Example of my PoC bevy egui commands-based integration

simple.rs

use bevy::{
    app::{App, Update},
    prelude::{Commands, ResMut, Resource, World},
    DefaultPlugins,
};
use bevy_egui::EguiPlugin;
use bevy_egui_commands::prelude::*;
use egui::{Button, Label, Layout, Response};

#[derive(Resource, Default)]
pub struct Counter(i32);

pub fn render(mut commands: Commands, text: ResMut<Counter>) {
    commands.root(TopBottomPanel::top("top"), |mut ui: UiCommands| {
        ui.add(Label::new("Top panel"), ());
    });
    commands.root(SidePanel::left("left"), |mut ui: UiCommands| {
        ui.container(Group, (), |mut ui: UiCommands| {
            ui.add(Label::new("Left panel"), ());
        });
    });
    commands.root(SidePanel::right("right"), |mut ui: UiCommands| {
        ui.container(Layout::bottom_up(egui::Align::Min), (), |mut ui: UiCommands| {
            ui.add(Label::new("Right panel"), ());
        });
    });
    commands.root(CentralPanel::default(), |mut ui: UiCommands| {
        ui.add(
            Button::new("Hello world!"),
            |world: &mut World, resp: Response| {
                let mut counter = world.get_resource_mut::<Counter>().unwrap();
                if resp.clicked() {
                    counter.0 += 1;
                }
            },
        );
        ui.add(Label::new(format!("Clicked: {}", text.0)), ());
    });
}

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(EguiPlugin)
        .init_resource::<Counter>()
        .add_systems(Update, render)
        .run();
}