FlightTask: update global reference

For the geo.h C library to convert between global and local frame
we need an up to date global reference which is currently inside the
vehicle_local_position message.

src/lib/FlightTasks/tasks/FlightTask.cpp

@@ -1,5 +1,6 @@
 #include "FlightTask.hpp"
 #include <mathlib/mathlib.h>
+#include <lib/ecl/geo/geo.h>
 
 constexpr uint64_t FlightTask::_timeout;
 // First index of empty_setpoint corresponds to time-stamp and requires a finite number.
@@ -101,8 +102,11 @@ bool FlightTask::_evaluateVehicleLocalPosition()
 			_dist_to_bottom =  _sub_vehicle_local_position->get().dist_bottom;
 		}
 
-		// estimator specified vehicle limits
-
+		// global frame reference coordinates to enable conversions
+		if (_sub_vehicle_local_position->get().xy_global && _sub_vehicle_local_position->get().z_global) {
+			globallocalconverter_init(_sub_vehicle_local_position->get().ref_lat, _sub_vehicle_local_position->get().ref_lon,
+						  _sub_vehicle_local_position->get().ref_alt, _sub_vehicle_local_position->get().ref_timestamp);
+		}
 
 		// We don't check here if states are valid or not.
 		// Validity checks are done in the sub-classes.

src/lib/FlightTasks/tasks/FlightTask.hpp

@@ -44,6 +44,7 @@
 #include <px4_module_params.h>
 #include <drivers/drv_hrt.h>
 #include <matrix/matrix/math.hpp>
+#include <uORB/Subscription.hpp>
 #include <uORB/topics/vehicle_local_position.h>
 #include <uORB/topics/vehicle_local_position_setpoint.h>
 #include <uORB/topics/vehicle_command.h>