EntropyCanvas::SceneGraph

EntropyCanvas::SceneGraph

Basic scene graph implementation. More…

#include <SceneGraph.h>

Inherits from EntropyCanvas::ISceneGraph

Public Functions

	Name
	~SceneGraph() override
virtual bool	tick(float deltaTime) override Tick the scene (process systems, observers, etc.).
virtual void	setTransform(flecs::entity entity, const Transform & transform) override Update Transform component (triggers observers).
virtual void	setParent(flecs::entity child, flecs::entity parent) override Set parent-child relationship.
void	registerComponentsWithCanToggle(flecs::world & world) Register all SDK components with CanToggle trait for a Flecs world.
virtual void	queryTransforms(std::function< void(flecs::entity, const Transform &)> callback) const override Query all entities with Transform component.
SceneGraph &	operator=(const SceneGraph & ) =delete
SceneGraph &	operator=(SceneGraph && ) =delete
virtual bool	modifyTransform(flecs::entity entity, std::function< void(Transform &)> callback) override Modify Transform component with a callback.
virtual flecs::world &	getWorld() override Get the underlying Flecs world (for advanced use).
virtual const flecs::world &	getWorld() const override
virtual std::optional< Transform >	getTransform(flecs::entity entity) const override Get Transform component from an entity.
virtual flecs::entity	getParent(flecs::entity entity) const override Get parent entity.
virtual size_t	getEntityCount() const override Get total entity count.
virtual std::vector< flecs::entity >	getChildren(flecs::entity entity) const override Get all children of an entity.
virtual void	destroyEntity(flecs::entity entity) override Destroy an entity and all its children (cascade delete via ChildOf).
virtual flecs::entity	createEntity(const char * name =nullptr, const Transform * transform =nullptr, flecs::entity parent =flecs::entity::null()) override Create a new entity with optional Transform component.
virtual void	clear() override Clear all entities (reset scene).
virtual void	addTransform(flecs::entity entity, const Transform & transform) override Add Transform component to an entity.
	SceneGraph()
	SceneGraph(const SceneGraph & ) =delete
	SceneGraph(SceneGraph && ) =delete

Protected Functions

	Name
virtual void	onTransformChanged(flecs::entity entity, const Transform & transform) Called when a Transform is modified (for subclass hooks).
virtual void	onEntityDestroying(flecs::entity entity) Called when an entity is about to be destroyed (for subclass hooks).
virtual void	onEntityCreated(flecs::entity entity) Called when an entity is created (for subclass hooks).

Protected Attributes

	Name
flecs::world	_world

Additional inherited members

Public Functions inherited from EntropyCanvas::ISceneGraph

	Name
virtual	~ISceneGraph() =default

Detailed Description

class EntropyCanvas::SceneGraph;

Basic scene graph implementation.

Provides entity management, hierarchy, and component operations using Flecs ECS. This is the base implementation suitable for clients and simple use cases.

For server-side persistence (USD, DeltaTracker, etc.), see PersistentSceneGraph in CanvasEngine.

Thread Safety:

• All mutation operations must be called from the creating thread
• Read operations (getTransform, getChildren, etc.) are safe from any thread

Public Functions Documentation

function ~SceneGraph

~SceneGraph() override

function tick

virtual bool tick(
    float deltaTime
) override

Tick the scene (process systems, observers, etc.).

Parameters:

• deltaTime Time step in seconds

Return: True if world is still active

Reimplements: EntropyCanvas::ISceneGraph::tick

function setTransform

virtual void setTransform(
    flecs::entity entity,
    const Transform & transform
) override

Update Transform component (triggers observers).

Parameters:

• entity Target entity
• transform New transform value

Reimplements: EntropyCanvas::ISceneGraph::setTransform

function setParent

virtual void setParent(
    flecs::entity child,
    flecs::entity parent
) override

Set parent-child relationship.

Parameters:

• child Child entity
• parent Parent entity (null to remove parent)

Reimplements: EntropyCanvas::ISceneGraph::setParent

function registerComponentsWithCanToggle

static void registerComponentsWithCanToggle(
    flecs::world & world
)

Register all SDK components with CanToggle trait for a Flecs world.

Parameters:

• world The Flecs world to register components in

This is the SINGLE place for CanToggle registration. Call this from any code that creates a Flecs world and needs to enable/disable entities.

function queryTransforms

virtual void queryTransforms(
    std::function< void(flecs::entity, const Transform &)> callback
) const override

Query all entities with Transform component.

Parameters:

• callback Function called for each entity

Reimplements: EntropyCanvas::ISceneGraph::queryTransforms

function operator=

SceneGraph & operator=(
    const SceneGraph &
) =delete

function operator=

SceneGraph & operator=(
    SceneGraph &&
) =delete

function modifyTransform

virtual bool modifyTransform(
    flecs::entity entity,
    std::function< void(Transform &)> callback
) override

Modify Transform component with a callback.

Parameters:

• entity Target entity
• callback Function to modify the transform

Return: True if entity has Transform and callback was executed

Reimplements: EntropyCanvas::ISceneGraph::modifyTransform

function getWorld

inline virtual flecs::world & getWorld() override

Get the underlying Flecs world (for advanced use).

Return: Reference to Flecs world

Reimplements: EntropyCanvas::ISceneGraph::getWorld

function getWorld

inline virtual const flecs::world & getWorld() const override

Reimplements: EntropyCanvas::ISceneGraph::getWorld

function getTransform

virtual std::optional< Transform > getTransform(
    flecs::entity entity
) const override

Get Transform component from an entity.

Parameters:

• entity Target entity

Return: Optional transform value

Reimplements: EntropyCanvas::ISceneGraph::getTransform

function getParent

virtual flecs::entity getParent(
    flecs::entity entity
) const override

Get parent entity.

Parameters:

• entity Child entity

Return: Parent entity (null if no parent)

Reimplements: EntropyCanvas::ISceneGraph::getParent

function getEntityCount

virtual size_t getEntityCount() const override

Get total entity count.

Reimplements: EntropyCanvas::ISceneGraph::getEntityCount

function getChildren

virtual std::vector< flecs::entity > getChildren(
    flecs::entity entity
) const override

Get all children of an entity.

Parameters:

• entity Parent entity

Return: Vector of child entities

Reimplements: EntropyCanvas::ISceneGraph::getChildren

function destroyEntity

virtual void destroyEntity(
    flecs::entity entity
) override

Destroy an entity and all its children (cascade delete via ChildOf).

Parameters:

• entity Entity to destroy

Reimplements: EntropyCanvas::ISceneGraph::destroyEntity

function createEntity

virtual flecs::entity createEntity(
    const char * name =nullptr,
    const Transform * transform =nullptr,
    flecs::entity parent =flecs::entity::null()
) override

Create a new entity with optional Transform component.

Parameters:

• name Optional entity name (for debugging)
• transform Optional initial transform
• parent Optional parent entity (creates ChildOf relationship)

Return: Flecs entity handle

Reimplements: EntropyCanvas::ISceneGraph::createEntity

function clear

virtual void clear() override

Clear all entities (reset scene).

Reimplements: EntropyCanvas::ISceneGraph::clear

function addTransform

virtual void addTransform(
    flecs::entity entity,
    const Transform & transform
) override

Add Transform component to an entity.

Parameters:

• entity Target entity
• transform Initial transform value

Reimplements: EntropyCanvas::ISceneGraph::addTransform

function SceneGraph

SceneGraph()

function SceneGraph

SceneGraph(
    const SceneGraph &
) =delete

function SceneGraph

SceneGraph(
    SceneGraph &&
) =delete

Protected Functions Documentation

function onTransformChanged

virtual void onTransformChanged(
    flecs::entity entity,
    const Transform & transform
)

Called when a Transform is modified (for subclass hooks).

Parameters:

• entity The entity whose transform changed
• transform The new transform value

function onEntityDestroying

virtual void onEntityDestroying(
    flecs::entity entity
)

Called when an entity is about to be destroyed (for subclass hooks).

Parameters:

• entity The entity being destroyed

function onEntityCreated

virtual void onEntityCreated(
    flecs::entity entity
)

Called when an entity is created (for subclass hooks).

Parameters:

• entity The created entity

Protected Attributes Documentation

variable _world

flecs::world _world;

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Updated on 2026-01-26 at 17:14:35 -0500