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 *   Copyright (c) 2017 PX4 Development Team. All rights reserved.
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 * modification, are permitted provided that the following conditions
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    used to endorse or promote products derived from this software
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/**
 * @file FlightManualAltitude.cpp
 */

#include "FlightTaskManualAltitude.hpp"
#include <float.h>

using namespace matrix;

void FlightTaskManualAltitude::_scaleSticks()
{
	/* Reuse same scaling as for stabilized */
	FlightTaskManualStabilized::_scaleSticks();

	/* Scale horizontal velocity with expo curve stick input*/
	const float vel_max_z = (_sticks(2) > 0.0f) ? _limits.speed_dn_max : _limits.speed_up_max;
	_velocity_setpoint(2) = vel_max_z * _sticks_expo(2);
}

void FlightTaskManualAltitude::_updateAltitudeLock()
{
	/* Depending on stick inputs and velocity, position is locked.
	 * If not locked, altitude setpoint is set to NAN.
	 */

	/* handle position and altitude hold */
	const bool apply_brake_z = fabsf(_velocity_setpoint(2)) <= FLT_EPSILON;
	const bool stopped_z = (MPC_HOLD_MAX_Z.get() < FLT_EPSILON || fabsf(_velocity(2)) < MPC_HOLD_MAX_Z.get());

	if (apply_brake_z && stopped_z && !PX4_ISFINITE(_position_setpoint(2))) {
		_position_setpoint(2) = _position(2);

		if ((PX4_ISFINITE(_dist_to_bottom) && _dist_to_bottom < SENS_FLOW_MINRNG.get())) {
			// if vehicle wants to keep altitude but is below minimum flow distance,
			// increase altitude to minimum flow distance
			_position_setpoint(2) = _position(2) - (SENS_FLOW_MINRNG.get() - _dist_to_bottom);
		}

	} else if (!apply_brake_z) {
		_position_setpoint(2) = NAN;
	}
}

void FlightTaskManualAltitude::_updateSetpoints()
{
	FlightTaskManualStabilized::_updateSetpoints(); // get yaw and thrust setpoints

	_thrust_setpoint *= NAN; // Don't need thrust setpoint from Stabilized mode.

	/* Thrust in xy are extracted directly from stick inputs. A magnitude of
	 * 1 means that maximum thrust along xy is required. A magnitude of 0 means no
	 * thrust along xy is required. The maximum thrust along xy depends on the thrust
	 * setpoint along z-direction, which is computed in PositionControl.cpp.
	 */
	Vector2f sp{_sticks(0), _sticks(1)};
	_rotateIntoHeadingFrame(sp);

	if (sp.length() > 1.0f) {
		sp.normalize();
	}

	_thrust_setpoint(0) = sp(0);
	_thrust_setpoint(1) = sp(1);

	_updateAltitudeLock();
}