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/****************************************************************************
 *
 *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
 *   Author: Thomas Gubler <thomasgubler@student.ethz.ch>
 *           Julian Oes <joes@student.ethz.ch>
 *           Lorenz Meier <lm@inf.ethz.ch>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/**
 * @file geo.h
 *
 * Definition of geo / math functions to perform geodesic calculations
 *
 * @author Thomas Gubler <thomasgubler@student.ethz.ch>
 * @author Julian Oes <joes@student.ethz.ch>
 * @author Lorenz Meier <lm@inf.ethz.ch>
 * Additional functions - @author Doug Weibel <douglas.weibel@colorado.edu>
 */

#pragma once

__BEGIN_DECLS

#include <stdbool.h>

#define CONSTANTS_ONE_G					9.80665f		/* m/s^2		*/
#define CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C		1.225f			/* kg/m^3		*/
#define CONSTANTS_AIR_GAS_CONST				287.1f 			/* J/(kg * K)		*/
#define CONSTANTS_ABSOLUTE_NULL_CELSIUS			-273.15f		/* °C			*/
#define CONSTANTS_RADIUS_OF_EARTH			6371000			/* meters (m)		*/

// XXX remove
struct crosstrack_error_s {
	bool past_end;		// Flag indicating we are past the end of the line/arc segment
	float distance;		// Distance in meters to closest point on line/arc
	float bearing;		// Bearing in radians to closest point on line/arc
} ;

/**
 * Initializes the map transformation.
 *
 * Initializes the transformation between the geographic coordinate system and the azimuthal equidistant plane
 * @param lat in degrees (47.1234567°, not 471234567°)
 * @param lon in degrees (8.1234567°, not 81234567°)
 */
__EXPORT void map_projection_init(double lat_0, double lon_0);

/**
 * Transforms a point in the geographic coordinate system to the local azimuthal equidistant plane
 * @param x north
 * @param y east
 * @param lat in degrees (47.1234567°, not 471234567°)
 * @param lon in degrees (8.1234567°, not 81234567°)
 */
__EXPORT void map_projection_project(double lat, double lon, float *x, float *y);

/**
 * Transforms a point in the local azimuthal equidistant plane to the geographic coordinate system
 *
 * @param x north
 * @param y east
 * @param lat in degrees (47.1234567°, not 471234567°)
 * @param lon in degrees (8.1234567°, not 81234567°)
 */
__EXPORT void map_projection_reproject(float x, float y, double *lat, double *lon);

/**
 * Returns the distance to the next waypoint in meters.
 *
 * @param lat_now current position in degrees (47.1234567°, not 471234567°)
 * @param lon_now current position in degrees (8.1234567°, not 81234567°)
 * @param lat_next next waypoint position in degrees (47.1234567°, not 471234567°)
 * @param lon_next next waypoint position in degrees (8.1234567°, not 81234567°)
 */
__EXPORT float get_distance_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next);

/**
 * Returns the bearing to the next waypoint in radians.
 *
 * @param lat_now current position in degrees (47.1234567°, not 471234567°)
 * @param lon_now current position in degrees (8.1234567°, not 81234567°)
 * @param lat_next next waypoint position in degrees (47.1234567°, not 471234567°)
 * @param lon_next next waypoint position in degrees (8.1234567°, not 81234567°)
 */
__EXPORT float get_bearing_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next);

__EXPORT void get_vector_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next, float* vx, float* vy);

__EXPORT void get_vector_to_next_waypoint_fast(double lat_now, double lon_now, double lat_next, double lon_next, float* vx, float* vy);

__EXPORT int get_distance_to_line(struct crosstrack_error_s * crosstrack_error, double lat_now, double lon_now, double lat_start, double lon_start, double lat_end, double lon_end);

__EXPORT int get_distance_to_arc(struct crosstrack_error_s * crosstrack_error, double lat_now, double lon_now, double lat_center, double lon_center,
		float radius, float arc_start_bearing, float arc_sweep);

__EXPORT float _wrap_180(float bearing);
__EXPORT float _wrap_360(float bearing);
__EXPORT float _wrap_pi(float bearing);
__EXPORT float _wrap_2pi(float bearing);

__END_DECLS