Simple cutscene manager and a test cutscene

Source/ProjectEleri/DialogueSystem/DialogueComponent.cpp

@@ -3,6 +3,7 @@
 
 #include "DialogueComponent.h"
 
+#include "DialogueSceneSubsystem.h"
 #include "DialogueSubsystem.h"
 #include "DialogueWidget.h"
 #include "EleriPlayerController.h"
@@ -35,6 +36,22 @@ void UDialogueComponent::BeginPlay()
 	EleriPlayerController = Cast<AEleriPlayerController>(UGameplayStatics::GetPlayerController(this, 0));
 }
 
+void UDialogueComponent::EndPlay(const EEndPlayReason::Type EndPlayReason)
+{
+	// A component taken down mid conversation still has to let go of a cutscene it is holding: the
+	// sequence would otherwise be left paused on its hold point for good, and the controls it took would
+	// belong to a scene that nobody is left to finish.
+	ReleaseHeldScene();
+
+	if (UDialogueSceneSubsystem* SceneSubsystem = UDialogueSceneSubsystem::Get(this))
+	{
+		SceneSubsystem->OnSceneHeld.RemoveAll(this);
+		SceneSubsystem->OnSceneFinished.RemoveAll(this);
+	}
+
+	Super::EndPlay(EndPlayReason);
+}
+
 void UDialogueComponent::OnDialogueLoaded()
 {
 	if(UGameInstance* GameInstance = UGameplayStatics::GetGameInstance(GetWorld()))
@@ -77,6 +94,35 @@ void UDialogueComponent::TriggerDialogue_Async(TSoftObjectPtr<USpeechDataAsset>
 }
 
 void UDialogueComponent::TriggerDialogue(USpeechDataAsset* DialogueAssetPath, const TMap<FString, FText>& ReplacementMap)
+{
+	if (DialogueAssetPath == nullptr) return;
+
+	// A dialogue can be a cutscene. Two shapes of that are supported, and the asset picks between them
+	// with its hold marker: a scene that plays through and hands over at its end, and a scene that plays
+	// as far as its hold point and stays there while the conversation happens inside it.
+	const EDialogueSceneStart SceneStart = StartDialogueScene(DialogueAssetPath, EDialogueSceneTiming::OnDialogueStart);
+
+	if (SceneStart != EDialogueSceneStart::None && DialogueAssetPath->bHoldDialogueForScene)
+	{
+		PendingDialogue = DialogueAssetPath;
+		PendingDialogueReplacementMap = ReplacementMap;
+
+		// Both beats are listened for on the off chance the other one arrives: a held scene reports its
+		// hold and later its end, and a scene that plays through only ever reports its end. Whichever
+		// comes first starts the dialogue, and StartPendingDialogue lets go of both.
+		if (UDialogueSceneSubsystem* SceneSubsystem = UDialogueSceneSubsystem::Get(this))
+		{
+			SceneSubsystem->OnSceneHeld.AddUniqueDynamic(this, &UDialogueComponent::OnDialogueSceneHeld);
+			SceneSubsystem->OnSceneFinished.AddUniqueDynamic(this, &UDialogueComponent::OnDialogueSceneFinished);
+		}
+
+		return;
+	}
+
+	StartDialogueInternal(DialogueAssetPath, ReplacementMap);
+}
+
+void UDialogueComponent::StartDialogueInternal(USpeechDataAsset* DialogueAssetPath, const TMap<FString, FText>& ReplacementMap)
 {
 	UDialogueSubsystem* DialogueSubsystem = UDialogueSubsystem::Get(this);
 	if (!DialogueSubsystem) return;
@@ -140,11 +186,27 @@ void UDialogueComponent::CloseDialogue()
 	if (!DialogueSubsystem) return;
 	DialogueSubsystem->EndDialogue();
 
+	// Held before the state below is cleared, because a scene that closes a conversation is played from
+	// the asset that is about to be forgotten.
+	const USpeechDataAsset* ClosedDialogue = CurrentActiveDialogue;
+
+	// A cutscene this conversation was happening inside of is let go of before anything else is tried:
+	// the sequence carries on from its hold point and plays its own tail, and while it is doing that no
+	// other scene can start anyway, which is why an end scene below is allowed to be refused.
+	ReleaseHeldScene();
+	
 	SelectedDialogueOptionIndex = 0;
 	CurrentLineIndex = 0;
 	CurrentActiveDialogue = nullptr;
 	UnbindControllerInput();
 	EleriPlayerController->ToggleDialogueWindow(false);
+
+	// Played last, once the window is down and the conversation is over, so the cutscene is what the
+	// player is left watching rather than something the dialogue box sits on top of.
+	if (ClosedDialogue != nullptr)
+	{
+		StartDialogueScene(ClosedDialogue, EDialogueSceneTiming::OnDialogueEnd);
+	}
 }
 
 void UDialogueComponent::AdvanceDialogue()
@@ -276,5 +338,93 @@ TArray<FText> UDialogueComponent::GetDialogueOptionsFromPlayerSpeakList(const TA
 	return Options;
 }
 
+EDialogueSceneStart UDialogueComponent::StartDialogueScene(const USpeechDataAsset* DialogueAsset, EDialogueSceneTiming Timing)
+{
+	if (DialogueAsset == nullptr || DialogueAsset->Scene.IsNull() || DialogueAsset->SceneTiming != Timing)
+	{
+		return EDialogueSceneStart::None;
+	}
+
+	UDialogueSceneSubsystem* SceneSubsystem = UDialogueSceneSubsystem::Get(this);
+	if (SceneSubsystem == nullptr)
+	{
+		return EDialogueSceneStart::None;
+	}
+
+	// The actor the component sits on goes in as the instigator, so a listener can tell which NPC a
+	// cutscene belongs to without having to remember what it asked for.
+	//
+	// A scene with a hold marker is asked to hold, and one without is asked to play through: that choice
+	// on the asset is the whole difference between a conversation that happens inside a cutscene and one
+	// that happens after it.
+	if (!DialogueAsset->SceneHoldMarker.IsNone())
+	{
+		return SceneSubsystem->PlaySceneHeld(DialogueAsset->Scene, DialogueAsset->SceneHoldMarker, GetOwner())
+			? EDialogueSceneStart::StartedHeld
+			: EDialogueSceneStart::None;
+	}
+
+	return SceneSubsystem->PlayScene(DialogueAsset->Scene, GetOwner())
+		? EDialogueSceneStart::Started
+		: EDialogueSceneStart::None;
+}
+
+void UDialogueComponent::OnDialogueSceneFinished(ULevelSequence* Scene, AActor* Instigator)
+{
+	bHoldingSceneForDialogue = false;
+	StartPendingDialogue();
+}
+
+void UDialogueComponent::OnDialogueSceneHeld(ULevelSequence* Scene, AActor* Instigator)
+{
+	// The scene is paused on its hold point and is staying there, so the conversation runs inside the
+	// cutscene and CloseDialogue is what lets it go again.
+	bHoldingSceneForDialogue = true;
+	StartPendingDialogue();
+}
+
+void UDialogueComponent::StartPendingDialogue()
+{
+	// Both scene events are let go of first: waiting behind a scene is a one-off, and a dialogue started
+	// from here may well have a scene of its own that must not be swallowed by a stale binding.
+	if (UDialogueSceneSubsystem* SceneSubsystem = UDialogueSceneSubsystem::Get(this))
+	{
+		SceneSubsystem->OnSceneHeld.RemoveDynamic(this, &UDialogueComponent::OnDialogueSceneHeld);
+		SceneSubsystem->OnSceneFinished.RemoveDynamic(this, &UDialogueComponent::OnDialogueSceneFinished);
+	}
+
+	USpeechDataAsset* WaitingDialogue = PendingDialogue;
+	PendingDialogue = nullptr;
+
+	// A scene that was not holding a dialogue still comes through here, because the bindings are made
+	// before the manager decides whether it can play anything. Waiting on nothing is the ordinary case.
+	if (WaitingDialogue == nullptr)
+	{
+		return;
+	}
+
+	const TMap<FString, FText> ReplacementMap = PendingDialogueReplacementMap;
+	PendingDialogueReplacementMap.Reset();
+
+	StartDialogueInternal(WaitingDialogue, ReplacementMap);
+}
+
+void UDialogueComponent::ReleaseHeldScene()
+{
+	if (!bHoldingSceneForDialogue)
+	{
+		return;
+	}
+
+	bHoldingSceneForDialogue = false;
+
+	// Letting the sequence go is all that is needed: it resumes from its hold point, plays its tail, and
+	// stops at the end of it, which is what returns the player's camera and their controls.
+	if (UDialogueSceneSubsystem* SceneSubsystem = UDialogueSceneSubsystem::Get(this))
+	{
+		SceneSubsystem->ResumeScene();
+	}
+}
+
 #undef LOCTEXT_NAMESPACE
 

Source/ProjectEleri/DialogueSystem/DialogueComponent.h

@@ -11,8 +11,26 @@
 struct FPlayerSpeakToDialogue;
 class AEleriPlayerController;
 class UDialogueWidget;
+class ULevelSequence;
 class UWidgetComponent;
 
+/**
+ * What happened when a dialogue asked for its scene, which is also the question "what is the dialogue
+ * waiting behind, if anything?".
+ */
+enum class EDialogueSceneStart : uint8
+{
+	/** No scene was due, or the one that was due could not start: the dialogue runs on its own */
+	None,
+
+	/** The scene is playing through, so the dialogue waits for its end */
+	Started,
+
+	/** The scene has been asked to hold, so the dialogue waits for the hold point and then runs inside
+	 *  the cutscene. The scene is let go again when the dialogue ends. */
+	StartedHeld
+};
+
 UCLASS(BlueprintType, Blueprintable)
 class PROJECTELERI_API UDialogueComponent : public UActorComponent
 {
@@ -49,6 +67,32 @@ protected:
 	void TriggerDialogueSelect(TArray<FText>& DialogueOptions, bool bIsDialogueStart);
 	UFUNCTION()
 	void OnDialogueOptionSelected(int32 Index);
+	/** Runs a dialogue. TriggerDialogue hands over to this once any scene in front of the dialogue has
+	 *  had its turn, so the conversation is set up in one place whichever way it was reached. */
+	void StartDialogueInternal(USpeechDataAsset* DialogueAsset, const TMap<FString, FText>& ReplacementMap);
+
+	/** Plays the scene the asset names, when it names one and it is due at Timing, and says what the
+	 *  dialogue is now waiting behind. None means nothing started and the dialogue carries on. */
+	EDialogueSceneStart StartDialogueScene(const USpeechDataAsset* DialogueAsset, EDialogueSceneTiming Timing);
+
+	/** A scene the dialogue was waiting behind has finished, so the dialogue starts. Bound on
+	 *  TriggerDialogue and let go of here, which is what keeps the wait to one conversation. */
+	UFUNCTION()
+	void OnDialogueSceneFinished(ULevelSequence* Scene, AActor* Instigator);
+
+	/** A scene the dialogue was waiting behind has reached its hold point, so the dialogue starts inside
+	 *  the cutscene. The scene stays where it is until the dialogue ends and lets it go. */
+	UFUNCTION()
+	void OnDialogueSceneHeld(ULevelSequence* Scene, AActor* Instigator);
+
+	/** Starts whatever dialogue was left waiting behind a scene, whichever beat it was waiting for, and
+	 *  lets go of both scene events so only one conversation can ever be waiting at a time. */
+	void StartPendingDialogue();
+
+	/** Lets go of a scene this dialogue put on hold, so the cutscene finishes and the player gets their
+	 *  controls back. Does nothing when this dialogue is not holding anything. */
+	void ReleaseHeldScene();
+
 	static TArray<FText> GetPlayerAsksFromDialogueList(const TArray<USpeechDataAsset*>& DialogueList);
 	static TArray<FText> GetDialogueOptionsFromPlayerSpeakList(const TArray<FPlayerSpeakToDialogue>& SpeakList);
 	
@@ -78,11 +122,27 @@ protected:
 	TMap<int32, FPlayerSpeakToDialogue> MappedDialogueOptions;
 	UPROPERTY(EditAnywhere, BlueprintReadWrite)
 	TMap<FString, FText> CurrentDialogueReplacementMap;
+	/** The dialogue held behind a scene that is still playing, and the replacement map it was asked
+	 *  for with. Kept rather than re-derived, because the caller that asked for the dialogue is not
+	 *  around by the time the cutscene ends. */
+	UPROPERTY()
+	TObjectPtr<USpeechDataAsset> PendingDialogue = nullptr;
+
+	UPROPERTY()
+	TMap<FString, FText> PendingDialogueReplacementMap;
+
+	/** True while this component is what is holding a cutscene open. It is what tells CloseDialogue
+	 *  that the scene has a tail to play before the conversation is really over. */
+	bool bHoldingSceneForDialogue = false;
 
 protected:
 	// Called when the game starts
 	virtual void BeginPlay() override;
 
+	/** A component that is taken down mid conversation still has to let go of a cutscene it is holding,
+	 *  or the player would be left standing in a paused shot with no controls and no way back. */
+	virtual void EndPlay(const EEndPlayReason::Type EndPlayReason) override;
+
 	UFUNCTION()
 	void OnDialogueLoaded();
 

Source/ProjectEleri/DialogueSystem/DialogueSceneSubsystem.cpp

@@ -0,0 +1,446 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+
+#include "DialogueSceneSubsystem.h"
+
+#include "EleriPlayerController.h"
+#include "Engine/World.h"
+#include "GameFramework/PlayerController.h"
+#include "Kismet/GameplayStatics.h"
+#include "LevelSequence.h"
+#include "LevelSequenceActor.h"
+#include "LevelSequencePlayer.h"
+#include "MovieScene.h"
+#include "MovieSceneSequencePlaybackSettings.h"
+
+UDialogueSceneSubsystem* UDialogueSceneSubsystem::Get(const UObject* WorldContext)
+{
+	const UGameInstance* GameInstance = UGameplayStatics::GetGameInstance(WorldContext);
+	return GameInstance != nullptr ? GameInstance->GetSubsystem<UDialogueSceneSubsystem>() : nullptr;
+}
+
+void UDialogueSceneSubsystem::Initialize(FSubsystemCollectionBase& Collection)
+{
+	Super::Initialize(Collection);
+
+	WorldCleanupHandle = FWorldDelegates::OnWorldCleanup.AddUObject(
+		this, &UDialogueSceneSubsystem::HandleWorldCleanup);
+}
+
+void UDialogueSceneSubsystem::Deinitialize()
+{
+	if (WorldCleanupHandle.IsValid())
+	{
+		FWorldDelegates::OnWorldCleanup.Remove(WorldCleanupHandle);
+		WorldCleanupHandle.Reset();
+	}
+
+	// Nothing here is stopped on the way out: the actor and the player live in a world that is being
+	// destroyed, and the controller this would hand controls back to is going with it. What is left to
+	// do is forget them, which is what keeps a scene that was running from being reported as still
+	// running in the next world.
+	ResetSceneTracking();
+	ActiveSequenceActor = nullptr;
+
+	Super::Deinitialize();
+}
+
+UWorld* UDialogueSceneSubsystem::GetSceneWorld() const
+{
+	const UGameInstance* GameInstance = GetGameInstance();
+	return GameInstance != nullptr ? GameInstance->GetWorld() : nullptr;
+}
+
+APlayerController* UDialogueSceneSubsystem::GetScenePlayerController() const
+{
+	UWorld* World = GetSceneWorld();
+	return World != nullptr ? World->GetFirstPlayerController() : nullptr;
+}
+
+bool UDialogueSceneSubsystem::PlayScene(TSoftObjectPtr<ULevelSequence> Scene, AActor* Instigator, bool bDisablePlayerControl)
+{
+	// One scene at a time. Two sequences at once would both be driving the camera and the player's
+	// actor, and whichever ended first would hand the controls back in the middle of the other one. So
+	// a request that arrives while a scene is running is refused rather than layered on top of it, and
+	// the caller carries on as though it had never asked. This is also what keeps a quest that changes
+	// status twice in one frame from cutting its own cutscene short.
+	if (bScenePlaying)
+	{
+		UE_LOG(LogTemp, Warning,
+			TEXT("[DialogueScene] '%s' was asked for while '%s' is still playing, so it was not started."),
+			*Scene.ToString(),
+			ActiveScene != nullptr ? *ActiveScene->GetName() : TEXT("<unknown>"));
+
+		return false;
+	}
+
+	if (Scene.IsNull())
+	{
+		return false;
+	}
+
+	// Blocking on the load is deliberate. The caller is asking for a cutscene it is about to hold
+	// everything up for anyway, and returning false here would leave a dialogue waiting on a scene
+	// that is never going to start. The object is already in memory whenever the caller got it from an
+	// asset it has loaded, which is the ordinary case.
+	ULevelSequence* LoadedScene = Scene.LoadSynchronous();
+	if (LoadedScene == nullptr)
+	{
+		UE_LOG(LogTemp, Warning, TEXT("[DialogueScene] '%s' could not be loaded, so no scene was played."),
+			*Scene.ToString());
+		return false;
+	}
+
+	return StartScene(LoadedScene, NAME_None, Instigator, bDisablePlayerControl);
+}
+
+bool UDialogueSceneSubsystem::PlaySceneHeld(TSoftObjectPtr<ULevelSequence> Scene, FName HoldMarker, AActor* Instigator, bool bDisablePlayerControl)
+{
+	if (bScenePlaying)
+	{
+		UE_LOG(LogTemp, Warning,
+			TEXT("[DialogueScene] '%s' was asked for, held, while '%s' is still playing, so it was not started."),
+			*Scene.ToString(),
+			ActiveScene != nullptr ? *ActiveScene->GetName() : TEXT("<unknown>"));
+
+		return false;
+	}
+
+	if (Scene.IsNull())
+	{
+		return false;
+	}
+
+	ULevelSequence* LoadedScene = Scene.LoadSynchronous();
+	if (LoadedScene == nullptr)
+	{
+		UE_LOG(LogTemp, Warning, TEXT("[DialogueScene] '%s' could not be loaded, so no scene was played."),
+			*Scene.ToString());
+		return false;
+	}
+
+	// A hold that cannot be resolved is dropped rather than passed on: the scene still plays, it just
+	// plays through, which is a cutscene with a missing beat instead of a cutscene that rewinds.
+	FName ResolvedHold = HoldMarker;
+	if (!HoldMarker.IsNone() && !TryResolveHoldMarker(LoadedScene, HoldMarker))
+	{
+		ResolvedHold = NAME_None;
+	}
+
+	return StartScene(LoadedScene, ResolvedHold, Instigator, bDisablePlayerControl);
+}
+
+bool UDialogueSceneSubsystem::TryResolveHoldMarker(const ULevelSequence* Scene, FName HoldMarker)
+{
+	const UMovieScene* MovieScene = Scene != nullptr ? Scene->GetMovieScene() : nullptr;
+	if (MovieScene == nullptr)
+	{
+		UE_LOG(LogTemp, Warning,
+			TEXT("[DialogueScene] '%s' has no movie scene, so it cannot be held."),
+			Scene != nullptr ? *Scene->GetName() : TEXT("<none>"));
+		return false;
+	}
+
+	const FString Label = HoldMarker.ToString();
+	const int32 MarkerIndex = MovieScene->FindMarkedFrameByLabel(Label);
+	if (MarkerIndex == INDEX_NONE)
+	{
+		UE_LOG(LogTemp, Warning,
+			TEXT("[DialogueScene] '%s' has no marker called '%s', so it will play through instead of holding. "
+				 "Add the marker in Sequencer, or clear the hold marker on the dialogue."),
+			*Scene->GetName(), *Label);
+		return false;
+	}
+
+	// The player resolves a marker it cannot find to its current time, and PlayTo reads a target that
+	// is not ahead of the cursor as a request to play backwards. A marker sitting at or before the
+	// start would therefore rewind the whole cutscene, so it is refused here where it can be reported.
+	const FFrameNumber MarkerFrame = MovieScene->GetMarkedFrames()[MarkerIndex].FrameNumber;
+	const TRangeBound<FFrameNumber> LowerBound = MovieScene->GetPlaybackRange().GetLowerBound();
+	const FFrameNumber StartFrame = LowerBound.IsOpen() ? FFrameNumber(0) : LowerBound.GetValue();
+	if (MarkerFrame <= StartFrame)
+	{
+		UE_LOG(LogTemp, Warning,
+			TEXT("[DialogueScene] marker '%s' on '%s' sits at or before the start of the sequence, so it cannot be "
+				 "held at. Move it after the first frame."),
+			*Label, *Scene->GetName());
+		return false;
+	}
+
+	return true;
+}
+
+bool UDialogueSceneSubsystem::StartScene(ULevelSequence* Scene, FName HoldMarker, AActor* Instigator, bool bDisablePlayerControl)
+{
+	UWorld* World = GetSceneWorld();
+	if (World == nullptr)
+	{
+		return false;
+	}
+
+	// One actor for the life of the subsystem, pointed at each new sequence, rather than one actor per
+	// scene. A level would otherwise collect an actor for every cutscene the player watched, and taking
+	// such an actor down would have to happen from inside the sequence player's very own finished
+	// callback, which is the one moment the player is still in the middle of broadcasting to it.
+	ULevelSequencePlayer* Player = nullptr;
+
+	if (!IsValid(ActiveSequenceActor.Get()))
+	{
+		FMovieSceneSequencePlaybackSettings Settings;
+		// Not auto-played by the factory: the delegates below are bound and the control is taken before
+		// the sequence is allowed to run, so a scene that ends on its first frame cannot outrun its own
+		// setup.
+		Settings.bAutoPlay = false;
+
+		ALevelSequenceActor* SequenceActor = nullptr;
+		Player = ULevelSequencePlayer::CreateLevelSequencePlayer(World, Scene, Settings, SequenceActor);
+		if (Player == nullptr || SequenceActor == nullptr)
+		{
+			return false;
+		}
+
+		ActiveSequenceActor = SequenceActor;
+	}
+	else
+	{
+		ActiveSequenceActor->SetSequence(Scene);
+
+		// SetSequence only takes while the sequence player is not running, which is the case here: the
+		// scene that used it has stopped. A refusal is reported as a scene that never started.
+		if (ActiveSequenceActor->GetSequence() != Scene)
+		{
+			return false;
+		}
+
+		Player = ActiveSequenceActor->GetSequencePlayer();
+		if (Player == nullptr)
+		{
+			return false;
+		}
+	}
+
+	ActiveScene = Scene;
+	ActivePlayer = Player;
+	SceneInstigator = Instigator;
+	bScenePlaying = true;
+	bControlTakenByScene = bDisablePlayerControl;
+	bHoldRequested = !HoldMarker.IsNone();
+	bSceneHeld = false;
+
+	// Both ends are listened for rather than only OnFinished, because Stop() takes the other route out
+	// and a scene cut short still has to give the player their controls back.
+	Player->OnFinished.AddDynamic(this, &UDialogueSceneSubsystem::HandleSceneFinished);
+	Player->OnStop.AddDynamic(this, &UDialogueSceneSubsystem::HandleSceneStopped);
+
+	// A hold is noticed through the player's own pause. PlayTo asks the player to pause itself on the
+	// marker frame, so the pause arriving *is* the hold being reached. It is only bound for a scene
+	// that asked to hold, so a pause from anywhere else cannot be read as one.
+	if (bHoldRequested)
+	{
+		Player->OnPause.AddDynamic(this, &UDialogueSceneSubsystem::HandleScenePaused);
+	}
+
+	if (bDisablePlayerControl)
+	{
+		TakePlayerControl();
+	}
+
+	// Announced before the sequence runs, so a listener is already listening when a scene that ends on
+	// its first frame reports itself finished from inside this call.
+	OnSceneStarted.Broadcast(Scene, Instigator);
+
+	if (bHoldRequested)
+	{
+		// Plays forward and stops itself on the marker. The label has already been checked against the
+		// sequence, so the player cannot resolve it to the current time and run the scene backwards.
+		FMovieSceneSequencePlaybackParams PlaybackParams(HoldMarker.ToString(), EUpdatePositionMethod::Play);
+		FMovieSceneSequencePlayToParams PlayToParams;
+		// Inclusive, so the marked frame itself is evaluated and the hold does not land a frame early.
+		PlayToParams.bExclusive = false;
+
+		Player->PlayTo(PlaybackParams, PlayToParams);
+	}
+	else
+	{
+		Player->Play();
+	}
+	
+	if (AEleriPlayerController* PlayerController = Cast<AEleriPlayerController>(GetScenePlayerController()))
+	{
+		PlayerController->GetMainGameWidget()->ToggleUiForCutscene(true);
+	}
+
+	return true;
+}
+
+void UDialogueSceneSubsystem::HandleScenePaused()
+{
+	// OnPause fires for any pause the player takes, so the hold is only announced for the one that was
+	// asked for, and only the first time: a listener that opens a dialogue here is not opening two.
+	if (!bHoldRequested || bSceneHeld || !bScenePlaying)
+	{
+		return;
+	}
+
+	bSceneHeld = true;
+
+	// The camera and everything else the scene was driving are still on screen and still frozen here,
+	// which is the whole point of the beat: a listener can put something of its own in front of it.
+	OnSceneHeld.Broadcast(ActiveScene, SceneInstigator.Get());
+}
+
+bool UDialogueSceneSubsystem::HoldScene()
+{
+	if (!bScenePlaying || !IsValid(ActivePlayer.Get()) || ActivePlayer->IsPaused())
+	{
+		return false;
+	}
+
+	// Marked as a hold before the pause is asked for, so the OnPause it causes is read as a hold point
+	// rather than as a pause from somewhere else.
+	bHoldRequested = true;
+	ActivePlayer->Pause();
+
+	return true;
+}
+
+bool UDialogueSceneSubsystem::ResumeScene()
+{
+	if (!bScenePlaying || !IsValid(ActivePlayer.Get()) || !ActivePlayer->IsPaused())
+	{
+		return false;
+	}
+
+	bSceneHeld = false;
+	bHoldRequested = false;
+
+	// Resumes from where it was held and runs the tail to its end, which is where the stop, the return
+	// of the player's camera and the hand-back of the controls all happen by themselves.
+	ActivePlayer->Play();
+
+	return true;
+}
+
+void UDialogueSceneSubsystem::StopScene()
+{
+	if (!bScenePlaying || ActivePlayer == nullptr)
+	{
+		return;
+	}
+
+	// Stop() reports through OnStop, which is the same path a scene that ran to its end takes, so the
+	// hand-back of the controls and the finished broadcast stay in the one place they are written.
+	ActivePlayer->Stop();
+}
+
+void UDialogueSceneSubsystem::HandleSceneFinished()
+{
+	FinishScene();
+}
+
+void UDialogueSceneSubsystem::HandleSceneStopped()
+{
+	FinishScene();
+}
+
+void UDialogueSceneSubsystem::FinishScene()
+{
+	if (!bScenePlaying)
+	{
+		// OnStop and OnFinished can both arrive for one scene, since a sequence that is stopped part way
+		// is stopped and one that reaches its end reports both. The flag is what makes the second
+		// arrival a no-op instead of a second hand-back of the controls.
+		return;
+	}
+
+	ULevelSequence* FinishedScene = ActiveScene;
+	AActor* Instigator = SceneInstigator.Get();
+
+	// The controls go back before anyone is told the scene is over, because a listener that starts a
+	// dialogue or another scene from here has to do it in a world the player already has back.
+	RestorePlayerControl();
+	ResetSceneTracking();
+	
+	if (AEleriPlayerController* PlayerController = Cast<AEleriPlayerController>(GetScenePlayerController()))
+	{
+		PlayerController->GetMainGameWidget()->ToggleUiForCutscene(false);
+	}
+
+	OnSceneFinished.Broadcast(FinishedScene, Instigator);
+}
+
+void UDialogueSceneSubsystem::ResetSceneTracking()
+{
+	if (ActivePlayer != nullptr)
+	{
+		// The player outlives this call, so its events have to be let go of explicitly: a scene that
+		// was stopped would otherwise report itself finished a second time.
+		ActivePlayer->OnFinished.RemoveAll(this);
+		ActivePlayer->OnStop.RemoveAll(this);
+		ActivePlayer->OnPause.RemoveAll(this);
+	}
+
+	ActivePlayer = nullptr;
+	ActiveScene = nullptr;
+	SceneInstigator = nullptr;
+	bScenePlaying = false;
+	bControlTakenByScene = false;
+
+	// A scene that is over cannot still be held, whichever way it ended: a stopped scene leaves the
+	// pause behind with it, and the next scene must not inherit the hold of the one before.
+	bHoldRequested = false;
+	bSceneHeld = false;
+
+	// ActiveSequenceActor is deliberately left alone: the actor it points at is reused by the next
+	// scene and belongs to the world, so it is taken down by the world going away and not by a scene
+	// ending.
+}
+
+void UDialogueSceneSubsystem::TakePlayerControl()
+{
+	APlayerController* PlayerController = GetScenePlayerController();
+	if (PlayerController == nullptr)
+	{
+		// No controller means no player to hold back, so the scene is recorded as one that never took
+		// the controls: handing them back later would be acting on a controller that did not exist
+		// when the scene started.
+		bControlTakenByScene = false;
+		return;
+	}
+
+	// Movement and looking only. The player stays visible and the HUD keeps drawing, because a cutscene
+	// that also hides both is a different thing from one that only wants the controls, and the two are
+	// a flag apart for a caller that wants the other.
+	PlayerController->SetCinematicMode(true, /*bHidePlayer=*/false, /*bAffectsHUD=*/false,
+		/*bAffectsMovement=*/true, /*bAffectsTurning=*/true);
+}
+
+void UDialogueSceneSubsystem::RestorePlayerControl()
+{
+	if (!bControlTakenByScene)
+	{
+		return;
+	}
+
+	if (APlayerController* PlayerController = GetScenePlayerController())
+	{
+		PlayerController->SetCinematicMode(false, /*bHidePlayer=*/false, /*bAffectsHUD=*/false,
+			/*bAffectsMovement=*/true, /*bAffectsTurning=*/true);
+	}
+}
+
+void UDialogueSceneSubsystem::HandleWorldCleanup(UWorld* World, bool bSessionEnded, bool bCleanupResources)
+{
+	(void)bSessionEnded;
+	(void)bCleanupResources;
+
+	// Only the world the scene is playing in matters. Another world coming down, an editor preview or a
+	// streaming world, must not be read as the scene being over, because the scene is still on screen
+	// in the first one.
+	if (World == nullptr || World != GetSceneWorld())
+	{
+		return;
+	}
+
+	ResetSceneTracking();
+}

Source/ProjectEleri/DialogueSystem/DialogueSceneSubsystem.h

@@ -0,0 +1,239 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Subsystems/GameInstanceSubsystem.h"
+#include "UObject/SoftObjectPtr.h"
+
+#include "DialogueSceneSubsystem.generated.h"
+
+class AActor;
+class ALevelSequenceActor;
+class APlayerController;
+class ULevelSequence;
+class ULevelSequencePlayer;
+class UWorld;
+
+DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnDialogueSceneStarted, ULevelSequence*, Scene, AActor*, Instigator);
+DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnDialogueSceneHeld, ULevelSequence*, Scene, AActor*, Instigator);
+DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnDialogueSceneFinished, ULevelSequence*, Scene, AActor*, Instigator);
+
+/**
+ * The one thing in the project that plays a cutscene.
+ *
+ * A dialogue scene is a level sequence and nothing more, which is what keeps writing one in Sequencer
+ * rather than in C++. What this subsystem adds on top of the sequence player is the part the engine
+ * does not do for a game: whoever asked for the scene owns the player while it runs, and the player is
+ * handed their controls back the moment it stops, however it stopped.
+ *
+ * That is why every caller goes through here instead of spawning an ALevelSequenceActor itself:
+ *
+ *  - The scene on screen is remembered, so a second request while one is running is refused rather
+ *    than two sequences fighting over the camera and over the player's actor.
+ *  - The controls are taken with APlayerController::SetCinematicMode, which is a flag on the controller
+ *    and therefore is not undone by the widget code that swaps input mapping contexts around a menu.
+ *  - OnFinished and OnStop are treated as one event, because a sequence can end either way and the
+ *    controls have to come back for both.
+ *
+ * A scene can also be held, which is what turns one sequence into a conversation rather than a film:
+ * the sequence plays as far as a marker and stays there, the camera cut and everything else it drove
+ * frozen on screen, while the world carries on and a dialogue plays over the top. When the dialogue is
+ * done the scene is let go and runs its tail, which is where the fade out and the release live. See
+ * PlaySceneHeld for the mechanics.
+ *
+ * A game instance subsystem, like the dialogue and quest subsystems and for the same reason: a scene
+ * started in one level must not still read as playing in the next, so the tracking is dropped when the
+ * world it was playing in is torn down.
+ */
+UCLASS()
+class PROJECTELERI_API UDialogueSceneSubsystem : public UGameInstanceSubsystem
+{
+	GENERATED_BODY()
+
+public:
+
+	// ----- Lifetime ---------------------------------------------------------------
+
+	virtual void Initialize(FSubsystemCollectionBase& Collection) override;
+	virtual void Deinitialize() override;
+
+	/** The subsystem of the game instance the context belongs to, or null when there is none. */
+	static UDialogueSceneSubsystem* Get(const UObject* WorldContext);
+
+	// ----- Delegates --------------------------------------------------------------
+
+	/** Fired as a scene starts, before it is played, so a listener can set up for a scene that may
+	 *  finish inside the very call that started it. */
+	UPROPERTY(BlueprintAssignable, Category = "Eleri|Dialogue")
+	FOnDialogueSceneStarted OnSceneStarted;
+
+	/** Fired once a scene is over and the player has their controls back. This is the event a dialogue
+	 *  waits on when a cutscene has to be seen before its first line. */
+	UPROPERTY(BlueprintAssignable, Category = "Eleri|Dialogue")
+	FOnDialogueSceneFinished OnSceneFinished;
+
+	/**
+	 * Fired when a scene has reached its hold point and is paused there.
+	 *
+	 * This is a different beat from OnSceneFinished and not a step on the way to it: the scene is still
+	 * on screen, still owns the camera, and is going to carry on later. A listener that starts the
+	 * dialogue from here is what puts a conversation inside a cutscene instead of after one.
+	 */
+	UPROPERTY(BlueprintAssignable, Category = "Eleri|Dialogue")
+	FOnDialogueSceneHeld OnSceneHeld;
+
+	// ----- Playing -----------------------------------------------------------------
+
+	/**
+	 * Plays Scene as a cutscene and keeps track of it until it stops.
+	 *
+	 * Instigator is whoever asked for the scene, reported back on both delegates so a listener can tell
+	 * the scene a quest started from the scene a conversation started. It is optional, because a scene
+	 * that belongs to no actor at all is a perfectly ordinary scene.
+	 *
+	 * bDisablePlayerControl takes the player's movement and looking away for the length of the scene
+	 * and is the default, since that is what makes a cutscene a cutscene. Pass false for a scene that
+	 * is only meant to drive the camera while the player keeps playing.
+	 *
+	 * Returns false when there is nothing to play, when the sequence could not be loaded, or when a
+	 * scene is already on screen. A caller that gets false is free to carry on as if it had never asked,
+	 * which is what lets a dialogue run instead of waiting for a cutscene that never started.
+	 */
+	UFUNCTION(BlueprintCallable, Category = "Eleri|Dialogue")
+	bool PlayScene(TSoftObjectPtr<ULevelSequence> Scene, AActor* Instigator = nullptr, bool bDisablePlayerControl = true);
+
+	/**
+	 * Plays Scene and holds it at the marker called HoldMarker instead of running it to its end.
+	 *
+	 * The sequence plays forward and pauses itself on reaching the marker, and pausing is all that is
+	 * needed to hold a shot: a paused player keeps everything it was driving, so the camera cut stays
+	 * possessed and the fade keeps its value, while the world itself carries on ticking. That is what
+	 * lets a dialogue run on top of a held shot rather than after it. OnSceneHeld is broadcast once the
+	 * hold has been reached; ResumeScene lets the sequence finish.
+	 *
+	 * A marker that is missing, or that sits before the start of the sequence, is reported and the
+	 * scene is played straight through instead. This is deliberate: the player resolves a marker label
+	 * it cannot find to its *current* time, which makes PlayTo run backwards, so an unresolved or
+	 * mistyped label has to be caught here rather than left to rewind the cutscene.
+	 *
+	 * Returns false on the same terms as PlayScene, and also when the sequence could not be read at all.
+	 */
+	UFUNCTION(BlueprintCallable, Category = "Eleri|Dialogue")
+	bool PlaySceneHeld(TSoftObjectPtr<ULevelSequence> Scene, FName HoldMarker, AActor* Instigator = nullptr, bool bDisablePlayerControl = true);
+
+	/** Cuts the scene on screen short. The player gets their controls back the same way they would have
+	 *  at the end of it, so nothing downstream can tell a stopped scene from a finished one. */
+	UFUNCTION(BlueprintCallable, Category = "Eleri|Dialogue")
+	void StopScene();
+
+	/** Pauses the scene on screen where it is. Drives OnSceneHeld the same way a hold point does, which
+	 *  is what makes a hold scriptable from a blueprint instead of only from a marker. */
+	UFUNCTION(BlueprintCallable, Category = "Eleri|Dialogue")
+	bool HoldScene();
+
+	/** Lets a held scene run on to its end. The player gets their controls back when it gets there, by
+	 *  the same path a scene that was never held takes. */
+	UFUNCTION(BlueprintCallable, Category = "Eleri|Dialogue")
+	bool ResumeScene();
+
+	UFUNCTION(BlueprintPure, Category = "Eleri|Dialogue")
+	bool IsScenePlaying() const { return bScenePlaying; }
+
+	/** True while the scene on screen is paused at a hold point, which is the state a dialogue that was
+	 *  started from inside a cutscene is running in. */
+	UFUNCTION(BlueprintPure, Category = "Eleri|Dialogue")
+	bool IsSceneHeld() const { return bSceneHeld; }
+
+	/** The sequence on screen, or null when there is none. */
+	UFUNCTION(BlueprintPure, Category = "Eleri|Dialogue")
+	ULevelSequence* GetActiveScene() const { return ActiveScene; }
+
+	/** Whoever asked for the scene on screen, or null when nobody did */
+	UFUNCTION(BlueprintPure, Category = "Eleri|Dialogue")
+	AActor* GetSceneInstigator() const { return SceneInstigator.Get(); }
+
+protected:
+
+	/** Both ends of a sequence arrive here, because a scene that runs to its end and a scene that is
+	 *  stopped have the same thing to do: hand the player back and announce it. */
+	UFUNCTION()
+	void HandleSceneFinished();
+
+	UFUNCTION()
+	void HandleSceneStopped();
+
+	/** Fired by the sequence player when it pauses, which is how a hold point is noticed: PlayTo asks
+	 *  the player to pause itself on the marker frame, so the pause *is* the arrival. Guarded so the
+	 *  hold is only ever announced once, because OnPause also fires for a pause nobody asked for. */
+	UFUNCTION()
+	void HandleScenePaused();
+
+	/** The world the scene was playing in is going away, so there is nobody left to hand the controls
+	 *  back to and the tracking is dropped instead of claiming a scene is still running. */
+	void HandleWorldCleanup(UWorld* World, bool bSessionEnded, bool bCleanupResources);
+
+private:
+
+	/** Puts the sequence on screen. Only reached once PlayScene has agreed there is room for one.
+	 *  HoldMarker is NAME_None for a scene that simply plays through; anything else has already been
+	 *  resolved against the sequence by TryResolveHoldMarker. */
+	bool StartScene(ULevelSequence* Scene, FName HoldMarker, AActor* Instigator, bool bDisablePlayerControl);
+
+	/** True when the sequence carries a usable marker of that name, meaning the scene can be held.
+	 *  Reports the two ways it cannot be: a missing label, and a label placed before the sequence
+	 *  starts, which would have PlayTo unwittingly run the scene backwards. */
+	static bool TryResolveHoldMarker(const ULevelSequence* Scene, FName HoldMarker);
+
+	/** The one place a scene ends, whether it ran to its end or was stopped, so that the hand-back and
+	 *  the broadcast can neither be missed nor happen twice. */
+	void FinishScene();
+
+	/** Forgets the sequence on screen, letting go of its delegates. The actor and the player are kept:
+	 *  the sequence actor is made once and pointed at each new scene, so it outlives any one of them,
+	 *  and it goes away with the world it was spawned into. */
+	void ResetSceneTracking();
+
+	/** Movement and looking are taken away from the player for the length of a scene. */
+	void TakePlayerControl();
+
+	/** Gives back exactly what TakePlayerControl took, and only when this subsystem is what took it. */
+	void RestorePlayerControl();
+
+	APlayerController* GetScenePlayerController() const;
+	UWorld* GetSceneWorld() const;
+
+	/** The sequence on screen, kept so a second request can be told what it collided with and so the
+	 *  finished broadcast can name the scene that ended. */
+	UPROPERTY()
+	TObjectPtr<ULevelSequence> ActiveScene = nullptr;
+
+	/** The actor the sequence plays through. Made for the first scene and reused by every one after it,
+	 *  so a level does not collect an actor per cutscene the player has watched, and so the actor is
+	 *  never taken down from inside the sequence player's own finished callback. */
+	UPROPERTY()
+	TObjectPtr<ALevelSequenceActor> ActiveSequenceActor = nullptr;
+
+	/** Hard, because a scene player is a plain UObject with nothing else holding on to it. */
+	UPROPERTY()
+	TObjectPtr<ULevelSequencePlayer> ActivePlayer = nullptr;
+
+	TWeakObjectPtr<AActor> SceneInstigator;
+
+	bool bScenePlaying = false;
+
+	/** True when the scene on screen was asked to hold, so a pause that arrives is the hold point
+	 *  being reached rather than a pause from somewhere else. */
+	bool bHoldRequested = false;
+
+	/** True while the scene on screen is paused at its hold point. It is the difference between a
+	 *  scene that is waiting to be let go and one that is simply playing. */
+	bool bSceneHeld = false;
+
+	/** True only while this subsystem is what holds the player's controls. A scene played with
+	 *  bDisablePlayerControl false must not hand back controls it never took, because that would turn
+	 *  a player somebody else had locked back on. */
+	bool bControlTakenByScene = false;
+
+	FDelegateHandle WorldCleanupHandle;
+};

Source/ProjectEleri/DialogueSystem/SpeechDataAsset.h

@@ -10,6 +10,7 @@
 
 struct FLineData;
 class USpeechDataAsset;
+class ULevelSequence;
 
 UENUM(BlueprintType)
 enum class EEventRequirementType : uint8
@@ -20,6 +21,23 @@ enum class EEventRequirementType : uint8
 	Max		UMETA(Hidden)
 };
 
+/**
+ * When a dialogue's scene plays.
+ *
+ * A scene at the front of a dialogue is the cutscene the conversation is about, and one at the back is
+ * the beat it ends on. There is no third option, because a scene that wants to run in the middle of a
+ * conversation is a second dialogue rather than a longer one.
+ */
+UENUM(BlueprintType)
+enum class EDialogueSceneTiming : uint8
+{
+	/** Before the first line, so the conversation happens after the cutscene rather than over it */
+	OnDialogueStart UMETA(DisplayName = "On Dialogue Start"),
+
+	/** Once the conversation is over and its window has closed */
+	OnDialogueEnd UMETA(DisplayName = "On Dialogue End")
+};
+
 USTRUCT(BlueprintType)
 struct FEventRequirement
 {
@@ -88,6 +106,52 @@ public:
 	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Eleri|Speech", meta = (Categories = "Quests"))
 	FGameplayTagContainer StartQuests;
 
+	/**
+	 * A cutscene this dialogue plays.
+	 *
+	 * It goes through UDialogueSceneSubsystem, which is what holds the player still for the length of
+	 * the sequence and gives the controls back the moment it stops. Leaving it unset makes an ordinary
+	 * conversation, which is why nothing else on this asset depends on it.
+	 */
+	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Cutscene")
+	TSoftObjectPtr<ULevelSequence> Scene;
+
+	/** Whether the scene opens the conversation or closes it */
+	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Cutscene", meta = (EditCondition = "!Scene.IsNull()", EditConditionHides))
+	EDialogueSceneTiming SceneTiming = EDialogueSceneTiming::OnDialogueStart;
+
+	/**
+	 * True to hold the dialogue until the scene has had its turn, so the lines cannot be read while the
+	 * cutscene is still running.
+	 *
+	 * The turn in question is the scene's hold point when it has one, and its end when it does not: a
+	 * scene with a hold marker is a cutscene the conversation happens *inside* of, and one without is a
+	 * cutscene the conversation happens after.
+	 *
+	 * Only a scene at the front of a dialogue can hold anything: one that closes the conversation has
+	 * nothing left to wait behind. When the scene is refused, because a quest started one of its own in
+	 * the same breath, the dialogue goes ahead rather than waiting for a cutscene that never began.
+	 */
+	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Cutscene", meta = (EditCondition = "!Scene.IsNull() && SceneTiming == EDialogueSceneTiming::OnDialogueStart", EditConditionHides))
+	bool bHoldDialogueForScene = true;
+
+	/**
+	 * Optional. The name of a marker in Scene for the dialogue to happen at.
+	 *
+	 * When it is set the scene plays only as far as that marker and holds there — the camera cut and
+	 * everything else it drove stay on screen — while the dialogue runs over the top of it. When the
+	 * dialogue ends the scene is let go and plays its tail, which is where the fade out and the release
+	 * of the camera belong. That is what makes one sequence a whole scene rather than an intro.
+	 *
+	 * Leave it empty for a scene that simply plays through before the dialogue starts.
+	 *
+	 * Author it as a Sequencer marker (the yellow ones on the timeline ruler, not a section) with its
+	 * Label set to this name, placed after the first frame. A name that does not match a marker, or one
+	 * placed at the very start, is reported in the log and the scene plays through instead.
+	 */
+	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Cutscene", meta = (EditCondition = "!Scene.IsNull() && SceneTiming == EDialogueSceneTiming::OnDialogueStart", EditConditionHides))
+	FName SceneHoldMarker;
+
 	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Eleri|Speech")
 	FText PlayerAsk;
 

Source/ProjectEleri/ProjectEleri.Build.cs

@@ -33,7 +33,9 @@ public class ProjectEleri : ModuleRules
 			"GameplayStateTreeModule",
 			"DirectiveUtilitiesRuntime",
 			"StatForge",
-			"InteractionSystem"
+			"InteractionSystem",
+			"LevelSequence",
+			"MovieScene"
 		});
 
 		PrivateDependencyModuleNames.AddRange(new string[]

Source/ProjectEleri/Public/UI/MainGameWidget.h

@@ -45,6 +45,9 @@ public:
 	UFUNCTION(BlueprintCallable, BlueprintImplementableEvent)
 	void FadeScreenByTime(float FadeTime = 1.f, float BlankScreenTime = 1.f);
 	
+	UFUNCTION(BlueprintImplementableEvent)
+	void ToggleUiForCutscene(bool bActive);
+
 	UFUNCTION(BlueprintCallable)
 	void TogglePlaceableUI(bool bEnabled);
 

Source/ProjectEleri/QuestSystem/QuestDataAsset.h

@@ -9,6 +9,7 @@
 
 #include "QuestDataAsset.generated.h"
 
+class ULevelSequence;
 class UTexture2D;
 
 /**
@@ -52,6 +53,22 @@ public:
 	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Quest", meta = (ClampMin = 0))
 	int32 DeadlineInDays = 0;
 
+	/**
+	 * Cutscenes the quest plays as it changes stage, keyed by the status it moves to.
+	 *
+	 * A stage a quest enters is a status, so this is what makes a quest able to show its own beat
+	 * without any blueprint being involved: the scene under Completed plays the moment the quest is
+	 * handed in, and the one under Failed plays when a deadline runs out, which is what makes failing a
+	 * quest something the player sees rather than something that happens to the journal.
+	 *
+	 * The scenes go through UDialogueSceneSubsystem, which is what holds the player still for the
+	 * length of the sequence and gives the controls back the moment it stops. One scene at a time is
+	 * played, so a quest that changes stage twice in a single frame shows the first scene it asked for
+	 * and stays quiet about the second.
+	 */
+	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Cutscene")
+	TMap<EQuestStatus, TSoftObjectPtr<ULevelSequence>> StatusScenes;
+
 	/** The steps, in the order the journal lists them. */
 	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Objectives", meta = (TitleProperty = "Description"))
 	TArray<FQuestObjective> Objectives;

Source/ProjectEleri/QuestSystem/QuestSubsystem.cpp

@@ -14,6 +14,7 @@
 #include "InventoryComponent.h"
 #include "MyCharacter.h"
 #include "ProjectEleri/Ai/NpcScheduleComponent.h"
+#include "ProjectEleri/DialogueSystem/DialogueSceneSubsystem.h"
 #include "ProjectEleri/DialogueSystem/DialogueSubsystem.h"
 #include "ProjectEleri/GameEventSystem/GameEventSubsystem.h"
 #include "ProjectEleri/Items/DataAssets/ItemDataAsset.h"
@@ -591,6 +592,33 @@ void UQuestSubsystem::SetQuestStatus(FQuestRuntimeState& State, EQuestStatus New
 	// quest, which can reallocate the map this state lives in.
 	UQuestDataAsset* Quest = State.Quest;
 	OnQuestStatusChanged.Broadcast(Quest, NewStatus);
+
+	// The stage's cutscene comes after the broadcast rather than before it, so a listener that reacts to
+	// the new status has already reacted by the time the scene takes the player's controls, and so the
+	// quest asset is not being read while that listener may still be writing to the quest map.
+	PlayStatusScene(Quest, NewStatus);
+}
+
+void UQuestSubsystem::PlayStatusScene(const UQuestDataAsset* Quest, EQuestStatus NewStatus)
+{
+	if (Quest == nullptr)
+	{
+		return;
+	}
+
+	const TSoftObjectPtr<ULevelSequence>* Scene = Quest->StatusScenes.Find(NewStatus);
+	if (Scene == nullptr || Scene->IsNull())
+	{
+		// Most quests have no scene for most stages, which is the ordinary case and not a fault.
+		return;
+	}
+
+	if (UDialogueSceneSubsystem* SceneSubsystem = UDialogueSceneSubsystem::Get(this))
+	{
+		// The player goes in as the instigator, because a quest is not an actor and the thing a scene
+		// listener wants to know is whose scene this is.
+		SceneSubsystem->PlayScene(*Scene, Cast<AActor>(GetTestContext()));
+	}
 }
 
 bool UQuestSubsystem::OfferQuest(FGameplayTag QuestTag)

Source/ProjectEleri/QuestSystem/QuestSubsystem.h

@@ -245,6 +245,11 @@ protected:
 	/** Moves a quest to a new status and announces it. Does nothing when it is already there. */
 	void SetQuestStatus(FQuestRuntimeState& State, EQuestStatus NewStatus);
 
+	/** Plays the cutscene the quest names for the stage it has just entered, if it names one. Called
+	 *  after the status has been announced, so a listener reacting to the stage is already listening
+	 *  by the time the scene takes the player's controls away. */
+	void PlayStatusScene(const UQuestDataAsset* Quest, EQuestStatus NewStatus);
+
 	/** Counts a step up, announcing it and completing it when it reaches what it asked for. Returns
 	 *  true when something changed. */
 	bool AdvanceObjective(FQuestRuntimeState& State, FName ObjectiveId, int32 Amount = 1);