ui: Beginning of UI-related stuff

- UiRoot component
- WindowSize resource and update_window_size system
- UiInventory and UiInventorySlot components
- UiInventory now shows player inventory slots

src/lib.rs

@@ -2,6 +2,7 @@ pub mod player;
 pub mod layout;
 pub mod input;
 pub mod inventory;
+pub mod ui;
 #[cfg(test)]
 mod tests;
 
@@ -19,6 +20,13 @@ pub enum InputAction {
     Interact,
 }
 
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default, States)]
+pub enum GameState {
+    #[default]
+    Running,
+    Inventory,
+}
+
 impl InputAction {
     pub fn default_input_map() -> InputMap<Self> {
         let input_map = InputMap::default()
@@ -51,12 +59,20 @@ fn camera_bundle() -> impl Bundle {
 
 fn setup_global(mut commands: Commands) {
     commands.spawn(camera_bundle());
+    commands.spawn(ui::UiRoot::new());
 }
 
 impl Plugin for ExpeditionPlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins(input::InputAssetPlugin::<InputAction>::default())
+            .init_state::<GameState>()
+            .insert_resource(ui::WindowSize::default())
             .add_systems(Startup, (player::setup_player, setup_global))
-            .add_systems(Update, player::handle_input);
+            .add_systems(Update, (
+                player::handle_input,
+                ui::update_window_size,
+            ))
+            .add_systems(OnEnter(GameState::Inventory), inventory::ui::setup_ui_inventory)
+            .add_systems(OnExit(GameState::Inventory), inventory::ui::clear_ui_inventory);
     }
 }