FreyrExtension¶

fr::FreyrExtension integrates Freyr into a Skirnir application. It registers all services (Scene, managers, thread pool) into the DI container and wires up components and systems before the application starts.

Registration¶

Pass it to skr::ApplicationBuilder::AddExtension with a configuration lambda:

skr::ApplicationBuilder()
    .AddExtension<fr::FreyrExtension>([](fr::FreyrExtension& freyr) {
        freyr
            .WithOptions([](fr::FreyrOptionsBuilder& opts) {
                opts.WithMaxEntities(500'000)
                    .WithThreadCount(4);
            })
            .WithComponent<Position>()
            .WithComponent<Velocity>()
            .WithSystem<MovementSystem>()
            .WithSystem<CollisionSystem>();
    })
    .Build<MyApp>();

All With* calls return *this, so they can be chained freely.

Methods¶

`WithComponent<T>()`¶

Registers a component type with the ComponentManager.

freyr.WithComponent<TransformComponent>();

Warning

Every component type used in the application must be registered before the first entity that uses it is created. Failing to register a component results in a runtime assertion.

Template parameter: T — must satisfy fr::IsComponent (i.e. inherit from fr::Component).

`WithSystem<T>()`¶

Registers a system type with the SystemManager and adds it as a singleton to the DI container so it can receive injected dependencies.

freyr.WithSystem<PhysicsSystem>();

Systems are constructed in registration order. If PhysicsSystem needs an EventManager, Skirnir resolves it automatically:

class PhysicsSystem : public fr::System {
public:
    PhysicsSystem(const Ref<fr::Scene>& scene, Ref<fr::EventManager> events)
        : System(scene), mEvents(events) {}
    // ...
};

Template parameter: T — must satisfy fr::IsSystem (i.e. inherit from fr::System).

`WithOptions(fn)`¶

Configures runtime parameters via a FreyrOptionsBuilder callback.

freyr.WithOptions([](fr::FreyrOptionsBuilder& opts) {
    opts.WithMaxEntities(1'000'000)
        .WithArchetypeChunkCapacity(512)
        .WithThreadCount(std::thread::hardware_concurrency())
        .WithFixedDeltaTime(1.0f / 60.0f)
        .WithExecutionStrategy(fr::FreyrExecutionStategy::ChunkAffinity);
});

See FreyrOptionsBuilder for all available options.