/****************************************************************************
*
* Copyright (c) 2012-2014 PX4 Development Team. All rights reserved.
*
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* 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
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* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
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/**
* @file geo.c
*
* 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>
* @author Anton Babushkin <anton.babushkin@me.com>
*/
#include <geo/geo.h>
#include <px4.h>
#include <unistd.h>
#include <pthread.h>
#include <stdio.h>
#include <math.h>
#include <stdbool.h>
#include <string.h>
#include <float.h>
__EXPORT float _wrap_pi(float bearing)
{
/* value is inf or NaN */
if (!isfinite(bearing)) {
return bearing;
}
int c = 0;
while (bearing >= M_PI_F) {
bearing -= M_TWOPI_F;
if (c++ > 3) {
return NAN;
}
}
c = 0;
while (bearing < -M_PI_F) {
bearing += M_TWOPI_F;
if (c++ > 3) {
return NAN;
}
}
return bearing;
}
__EXPORT float _wrap_2pi(float bearing)
{
/* value is inf or NaN */
if (!isfinite(bearing)) {
return bearing;
}
int c = 0;
while (bearing >= M_TWOPI_F) {
bearing -= M_TWOPI_F;
if (c++ > 3) {
return NAN;
}
}
c = 0;
while (bearing < 0.0f) {
bearing += M_TWOPI_F;
if (c++ > 3) {
return NAN;
}
}
return bearing;
}
__EXPORT float _wrap_180(float bearing)
{
/* value is inf or NaN */
if (!isfinite(bearing)) {
return bearing;
}
int c = 0;
while (bearing >= 180.0f) {
bearing -= 360.0f;
if (c++ > 3) {
return NAN;
}
}
c = 0;
while (bearing < -180.0f) {
bearing += 360.0f;
if (c++ > 3) {
return NAN;
}
}
return bearing;
}
__EXPORT float _wrap_360(float bearing)
{
/* value is inf or NaN */
if (!isfinite(bearing)) {
return bearing;
}
int c = 0;
while (bearing >= 360.0f) {
bearing -= 360.0f;
if (c++ > 3) {
return NAN;
}
}
c = 0;
while (bearing < 0.0f) {
bearing += 360.0f;
if (c++ > 3) {
return NAN;
}
}
return bearing;
}
__EXPORT bool map_projection_initialized(const struct map_projection_reference_s *ref)
{
return ref->init_done;
}
__EXPORT uint64_t map_projection_timestamp(const struct map_projection_reference_s *ref)
{
return ref->timestamp;
}
__EXPORT int map_projection_init_timestamped(struct map_projection_reference_s *ref, double lat_0, double lon_0, uint64_t timestamp) //lat_0, lon_0 are expected to be in correct format: -> 47.1234567 and not 471234567
{
ref->lat_rad = lat_0 * M_DEG_TO_RAD;
ref->lon_rad = lon_0 * M_DEG_TO_RAD;
ref->sin_lat = sin(ref->lat_rad);
ref->cos_lat = cos(ref->lat_rad);
ref->timestamp = timestamp;
ref->init_done = true;
return 0;
}
__EXPORT int map_projection_init(struct map_projection_reference_s *ref, double lat_0, double lon_0) //lat_0, lon_0 are expected to be in correct format: -> 47.1234567 and not 471234567
{
return map_projection_init_timestamped(ref, lat_0, lon_0, px4::get_time_micros());
}
__EXPORT int map_projection_reference(const struct map_projection_reference_s *ref, double *ref_lat_rad, double *ref_lon_rad)
{
if (!map_projection_initialized(ref)) {
return -1;
}
*ref_lat_rad = ref->lat_rad;
*ref_lon_rad = ref->lon_rad;
return 0;
}
__EXPORT int map_projection_project(const struct map_projection_reference_s *ref, double lat, double lon, float *x, float *y)
{
if (!map_projection_initialized(ref)) {
return -1;
}
double lat_rad = lat * M_DEG_TO_RAD;
double lon_rad = lon * M_DEG_TO_RAD;
double sin_lat = sin(lat_rad);
double cos_lat = cos(lat_rad);
double cos_d_lon = cos(lon_rad - ref->lon_rad);
double c = acos(ref->sin_lat * sin_lat + ref->cos_lat * cos_lat * cos_d_lon);
double k = (fabs(c) < DBL_EPSILON) ? 1.0 : (c / sin(c));
*x = k * (ref->cos_lat * sin_lat - ref->sin_lat * cos_lat * cos_d_lon) * CONSTANTS_RADIUS_OF_EARTH;
*y = k * cos_lat * sin(lon_rad - ref->lon_rad) * CONSTANTS_RADIUS_OF_EARTH;
return 0;
}
__EXPORT int map_projection_reproject(const struct map_projection_reference_s *ref, float x, float y, double *lat, double *lon)
{
if (!map_projection_initialized(ref)) {
return -1;
}
double x_rad = x / CONSTANTS_RADIUS_OF_EARTH;
double y_rad = y / CONSTANTS_RADIUS_OF_EARTH;
double c = sqrtf(x_rad * x_rad + y_rad * y_rad);
double sin_c = sin(c);
double cos_c = cos(c);
double lat_rad;
double lon_rad;
if (fabs(c) > DBL_EPSILON) {
lat_rad = asin(cos_c * ref->sin_lat + (x_rad * sin_c * ref->cos_lat) / c);
lon_rad = (ref->lon_rad + atan2(y_rad * sin_c, c * ref->cos_lat * cos_c - x_rad * ref->sin_lat * sin_c));
} else {
lat_rad = ref->lat_rad;
lon_rad = ref->lon_rad;
}
*lat = lat_rad * 180.0 / M_PI;
*lon = lon_rad * 180.0 / M_PI;
return 0;
}
