Pedro Pathing is a very convenient way to use completely splines in your code, it is a little more advanced than Road Runner (RR) in that it uses more force correctors like centrifugal force and it uses several more PID's. I would only recommend this to experienced coders as tuning this is much more difficult than RR.
It can be found at:https://github.com/brotherhobo/Pedro-Pathing-Quickstart/blob/master/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/pedroPathing/README.md