crates/border-wars/Cargo.toml

@@ -8,3 +8,7 @@ authors = ["CoCoSol"]
 
 [lints]
 workspace = true
+
+[dependencies]
+bevy = "0.12.1"
+bevy_egui = "0.24.0"

crates/border-wars/src/lib.rs

@@ -0,0 +1,19 @@
+//! The file that contains utility functions, enums, structs for the game.
+
+use bevy::prelude::*;
+
+pub mod menu;
+
+/// The state of the game.
+#[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Hash, States)]
+pub enum GameState {
+    /// When we are in the main menu.
+    #[default]
+    Menu,
+
+    /// When we are in the lobby waiting for players to join the game.
+    Lobby,
+
+    /// When we play this wonderful game.
+    Game,
+}

crates/border-wars/src/main.rs

@@ -1,5 +1,13 @@
-//! A simple program that prints "Hello, world!" to the terminal.
+//! The main entry point of the game.
+
+use bevy::prelude::*;
+use border_wars::menu::MenuPlugin;
+use border_wars::GameState;
 
 fn main() {
-    println!("Hello, world!");
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_state::<GameState>()
+        .add_plugins(MenuPlugin)
+        .run();
 }

crates/border-wars/src/menu.rs

@@ -0,0 +1,48 @@
+//! The main menu of the game.
+
+use bevy::prelude::*;
+use bevy_egui::{egui, EguiContexts, EguiPlugin};
+
+use crate::GameState;
+
+/// The plugin for the menu.
+pub struct MenuPlugin;
+
+impl Plugin for MenuPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_plugins(EguiPlugin).add_systems(
+            Update,
+            menu_ui.run_if(state_exists_and_equals(GameState::Menu)),
+        );
+    }
+}
+/// Display the UI of the menu to host a game or join one.
+fn menu_ui(
+    mut ctx: EguiContexts,
+    mut connection_string: Local<String>,
+    mut next_state: ResMut<NextState<GameState>>,
+) {
+    egui::CentralPanel::default().show(ctx.ctx_mut(), |ui| {
+        ui.heading("Border Wars");
+
+        ui.separator();
+
+        ui.label("Connect to an existing game:");
+        ui.horizontal(|ui| {
+            ui.label("Game ID: ");
+            ui.text_edit_singleline(&mut *connection_string);
+
+            if ui.button("Join").clicked() {
+                next_state.set(GameState::Game);
+                // TODO: connect to the game
+            }
+        });
+
+        ui.separator();
+
+        if ui.button("Create new game").clicked() {
+            next_state.set(GameState::Lobby);
+            // TODO: create a new game
+        }
+    });
+}