Old API

Before the easy API, the code reached the scene and the input through longer paths. All of that still works: the easy API adds to the old one.

Before	Now (easy API)
`scene().spawn<Bullet>(x, y)`	`spawn<Bullet>(x, y, "Instancias")`
`scene().all<Enemy>()` with a `for`	`each<Enemy>([](Enemy& e) { ... })`
`scene().count<Enemy>()`	`count<Enemy>()`
`Input::held(Key::Left)`	`held(Key::Left)`
`Input::pressed(Key::Space)`	`pressed(Key::Space)`
`Input::mouseX()`	`mouseX()`
`touching<Enemy>()`	`findAt<Enemy>(x, y)`
`touching<Wall>(x + 2, y) != nullptr`	`collidesAt<Wall>(x + 2, y)`
`brasa::goToScene("Level2")`	`goTo("Level2")`
a counter decremented in `onUpdate`	`after(steps, ...)`
a random function of your own (such as `randomRange`)	`random(a, b)`

What only exists in the old form

scene() gives access to the current scene: the camera (scene().camera), the size (scene().width, scene().height), the background color and scene().alive(), the list of all the instances.
Input::mouseGuiX() and Input::mouseGuiY(): the mouse in screen coordinates, for menus.
Free functions, outside objects, use the prefix: brasa::goToScene, brasa::quit.