OSG_BASE_DLLMAPPING
bool intersect(const BoxVolume &box, const SphereVolume &sphere)
{
// source:
// J. Arvo. A simple method for box-sphere intersection testing.
// In A. Glassner, editor, Graphics Gems, pp. 335-339,
// Academic Press, Boston, MA, 1990
bool retCode;
if(box.isEmpty() == true || sphere.isEmpty() == true)
{
retCode = false;
}
else if(box.isInfinite() == true || sphere.isInfinite() == true)
{
retCode = true;
}
else
{
Real32 s;
Real32 d = 0.f;
//find the square of the distance from the sphere to the box
for(Int32 i = 0; i < 3; i++)
{
if(sphere.getCenter()[i] < box.getMin()[i])
{
s = sphere.getCenter()[i] - box.getMin()[i];
d += s * s;
}
else if(sphere.getCenter()[i] > box.getMax()[i])
{
s = sphere.getCenter()[i] - box.getMax()[i];
d += s * s;
}
}
retCode = (d <= (sphere.getRadius() * sphere.getRadius()));
}
return retCode;
}
bool Line::intersect(const SphereVolume &sphere,
Real &enter,
Real &exit ) const
{
Vec3r v;
Pnt3r center;
sphere.getCenter(center);
Real radius;
Real h;
Real b;
Real d;
Real t1;
Real t2;
radius = sphere.getRadius();
v = center - _pos;
h = (v.dot(v))-(radius * radius);
b = (v.dot(_dir));
if(h >= 0.f && b <= 0.f)
return false;
d = b * b - h;
if(d < 0.f)
return false;
d = osgSqrt(d);
t1 = b - d;
// if (t1 > 1)
// return false;
t2 = b + d;
if( t1 < TypeTraits<Real>::getDefaultEps() )
{
if( t2 < TypeTraits<Real>::getDefaultEps() /*|| t2 > 1*/)
{
return false;
}
}
enter = t1;
exit = t2;
return true;
}
OSG_BASE_DLLMAPPING
bool intersect(const SphereVolume &sphere, const FrustumVolume &frustum)
{
const Plane *frust = frustum.getPlanes();
//check the center of the sphere with each plane of the frustum
for(Int32 i = 0; i < 6; i++)
{
if(frust[i].distance(sphere.getCenter()) < -sphere.getRadius())
return false;
}
return true;
}
OSG_BASE_DLLMAPPING
bool intersect(const SphereVolume &sphere1, const SphereVolume &sphere2)
{
bool retCode = false;
Real32 dist = (sphere2.getCenter() - sphere1.getCenter()).length();
if(sphere1.isEmpty() || sphere2.isEmpty())
{
retCode = false;
}
else if(sphere1.isInfinite() || sphere2.isInfinite())
{
retCode = true;
}
else if(dist < sphere1.getRadius() + sphere2.getRadius())
{
// the distance between the center of the 2 spheres is bigger
// than the sum of the 2 radiuses
retCode = true;
}
return retCode;
}
OSG_BASE_DLLMAPPING
bool intersect(const SphereVolume &sphere, const CylinderVolume &cylinder)
{
bool retCode;
Pnt3f apos;
Vec3f adir;
cylinder.getAxis(apos, adir);
if(sphere.isEmpty() || cylinder.isEmpty())
{
retCode = false;
}
else if(sphere.isInfinite() || cylinder.isInfinite())
{
retCode = true;
}
else
{
Real32 d = 0.f, s1 = 0.f, s2 = 0.f;
Pnt3f c;
Vec3f u, u1, u2;
//get the distance between the upper and lower point of the cylinder
// and the sphere center
s1 = (apos - sphere.getCenter()).length();
s2 = (apos + adir - sphere.getCenter()).length();
if ((s1<=DBL_EPSILON) || (s2<=DBL_EPSILON))
return true;
//check the smallest distance and set the vector coordinate
if(s1 <= s2)
{
d = s1;
c = apos;
}
else
{
d = s2;
c = apos + adir;
}
// decompose the vector in u1 and u2 which are parallel and
// perpendicular to the cylinder axis respectively
u = ((d - sphere.getRadius()) / d) * (c - sphere.getCenter());
u1 = (u[0] * adir[0] + u[1] * adir[1] + u[2] * adir[2]) /
(adir.length() * adir.length()) * adir;
u2 = u - u1;
if(u2.length() <= 10e-6)
{
retCode = (d <= sphere.getRadius());
}
else
{
retCode = (u2.length() <= cylinder.getRadius());
}
}
return retCode;
}
OSG_BASE_DLLMAPPING
void extend(CylinderVolume &srcVol, const SphereVolume &vol)
{
Pnt3f min, max, min1, max1, min2, max2, apos;
Vec2f p;
Vec3f adir;
Real32 r;
if((!srcVol.isValid () && !srcVol.isEmpty()) ||
srcVol.isInfinite() ||
srcVol.isStatic () )
{
return;
}
if(!vol.isValid())
return;
if(srcVol.isEmpty())
{
if(vol.isEmpty())
{
return;
}
else
{
r = vol.getRadius();
apos = Pnt3f(vol.getCenter().x() - r,
vol.getCenter().y() - r,
vol.getCenter().z() - r);
adir = Vec3f(vol.getCenter().x() + r - apos.x(),
vol.getCenter().y() + r - apos.y(),
vol.getCenter().z() + r - apos.z());
srcVol.setValue(apos, adir, r);
return;
}
}
else if(vol.isEmpty())
{
return;
}
srcVol.getBounds(min, max);
vol .getBounds(min1, max1);
min2 = Pnt3f(osgMin(min.x(), min1.x()),
osgMin(min.y(), min1.y()),
osgMin(min.z(), min1.z()));
max2 = Pnt3f(osgMax(max.x(), max1.x()),
osgMax(max.y(), max1.y()),
osgMax(max.z(), max1.z()));
p = Vec2f(max2.x() - min2.x(), max2.y() - min2.y());
r = (p.length()) * 0.5f;
adir = Vec3f(0.f, 0.f, max2.z() - min2.z());
apos = Pnt3f(p.x(), p.y(), min2.z());
srcVol.setValue(apos, adir, r);
return;
}
