GameFramework.AiPathData.GetNearstPoint C# (CSharp) Method

        public bool GetNearstPoint(Vector3 pt, ref Vector3 tp)
        {
            bool ret = false;
              if (null != m_Path && m_PathStart >= 0 && m_PathStart + m_PathLength >= 1 && m_PathStart + m_PathLength <= m_Path.Count) {
            if (m_Path.Count > 0) {
              float dist = Geometry.PointToPolylineDistance(pt, m_Path, m_PathStart, m_PathLength, ref tp);
              float r = Geometry.Relation(pt, m_StartPos, m_Path[0]);
              if (r >= 0 && r <= 1) {
            Vector3 t = Geometry.Perpendicular(pt, m_StartPos, m_Path[0]);
            if (Geometry.DistanceSquare(pt, t) < dist * dist)
              tp = t;
            ret = true;
              } else if (dist < 1000) {
            ret = true;
              }
            }
              }
              return ret;
        }