Resources

Resources are global, one-per-game values shared between systems: asset tables, input state, the network host, project paths, scene management. They are not attached to entities.

Adding and reading

auto& assets = registry.AddResource<Engine::AssetManager>();
auto& input  = registry.GetResource<Engine::InputManager>(); // throws if missing
bool has     = registry.HasResource<Engine::InputManager>();

AddResource<T>(args...) constructs in place and returns a reference. GetResource<T>() throws ErrorEcs if the resource is missing. Guard shared resources with HasResource<T>() inside plugins so two plugins do not add the same one twice.

Built-in resources

Resource	Provided by	Purpose
AssetManager	SpritePlugin / AudioPlugin	Loaded sprites, sounds, music, fonts
InputManager	InputPlugin	Controller instances per player
VirtualResolution	Application	Virtual canvas and letterboxing
LaunchOptions	Application	Command-line arguments
ProjectContext	Editor / scene loading	Project folder and path resolution
SceneManager	Scene loading	Pending scene switch requests
State<T> / NextState<T> / StateTransitionEvent<T>	User	State machine state
NetworkHostResource	MultiplayerPlugin	ENet host and polling
PacketRegistryResource	MultiplayerPlugin	Deterministic packet name-to-id map
PacketRouterResource	MultiplayerPlugin	Packet id-to-handler dispatch
PlayerInputState	MultiplayerPlugin	Server-side network id to last input
PlayerSlotState	MultiplayerPlugin	Network id to color slot (max 5)
PrefabSpawner	Serialization::SceneSerializer	Runtime prefab instantiation hook
EditorMode	Editor	Tag resource that keeps ScriptSystem idle in the editor

Component vs. resource

Use a component for anything that is one per entity (position, health, sprite). Use a resource for anything that is one per game (asset table, input state, network host). A system can read both in the same frame.