ardupilot/libraries/AC_Avoidance/AP_OABendyRuler.h

#pragma once

#include <AP_Common/AP_Common.h>
#include <AP_Common/Location.h>
#include <AP_Math/AP_Math.h>
#include <AP_HAL/AP_HAL.h>

/*
 * BendyRuler avoidance algorithm for avoiding the polygon and circular fence and dynamic objects detected by the proximity sensor
 */
class AP_OABendyRuler {
public:

    AP_OABendyRuler() {}

    /* Do not allow copies */
    AP_OABendyRuler(const AP_OABendyRuler &other) = delete;
    AP_OABendyRuler &operator=(const AP_OABendyRuler&) = delete;

    // send configuration info stored in front end parameters
    void set_config(float lookahead, float margin_max) { _lookahead = MAX(lookahead, 1.0f); _margin_max = MAX(margin_max, 0.0f); }

    // run background task to find best path and update avoidance_results
    // returns true and populates origin_new and destination_new if OA is required.  returns false if OA is not required
    bool update(const Location& current_loc, const Location& destination, const Vector2f &ground_speed_vec, Location &origin_new, Location &destination_new);

private:

    // calculate minimum distance between a path and any obstacle
    float calc_avoidance_margin(const Location &start, const Location &end);

    // calculate minimum distance between a path and the circular fence (centered on home)
    // on success returns true and updates margin
    bool calc_margin_from_circular_fence(const Location &start, const Location &end, float &margin);

    // calculate minimum distance between a path and the polygon fence
    // on success returns true and updates margin
    bool calc_margin_from_polygon_fence(const Location &start, const Location &end, float &margin);

    // calculate minimum distance between a path and proximity sensor obstacles
    // on success returns true and updates margin
    bool calc_margin_from_object_database(const Location &start, const Location &end, float &margin);

    // configuration parameters
    float _lookahead;               // object avoidance will look this many meters ahead of vehicle
    float _margin_max;              // object avoidance will ignore objects more than this many meters from vehicle

    // internal variables used by background thread
    float _current_lookahead;       // distance (in meters) ahead of the vehicle we are looking for obstacles
};