void
plane::
extendBy ( const sphere& sphereIn )
{
if ( !sphereIn.isEmpty() )
{
vec3 pos ( math::vec3::NoInit );
ValueType radius;
sphereIn.get ( pos, radius );
vec3 dir = normal;
dir.normalize ();
vec3 pt = pos + dir * radius;
extendBy ( pt );
pt = pos - dir * radius;
extendBy ( pt );
}
}
void
sphere::
extendBy ( const sphere& sphere )
{
if ( this == &sphere )
return; // no extend by self.
if ( sphere.isEmpty () )
return; // do nothing with empty spheres
if ( isEmpty () )
{
*this = sphere;
}
else
{
// this finds the vector seperating this and sphere and add to
// the length the radius of the other sphere to get a point on
// the far side of sphere... it then calls extendBy with the
// calculated point
vec3 diff ( sphere.center );
diff -= center;
ValueType diffLen = diff.length ();
diff /= diffLen;
diffLen += sphere.radius;
diff *= diffLen;
diff += center;
extendBy ( diff );
}
}