Add placed actor persistence foundation

AGRARIAN_FOUNDATION_STATUS.md

@@ -24,6 +24,9 @@
 - [x] Resource nodes can use item definition assets for harvest yields.
 - [x] Building placement component added.
 - [x] Character now owns a building placement component.
+- [x] Persistent actor component added.
+- [x] Persistence subsystem can capture and restore saveable world actors.
+- [x] Primitive shelter actor is marked as a persistent world actor.
 
 ## Next Unreal Editor Tasks
 
@@ -45,6 +48,6 @@
 - [x] Add building placement component.
 - [x] Add simple crafting recipe defaults or data asset pipeline.
 - [x] Add item definition data asset class.
-- [ ] Add save/load capture for placed actors.
+- [x] Add save/load capture for placed actors.
 - [ ] Add admin/dev console commands.
 - [ ] Add wildlife base actor.

Source/AgrarianGame/AgrarianPersistenceSubsystem.cpp

@@ -1,7 +1,10 @@
 // Copyright Pacificao. All Rights Reserved.
 
 #include "AgrarianPersistenceSubsystem.h"
+#include "AgrarianPersistentActorComponent.h"
 #include "AgrarianSaveGame.h"
+#include "EngineUtils.h"
+#include "Engine/World.h"
 #include "Kismet/GameplayStatics.h"
 
 UAgrarianSaveGame* UAgrarianPersistenceSubsystem::CreateEmptySave() const
@@ -31,3 +34,121 @@ bool UAgrarianPersistenceSubsystem::DoesSaveExist() const
 {
 	return UGameplayStatics::DoesSaveGameExist(DefaultSlotName, UserIndex);
 }
+
+void UAgrarianPersistenceSubsystem::RegisterWorldActorClass(FName ActorTypeId, TSubclassOf<AActor> ActorClass)
+{
+	if (ActorTypeId != NAME_None && ActorClass)
+	{
+		WorldActorClassRegistry.Add(ActorTypeId, ActorClass);
+	}
+}
+
+int32 UAgrarianPersistenceSubsystem::CaptureWorldActors(UAgrarianSaveGame* SaveGame) const
+{
+	if (!SaveGame)
+	{
+		return 0;
+	}
+
+	TArray<UAgrarianPersistentActorComponent*> PersistentComponents;
+	FindPersistentComponents(PersistentComponents);
+
+	SaveGame->WorldActors.Reset();
+	for (const UAgrarianPersistentActorComponent* Component : PersistentComponents)
+	{
+		if (Component && Component->IsSaveable())
+		{
+			SaveGame->WorldActors.Add(Component->CaptureSaveState());
+		}
+	}
+
+	return SaveGame->WorldActors.Num();
+}
+
+int32 UAgrarianPersistenceSubsystem::RestoreWorldActors(const UAgrarianSaveGame* SaveGame, bool bClearExistingActors) const
+{
+	UWorld* World = GetWorld();
+	if (!World || !SaveGame)
+	{
+		return 0;
+	}
+
+	if (bClearExistingActors)
+	{
+		TArray<UAgrarianPersistentActorComponent*> ExistingComponents;
+		FindPersistentComponents(ExistingComponents);
+
+		for (UAgrarianPersistentActorComponent* Component : ExistingComponents)
+		{
+			if (AActor* Owner = Component ? Component->GetOwner() : nullptr)
+			{
+				Owner->Destroy();
+			}
+		}
+	}
+
+	int32 RestoredCount = 0;
+	for (const FAgrarianSavedWorldActor& SavedActor : SaveGame->WorldActors)
+	{
+		const TSubclassOf<AActor>* ActorClass = WorldActorClassRegistry.Find(SavedActor.ActorTypeId);
+		if (!ActorClass || !(*ActorClass))
+		{
+			continue;
+		}
+
+		FActorSpawnParameters SpawnParams;
+		SpawnParams.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
+
+		AActor* SpawnedActor = World->SpawnActor<AActor>(*ActorClass, SavedActor.Transform, SpawnParams);
+		if (!SpawnedActor)
+		{
+			continue;
+		}
+
+		if (UAgrarianPersistentActorComponent* Component = SpawnedActor->FindComponentByClass<UAgrarianPersistentActorComponent>())
+		{
+			Component->ApplySaveState(SavedActor);
+		}
+
+		RestoredCount++;
+	}
+
+	return RestoredCount;
+}
+
+bool UAgrarianPersistenceSubsystem::SaveCurrentWorld() const
+{
+	UAgrarianSaveGame* SaveGame = LoadOrCreateSave();
+	if (!SaveGame)
+	{
+		return false;
+	}
+
+	CaptureWorldActors(SaveGame);
+	return WriteSave(SaveGame);
+}
+
+void UAgrarianPersistenceSubsystem::FindPersistentComponents(TArray<UAgrarianPersistentActorComponent*>& OutComponents) const
+{
+	OutComponents.Reset();
+
+	UWorld* World = GetWorld();
+	if (!World)
+	{
+		return;
+	}
+
+	for (TActorIterator<AActor> ActorIt(World); ActorIt; ++ActorIt)
+	{
+		AActor* Actor = *ActorIt;
+		if (!Actor || Actor->IsPendingKillPending())
+		{
+			continue;
+		}
+
+		if (UAgrarianPersistentActorComponent* Component = Actor->FindComponentByClass<UAgrarianPersistentActorComponent>())
+		{
+			OutComponents.Add(Component);
+		}
+	}
+}

Source/AgrarianGame/AgrarianPersistenceSubsystem.h

@@ -7,6 +7,7 @@
 #include "AgrarianPersistenceSubsystem.generated.h"
 
 class UAgrarianSaveGame;
+class UAgrarianPersistentActorComponent;
 
 UCLASS()
 class UAgrarianPersistenceSubsystem : public UGameInstanceSubsystem
@@ -20,6 +21,9 @@ public:
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Persistence")
 	int32 UserIndex = 0;
 
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Persistence")
+	TMap<FName, TSubclassOf<AActor>> WorldActorClassRegistry;
+
 	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
 	UAgrarianSaveGame* CreateEmptySave() const;
 
@@ -31,4 +35,19 @@ public:
 
 	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
 	bool DoesSaveExist() const;
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	void RegisterWorldActorClass(FName ActorTypeId, TSubclassOf<AActor> ActorClass);
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	int32 CaptureWorldActors(UAgrarianSaveGame* SaveGame) const;
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	int32 RestoreWorldActors(const UAgrarianSaveGame* SaveGame, bool bClearExistingActors = true) const;
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	bool SaveCurrentWorld() const;
+
+protected:
+	void FindPersistentComponents(TArray<UAgrarianPersistentActorComponent*>& OutComponents) const;
 };

Source/AgrarianGame/AgrarianPersistentActorComponent.cpp

@@ -0,0 +1,44 @@
+// Copyright Pacificao. All Rights Reserved.
+
+#include "AgrarianPersistentActorComponent.h"
+
+UAgrarianPersistentActorComponent::UAgrarianPersistentActorComponent()
+{
+	PrimaryComponentTick.bCanEverTick = false;
+}
+
+bool UAgrarianPersistentActorComponent::IsSaveable() const
+{
+	return ActorTypeId != NAME_None && GetOwner() != nullptr;
+}
+
+FAgrarianSavedWorldActor UAgrarianPersistentActorComponent::CaptureSaveState() const
+{
+	FAgrarianSavedWorldActor SavedActor;
+	SavedActor.ActorTypeId = ActorTypeId;
+	SavedActor.StringState = StringState;
+	SavedActor.NumberState = NumberState;
+
+	if (bSaveTransform && GetOwner())
+	{
+		SavedActor.Transform = GetOwner()->GetActorTransform();
+	}
+
+	return SavedActor;
+}
+
+void UAgrarianPersistentActorComponent::ApplySaveState(const FAgrarianSavedWorldActor& SavedActor)
+{
+	StringState = SavedActor.StringState;
+	NumberState = SavedActor.NumberState;
+
+	if (ActorTypeId == NAME_None)
+	{
+		ActorTypeId = SavedActor.ActorTypeId;
+	}
+
+	if (bSaveTransform && GetOwner())
+	{
+		GetOwner()->SetActorTransform(SavedActor.Transform);
+	}
+}

Source/AgrarianGame/AgrarianPersistentActorComponent.h

@@ -0,0 +1,38 @@
+// Copyright Pacificao. All Rights Reserved.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Components/ActorComponent.h"
+#include "AgrarianSaveGame.h"
+#include "AgrarianPersistentActorComponent.generated.h"
+
+UCLASS(ClassGroup = (Agrarian), BlueprintType, Blueprintable, meta = (BlueprintSpawnableComponent))
+class UAgrarianPersistentActorComponent : public UActorComponent
+{
+	GENERATED_BODY()
+
+public:
+	UAgrarianPersistentActorComponent();
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Persistence")
+	FName ActorTypeId = NAME_None;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Persistence")
+	bool bSaveTransform = true;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Persistence")
+	TMap<FName, FString> StringState;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Persistence")
+	TMap<FName, float> NumberState;
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	bool IsSaveable() const;
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	FAgrarianSavedWorldActor CaptureSaveState() const;
+
+	UFUNCTION(BlueprintCallable, Category = "Agrarian|Persistence")
+	void ApplySaveState(const FAgrarianSavedWorldActor& SavedActor);
+};

Source/AgrarianGame/AgrarianShelterActor.cpp

@@ -1,6 +1,7 @@
 // Copyright Pacificao. All Rights Reserved.
 
 #include "AgrarianShelterActor.h"
+#include "AgrarianPersistentActorComponent.h"
 #include "Components/BoxComponent.h"
 #include "Components/StaticMeshComponent.h"
 
@@ -15,4 +16,7 @@ AAgrarianShelterActor::AAgrarianShelterActor()
 	ProtectionVolume->SetupAttachment(RootComponent);
 	ProtectionVolume->SetBoxExtent(FVector(250.0f, 250.0f, 180.0f));
 	ProtectionVolume->SetCollisionProfileName(TEXT("OverlapAllDynamic"));
+
+	PersistentActorComponent = CreateDefaultSubobject<UAgrarianPersistentActorComponent>(TEXT("PersistentActorComponent"));
+	PersistentActorComponent->ActorTypeId = TEXT("primitive_shelter");
 }

Source/AgrarianGame/AgrarianShelterActor.h

@@ -7,6 +7,7 @@
 #include "AgrarianShelterActor.generated.h"
 
 class UBoxComponent;
+class UAgrarianPersistentActorComponent;
 class UStaticMeshComponent;
 
 UCLASS(Blueprintable)
@@ -23,6 +24,9 @@ public:
 	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Agrarian|Shelter")
 	TObjectPtr<UBoxComponent> ProtectionVolume;
 
+	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Agrarian|Shelter")
+	TObjectPtr<UAgrarianPersistentActorComponent> PersistentActorComponent;
+
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Agrarian|Shelter", meta = (ClampMin = "0", ClampMax = "1"))
 	float WeatherProtection = 0.65f;
 };