# Quickstart

Get a window open in under 20 lines.

## 2D — Moving Rectangle

```python
from simvx.core import Node2D, InputMap, Key, Input, Vec2
from simvx.graphics import App

class Player(Node2D):
    def ready(self):
        InputMap.add_action("left", [Key.A, Key.LEFT])
        InputMap.add_action("right", [Key.D, Key.RIGHT])
        InputMap.add_action("up", [Key.W, Key.UP])
        InputMap.add_action("down", [Key.S, Key.DOWN])

    def process(self, dt):
        self.position += Input.get_vector("left", "right", "up", "down") * 200 * dt

    def draw(self, renderer):
        renderer.draw_rect((self.position.x, self.position.y), (60, 60), colour=(51, 102, 255))

App(width=800, height=600, title="Quickstart").run(Player(position=Vec2(370, 270)))
```

Save as `quickstart.py` and run:

```bash
uv run python quickstart.py
```

## 3D — Spinning Cube

```python
from simvx.core import Node, Camera3D, MeshInstance3D, Mesh, Material
from simvx.graphics import App

class Game(Node):
    def ready(self):
        cam = Camera3D(position=(0, 3, 8))
        cam.look_at((0, 0, 0))
        self.add_child(cam)
        self.cube = self.add_child(MeshInstance3D(mesh=Mesh.cube(), material=Material(colour=(1, 0, 0))))

    def process(self, dt):
        self.cube.rotate((0, 1, 0), 90 * dt)

App(width=1280, height=720, title="3D Quickstart").run(Game())
```

## What's Happening

1. **Node subclass** — Override `ready()` for setup, `process(dt)` for per-frame logic, `draw()` for 2D rendering.
2. **Input** — `InputMap.add_action()` binds named actions to `Key` enums. `Input.get_vector()` returns a normalised direction.
3. **App** — Creates a Vulkan window and runs the game loop. One line to launch.

## Next Steps

- {doc}`tutorial_2d` — Build a complete Pong game step by step
- {doc}`tutorial_3d` — Build a 3D asteroid dodger
- {doc}`cheatsheet` — Quick reference for common patterns