ardupilot/libraries/AC_AttitudeControl/AC_PosControl_Sub.h

#pragma once

#include "AC_PosControl.h"

#define POSCONTROL_JERK_RATIO                   1.0f    // Defines the time it takes to reach the requested acceleration

class AC_PosControl_Sub : public AC_PosControl {
public:
    using AC_PosControl::AC_PosControl;

    /// set_alt_max - sets maximum altitude above the ekf origin in cm
    ///   only enforced when set_pos_target_z_from_climb_rate_cm is used
    ///   set to zero to disable limit
    void set_alt_max(float alt) { _alt_max = alt; }

    /// set_alt_min - sets the minimum altitude (maximum depth) in cm
    ///   only enforced when set_pos_target_z_from_climb_rate_cm is used
    ///   set to zero to disable limit
    void set_alt_min(float alt) { _alt_min = alt; }

private:
    float       _alt_max; // max altitude - should be updated from the main code with altitude limit from fence
    float       _alt_min; // min altitude - should be updated from the main code with altitude limit from fence
};