bool LineSegmentIntersector::intersects(const osg::BoundingSphere& bs)
{
// if bs not valid then return true based on the assumption that an invalid sphere is yet to be defined.
if (!bs.valid()) return true;
osg::Vec3d sm = _start - bs._center;
double c = sm.length2()-bs._radius*bs._radius;
if (c<0.0) return true;
osg::Vec3d se = _end-_start;
double a = se.length2();
double b = (sm*se)*2.0;
double d = b*b-4.0*a*c;
if (d<0.0) return false;
d = sqrt(d);
double div = 1.0/(2.0*a);
double r1 = (-b-d)*div;
double r2 = (-b+d)*div;
if (r1<=0.0 && r2<=0.0) return false;
if (r1>=1.0 && r2>=1.0) return false;
// passed all the rejection tests so line must intersect bounding sphere, return true.
return true;
}
bool PrimitiveIntersector::intersects(const osg::BoundingSphere& bs)
{
// if bs not valid then return true based on the assumption that an invalid sphere is yet to be defined.
if (!bs.valid()) return true;
osg::Vec3d sm = _start - bs._center;
double c = sm.length2()-bs._radius*bs._radius;
if (c<0.0) return true;
osg::Vec3d se = _end-_start;
double a = se.length2();
double b = (sm*se)*2.0;
double d = b*b-4.0*a*c;
if (d<0.0) return false;
d = sqrt(d);
double div = 1.0/(2.0*a);
double r1 = (-b-d)*div;
double r2 = (-b+d)*div;
if (r1<=0.0 && r2<=0.0) return false;
if (r1>=1.0 && r2>=1.0) return false;
if (_intersectionLimit == LIMIT_NEAREST && !getIntersections().empty())
{
double ratio = (sm.length() - bs._radius) / sqrt(a);
if (ratio >= getIntersections().begin()->ratio) return false;
}
// passed all the rejection tests so line must intersect bounding sphere, return true.
return true;
}