Unreal的起动模式，是并行化，先把所有的resource加载，然后设置，event事件。
PreInitModules¶
- basic - Engine,Render,AnimGraphRuntime - Landscape,ShaderCore
- platformSpecic
StartupCoreModules¶
- Core,Networking,Messaging,SessionServices
- Slate,SlateReflector,UMG,...
FEngineLoop::PreInit¶
这里主要处理 命令行参数，以及environment 设定，例如Workingspace，游戏的名字 等等。
- malloc profiler proxy 也是这里启动的。
- LogConsole
- 把当前线程注册成GameThread
- 初使化数学库的随机数中种子
- 初使化TaskGraphSystem,以及线程的profiling,并在后面初始化线程池
- loadCoreModules()
- GThreadPool GlobalThreadPool
- InitGamePHys()
- RHIInit
- 游戏资源的加载是ProcessNewlyLoadedUobjects()
FEngineLoop::Init¶
- 判断是editor还是game.
- MovePlayer
- InitTime
- load AutomationWorker
- GEngine::Init
- PostEngineInit
UGameEngine::Init¶
- UEngine::Init
- Load and apply user game settings
- Create GameInstance
- Initialize VIewport
- StartGameInstance
AndroidMain¶
- wait for JVM thread
- change the fd_limit
- Setup Joystick support with dlopen(“libandroid.so”)
- Setup Keymap
- wait for java activity OnCreate to Finish
- Initialize file system access
- GEgnineLoop.PreInit
- InitHMDs
- EEngineLoop.Init()
- deal while loop for tick until done. - FAppEvent Ticket - GEngineLoop.Tick
- exit
- 初使化RenderingEngineVarCache
- loadPreInitMOdules()
- 读配置文件/Scripts/Engine.xxSetting
- 创建SlateApplcation
- 初使化 RHIInit
- InitGamePhys
- RHIPostInit
- GEngineInit
- RunAutomation Smoketests
LoadMap¶
- SpawnAllLocalPlayer
- SetPlayer中会来处理 键盘mapping,以及一些事件callback都是在这里设置的。每一个player都可以不一样。
FEngineLoop::Tick¶
- Profilier FrameSync
- 更新ConsoleVariable
- ENQEUE_UNIQUE_RENDER_COMMAND
- UpdateTimeAndHandleMaxTickRate
- TickPFSChart
- Update memory allcator stats
- FStats::AdvanceFrame
- Handle some per-frame tasks on the rendering thread,主要是DeferredUpdateRendering
- GEngine->Tick
- ShaderCompiling
- GDistanceFieldAsyncQueue->ProcessAsyncTasks
- Tick Slate application
- ClearPendingStatGroups
- FModuleManager::GetModuleChecked<IAutomationWorkerModule>(AutomationWorkerModuleName).Tick() 这就是Hot compilable里的实现
- RHITick
- Find the objects which need to be cleaned up the next frame
- Cleanup
- FTicker::GetCoreTicker().Tick
- FSingleThreadManager::get().Tick()
- GEngine->TickDeferredCommands();
- ENQUEUE_UNIQUE_RENDER_COMMAND, ENDFrame
- Check for async platform hardware survey results
- Set CPU utilization stats
- Set the UObject count stat
UGameEngine::Tick¶
- Tick the modulemanager //HotReload->Tick()
- updateViewPort
- Update subsystems
- Begin ticking worlds
- Tick all travel and Pending NetGames(Seamless,server,client)
- UpdateSkyCaptureContents
- UpdateReflectionCaptureContents
- Tick the world
- Issue cause event
- Tick the Viewport
- Render everything //RedrawViewports();
- Update Audio
- Rendering Thread commands ENQUEUE_UNIQUE_RENDER_COMMAND_TWOPARAMETER
- Tick animation recorder
UWorld::Tick¶
- UMETA Pre Physics
- Start Physics
- During Physics
- End Physics
- Post Physics
- Fost Update Work
- Last Demotable
- Newly Spawned
Steps
- UpdateWorld’s subsystems (NavigationSystem for now)
- BeginFrame
- Doing ActorTicks
- PrePhysics
- CollisionTreeBuild
- RunTickGroup(TG_startPhysics) - call TaskGraph to do the work.
- TickAsyncWorks
- WaitForAsyncWork
- TickableObject->Tick
- Update cameras and streams volumes
- EndFrame
- Update profiler data
- UpdateSpeedTreeWind
- FXSystem->Tick ??
- garbageCollection
PhysScense¶
FPhysScene::EndFrame/StartEndFrame,
FinishPHysicsSim ->EndFrame
// the physics tick functions
void FStartPhysicsTickFunction::ExecuteTick(float DeltaTime, enum ELevelTick TickType, ENamedThreads::Type CurrentThread, const FGraphEventRef& MyCompletionGraphEvent) void FEndPhysicsTickFunction::ExecuteTick(float De
Module的加载与管理¶
C:UnrealEngine-4.10EngineSourceRuntimeCorePrivateModulesModuleManager.cpp
其后台都是使用的DLL动态库加载，但是原始的动态库接口函数dlopen/dlsym/dlclose只提供了内容加载代码区，然后自己手工的把函数找出来。 同时虽然用一些常规的方法可以知道有些函数在这个DLL中，但是自动导出这些函数来供其他函数使用。这个方法可以用脚本语言这样来做，例如 python这些都已经实现的。 Unreal也是自己实现了类似于SWIG这样的接口，这样自己所有函数都可以实现动态的加载。 并且Unreal也自己记录哪些dll的加载了，所些没有加载。以及改动。并且在tick时实时的加载。