Deki::Engine Class Reference

Engine singleton: owns the scene system, lifecycle and frame loop. More...

#include <deki/Engine.h>

Classes
struct	FrameTimings
	How long the parts of a frame took, in milliseconds of the engine's clock: update (input, lifecycle, update callbacks), render and present. More...

Public Member Functions
const EngineHost &	GetHost () const
void	Shutdown ()
	Shuts the engine down and frees its resources.
void	Update (uint32_t deltaTime)
	Runs one frame. deltaTime is milliseconds since the last call.
void	ProcessLifecycle ()
	Runs Awake, Start and Update on the active scene, and handles a scene change made during them.
void	Render ()
	Renders the current scene into the render system's framebuffer.
void	PresentFrame ()
	Sends the render system's framebuffer to the display.
void	RequestFullRefresh ()
	Makes the next present cover the whole screen, including the display's own RequestFullRefresh.
size_t	RegisterUpdate (const UpdateCallback &callback)
	Calls callback every frame. Returns an id for UnregisterUpdate.
void	UnregisterUpdate (size_t id)
	Removes the callback that RegisterUpdate returned id for.
void	RunUpdateCallbacks (uint32_t deltaTime)
	Runs the registered update callbacks once.
void	SetRootScene (Scene *scene, bool takeOwnership=true)
	Makes scene the root scene.
Scene *	GetRootScene () const
	The root scene, or nullptr when none is set.
Scene *	CreateScene ()
	Creates an empty scene.
IRenderSystem &	GetRenderer () const
	The installed render system.
SceneSystem &	GetSceneSystem () const
LifecycleManager *	GetLifecycleManager () const
IRenderSystem *	GetRenderSystem () const
	The render system, or nullptr when no rendering package is loaded.
void	SetRenderSystem (IRenderSystem *rs)
	Called by a rendering package when it registers. The package owns rs.
IInputSystem *	GetInputSystem () const
	The input system, or nullptr when no input package is loaded.
void	SetInputSystem (IInputSystem *is)
	Called by an input package when it registers. The package owns is.
IDisplay *	GetDisplay () const
	The active display, set by a display package through SetDisplay(), or nullptr when none is loaded.
void	SetDisplay (IDisplay *display, const std::string &name="")
	Registers the active display; SDL3Display, LovyanGFXDisplay, EditorDisplay and the like call it when their package loads.
const std::string &	GetDisplayName () const
	Display name set by the registering package, such as "SDL3".
bool	IsDisplayInitialized () const
	True when a display is registered and its IsInitialized() is true.
bool	IsInitialized () const
void	SetGameUpdateCallback (const GameUpdateCallback &callback)
	Sets the callback that runs game logic each frame.
void	SetTargetFPS (uint32_t fps)
	Frame rate the main loop aims for. The default is 30.
void	RunMainLoop ()
	Runs the main loop (timing, platform updates, rendering, callbacks) until StopMainLoop().
void	StopMainLoop ()
bool	IsRunning () const
void	MarkDirty ()
	Asks for a redraw.
bool	IsDirty () const
	True when a redraw is needed.
FrameTimings	GetLastFrameTimings () const
	How long the parts of the last frame took: see FrameTimings.
const uint8_t *	GetFrameBuffer () const
int32_t	GetScreenWidth () const
int32_t	GetScreenHeight () const
ColorFormat	GetFrameBufferFormat () const
EngineSettings &	GetSettings ()
const EngineSettings &	GetSettings () const

Static Public Member Functions
static Engine &	GetInstance ()
static bool	Initialize ()
	Starts the engine from the active project settings, with EngineHost::Editor() in editor builds and EngineHost::Device() otherwise.
static bool	Initialize (const EngineHost &host)
	Starts the engine with the given host configuration.
static bool	IsRuntimeMode ()
	True on a device, and in the editor during play mode.
static void	SetRuntimeMode (bool runtime)
	Called by the editor's play mode when it starts and stops.

Detailed Description

Engine singleton: owns the scene system, lifecycle and frame loop.

Holds the active scene graph through SceneSystem, drives the component lifecycle (Awake, Start, Update) through LifecycleManager, and calls whichever render, input and display providers packages have installed. The providers are optional, so a headless or editor-hosted engine is the same class with null providers.

Member Function Documentation

GetInstance()

Engine & Deki::Engine::GetInstance ( )

static

Initialize() [1/2]

bool Deki::Engine::Initialize ( )

static

Starts the engine from the active project settings, with EngineHost::Editor() in editor builds and EngineHost::Device() otherwise.

Returns false on failure.

Initialize() [2/2]

bool Deki::Engine::Initialize ( const EngineHost & host )

static

Starts the engine with the given host configuration.

GetHost()

const EngineHost & Deki::Engine::GetHost ( ) const

inline

Shutdown()

void Deki::Engine::Shutdown

(

)

Shuts the engine down and frees its resources.

Update()

void Deki::Engine::Update

(

uint32_t

deltaTime

)

Runs one frame. deltaTime is milliseconds since the last call.

ProcessLifecycle()

void Deki::Engine::ProcessLifecycle

(

)

Runs Awake, Start and Update on the active scene, and handles a scene change made during them.

Render()

void Deki::Engine::Render

(

)

Renders the current scene into the render system's framebuffer.

PresentFrame()

void Deki::Engine::PresentFrame

(

)

Sends the render system's framebuffer to the display.

When the display can present partial frames, only the changed rectangles are sent (IRenderSystem::GetPresentRects + IDisplay::PresentRegions); otherwise the whole frame. Every present in the engine goes through here.

RequestFullRefresh()

void Deki::Engine::RequestFullRefresh

(

)

Makes the next present cover the whole screen, including the display's own RequestFullRefresh.

RegisterUpdate()

size_t Deki::Engine::RegisterUpdate

(

const UpdateCallback &

callback

)

Calls callback every frame. Returns an id for UnregisterUpdate.

UnregisterUpdate()

void Deki::Engine::UnregisterUpdate

(

size_t

id

)

Removes the callback that RegisterUpdate returned id for.

A package DLL that registers a callback must unregister it before it unloads, or the engine calls into unmapped code on the next frame.

RunUpdateCallbacks()

void Deki::Engine::RunUpdateCallbacks

(

uint32_t

deltaTime

)

Runs the registered update callbacks once.

deltaTime is milliseconds since the previous call. Update() does this itself; hosts that drive the lifecycle by hand (the editor's play mode) call it so package systems (tweens, ...) tick there as they do on a device.

SetRootScene()

void Deki::Engine::SetRootScene	(	Scene *	scene,
		bool	takeOwnership = true )

Makes scene the root scene.

With takeOwnership, the engine deletes it when it is replaced or on shutdown.

GetRootScene()

Scene * Deki::Engine::GetRootScene

(

)

const

The root scene, or nullptr when none is set.

CreateScene()

Scene * Deki::Engine::CreateScene

(

)

Creates an empty scene.

GetRenderer()

IRenderSystem & Deki::Engine::GetRenderer ( ) const

inline

The installed render system.

Call it only when one is installed (see GetRenderSystem).

GetSceneSystem()

SceneSystem & Deki::Engine::GetSceneSystem ( ) const

inline

GetLifecycleManager()

LifecycleManager * Deki::Engine::GetLifecycleManager ( ) const

inline

GetRenderSystem()

IRenderSystem * Deki::Engine::GetRenderSystem ( ) const

inline

The render system, or nullptr when no rendering package is loaded.

SetRenderSystem()

void Deki::Engine::SetRenderSystem ( IRenderSystem * rs )

inline

Called by a rendering package when it registers. The package owns rs.

GetInputSystem()

IInputSystem * Deki::Engine::GetInputSystem ( ) const

inline

The input system, or nullptr when no input package is loaded.

SetInputSystem()

void Deki::Engine::SetInputSystem ( IInputSystem * is )

inline

Called by an input package when it registers. The package owns is.

GetDisplay()

IDisplay * Deki::Engine::GetDisplay ( ) const

inline

The active display, set by a display package through SetDisplay(), or nullptr when none is loaded.

SetDisplay()

void Deki::Engine::SetDisplay	(	IDisplay *	display,
		const std::string &	name = "" )

Registers the active display; SDL3Display, LovyanGFXDisplay, EditorDisplay and the like call it when their package loads.

The package owns the display. The engine keeps the pointer and a name for diagnostics, and sizes the framebuffer to the display, so every target renders at its own native resolution.

GetDisplayName()

const std::string & Deki::Engine::GetDisplayName ( ) const

inline

Display name set by the registering package, such as "SDL3".

IsDisplayInitialized()

bool Deki::Engine::IsDisplayInitialized ( ) const

inline

True when a display is registered and its IsInitialized() is true.

IsInitialized()

bool Deki::Engine::IsInitialized ( ) const

inline

IsRuntimeMode()

bool Deki::Engine::IsRuntimeMode ( )

static

True on a device, and in the editor during play mode.

In runtime mode components follow the device code path: no editor GUID sync, no font preview, no on-demand baking.

SetRuntimeMode()

void Deki::Engine::SetRuntimeMode ( bool runtime )

static

Called by the editor's play mode when it starts and stops.

SetGameUpdateCallback()

void Deki::Engine::SetGameUpdateCallback

(

const GameUpdateCallback &

callback

)

Sets the callback that runs game logic each frame.

SetTargetFPS()

void Deki::Engine::SetTargetFPS

(

uint32_t

fps

)

Frame rate the main loop aims for. The default is 30.

RunMainLoop()

void Deki::Engine::RunMainLoop

(

)

Runs the main loop (timing, platform updates, rendering, callbacks) until StopMainLoop().

StopMainLoop()

void Deki::Engine::StopMainLoop

(

)

IsRunning()

bool Deki::Engine::IsRunning ( ) const

inline

MarkDirty()

void Deki::Engine::MarkDirty ( )

inline

Asks for a redraw.

IsDirty()

bool Deki::Engine::IsDirty ( ) const

inline

True when a redraw is needed.

GetLastFrameTimings()

FrameTimings Deki::Engine::GetLastFrameTimings ( ) const

inline

How long the parts of the last frame took: see FrameTimings.

GetFrameBuffer()

const uint8_t * Deki::Engine::GetFrameBuffer

(

)

const

GetScreenWidth()

int32_t Deki::Engine::GetScreenWidth

(

)

const

GetScreenHeight()

int32_t Deki::Engine::GetScreenHeight

(

)

const

GetFrameBufferFormat()

ColorFormat Deki::Engine::GetFrameBufferFormat

(

)

const

GetSettings() [1/2]

EngineSettings & Deki::Engine::GetSettings ( )

inline

GetSettings() [2/2]

const EngineSettings & Deki::Engine::GetSettings ( ) const

inline

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

• deki-engine/include/deki/Engine.h