using UnityEngine;

namespace R0bbie.VRSubtitles
{
    /// <summary>
    /// Some useful Math functions
    /// </summary>
    public class Math
    {
        
        /// <summary>
        /// 
        /// </summary>
        /// <param name="a"></param>
        /// <param name="b"></param>
        /// <param name="n"></param>
        /// <returns></returns>
        public static float SignedAngleBetween(Vector3 a, Vector3 b, Vector3 n)
        {
            // angle in [0,180]
            float angle = Vector3.Angle(a,b);
            float sign = Mathf.Sign(Vector3.Dot(n,Vector3.Cross(a,b)));

            // angle in [-179,180]
            float signed_angle = angle * sign;

            return signed_angle;
        }
        
    }

}