Engine API¶

This page points you to the main engine entry points.

ArepyEngine is the main object that owns shared services and worlds.
SystemPipeline helps organize the order in which systems run.
SystemState stores the state object used by stateful systems.

Start here if you want to...¶

open a window and boot the engine with ArepyEngine(...)
create or switch scenes with create_world(...) and set_current_world(...)
expose shared services such as rendering, input, audio, assets, and events
understand when engine hooks and world hooks run during a frame

Main concepts¶

`ArepyEngine`¶

ArepyEngine owns the application-level services and the runtime loop.

The most important calls are:

engine = ArepyEngine(title="My Game")
world = engine.create_world("main")
engine.set_current_world("main")
engine.run()

Engine resources are global. They are visible from every world and include objects such as Display, Renderer2D, Renderer3D, Input, AudioDevice, AssetStore, and EventManager.

Worlds managed by the engine¶

When you create a world through the engine, that world receives access to the engine's global resources and can also define local resources of its own.

That makes this pattern possible:

class DialogueState:
    def __init__(self) -> None:
        self.current_line = 0


world = engine.create_world("dialogue")
world.add_resource(DialogueState())

Inside systems registered on that world, DialogueState resolves locally, while services such as Renderer2D still come from the engine.

Engine hooks vs world hooks¶

ArepyEngine still exposes its own hooks:

on_startup()
on_update()
on_render()
on_shutdown()

In addition, each world can register:

world.on_startup
world.on_update
world.on_render
world.on_shutdown

Use engine hooks for app-wide behavior. Use world hooks for scene-specific setup, teardown, or small pieces of orchestration that belong to one world.

Good companion pages¶

Generated reference¶

Where to keep reading¶

For the full module layout, browse the generated module reference in API Reference.
For a friendlier walkthrough, start with the guide pages about engine lifecycle and resources.