UnityEditor.MathUtils.IntersectRaySphere C# (CSharp) Method

        public static bool IntersectRaySphere(Ray ray, Vector3 sphereOrigin, float sphereRadius, ref float t, ref Vector3 q)
        {
            Vector3 lhs = ray.origin - sphereOrigin;
            float num = Vector3.Dot(lhs, ray.direction);
            float num2 = Vector3.Dot(lhs, lhs) - (sphereRadius * sphereRadius);
            if ((num2 > 0f) && (num > 0f))
            {
                return false;
            }
            float f = (num * num) - num2;
            if (f < 0f)
            {
                return false;
            }
            t = -num - Mathf.Sqrt(f);
            if (t < 0f)
            {
                t = 0f;
            }
            q = ray.origin + (t * ray.direction);
            return true;
        }

        public static int FindNearest(Vector2 point, Transform cloudTransform, IEditablePoint points)
        {
            Ray ray = HandleUtility.GUIPointToWorldRay(point);
            Dictionary <int, float> dictionary = new Dictionary <int, float>();

            for (int i = 0; i < points.Count; i++)
            {
                float   num  = 0f;
                Vector3 zero = Vector3.zero;
                if (MathUtils.IntersectRaySphere(ray, cloudTransform.TransformPoint(points.GetPosition(i)), points.GetPointScale() * 0.5f, ref num, ref zero))
                {
                    if (num > 0f)
                    {
                        dictionary.Add(i, num);
                    }
                }
            }
            int result;

            if (dictionary.Count <= 0)
            {
                result = -1;
            }
            else
            {
                IOrderedEnumerable <KeyValuePair <int, float> > source = from x in dictionary
                                                                         orderby x.Value
                                                                         select x;
                result = source.First <KeyValuePair <int, float> >().Key;
            }
            return(result);
        }