Game Instance and AActor variable

Development Programming & Scripting
1

Hey guys,

So I’ve been working on a basic game for the Windows Platform lately, and I have a level transition system prototype roughed out, where it would Serialize player data to a binary file and load it back into the player character on level load.

Now I came across Ramas wiki tutorial: Game Instance, Custom Game Instance For Inter-Level Persistent Data Storage, not knowing of Game Instance. Now I’ve done a few successful tests with my own Game Instance class, with basic types such as FStrings and uint32. Obviously these values remain persistent on level changes, but I am wanting to work with UObjects, specifically a derived ACharacter class. Consider the following:

//Game Instance .h

public:

        UPROPERTY(EditAnywhere, BlueprintReadWrite)
        AplayerCharacter * playerStorage;

//On Level Load in playerCharacter.cpp

        UMainGameInstance * inst = Cast<UMainGameInstance>(GetGameInstance());

        if(!inst)
        {
            //LogFunction
            return;
        }

        inst->playerStorage = this;

Now assigning and testing playerStorage variables work in the scope that it was declared in, but if I try the following:

        UMainGameInstance * inst = Cast<UMainGameInstance>(GetGameInstance());
    
         if(!inst)
         {
            //LogFunction
            return;
         }
    
         FString testString = inst->playerStorage->GetCustomName();

Will always toggle a breakpoint in Visual Studio(As I am debugging in DebugGame Editor). For some reason, and I don’t know why, inst->playerStorage is always NULL outside the scope when I assigned its value. Yet if I used say an actual FString, it will work.

This got me onto thinking, if there is no way to achieve this, would I be better off creating a structure with all the variables from my AplayerCharacter class and just use the structure in the game instance class?

Note* In small words, I am trying to store my player data for loading a level, then loading the player data back in, without saving to file.

Edit * Using structures accomplishes this, but with manually writing out all the variables. So I would like to know if I can store a copy of the AplayerCharacter in the game instance class, and have it work out of scope?

Thanks Guys,

2

So far this suffices as a solution to my problem.

 struct FcharData
    {
    	GENERATED_USTRUCT_BODY()
    
    public:
    
    	UPROPERTY()
    	FString playerName;
    
    	UPROPERTY()
    	bool bPlayerBeganGame;
    
    	UPROPERTY()
    	FString LastLevelName;
    
    	UPROPERTY()
    	FString currentLevel;
    
    	UPROPERTY()
    	bool bIsTransitioning;
    
    	UPROPERTY()
    	bool bLoadedFromSave;
    
    	FcharData()
    	{
    		playerName = "";
    		bPlayerBeganGame = false;
    		LastLevelName = "";
    		currentLevel = "";
    		bIsTransitioning = false; 
    		bLoadedFromSave = false;
    	}
    
    	FcharData(AplayerCharacter * inPlayer)
    	{
    		playerName = inPlayer->PlayerName;
    		bPlayerBeganGame = inPlayer->bPlayerBeganGame;
    		LastLevelName = inPlayer->LastLevelName;
    		currentLevel = inPlayer->currentLevel;
    		bIsTransitioning = inPlayer->bIsPlayerTransitioningLevel;
    		bLoadedFromSave = inPlayer->bLoadedFromSave;
    	}
    
    	void FillPlayerData(AplayerCharacter & inPlayer)
    	{
    		inPlayer.PlayerName = playerName;
    		inPlayer.bPlayerBeganGame = bPlayerBeganGame;
    		inPlayer.LastLevelName = LastLevelName;
    		inPlayer.currentLevel = currentLevel;
    		inPlayer.bIsPlayerTransitioningLevel = bIsTransitioning;
    		inPlayer.bLoadedFromSave = bLoadedFromSave;
    	}
    };

Though I am wondering why my original idea of AplayerCharacter * player = this; is not working. Could ‘player’ be getting garbage collected? seeings as it is a pointer.

3

Hey Aaron, i need some help. In the same Rama tutorial how did you used
“USolusGameInstance* SGI = Cast(GetGameInstance()); if(SGI) {
SGI->InterLevelPersistentValue++;
ClientMessage(FString::FromInt(SGI->InterLevelPersistentValue));
}`”
is there any intialization of SGI or USolusGameInstance or cast, if yes then where and which data types?

4

because iam trying to use InterLevelPersistentValue in another class, but dont know how to do it.