GameLoop Class

Central orchestrator for the game update cycle. More...

Declaration

class helios::engine::runtime::gameloop::GameLoop { ... }

Base class

class	PassCommitListener
	Interface for receiving notifications when a pass reaches its commit point. More...

Public Constructors Index

	GameLoop (GameWorld &gameWorld)
	Constructs a GameLoop bound to a GameWorld. More...

Public Member Functions Index

helios::engine::runtime::gameloop::Phase &	phase (const helios::engine::runtime::gameloop::PhaseType phaseType) noexcept
	Returns a reference to the specified phase. More...
void	init (GameWorld &gameWorld)
	Initializes the GameLoop and all registered phases and passes. More...
GameWorld &	gameWorld () noexcept
void	update (GameWorld &gameWorld, float deltaTime, const helios::engine::input::InputSnapshot &inputSnapshot) noexcept
	Executes one full frame update across all phases. More...
bool	isRunning (GameWorld &gameWorld) const noexcept

Protected Member Functions Index

void	onPassCommit (const CommitPoint commitPoint, GameWorld &gameWorld, UpdateContext &updateContext) noexcept
	Commits pass-level state based on the specified CommitPoint flags. More...
void	phaseCommit (GameWorld &gameWorld, UpdateContext &updateContext)
	Commits phase-level events and flushes commands and managers. More...

Protected Member Attributes Index

GameWorld &	gameWorld_
helios::engine::runtime::gameloop::Phase	prePhase_
	The pre-update phase, executed before main gameplay logic. More...
helios::engine::runtime::gameloop::Phase	mainPhase_
	The main update phase for core gameplay systems. More...
helios::engine::runtime::gameloop::Phase	postPhase_
	The post-update phase for cleanup and synchronization. More...
helios::engine::runtime::messaging::event::GameLoopEventBus	phaseEventBus_ {}
	Event bus for phase-level event propagation. More...
helios::engine::runtime::messaging::event::GameLoopEventBus	passEventBus_ {}
	Event bus for pass-level event propagation. More...
helios::engine::runtime::messaging::event::GameLoopEventBus	frameEventBus_ {}
	Event bus for frame-level event propagation. More...
float	totalTime_ = 0.0f
	Accumulated total time since the first frame, in seconds. More...

Private Member Attributes Index

bool	initialized_ = false
	Flag indicating whether init() has been called. More...

Protected Static Attributes Index

static const helios::engine::util::log::Logger &	logger_ = ...
	The logger used with this GameLoop instance. More...

Description

Central orchestrator for the game update cycle.

The GameLoop manages the execution of game systems across three distinct phases: Pre, Main, and Post. Each phase can contain multiple passes, and each pass can have a configurable commit point for fine-grained synchronization control.

Definition at line 88 of file GameLoop.ixx.

Public Constructors

GameLoop()

helios::engine::runtime::gameloop::GameLoop::GameLoop (GameWorld & gameWorld)

inline

Constructs a GameLoop bound to a GameWorld.

Initializes all phases with the same GameWorld reference so passes can resolve world-owned resources (for example command buffers) during system registration.

Parameters

gameWorld

The GameWorld associated with this GameLoop.

Definition at line 264 of file GameLoop.ixx.

264 GameLoop(GameWorld& gameWorld) : gameWorld_(gameWorld), prePhase_(*this, gameWorld_), mainPhase_(*this, gameWorld_), postPhase_(*this, gameWorld_) {};

Public Member Functions

gameWorld()

GameWorld & helios::engine::runtime::gameloop::GameLoop::gameWorld ()

inline noexcept

Definition at line 327 of file GameLoop.ixx.

327 GameWorld& gameWorld() noexcept {

328 return gameWorld_;

329 }

Reference gameWorld_.

Referenced by init, isRunning, onPassCommit, phaseCommit and update.

init()

void helios::engine::runtime::gameloop::GameLoop::init (GameWorld & gameWorld)

inline

Initializes the GameLoop and all registered phases and passes.

Iterates through all phases (Pre, Main, Post) and calls their init() methods, which in turn initialize all registered passes and systems. Systems receive a reference to the GameWorld for component queries and entity access.

Must be called exactly once before the first update() call.

Parameters

gameWorld

Reference to the game world to initialize with.

Precondition

Must not have been called before (asserts on multiple calls).

See Also

Phase::init()

See Also

Pass::init()

See Also

System::init()

Definition at line 311 of file GameLoop.ixx.

311 void init(GameWorld& gameWorld) {

312

313 assert(!initialized_ && "init() already called");

314

315 prePhase_.init(gameWorld);

316 prePhase_.addPassCommitListener(this);

317

318 mainPhase_.init(gameWorld);

319 mainPhase_.addPassCommitListener(this);

320

321 postPhase_.init(gameWorld);

322 postPhase_.addPassCommitListener(this);

323

324 initialized_ = true;

325 }

References helios::engine::runtime::gameloop::Phase::addPassCommitListener, gameWorld, mainPhase_, postPhase_, prePhase_ and helios::engine::runtime::registerComponents.

isRunning()

bool helios::engine::runtime::gameloop::GameLoop::isRunning (GameWorld & gameWorld)

inline noexcept

Definition at line 398 of file GameLoop.ixx.

398 [[nodiscard]] bool isRunning( GameWorld& gameWorld) const noexcept {

399 return initialized_ && !gameWorld.session().isDestroyed();

400 }

References gameWorld, helios::engine::runtime::world::Session::isDestroyed and helios::engine::runtime::world::GameWorld::session.

phase()

helios::engine::runtime::gameloop::Phase & helios::engine::runtime::gameloop::GameLoop::phase (const helios::engine::runtime::gameloop::PhaseType phaseType)

inline noexcept

Returns a reference to the specified phase.

Parameters

phaseType

The type of phase to retrieve (Pre, Main, or Post).

Returns

Reference to the requested Phase.

Definition at line 274 of file GameLoop.ixx.

274 [[nodiscard]] helios::engine::runtime::gameloop::Phase& phase(const helios::engine::runtime::gameloop::PhaseType phaseType) noexcept {

275

276 switch (phaseType) {

277 case helios::engine::runtime::gameloop::PhaseType::Pre:

278 return prePhase_;

279 break;

280 case helios::engine::runtime::gameloop::PhaseType::Main:

281 return mainPhase_;

282 break;

283 case helios::engine::runtime::gameloop::PhaseType::Post:

284 return postPhase_;

285 break;

286 }

287

288 std::unreachable();

289

290 }

References helios::engine::runtime::gameloop::Main, mainPhase_, helios::engine::runtime::gameloop::Post, postPhase_, helios::engine::runtime::gameloop::Pre, prePhase_ and helios::engine::runtime::registerComponents.

update()

void helios::engine::runtime::gameloop::GameLoop::update (GameWorld & gameWorld, float deltaTime, const helios::engine::input::InputSnapshot & inputSnapshot)

inline noexcept

Executes one full frame update across all phases.

Iterates through Pre, Main, and Post phases, updating all registered systems and committing events and commands after each phase. The frame lifecycle:

1. Pre Phase: Input processing, command generation, preparation
2. Main Phase: Core gameplay logic, physics, collision detection
3. Post Phase: Cleanup, synchronization, rendering preparation

After each phase, phaseCommit() is called to:

• Swap phase event buffers (events become readable in next phase)
• Clear pass event buffers
• Flush command buffer
• Flush managers

After the Post phase, the frame event bus is swapped, making frame-level events readable in the next frame.

Parameters

gameWorld	Reference to the game world.
deltaTime	Time elapsed since the last frame in seconds.
inputSnapshot	Snapshot of the current input state.
viewportSnapshots	Snapshots of viewports registered with an id.

Precondition

init() must have been called before the first update.

See Also

Phase

See Also

phaseCommit()

See Also

UpdateContext

Definition at line 361 of file GameLoop.ixx.

361 void update(

362 GameWorld& gameWorld,

363 float deltaTime,

364 const helios::engine::input::InputSnapshot& inputSnapshot

365 ) noexcept {

366

367 assert(initialized_ && "GameLoop not initialized");

368

369 totalTime_ += deltaTime;

370

371 auto updateContext = UpdateContext(

372 gameWorld.session(),

373 gameWorld.runtimeEnvironment(),

374 deltaTime,

375 totalTime_,

376 phaseEventBus_,

377 passEventBus_,

378 frameEventBus_,

379 inputSnapshot,

380 gameWorld.level(),

381 gameWorld.engineWorld()

382 );

383

384 auto& session = gameWorld.session();

385

386 // gameloop phases

387 prePhase_.update(gameWorld, updateContext);

388 phaseCommit(gameWorld, updateContext);

389

390 mainPhase_.update(gameWorld, updateContext);

391 phaseCommit(gameWorld, updateContext);

392

393 postPhase_.update(gameWorld, updateContext);

394 phaseCommit(gameWorld, updateContext);

395 frameEventBus_.swapBuffers();

396 }

References helios::engine::runtime::world::GameWorld::engineWorld, frameEventBus_, gameWorld, helios::engine::runtime::world::GameWorld::level, mainPhase_, passEventBus_, phaseCommit, phaseEventBus_, postPhase_, prePhase_, helios::engine::runtime::registerComponents, helios::engine::runtime::world::GameWorld::runtimeEnvironment, helios::engine::runtime::world::GameWorld::session, helios::engine::core::container::buffer::TypeIndexedDoubleBuffer< Indexer >::swapBuffers and totalTime_.

Protected Member Functions

onPassCommit()

void helios::engine::runtime::gameloop::GameLoop::onPassCommit (const CommitPoint commitPoint, GameWorld & gameWorld, UpdateContext & updateContext)

inline noexcept protected virtual

Commits pass-level state based on the specified CommitPoint flags.

Called after each pass that has a commit point configured. The CommitPoint flags determine which synchronization actions are performed:

• PassEvents: Swaps pass event bus buffers, making events pushed via UpdateContext::pushPass() readable in subsequent passes.
• FlushCommands: Executes pending commands from the CommandBuffer.
• FlushManagers: Processes manager requests (e.g., spawning from pools).

The order is: FlushCommands → FlushManagers → PassEvents. Commands must be flushed before managers to ensure spawn requests are generated before being processed.

Parameters

commitPoint	The flags specifying which actions to perform.
gameWorld	The game world where the commit occured.
updateContext	The current update context.

See Also

CommitPoint

See Also

Pass::addCommitPoint()

See Also

UpdateContext::pushPass()

See Also

UpdateContext::readPass()

Definition at line 198 of file GameLoop.ixx.

198 void onPassCommit(

199 const CommitPoint commitPoint,

200 GameWorld& gameWorld,

201 UpdateContext& updateContext) noexcept {

202

203 // commands must be executed before Managers

204 if ((commitPoint & CommitPoint::FlushCommands) == CommitPoint::FlushCommands) {

205 gameWorld.flushCommandBuffers(updateContext);

206 }

207

208 if ((commitPoint & CommitPoint::FlushManagers) == CommitPoint::FlushManagers) {

209 gameWorld.flushManagers(updateContext);

210 }

211

212 // managers might create pass events

213 if ((commitPoint & CommitPoint::PassEvents) == CommitPoint::PassEvents) {

214 passEventBus_.swapBuffers();

215 }

216

217 }

References helios::engine::runtime::world::GameWorld::flushCommandBuffers, helios::engine::runtime::gameloop::FlushCommands, helios::engine::runtime::gameloop::FlushManagers, helios::engine::runtime::world::GameWorld::flushManagers, gameWorld, passEventBus_, helios::engine::runtime::gameloop::PassEvents, helios::engine::runtime::registerComponents and helios::engine::core::container::buffer::TypeIndexedDoubleBuffer< Indexer >::swapBuffers.

phaseCommit()

void helios::engine::runtime::gameloop::GameLoop::phaseCommit (GameWorld & gameWorld, UpdateContext & updateContext)

inline protected

Commits phase-level events and flushes commands and managers.

Called after each phase completes. This method:

1. Clears pass event buffers for the new phase.
2. Flushes the command buffer, executing deferred commands.
3. Flushes managers, allowing to process any request generated by the commands.
4. Swaps phase event bus buffers, making events readable in the next phase.

Parameters

gameWorld	Reference to the game world.
updateContext	The current update context.

See Also

UpdateContext::pushPhase()

See Also

UpdateContext::readPhase()

Definition at line 235 of file GameLoop.ixx.

235 void phaseCommit(

236 GameWorld& gameWorld,

237 UpdateContext& updateContext) {

238

239 passEventBus_.clearAll();

240

241 // command buffers generate requests for managers, so this comes first

242 gameWorld.flushCommandBuffers(updateContext);

243

244 // managers process requests

245 gameWorld.flushManagers(updateContext);

246

247 // make sure flushed managers make their events available to the phase event bus

248 phaseEventBus_.swapBuffers();

249 }

References helios::engine::core::container::buffer::TypeIndexedDoubleBuffer< Indexer >::clearAll, helios::engine::runtime::world::GameWorld::flushCommandBuffers, helios::engine::runtime::world::GameWorld::flushManagers, gameWorld, passEventBus_, phaseEventBus_, helios::engine::runtime::registerComponents and helios::engine::core::container::buffer::TypeIndexedDoubleBuffer< Indexer >::swapBuffers.

Referenced by update.

Protected Member Attributes

frameEventBus_

helios::engine::runtime::messaging::event::GameLoopEventBus helios::engine::runtime::gameloop::GameLoop::frameEventBus_ {}

protected

Event bus for frame-level event propagation.

Events pushed via UpdateContext::pushFrame() are buffered here and become readable in the next frame via UpdateContext::readFrame(). The buffer swap occurs at the end of the Post phase.

Frame-level events persist across all phases within a frame and are useful for cross-frame communication (e.g., collision events that should be processed in the next frame).

See Also

UpdateContext::pushFrame()

See Also

UpdateContext::readFrame()

Definition at line 165 of file GameLoop.ixx.

165 helios::engine::runtime::messaging::event::GameLoopEventBus frameEventBus_{};

Referenced by update.

gameWorld_

GameWorld& helios::engine::runtime::gameloop::GameLoop::gameWorld_

protected

Definition at line 107 of file GameLoop.ixx.

107 GameWorld& gameWorld_;

Referenced by gameWorld.

mainPhase_

helios::engine::runtime::gameloop::Phase helios::engine::runtime::gameloop::GameLoop::mainPhase_

protected

The main update phase for core gameplay systems.

Definition at line 118 of file GameLoop.ixx.

118 helios::engine::runtime::gameloop::Phase mainPhase_;

Referenced by init, phase and update.

passEventBus_

helios::engine::runtime::messaging::event::GameLoopEventBus helios::engine::runtime::gameloop::GameLoop::passEventBus_ {}

protected

Event bus for pass-level event propagation.

Events pushed via UpdateContext::pushPass() are buffered here and become readable in subsequent passes via UpdateContext::readPass(). The buffer swap occurs when a pass has a commit point.

See Also

UpdateContext::pushPass()

See Also

UpdateContext::readPass()

See Also

Pass::addCommitPoint()

Definition at line 149 of file GameLoop.ixx.

149 helios::engine::runtime::messaging::event::GameLoopEventBus passEventBus_{};

Referenced by onPassCommit, phaseCommit and update.

phaseEventBus_

helios::engine::runtime::messaging::event::GameLoopEventBus helios::engine::runtime::gameloop::GameLoop::phaseEventBus_ {}

protected

Event bus for phase-level event propagation.

Events pushed via UpdateContext::pushPhase() are buffered here and become readable in the next phase via UpdateContext::readPhase(). The buffer swap occurs in phaseCommit().

See Also

UpdateContext::pushPhase()

See Also

UpdateContext::readPhase()

Definition at line 136 of file GameLoop.ixx.

136 helios::engine::runtime::messaging::event::GameLoopEventBus phaseEventBus_{};

Referenced by phaseCommit and update.

postPhase_

helios::engine::runtime::gameloop::Phase helios::engine::runtime::gameloop::GameLoop::postPhase_

protected

The post-update phase for cleanup and synchronization.

Definition at line 123 of file GameLoop.ixx.

123 helios::engine::runtime::gameloop::Phase postPhase_;

Referenced by init, phase and update.

prePhase_

helios::engine::runtime::gameloop::Phase helios::engine::runtime::gameloop::GameLoop::prePhase_

protected

The pre-update phase, executed before main gameplay logic.

Definition at line 113 of file GameLoop.ixx.

113 helios::engine::runtime::gameloop::Phase prePhase_;

Referenced by init, phase and update.

totalTime_

float helios::engine::runtime::gameloop::GameLoop::totalTime_ = 0.0f

protected

Accumulated total time since the first frame, in seconds.

Definition at line 170 of file GameLoop.ixx.

170 float totalTime_ = 0.0f;

Referenced by update.

Private Member Attributes

initialized_

bool helios::engine::runtime::gameloop::GameLoop::initialized_ = false

Flag indicating whether init() has been called.

Used to assert that init() is called exactly once before the first update() and to prevent multiple initializations.

Definition at line 97 of file GameLoop.ixx.

97 bool initialized_ = false;

Protected Static Attributes

logger_

const helios::engine::util::log::Logger& helios::engine::runtime::gameloop::GameLoop::logger_

protected static

The logger used with this GameLoop instance.

Initialiser

= helios::engine::util::log::LogManager::loggerForScope( HELIOS_LOG_SCOPE)

Definition at line 105 of file GameLoop.ixx.

105 inline static const helios::engine::util::log::Logger& logger_ = helios::engine::util::log::LogManager::loggerForScope(

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The documentation for this class was generated from the following file:

• GameLoop.ixx

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