/****************************************************************************
 *
 *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
 *   Author: @author Lorenz Meier <lm@inf.ethz.ch>
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 *    used to endorse or promote products derived from this software
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/**
 * @file optical_flow.h
 * Definition of the optical flow uORB topic.
 */

#ifndef TOPIC_OPTICAL_FLOW_H_
#define TOPIC_OPTICAL_FLOW_H_

#include <stdint.h>
#include <stdbool.h>
#include "../uORB.h"

/**
 * @addtogroup topics
 */

/**
 * Optical flow in NED body frame in SI units.
 *
 * @see http://en.wikipedia.org/wiki/International_System_of_Units
 */
struct optical_flow_s {

	uint64_t timestamp;		/**< in microseconds since system start          */

	int16_t flow_raw_x;		/**< flow in pixels in X direction, not rotation-compensated */
	int16_t flow_raw_y;		/**< flow in pixels in Y direction, not rotation-compensated */
	float flow_comp_x_m;		/**< speed over ground in meters, rotation-compensated */
	float flow_comp_y_m;		/**< speed over ground in meters, rotation-compensated */
	float ground_distance_m;	/**< Altitude / distance to ground in meters */
	uint8_t	quality;		/**< Quality of the measurement, 0: bad quality, 255: maximum quality */
	uint8_t sensor_id;		/**< id of the sensor emitting the flow value */

};

/**
 * @}
 */

/* register this as object request broker structure */
ORB_DECLARE(optical_flow);

#endif