Add data manager module and fence support to navigator

- Add function to geo.c to determine if global position is inside fence
- Add navigator support/commands for maintaining fence coords.
- Add data manager module to support persistence fence storage. Can
store other data, but only used for fence at this time.
- Add unit tests for data manager

src/lib/geo/geo.c

@@ -465,4 +465,26 @@ __EXPORT float _wrap_360(float bearing)
 	return bearing;
 }
 
+__EXPORT bool inside_geofence(const struct vehicle_global_position_s *vehicle, const struct fence_s *fence)
+{
+
+	/* Adaptation of algorithm originally presented as
+	 * PNPOLY - Point Inclusion in Polygon Test
+	 * W. Randolph Franklin (WRF) */
+
+	unsigned int i, j, vertices = fence->count;
+	bool c = false;
+	double lat = vehicle->lat / 1e7;
+	double lon = vehicle->lon / 1e7;
+
+	// skip vertex 0 (return point)
+	for (i = 0, j = vertices - 1; i < vertices; j = i++)
+		if (((fence->vertices[i].lon) >= lon != (fence->vertices[j].lon >= lon)) &&
+		    (lat <= (fence->vertices[j].lat - fence->vertices[i].lat) * (lon - fence->vertices[i].lon) /
+		     (fence->vertices[j].lon - fence->vertices[i].lon) + fence->vertices[i].lat))
+			c = !c;
+	return c;
+}
+
+
 

src/lib/geo/geo.h

@@ -47,6 +47,9 @@
 
 #pragma once
 
+#include "uORB/topics/fence.h"
+#include "uORB/topics/vehicle_global_position.h"
+
 __BEGIN_DECLS
 
 #include <stdbool.h>
@@ -126,4 +129,15 @@ __EXPORT float _wrap_360(float bearing);
 __EXPORT float _wrap_pi(float bearing);
 __EXPORT float _wrap_2pi(float bearing);
 
+/**
+ * Return whether craft is inside geofence.
+ *
+ * Calculate whether point is inside arbitrary polygon
+ * @param craft pointer craft coordinates
+ * @param fence pointer to array of coordinates, one per vertex. First and last vertex are assumed connected
+ * @return true: craft is inside fence, false:craft is outside fence
+ */
+__EXPORT bool inside_geofence(const struct vehicle_global_position_s *craft, const struct fence_s *fence);
+
+
 __END_DECLS