Local Player

The local player refers to a player on a client machine that is typically associated with a few things:

• Player Controller (APlayerController)
• Player State (APlayerState)
• Pawn (APawn)
• Game State (AGameState)
• Game Mode (AGameModeBase)
• Game Instance (UGameInstance)

Wow, that's a lot of shit to keep track of. If you want to support local multiplayer or local couch co-op, it gets worse! Fortunately, we have FLocalPlayerContext to help with that.

Local Player Context?

Local Player Context (FLocalPlayerContext) is a struct declared in LocalPlayer.h that will "wrap" a ULocalPlayer and give you an insane amount of access methods that you're probably already doing on your own.

INFO

This is not a blueprint exposed struct.

Here are some problems FLocalPlayerContext can solve for you:

Consistent Access Methods

/** 
* You can get Local Player in a number of ways, but
* establishing context is just as easy as constructing an instance
* of it like so.
*/
FLocalPlayerContext Context = FLocalPlayerContext(PlayerController->GetLocalPlayer());

APlayerController* MyController = Context.GetPlayerController();
AGameState* MyGameState = Context.GetMyGameState();
/** ... and so on */

Check for LocalPlayer Association

FLocalPlayerContext exposes a method bool IsFromLocalPlayer(AActor* ActorToTest) that will check against the player state, player controller and player-controlled pawn to see if any of them are associated with the local player. This means an easier time checking against other Actors like network-owned player states or networked pawns.

You can even use this in UWidgetComponent logic to determine if a piece of UI attached to an Actor is owned by the local player or just an NPC.

Supercharge Widgets

You can use this context object and maybe a paradigm for data access to allow all of your systems to grab easy references to UObject and AActor pointers.

Well fuck, as it turns out, UUserWidget exposes a method:

UMG_API const FLocalPlayerContext& GetPlayerContext() const;

Well. That's useful as hell. It even sets all of its instanced subwidgets in the widget tree. Here's SetPlayerContext from UUserWidget (lightly pseudocoded so Epic doesn't rock my shit).

/** God damn. This is cool */
void UUserWidget::SetPlayerContext(const FLocalPlayerContext& InPlayerContext)
{
	PlayerContext = InPlayerContext;
	CachedWorld.Reset();

	if (/** Widget Tree is valid */)
	{
        /** 
        * 1. For each widget, run a Lambda function that accepts a 
        *    UWidget* parameter
        * 2. Cast the lambda param to UUserWidget. If valid, call 
             SetPlayerContext on it, passing in the InPlayerContext
        */
	}

}

At-a-glance

struct FLocalPlayerContext {
    /** Access methods that let you establish context a number of ways */
    ENGINE_API FLocalPlayerContext();
	ENGINE_API FLocalPlayerContext(const class ULocalPlayer*, UWorld* = nullptr);
	ENGINE_API FLocalPlayerContext(const class APlayerController*);

    /** ... */

    /** I genuinely think this is one of the best functions in this thing */
    ENGINE_API bool IsFromLocalPlayer(const AActor* ActorToTest) const;

    /** Getters for every common thing you find yourself trying to get anyway: */
    	ENGINE_API UGameInstance* GetGameInstance() const;
        ENGINE_API class ULocalPlayer* GetLocalPlayer() const;

        /**
         * GetPlayerController, GetGameState, GetPlayerState, and GetPawn
         * all also have templatized flavors of these functions in this context 
         * just in case you need to cast. They also allow passing in a boolean
         * to perform a Cast vs. a CastChecked.
         */
        ENGINE_API class APlayerController* GetPlayerController() const;
        ENGINE_API class AGameStateBase* GetGameState() const;
        ENGINE_API class APlayerState* GetPlayerState() const;
        ENGINE_API class APawn* GetPawn() const;

        /** Lmfao who the fuck uses this */
        ENGINE_API class AHUD* GetHUD() const;

}

Wow. What a utility! All for free!

Additional Notes

• This is probably stupid powerful if you combine it with a Viewmodel or something that can auto update.
• If you have a Player Controller reference that is valid, then it should be guaranteed you have a ULocalPlayer to use.