udacity/FCND-Controls-CPP — reverse-engineered prompt

Please finish this Udacity quadcopter controls simulator project for me. Right now the drone just falls, and I want it to actually fly correctly in the provided scenarios.

Implement the C++ controller so the quad can hold altitude, control attitude, track position, follow the test trajectories, and recover when external forces are applied with the arrow keys. Tune the controller values so the simulator behaves smoothly and passes the project evaluation scenarios as much as possible. Keep the existing simulator and project structure intact, and focus the work on the controller code and the tuning config that the README points to.

Use the included Python controller reference if it helps, but make the final result work in this C++ simulator. Please make sure it still builds normally with the existing CMake or IDE setup, and add clear comments where the control math is implemented so I can understand what each part is doing.