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 * modification, are permitted provided that the following conditions
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/**
 * @file Takeoff.cpp
 *
 * Helper class to Takeoff
 *
 * @author Lorenz Meier <lorenz@px4.io
 */

#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>
#include <fcntl.h>

#include <systemlib/mavlink_log.h>
#include <systemlib/err.h>

#include <uORB/uORB.h>
#include <uORB/topics/position_setpoint_triplet.h>

#include "takeoff.h"
#include "navigator.h"

Takeoff::Takeoff(Navigator *navigator, const char *name) :
	MissionBlock(navigator, name),
	_param_min_alt(this, "MIS_TAKEOFF_ALT", false)
{
	// load initial params
	updateParams();
}

Takeoff::~Takeoff()
{
}

void
Takeoff::on_inactive()
{
}

void
Takeoff::on_activation()
{
	set_takeoff_position();
}

void
Takeoff::on_active()
{
	struct position_setpoint_triplet_s *rep = _navigator->get_takeoff_triplet();

	if (rep->current.valid) {
		// reset the position
		set_takeoff_position();

	} else if (is_mission_item_reached() && !_navigator->get_mission_result()->finished) {
		_navigator->get_mission_result()->finished = true;
		_navigator->set_mission_result_updated();

		// set loiter item so position controllers stop doing takeoff logic
		set_loiter_item(&_mission_item);
		struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();
		mission_item_to_position_setpoint(&_mission_item, &pos_sp_triplet->current);
		_navigator->set_position_setpoint_triplet_updated();
	}
}

void
Takeoff::set_takeoff_position()
{
	struct position_setpoint_triplet_s *rep = _navigator->get_takeoff_triplet();

	float abs_altitude = 0.0f;

	float min_abs_altitude;

	if (_navigator->home_position_valid()) { //only use home position if it is valid
		min_abs_altitude = _navigator->get_global_position()->alt + _param_min_alt.get();

	} else { //e.g. flow
		min_abs_altitude = _param_min_alt.get();
	}

	// Use altitude if it has been set. If home position is invalid use min_abs_altitude
	if (rep->current.valid && PX4_ISFINITE(rep->current.alt) && _navigator->home_position_valid()) {
		abs_altitude = rep->current.alt;

		// If the altitude suggestion is lower than home + minimum clearance, raise it and complain.
		if (abs_altitude < min_abs_altitude) {
			abs_altitude = min_abs_altitude;
			mavlink_log_critical(_navigator->get_mavlink_log_pub(),
					     "Using minimum takeoff altitude: %.2f m", (double)_param_min_alt.get());
		}

	} else {
		// Use home + minimum clearance but only notify.
		abs_altitude = min_abs_altitude;
		mavlink_log_info(_navigator->get_mavlink_log_pub(),
				 "Using minimum takeoff altitude: %.2f m", (double)_param_min_alt.get());
	}


	if (abs_altitude < _navigator->get_global_position()->alt) {
		// If the suggestion is lower than our current alt, let's not go down.
		abs_altitude = _navigator->get_global_position()->alt;
		mavlink_log_critical(_navigator->get_mavlink_log_pub(),
				     "Already higher than takeoff altitude");
	}

	// set current mission item to takeoff
	set_takeoff_item(&_mission_item, abs_altitude);
	_navigator->get_mission_result()->reached = false;
	_navigator->get_mission_result()->finished = false;
	_navigator->set_mission_result_updated();
	reset_mission_item_reached();

	// convert mission item to current setpoint
	struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();
	mission_item_to_position_setpoint(&_mission_item, &pos_sp_triplet->current);
	pos_sp_triplet->previous.valid = false;
	pos_sp_triplet->current.yaw_valid = true;
	pos_sp_triplet->next.valid = false;

	if (rep->current.valid) {

		// Go on and check which changes had been requested
		if (PX4_ISFINITE(rep->current.yaw)) {
			pos_sp_triplet->current.yaw = rep->current.yaw;
		}

		if (PX4_ISFINITE(rep->current.lat) && PX4_ISFINITE(rep->current.lon)) {
			pos_sp_triplet->current.lat = rep->current.lat;
			pos_sp_triplet->current.lon = rep->current.lon;
		}

		// mark this as done
		memset(rep, 0, sizeof(*rep));
	}

	_navigator->set_can_loiter_at_sp(true);

	_navigator->set_position_setpoint_triplet_updated();
}