(r3 == c.squared_radius());
// No need to test the constructors based on intersection
// _test_intersect_construct will test it
}