Use a game instance to hold the server

Source/Carla/Game/CarlaGameInstance.cpp

@@ -0,0 +1,21 @@
+// CARLA, Copyright (C) 2017 Computer Vision Center (CVC)
+
+#include "Carla.h"
+#include "CarlaGameInstance.h"
+
+#include "CarlaGameController.h"
+#include "MockGameController.h"
+
+UCarlaGameInstance::~UCarlaGameInstance() {}
+
+void UCarlaGameInstance::InitializeGameControllerIfNotPresent(bool bUseMockController)
+{
+  if (GameController == nullptr) {
+    if (bUseMockController) {
+      GameController = MakeUnique<MockGameController>();
+      UE_LOG(LogCarla, Warning, TEXT("Using mock CARLA controller"));
+    } else {
+      GameController = MakeUnique<CarlaGameController>();
+    }
+  }
+}

Source/Carla/Game/CarlaGameInstance.h

@@ -0,0 +1,32 @@
+// CARLA, Copyright (C) 2017 Computer Vision Center (CVC)
+
+#pragma once
+
+#include "Engine/GameInstance.h"
+#include "CarlaGameControllerBase.h"
+#include "CarlaGameInstance.generated.h"
+
+/**
+ *
+ */
+UCLASS()
+class CARLA_API UCarlaGameInstance : public UGameInstance
+{
+  GENERATED_BODY()
+
+public:
+
+  ~UCarlaGameInstance();
+
+  void InitializeGameControllerIfNotPresent(bool bUseMockController);
+
+  CarlaGameControllerBase &GetGameController()
+  {
+    check(GameController != nullptr);
+    return *GameController;
+  }
+
+private:
+
+  TUniquePtr<CarlaGameControllerBase> GameController;
+};

Source/Carla/Game/CarlaGameMode.cpp

@@ -7,12 +7,10 @@
 #include "EngineUtils.h"
 #include "GameFramework/PlayerStart.h"
 
-#include "CarlaGameController.h"
+#include "CarlaGameInstance.h"
 #include "CarlaGameState.h"
 #include "CarlaPlayerState.h"
-#include "CarlaPlayerState.h"
 #include "CarlaVehicleController.h"
-#include "MockGameController.h"
 
 ACarlaGameMode::ACarlaGameMode() :
   Super(),
@@ -21,6 +19,7 @@ ACarlaGameMode::ACarlaGameMode() :
   PlayerControllerClass = ACarlaVehicleController::StaticClass();
   GameStateClass = ACarlaGameState::StaticClass();
   PlayerStateClass = ACarlaPlayerState::StaticClass();
+
   PrimaryActorTick.bCanEverTick = true;
 }
 
@@ -31,12 +30,12 @@ void ACarlaGameMode::InitGame(
 {
   Super::InitGame(MapName, Options, ErrorMessage);
 
-  if (bUseMockController) {
-    GameController = MakeUnique<MockGameController>();
-    UE_LOG(LogCarla, Warning, TEXT("Using mock CARLA controller"));
-  } else {
-    GameController = MakeUnique<CarlaGameController>();
-  }
+  UCarlaGameInstance *GameInstance = Cast<UCarlaGameInstance>(GetGameInstance());
+  checkf(
+      GameInstance != nullptr,
+      TEXT("GameInstance is not a UCarlaGameInstance, did you forget to set it in the project settings?"));
+  GameInstance->InitializeGameControllerIfNotPresent(bUseMockController);
+  GameController = &GameInstance->GetGameController();
 }
 
 void ACarlaGameMode::RestartPlayer(AController* NewPlayer)

Source/Carla/Game/CarlaGameMode.h

@@ -40,5 +40,5 @@ private:
       AController *Player,
       TArray<APlayerStart *> &UnOccupiedStartPoints);
 
-  TUniquePtr<CarlaGameControllerBase> GameController;
+  CarlaGameControllerBase *GameController;
 };