Fix ray-sphere intersection: return an interval

This commit is contained in:
Nikita Lisitsa 2021-12-23 10:56:58 +03:00
parent 8eae072ec1
commit e0312b66b1

View file

@ -211,17 +211,21 @@ namespace psemek::geom
} }
template <typename T, std::size_t N> template <typename T, std::size_t N>
std::optional<std::pair<T, T>> intersection(ray<T, N> const & r, sphere<T, N> const & s) interval<T> intersection(ray<T, N> const & r, sphere<T, N> const & s)
{ {
auto d = r.origin - s.center; auto d = r.origin - s.center;
return solve_quadratic(length_sqr(r.direction), T{2} * dot(r.direction, d), length_sqr(d) - sqr(s.radius)); auto ir = solve_quadratic(length_sqr(r.direction), T{2} * dot(r.direction, d), length_sqr(d) - sqr(s.radius));
if (!ir)
return {};
return {ir->first, ir->second};
} }
template <typename T, std::size_t N, typename = std::enable_if_t<(N > 2)>> template <typename T, std::size_t N>
bool intersect(ray<T, N> const & r, sphere<T, N> const & s) bool intersect(ray<T, N> const & r, sphere<T, N> const & s)
{ {
return static_cast<bool>(intersection(r, s)); return intersection(r, s).empty();
} }
} }