Merge branch 'kschuster' into 'develop'

squared frobenius norm and angle_between fix

See merge request !33

src/typed-geometry/functions/angle.hh

@@ -24,14 +24,19 @@ TG_NODISCARD constexpr angle_t<fractional_result<ScalarT>> angle_between(vec<D,
 template <int D, class ScalarT>
 TG_NODISCARD constexpr angle_t<fractional_result<ScalarT>> angle_between(dir<D, ScalarT> const& a, dir<D, ScalarT> const& b)
 {
-    return acos(saturate(dot(a, b)));
+    constexpr auto lower = decltype (dot(normal(a), normal(b)))(-1);
+    constexpr auto upper = decltype (dot(normal(a), normal(b)))(1);
+    return acos(clamp(dot(a, b), lower, upper));
 }
 
 // returns the angle between any two objects with unambiguous normals. The result is in 0..pi (0°..180°)
 template <class A, class B>
 TG_NODISCARD constexpr auto angle_between(A const& a, B const& b) -> decltype(acos(dot(normal(a), normal(b))))
 {
-    return acos(saturate(dot(normal(a), normal(b))));
+    // TODO(ks): call to angle_between(dir, dir)?
+    constexpr auto lower = decltype (dot(normal(a), normal(b)))(-1);
+    constexpr auto upper = decltype (dot(normal(a), normal(b)))(1);
+    return acos(clamp(dot(normal(a), normal(b))), lower, upper);
 }
 
 // Returns the angle of a rotation of a towards b about the orthogonal_axis

src/typed-geometry/functions/norm.hh

@@ -33,14 +33,21 @@ TG_NODISCARD constexpr T norm(vec<4, T> const& v, T p)
 }
 
 template <int C, int R, class T>
-TG_NODISCARD constexpr T frobenius_norm(mat<C, R, T> const& v)
+TG_NODISCARD constexpr T frobenius_norm_sqr(mat<C, R, T> const& v)
 {
-    static_assert(is_floating_point<T>, "frobenius_norm only works on f32/f64");
+    static_assert(is_floating_point<T>, "frobenius_norm_sqr only works on f32/f64");
     auto s = T(0);
     for (auto x = 0; x < C; ++x)
         for (auto y = 0; y < R; ++y)
             s += tg::pow2(v[x][y]);
-    return tg::sqrt(s);
+    return s;
+}
+
+template <int C, int R, class T>
+TG_NODISCARD constexpr T frobenius_norm(mat<C, R, T> const& v)
+{
+    static_assert(is_floating_point<T>, "frobenius_norm only works on f32/f64");
+    return tg::sqrt(frobenius_norm_sqr(v));
 }
 
 }