/apps/demos/scenery: drift ! steer !

include/twn_vec.h

@@ -86,6 +86,10 @@ static inline Vec3 vec3_norm(Vec3 a) {
     return vec3_scale(a, 1.0f / n);
 }
 
+static inline float vec3_angle(Vec3 a, Vec3 b) {
+    return acosf(vec3_dot(vec3_norm(a), vec3_norm(b)));
+}
+
 static inline Vec3 vec3_rotate(Vec3 v, float angle, Vec3 axis) {
     /* from cglm */
     Vec3 v1, v2, k;