inline typename Cylinder<T>::position_type
random_position(Cylinder<T> const& shape, Trng& rng)
{
// -1 < rng() < 1. See for example CylindricalSurface.hpp.
return add(shape.position(),
multiply(shape.unit_z(), rng() * shape.half_length()));
}
inline typename Cylinder<T_>::length_type
distance(Cylinder<T_> const& obj,
typename Cylinder<T_>::position_type const& pos)
{
typedef typename Cylinder<T_>::position_type position_type;
typedef typename Cylinder<T_>::length_type length_type;
/* First compute the (z,r) components of pos in a coordinate system
* defined by the vectors unitR and unit_z, where unitR is
* choosen such that unitR and unit_z define a plane in which
* pos lies. */
const std::pair<length_type, length_type> r_z(to_internal(obj, pos));
/* Then compute distance to cylinder. */
const length_type dz(std::fabs(r_z.second) - obj.half_length());
const length_type dr(r_z.first - obj.radius());
length_type distance;
if (dz > 0)
{
// pos is (either) to the right or to the left of the cylinder.
if (r_z.first > obj.radius())
{
// Compute distance to edge.
distance = std::sqrt( dz * dz + dr * dr );
}
else
{
distance = dz;
}
}
else
{
if (dr > obj.radius())
{
// pos is somewhere 'parallel' to the cylinder.
distance = dr;
}
else
{
// Inside cylinder.
distance = std::max(dr, dz);
}
}
return distance;
}
bool operator==(const Cylinder& rhs) const
{
return position_ == rhs.position() && radius_ == rhs.radius() && unit_z_ == rhs.unit_z() && half_length_ == rhs.half_length();
}