UE学习日志#11GAS--ASC源码简要分析9 AbilitySystemGlobals分析2 初始化相关

1 static UAbilitySystemGlobals& Get()

保证了是单例，IGameplayAbilitiesModule继承了IModuleInterface

	/** Gets the single instance of the globals object, will create it as necessary */static UAbilitySystemGlobals& Get(){return *IGameplayAbilitiesModule::Get().GetAbilitySystemGlobals();}

2 InitGlobalData相关

2.1 InitGlobalData

确保不会再次初始化

获取一些列初值

绑定到指定回调

void UAbilitySystemGlobals::InitGlobalData()
{// Make sure the user didn't try to initialize the system again (we call InitGlobalData automatically in UE5.3+).if (IsAbilitySystemGlobalsInitialized()){return;}bInitialized = true;LLM_SCOPE(TEXT("AbilitySystem"));GetGlobalCurveTable();GetGlobalAttributeMetaDataTable();InitAttributeDefaults();ReloadAttributeDefaults();GetGameplayCueManager();GetGameplayTagResponseTable();InitGlobalTags();PerformDeveloperSettingsUpgrade();InitTargetDataScriptStructCache();// Register for PreloadMap so cleanup can occur on map transitionsFCoreUObjectDelegates::PreLoadMapWithContext.AddUObject(this, &UAbilitySystemGlobals::HandlePreLoadMap);#if WITH_EDITOR// Register in editor for PreBeginPlay so cleanup can occur when we start a PIE sessionif (GIsEditor){FEditorDelegates::PreBeginPIE.AddUObject(this, &UAbilitySystemGlobals::OnPreBeginPIE);}
#endif
}

2.2 IsAbilitySystemGlobalsInitialized

朴实无华返回bInitialized

bool UAbilitySystemGlobals::IsAbilitySystemGlobalsInitialized() const
{return bInitialized;
}

2.3 GetGlobalCurveTable和GetGlobalAttributeMetaDataTable

从UGameplayAbilitiesDeveloperSettings中获取GlobalCurveTableName然后TryLoad

UCurveTable * UAbilitySystemGlobals::GetGlobalCurveTable()
{if (!GlobalCurveTable){const UGameplayAbilitiesDeveloperSettings* DeveloperSettings = GetDefault<UGameplayAbilitiesDeveloperSettings>();if (DeveloperSettings->GlobalCurveTableName.IsValid()){GlobalCurveTable = Cast<UCurveTable>(DeveloperSettings->GlobalCurveTableName.TryLoad());}}return GlobalCurveTable;
}

 GetGlobalAttributeMetaDataTable同理

UDataTable * UAbilitySystemGlobals::GetGlobalAttributeMetaDataTable()
{	if (!GlobalAttributeMetaDataTable){const UGameplayAbilitiesDeveloperSettings* DeveloperSettings = GetDefault<UGameplayAbilitiesDeveloperSettings>();if (DeveloperSettings->GlobalAttributeMetaDataTableName.IsValid()){GlobalAttributeMetaDataTable = Cast<UDataTable>(DeveloperSettings->GlobalAttributeMetaDataTableName.TryLoad());}}return GlobalAttributeMetaDataTable;
}

2.4 InitAttributeDefaults/GetGlobalAttributeSetDefaultsTablePaths

2.4.1 InitAttributeDefaults

先获取AttributeSetDefaultsTable的路径软引用

然后依次遍历路径，尝试Load，TryLoad是同步加载，可能会阻塞，常用于小资源加载

void UAbilitySystemGlobals::InitAttributeDefaults()
{TArray<FSoftObjectPath> AttribSetDefaultsTables = GetGlobalAttributeSetDefaultsTablePaths();for (const FSoftObjectPath& AttribSetDefaultsTablePath : AttribSetDefaultsTables){if (AttribSetDefaultsTablePath.IsValid()){UCurveTable* AttribTable = Cast<UCurveTable>(AttribSetDefaultsTablePath.TryLoad());if (ensureMsgf(AttribTable, TEXT("Could not load Global AttributeSet Defaults Table: %s"), *AttribSetDefaultsTablePath.ToString())){GlobalAttributeDefaultsTables.AddUnique(AttribTable);}}}
}

2.4.2 GetGlobalAttributeSetDefaultsTablePaths

PRAGMA_DISABLE/ENABLE_DEPRECATION_WARNINGS关闭和开启警告，中间的部分弃用，单个的全局tablename，保留以兼容

之后还是通过UGameplayAbilitiesDeveloperSettings获取

TArray<FSoftObjectPath> UAbilitySystemGlobals::GetGlobalAttributeSetDefaultsTablePaths() const
{TArray<FSoftObjectPath> AttribSetDefaultsTables;PRAGMA_DISABLE_DEPRECATION_WARNINGS// Handle deprecated, single global table nameif (GlobalAttributeSetDefaultsTableName.IsValid()){AttribSetDefaultsTables.Add(GlobalAttributeSetDefaultsTableName);}PRAGMA_ENABLE_DEPRECATION_WARNINGSconst UGameplayAbilitiesDeveloperSettings* DeveloperSettings = GetDefault<UGameplayAbilitiesDeveloperSettings>();AttribSetDefaultsTables.Append(DeveloperSettings->GlobalAttributeSetDefaultsTableNames);return AttribSetDefaultsTables;
}

 2.5 ReloadAttributeDefaults

重新加载GlobalAttributeDefaultsTables

如果在编辑器模式下，注册重新加载的回调

一个布尔变量确保只注册过一次

void UAbilitySystemGlobals::ReloadAttributeDefaults()
{if (!GlobalAttributeDefaultsTables.IsEmpty()){AllocAttributeSetInitter();GetAttributeSetInitter()->PreloadAttributeSetData(GlobalAttributeDefaultsTables);// Subscribe for reimports if in the editor
#if WITH_EDITORif (GIsEditor && !RegisteredReimportCallback){GEditor->GetEditorSubsystem<UImportSubsystem>()->OnAssetReimport.AddUObject(this, &UAbilitySystemGlobals::OnTableReimported);RegisteredReimportCallback = true;}
#endif}
}

2.6 GetGameplayCueManager

通过DeveloperSettings的Name或者Class来创建GlobalGameplayCueManager

回调OnCreated

判断是否要在Start加载ObjectLibraries

UGameplayCueManager* UAbilitySystemGlobals::GetGameplayCueManager()
{if (GlobalGameplayCueManager == nullptr){const UGameplayAbilitiesDeveloperSettings* DeveloperSettings = GetDefault<UGameplayAbilitiesDeveloperSettings>();// Loads mud specific gameplaycue manager object if specifiedif (GlobalGameplayCueManager == nullptr && DeveloperSettings->GlobalGameplayCueManagerName.IsValid()){GlobalGameplayCueManager = LoadObject<UGameplayCueManager>(nullptr, *DeveloperSettings->GlobalGameplayCueManagerName.ToString(), nullptr, LOAD_None, nullptr);if (GlobalGameplayCueManager == nullptr){ABILITY_LOG(Error, TEXT("Unable to Load GameplayCueManager %s"), *DeveloperSettings->GlobalGameplayCueManagerName.ToString() );}}// Load specific gameplaycue manager class if specifiedif ( GlobalGameplayCueManager == nullptr && DeveloperSettings->GlobalGameplayCueManagerClass.IsValid() ){UClass* GCMClass = LoadClass<UObject>(nullptr, *DeveloperSettings->GlobalGameplayCueManagerClass.ToString(), nullptr, LOAD_None, nullptr);if (GCMClass){GlobalGameplayCueManager = NewObject<UGameplayCueManager>(this, GCMClass, NAME_None);}}if ( GlobalGameplayCueManager == nullptr){// Fallback to base native classGlobalGameplayCueManager = NewObject<UGameplayCueManager>(this, UGameplayCueManager::StaticClass(), NAME_None);}GlobalGameplayCueManager->OnCreated();if (GetGameplayCueNotifyPaths().IsEmpty()){AddGameplayCueNotifyPath(TEXT("/Game"));ABILITY_LOG(Warning, TEXT("No GameplayCueNotifyPaths were specified in DefaultGame.ini under [/Script/GameplayAbilities.AbilitySystemGlobals]. Falling back to using all of /Game/. This may be slow on large projects. Consider specifying which paths are to be searched."));}if (GlobalGameplayCueManager->ShouldAsyncLoadObjectLibrariesAtStart()){StartAsyncLoadingObjectLibraries();}}check(GlobalGameplayCueManager);return GlobalGameplayCueManager;
}

2.7 GetGameplayTagResponseTable

还是从DeveloperSettings里获取

UGameplayTagReponseTable* UAbilitySystemGlobals::GetGameplayTagResponseTable()
{const UGameplayAbilitiesDeveloperSettings* DeveloperSettings = GetDefault<UGameplayAbilitiesDeveloperSettings>();if (GameplayTagResponseTable == nullptr && DeveloperSettings->GameplayTagResponseTableName.IsValid()){GameplayTagResponseTable = LoadObject<UGameplayTagReponseTable>(nullptr, *DeveloperSettings->GameplayTagResponseTableName.ToString(), nullptr, LOAD_None, nullptr);}return GameplayTagResponseTable;
}

2.8 InitGlobalTags

 标记激活失败的原因的标签

void UAbilitySystemGlobals::InitGlobalTags()
{auto TagFromDeprecatedName = [](FGameplayTag& Tag, FName DeprecatedName){if (!Tag.IsValid() && !DeprecatedName.IsNone()){Tag = FGameplayTag::RequestGameplayTag(DeprecatedName);return true;}return false;};PRAGMA_DISABLE_DEPRECATION_WARNINGSTagFromDeprecatedName(ActivateFailIsDeadTag, ActivateFailIsDeadName);TagFromDeprecatedName(ActivateFailCooldownTag, ActivateFailCooldownName);TagFromDeprecatedName(ActivateFailCostTag, ActivateFailCostName);TagFromDeprecatedName(ActivateFailTagsBlockedTag, ActivateFailTagsBlockedName);TagFromDeprecatedName(ActivateFailTagsMissingTag, ActivateFailTagsMissingName);TagFromDeprecatedName(ActivateFailNetworkingTag, ActivateFailNetworkingName);
PRAGMA_ENABLE_DEPRECATION_WARNINGS
}

2.9 PerformDeveloperSettingsUpgrade

先定义一个lambda表达式用于同步标签

检查是否需要更新

若需要更新就把Settings里的标签同步到Globals里

void UAbilitySystemGlobals::PerformDeveloperSettingsUpgrade()
{auto SyncTag = [](FGameplayTag& DestinationTag, const FGameplayTag& OurTag){if (OurTag.IsValid() && DestinationTag != OurTag){DestinationTag = OurTag;return true;}return false;};UGameplayAbilitiesDeveloperSettings* DeveloperSettings = GetMutableDefault<UGameplayAbilitiesDeveloperSettings>();bool bUpgraded = false;bUpgraded |= SyncTag(DeveloperSettings->ActivateFailCooldownTag, ActivateFailCooldownTag);bUpgraded |= SyncTag(DeveloperSettings->ActivateFailCostTag, ActivateFailCostTag);bUpgraded |= SyncTag(DeveloperSettings->ActivateFailNetworkingTag, ActivateFailNetworkingTag);bUpgraded |= SyncTag(DeveloperSettings->ActivateFailTagsBlockedTag, ActivateFailTagsBlockedTag);bUpgraded |= SyncTag(DeveloperSettings->ActivateFailTagsMissingTag, ActivateFailTagsMissingTag);if (bUpgraded){UE_LOG(LogAbilitySystem, Warning, TEXT("AbilitySystemGlobals' Tags did not agree with GameplayAbilitiesDeveloperSettings.  Updating GameplayAbilitiesDeveloperSettings Config to use Tags from AbilitySystemGlobals"));bool bSuccess = DeveloperSettings->TryUpdateDefaultConfigFile();if (!bSuccess){UE_LOG(LogAbilitySystem, Warning, TEXT("AbilitySystemGlobals config file (DefaultGame.ini) couldn't be saved. Make sure the file is writable to update it."));}}// Now that the upgrade is done, copy any settings set in the DeveloperSettings back to here (so calls to UAbilitySystemGlobals::Get().SomeTag work)SyncTag(ActivateFailCooldownTag, DeveloperSettings->ActivateFailCooldownTag);SyncTag(ActivateFailCostTag, DeveloperSettings->ActivateFailCostTag);SyncTag(ActivateFailNetworkingTag, DeveloperSettings->ActivateFailNetworkingTag);SyncTag(ActivateFailTagsBlockedTag, DeveloperSettings->ActivateFailTagsBlockedTag);SyncTag(ActivateFailTagsMissingTag, DeveloperSettings->ActivateFailTagsMissingTag);
}

2.10 InitTargetDataScriptStructCache

这个暂时还不太清楚作用，暂放一下

void UAbilitySystemGlobals::InitTargetDataScriptStructCache()
{TargetDataStructCache.InitForType(FGameplayAbilityTargetData::StaticStruct());EffectContextStructCache.InitForType(FGameplayEffectContext::StaticStruct());
}