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/**
 * @file FlightTaskTranstion.cpp
 */

#include "FlightTaskTransition.hpp"

bool FlightTaskTransition::updateInitialize()
{
	return FlightTask::updateInitialize();
}

bool FlightTaskTransition::activate(vehicle_local_position_setpoint_s last_setpoint)
{
	checkSetpoints(last_setpoint);
	_transition_altitude = last_setpoint.z;
	_transition_yaw = last_setpoint.yaw;
	_acceleration_setpoint.setAll(0.f);
	_velocity_prev = _velocity;
	return FlightTask::activate(last_setpoint);
}

void FlightTaskTransition::checkSetpoints(vehicle_local_position_setpoint_s &setpoints)
{
	// If the setpoint is unknown, set to the current estimate
	if (!PX4_ISFINITE(setpoints.z)) { setpoints.z = _position(2); }

	if (!PX4_ISFINITE(setpoints.yaw)) { setpoints.yaw = _yaw; }
}

void FlightTaskTransition::updateAccelerationEstimate()
{
	// Estimate the acceleration by filtering the raw derivative of the velocity estimate
	// This is done to provide a good estimate of the current acceleration to the next flight task after back-transition
	_acceleration_setpoint = 0.9f * _acceleration_setpoint + 0.1f * (_velocity - _velocity_prev) / _deltatime;

	if (!PX4_ISFINITE(_acceleration_setpoint(0)) ||
	    !PX4_ISFINITE(_acceleration_setpoint(1)) ||
	    !PX4_ISFINITE(_acceleration_setpoint(2))) {
		_acceleration_setpoint.setAll(0.f);
	}

	_velocity_prev = _velocity;
}

bool FlightTaskTransition::update()
{
	// level wings during the transition, altitude should be controlled
	_thrust_setpoint(0) = _thrust_setpoint(1) = 0.0f;
	_thrust_setpoint(2) = NAN;
	_position_setpoint *= NAN;
	_velocity_setpoint *= NAN;
	_position_setpoint(2) = _transition_altitude;

	updateAccelerationEstimate();

	_yaw_setpoint = _transition_yaw;
	return true;
}