namespace {
/// map p onto cube, s gives the surface, u and v the position in [-1,1]
void cubemap(const glm::dvec3 &p, int &s, double &u, double &v) noexcept {
namespace {
/// map p onto cube, s gives the surface, u and v the position in [-1,1]
void cubemap(const glm::dvec3 &p, int &s, double &u, double &v) noexcept {