message: implement func frenet coordinate from driving corridor center
diff: @@ -39,7 +39,8 @@ inline float angle_diff(const float& angle1, const float& angle2) {
  }
  inline float signed_angle_diff(const float& angle1, const float& angle2) {
  - return norm_0_2PI(angle1) - norm_0_2PI(angle2);
  + auto adiff = angle1 - angle2;
  + return std::fmod(adiff + B_PI, B_2PI) - B_PI;
  }
  