Lyra学习笔记 Experience流程梳理

前言

这篇主要将视角放在Experience的流程，所以不会涉及一些更深的东西

之后ULyraExperienceManagerComponent简称为EMC

1 创建

完事开头难，首先找到了管理Experience的组件，那么它的初始化位置在哪？
其作为ALyraGameState的成员，在构造函数中用CreateDefaultSubobject创建。

//LyraGameState.h
private:// Handles loading and managing the current gameplay experienceUPROPERTY()TObjectPtr<ULyraExperienceManagerComponent>ExperienceManagerComponent;//LyraGameState.cpp
ALyraGameState::ALyraGameState(const FObjectInitializer& ObjectInitializer): Super(ObjectInitializer)
{...ExperienceManagerComponent = CreateDefaultSubobject<ULyraExperienceManagerComponent>(TEXT("ExperienceManagerComponent"));...
}

2 加载

结合EMC中的这个枚举梳理，初始为Unloaded：

//LyraExperienceManagerComponent.h
ELyraExperienceLoadState LoadState = ELyraExperienceLoadState::Unloaded;
//其定义
enum class ELyraExperienceLoadState
{Unloaded,Loading,LoadingGameFeatures,LoadingChaosTestingDelay,ExecutingActions,Loaded,Deactivating
};

结合之前的地图加载流程分析，加载的流程开始于ULyraExperienceManagerComponent::SetCurrentExperience->

ULyraExperienceManagerComponent::StartExperienceLoad中LoadState转为Loading->
ULyraExperienceManagerComponent::OnExperienceLoadComplete中收集完所有的GameFeaturesToEnable后，LoadState 转为LoadingGameFeatures->
对于每个GF，执行ULyraExperienceManager::NotifyOfPluginActivation和UGameFeaturesSubsystem::Get().LoadAndActivateGameFeaturePlugin->

先忽略测试用状态LoadingChaosTestingDelay

ULyraExperienceManagerComponent::OnExperienceFullLoadCompleted中状态转为ExecutingActions并开始执行Actions，执行顺序为Experience本身Acitons中的每一个Action、遍历ActionSets，每一个ActionSets的Actions的每一个Action，对于单个Action，顺序执行OnGameFeatureRegistering()、OnGameFeatureLoading()、OnGameFeatureActivating(Context)->
Action执行完成后，状态进入Loaded，然后分别是OnExperienceLoaded三个优先级的多播

3 Deactivate

EndPlay触发DeActive->
DeActive涉及的GameFeature->
状态转为Deactivating->
同理按顺序触发每个Action的OnGameFeatureDeactivating、OnGameFeatureUnregistering()->
状态转为Unloaded ，CurrentExperience = nullptr;

4 总结与图示