AP_OpticalFlow: Update test declaration

Declare a dummy vehicle to get a dummy ahrs. No problem since this code
is not used apart from compilation. Needed to declare an optical flow.

libraries/AP_OpticalFlow/examples/AP_OpticalFlow_test/AP_OpticalFlow_test.cpp

@@ -3,12 +3,35 @@
  *  Code by Randy Mackay. DIYDrones.com
  */
 
+#include <AP_AHRS/AP_AHRS.h>
+#include <AP_Baro/AP_Baro.h>
+#include <AP_Compass/AP_Compass.h>
+#include <AP_GPS/AP_GPS.h>
 #include <AP_HAL/AP_HAL.h>
+#include <AP_InertialSensor/AP_InertialSensor.h>
+#include <AP_NavEKF2/AP_NavEKF2.h>
+#include <AP_NavEKF/AP_NavEKF.h>
 #include <AP_OpticalFlow/AP_OpticalFlow.h>
+#include <AP_RangeFinder/AP_RangeFinder.h>
 
 const AP_HAL::HAL& hal = AP_HAL::get_HAL();
 
-static OpticalFlow optflow;
+class DummyVehicle {
+public:
+    AP_GPS gps;
+    AP_Baro barometer;
+    Compass compass;
+    AP_InertialSensor ins;
+    AP_SerialManager serial_manager;
+    RangeFinder sonar {serial_manager};
+    AP_AHRS_NavEKF ahrs{ins, barometer, gps, sonar, EKF, EKF2,
+                        AP_AHRS_NavEKF::FLAG_ALWAYS_USE_EKF};
+    NavEKF EKF{&ahrs, barometer, sonar};
+    NavEKF2 EKF2{&ahrs, barometer, sonar};
+};
+
+static DummyVehicle vehicle;
+static OpticalFlow optflow(vehicle.ahrs);
 
 void setup()
 {

libraries/AP_OpticalFlow/examples/AP_OpticalFlow_test/make.inc

@@ -21,3 +21,7 @@ LIBRARIES += DataFlash
 LIBRARIES += Filter
 LIBRARIES += GCS_MAVLink
 LIBRARIES += StorageManager
+LIBRARIES += AP_NavEKF
+LIBRARIES += AP_NavEKF2
+LIBRARIES += AP_RangeFinder
+LIBRARIES += AP_SerialManager