// do_circle - initiate moving in a circle
void Copter::do_circle(const AP_Mission::Mission_Command& cmd)
{
    Location_Class circle_center(cmd.content.location);

    // default lat/lon to current position if not provided
    // To-Do: use stopping point or position_controller's target instead of current location to avoid jerk?
    if (circle_center.lat == 0 && circle_center.lng == 0) {
        circle_center.lat = current_loc.lat;
        circle_center.lng = current_loc.lng;
    }

    // default target altitude to current altitude if not provided
    if (circle_center.alt == 0) {
        int32_t curr_alt;
        if (current_loc.get_alt_cm(circle_center.get_alt_frame(),curr_alt)) {
            // circle altitude uses frame from command
            circle_center.set_alt_cm(curr_alt,circle_center.get_alt_frame());
        } else {
            // default to current altitude above origin
            circle_center.set_alt_cm(current_loc.alt, current_loc.get_alt_frame());
            Log_Write_Error(ERROR_SUBSYSTEM_TERRAIN, ERROR_CODE_MISSING_TERRAIN_DATA);
        }
    }

    // calculate radius
    uint8_t circle_radius_m = HIGHBYTE(cmd.p1); // circle radius held in high byte of p1

    // move to edge of circle (verify_circle) will ensure we begin circling once we reach the edge
    auto_circle_movetoedge_start(circle_center, circle_radius_m);
}
// do_circle - initiate moving in a circle
void Copter::do_circle(const AP_Mission::Mission_Command& cmd)
{
    Vector3f curr_pos = inertial_nav.get_position();
    Vector3f circle_center = pv_location_to_vector(cmd.content.location);
    uint8_t circle_radius_m = HIGHBYTE(cmd.p1); // circle radius held in high byte of p1
    bool move_to_edge_required = false;

    // set target altitude if not provided
    if (cmd.content.location.alt == 0) {
        circle_center.z = curr_pos.z;
    } else {
        move_to_edge_required = true;
    }

    // set lat/lon position if not provided
    // To-Do: use previous command's destination if it was a straight line or spline waypoint command
    if (cmd.content.location.lat == 0 && cmd.content.location.lng == 0) {
        circle_center.x = curr_pos.x;
        circle_center.y = curr_pos.y;
    } else {
        move_to_edge_required = true;
    }

    // set circle controller's center
    circle_nav.set_center(circle_center);

    // set circle radius
    if (circle_radius_m != 0) {
        circle_nav.set_radius((float)circle_radius_m * 100.0f);
    }

    // check if we need to move to edge of circle
    if (move_to_edge_required) {
        // move to edge of circle (verify_circle) will ensure we begin circling once we reach the edge
        auto_circle_movetoedge_start();
    } else {
        // start circling
        auto_circle_start();
    }
}