use bevy::prelude::*;

fn main() {
    App::new()
        .add_systems(Startup, setup)
        .add_plugins(DefaultPlugins)
        .run();
}
fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<ColorMaterial>>,
) {
    commands.spawn((Camera2d, Camera::default()));
    commands.spawn((
        Mesh2d(
            meshes.add(
                Circle {
                    radius: CONFIG.small,
                }
                .mesh()
                .build(),
            ),
        ),
        MeshMaterial2d(materials.add(Color::WHITE)),
    ));
}
struct Config {
    small: f32,
}
const CONFIG: Config = Config { small: 20. };