ArduCopter: support option to retract mount when landing

Author: peterbarker

ArduCopter/Copter.h

@@ -597,6 +597,11 @@ class Copter : public AP_Vehicle {
 
     bool standby_active;
 
+#if HAL_MOUNT_ENABLED
+    // true if the last time we checked the flightmode was landing:
+    bool was_landing;
+#endif
+
     static const AP_Scheduler::Task scheduler_tasks[];
     static const AP_Param::Info var_info[];
     static const struct LogStructure log_structure[];

ArduCopter/mode.cpp

@@ -422,6 +422,16 @@ void Copter::update_flight_mode()
     surface_tracking.invalidate_for_logging();  // invalidate surface tracking alt, flight mode will set to true if used
 
     flightmode->run();
+
+#if HAL_MOUNT_ENABLED
+    {
+        const bool is_landing = flightmode->is_landing();
+        if (is_landing && !was_landing) {
+            camera_mount.vehicle_has_started_to_land();
+        }
+        was_landing = is_landing;
+    }
+#endif
 }
 
 // exit_mode - high level call to organise cleanup as a flight mode is exited