Implemented the save system base

Config/DefaultEngine.ini

@@ -4,6 +4,7 @@
 GameDefaultMap=/Game/Legumix/MainMenu/LVL_MainMenu.LVL_MainMenu
 GlobalDefaultGameMode=/Game/Legumix/BP_GameMode.BP_GameMode_C
 EditorStartupMap=/Game/Legumix/Levels/LVL_GYM_00.LVL_GYM_00
+GameInstanceClass=/Game/Legumix/BP_GameInstance.BP_GameInstance_C
 
 [/Script/Engine.RendererSettings]
 r.AllowStaticLighting=False

Source/LegumeMix/Private/LMGameInstance.cpp

@@ -0,0 +1,66 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+
+#include "LMGameInstance.h"
+
+#include "LMSaveGame.h"
+#include "Kismet/GameplayStatics.h"
+
+void ULMGameInstance::SaveSettings()
+{
+	const bool bSuccess = UGameplayStatics::SaveGameToSlot(SaveGame, SaveGameSlot, UserIndex);
+	if (!bSuccess)
+	{
+		UE_LOG(LogTemp, Error, TEXT("Failed to save game settings."));
+	}
+	else
+	{
+		UE_LOG(LogTemp, Display, TEXT("Saved game settings"));
+	}
+	SettingsSaved(SaveGameSlot, UserIndex, bSuccess);
+}
+
+void ULMGameInstance::AsyncSaveSettings()
+{
+	FAsyncSaveGameToSlotDelegate SavedDelegate;
+	SavedDelegate.BindUObject(this, &ULMGameInstance::SettingsSaved);
+	
+	UGameplayStatics::AsyncSaveGameToSlot(SaveGame, SaveGameSlot, UserIndex, SavedDelegate);
+}
+
+void ULMGameInstance::SettingsSaved_Implementation(const FString& SlotName, const int32 UserIndex, bool bSuccess)
+{
+	if (!bSuccess)
+	{
+		UE_LOG(LogTemp, Error, TEXT("Failed to save game settings %s with user %i."), *SlotName, UserIndex);
+	}
+	else
+	{
+		UE_LOG(LogTemp, Display, TEXT("Successfully saved game settings %s for user %i"), *SlotName, UserIndex);
+	}
+}
+
+void ULMGameInstance::LoadSettings()
+{
+	if (ULMSaveGame* UnrealSaveGame = Cast<ULMSaveGame>(UGameplayStatics::LoadGameFromSlot(SaveGameSlot, UserIndex)))
+	{
+		SaveGame = UnrealSaveGame;
+		UE_LOG(LogTemp, Display, TEXT("Loaded game settings !"));
+	}
+	else
+	{
+		if (!SaveGame)
+		{
+			SaveGame = CastChecked<ULMSaveGame>(UGameplayStatics::CreateSaveGameObject(ULMSaveGame::StaticClass()));
+		}
+		
+		if (!UGameplayStatics::SaveGameToSlot(SaveGame, SaveGameSlot, UserIndex))
+		{
+			UE_LOG(LogTemp, Error, TEXT("Failed to create settings save."))
+		}
+		else
+		{
+			UE_LOG(LogTemp, Display, TEXT("Created game settings."));
+		}
+	}
+}

Source/LegumeMix/Private/LMSaveGame.cpp

@@ -0,0 +1,4 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+
+#include "LMSaveGame.h"

Source/LegumeMix/Public/LMGameInstance.h

@@ -0,0 +1,59 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Engine/GameInstance.h"
+#include "LMGameInstance.generated.h"
+
+class ULMSaveGame;
+/**
+ * 
+ */
+UCLASS()
+class LEGUMEMIX_API ULMGameInstance : public UGameInstance
+{
+	GENERATED_BODY()
+
+public:
+	/**
+	 * Saves the current settings.
+	 */
+	UFUNCTION(BlueprintCallable, Category=Legumix)
+	void SaveSettings();
+	/**
+	 * Saves the current settings asynchronously.
+	 */
+	UFUNCTION(BlueprintCallable, Category=Legumix)
+	void AsyncSaveSettings();
+
+	/**
+	 * Callback called when a save is finalized.
+	 * @param SlotName The slot that was saved.
+	 * @param UserIndex The user index assigned to the slot.
+	 * @param bSuccess Whether the save succeeded or not.
+	 */
+	UFUNCTION(BlueprintNativeEvent, Category=Legumix)
+	void SettingsSaved(const FString& SlotName, int32 UserIndex, bool bSuccess);
+
+	/**
+	 * Load the save settings.
+	 */
+	UFUNCTION(BlueprintCallable, Category=Legumix)
+	void LoadSettings();
+
+private:
+	/**
+	 * The save game to use.
+	 */
+	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category=Legumix, meta=(AllowPrivateAccess=true))
+	TObjectPtr<ULMSaveGame> SaveGame;
+
+	/**
+	 * The save game slot to use for the save.
+	 */
+	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category=Legumix, meta=(AllowPrivateAccess=true))
+	FString SaveGameSlot;
+
+	int UserIndex = 0;
+};

Source/LegumeMix/Public/LMSaveGame.h

@@ -0,0 +1,16 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "GameFramework/SaveGame.h"
+#include "LMSaveGame.generated.h"
+
+/**
+ * 
+ */
+UCLASS()
+class LEGUMEMIX_API ULMSaveGame : public USaveGame
+{
+	GENERATED_BODY()
+};