PX4-Autopilot/src/modules/navigator/geofence.cpp

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/**
 * @file geofence.cpp
 * Provides functions for handling the geofence
 *
 * @author Jean Cyr <jean.m.cyr@gmail.com>
 * @author Thomas Gubler <thomasgubler@gmail.com>
 */
#include "geofence.h"

#include <uORB/topics/vehicle_global_position.h>
#include <string.h>
#include <dataman/dataman.h>
#include <systemlib/err.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <nuttx/config.h>
#include <unistd.h>


/* Oddly, ERROR is not defined for C++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;

Geofence::Geofence() :
		SuperBlock(NULL, "GF"),
		_fence_pub(-1),
		_altitude_min(0),
		_altitude_max(0),
		_verticesCount(0),
		param_geofence_on(this, "ON")
{
	/* Load initial params */
	updateParams();
}

Geofence::~Geofence()
{

}


bool Geofence::inside(const struct vehicle_global_position_s *vehicle)
{
	double lat = vehicle->lat / 1e7d;
	double lon = vehicle->lon / 1e7d;
	float	alt = vehicle->alt;

	return inside(lat, lon, vehicle->alt);
}

bool Geofence::inside(double lat, double lon, float altitude)
{
	/* Return true if geofence is disabled */
	if (param_geofence_on.get() != 1)
		return true;

	if (valid()) {

		if (!isEmpty()) {
			/* Vertical check */
			if (altitude > _altitude_max || altitude < _altitude_min)
				return false;

			/*Horizontal check */
			/* Adaptation of algorithm originally presented as
			 * PNPOLY - Point Inclusion in Polygon Test
			 * W. Randolph Franklin (WRF) */

			bool c = false;

			struct fence_vertex_s temp_vertex_i;
			struct fence_vertex_s temp_vertex_j;

			/* Red until fence is finished */
			for (unsigned i = 0, j = _verticesCount - 1; i < _verticesCount; j = i++) {
				if (dm_read(DM_KEY_FENCE_POINTS, i, &temp_vertex_i, sizeof(struct fence_vertex_s)) != sizeof(struct fence_vertex_s)) {
					break;
				}
				if (dm_read(DM_KEY_FENCE_POINTS, j, &temp_vertex_j, sizeof(struct fence_vertex_s)) != sizeof(struct fence_vertex_s)) {
					break;
				}

				// skip vertex 0 (return point)
				if (((temp_vertex_i.lon) >= lon != (temp_vertex_j.lon >= lon)) &&
							(lat <= (temp_vertex_j.lat - temp_vertex_i.lat) * (lon - temp_vertex_i.lon) /
							 (temp_vertex_j.lon - temp_vertex_i.lon) + temp_vertex_i.lat)) {
							c = !c;
				}

			}

			return c;
		} else {
			/* Empty fence --> accept all points */
			return true;
		}

	} else {
		/* Invalid fence --> accept all points */
		return true;
	}
}

bool
Geofence::valid()
{
	// NULL fence is valid
	if (isEmpty())
		return true;

	// Otherwise
	if ((_verticesCount < 4) || (_verticesCount > GEOFENCE_MAX_VERTICES)) {
		warnx("Fence must have at least 3 sides and not more than %d", GEOFENCE_MAX_VERTICES - 1);
		return false;
	}

	return true;
}

void
Geofence::addPoint(int argc, char *argv[])
{
	int ix, last;
	double lon, lat;
	struct fence_vertex_s vertex;
	char *end;

	if ((argc == 1) && (strcmp("-clear", argv[0]) == 0)) {
		dm_clear(DM_KEY_FENCE_POINTS);
		publishFence(0);
		return;
	}

	if (argc < 3)
		errx(1, "Specify: -clear | sequence latitude longitude [-publish]");

	ix = atoi(argv[0]);
	if (ix >= DM_KEY_FENCE_POINTS_MAX)
		errx(1, "Sequence must be less than %d", DM_KEY_FENCE_POINTS_MAX);

	lat = strtod(argv[1], &end);
	lon = strtod(argv[2], &end);

	last = 0;
	if ((argc > 3) && (strcmp(argv[3], "-publish") == 0))
		last = 1;

	vertex.lat = (float)lat;
	vertex.lon = (float)lon;

	if (dm_write(DM_KEY_FENCE_POINTS, ix, DM_PERSIST_POWER_ON_RESET, &vertex, sizeof(vertex)) == sizeof(vertex)) {
		if (last)
			publishFence((unsigned)ix + 1);
		return;
	}

	errx(1, "can't store fence point");
}

void
Geofence::publishFence(unsigned vertices)
{
	if (_fence_pub == -1)
		_fence_pub = orb_advertise(ORB_ID(fence), &vertices);
	else
		orb_publish(ORB_ID(fence), _fence_pub, &vertices);
}

int
Geofence::loadFromFile(const char *filename)
{
	FILE		*fp;
	char		line[120];
	int			pointCounter = 0;
	bool		gotVertical = false;
	const char commentChar = '#';

	/* Make sure no data is left in the datamanager */
	clearDm();

	/* open the mixer definition file */
	fp = fopen(GEOFENCE_FILENAME, "r");
	if (fp == NULL) {
		return ERROR;
	}

	/* create geofence points from valid lines and store in DM */
	for (;;) {

		/* get a line, bail on error/EOF */
		if (fgets(line, sizeof(line), fp) == NULL)
			break;

		/* Trim leading whitespace */
		size_t textStart = 0;
		while((textStart < sizeof(line)/sizeof(char)) && isspace(line[textStart])) textStart++;

		/* if the line starts with #, skip */
		if (line[textStart] == commentChar)
			continue;

		if (gotVertical) {
			/* Parse the line as a geofence point */
			struct fence_vertex_s vertex;

			/* if the line starts with DMS, this means that the coordinate is given as degree minute second instead of decimal degrees */
			if (line[textStart] == 'D' && line[textStart + 1] == 'M' && line[textStart + 2] == 'S') {
				/* Handle degree minute second format */
				float lat_d, lat_m, lat_s, lon_d, lon_m, lon_s;

				if (sscanf(line, "DMS %f %f %f %f %f %f", &lat_d, &lat_m, &lat_s, &lon_d, &lon_m, &lon_s) != 6)
					return ERROR;

//				warnx("Geofence DMS: %.5f %.5f %.5f ; %.5f %.5f %.5f", (double)lat_d, (double)lat_m, (double)lat_s, (double)lon_d, (double)lon_m, (double)lon_s);

				vertex.lat = lat_d + lat_m/60.0f + lat_s/3600.0f;
				vertex.lon = lon_d + lon_m/60.0f + lon_s/3600.0f;

			} else {
				/* Handle decimal degree format */

				if (sscanf(line, "%f %f", &(vertex.lat), &(vertex.lon)) != 2)
					return ERROR;
			}

			if (dm_write(DM_KEY_FENCE_POINTS, pointCounter, DM_PERSIST_POWER_ON_RESET, &vertex, sizeof(vertex)) != sizeof(vertex))
								return ERROR;

			warnx("Geofence: point: %d, lat %.5f: lon: %.5f", pointCounter,  (double)vertex.lat, (double)vertex.lon);

			pointCounter++;
		} else {
			/* Parse the line as the vertical limits */
			if (sscanf(line, "%f %f", &_altitude_min, &_altitude_max) != 2)
				return ERROR;


			warnx("Geofence: alt min: %.4f, alt_max: %.4f", (double)_altitude_min, (double)_altitude_max);
			gotVertical = true;
		}


	}

	fclose(fp);

	/* Check if import was successful */
	if(gotVertical && pointCounter > 0)
	{
		_verticesCount = pointCounter;
		warnx("Geofence: imported successfully");
	} else {
		warnx("Geofence: import error");
	}

	return ERROR;
}

int Geofence::clearDm()
{
	dm_clear(DM_KEY_FENCE_POINTS);
}