From ab993be4768f93ed868f6ee6e180d0ab1b79178b Mon Sep 17 00:00:00 2001
From: 2ndbeam <2ndbeam@disroot.org>
Date: Mon, 9 Mar 2026 13:59:51 +0300
Subject: [PATCH] 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
---
 Cargo.toml           |  2 +-
 src/inventory/mod.rs |  5 +++
 src/inventory/ui.rs  | 93 ++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs           | 18 ++++++++-
 src/player.rs        | 36 +++++++++++++----
 src/ui.rs            | 39 +++++++++++++++++++
 6 files changed, 183 insertions(+), 10 deletions(-)
 create mode 100644 src/inventory/ui.rs
 create mode 100644 src/ui.rs

diff --git a/Cargo.toml b/Cargo.toml
index 66fde66..6801f05 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,7 +6,7 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-bevy = { version = "0.18.0" }
+bevy = { version = "0.18.0", features = ["debug"] }
 bevy_common_assets = { version = "0.15.0", features = ["toml"] }
 bevy_input = { version = "0.18.0", features = ["serde", "serialize"] }
 leafwing-input-manager = "0.20.0"
diff --git a/src/inventory/mod.rs b/src/inventory/mod.rs
index d070aaf..eb9abca 100644
--- a/src/inventory/mod.rs
+++ b/src/inventory/mod.rs
@@ -1,12 +1,17 @@
 use bevy::prelude::*;
 
 pub mod item;
+pub mod ui;
 
 #[derive(Component)]
 pub struct Inventory {
     pub size: UVec2,
 }
 
+/// Marker that this inventory will show up when UI is built
+#[derive(Component)]
+pub struct ActiveInventory;
+
 impl Inventory {
     pub fn new(size: UVec2) -> Self {
         Self { size }
diff --git a/src/inventory/ui.rs b/src/inventory/ui.rs
new file mode 100644
index 0000000..61e27a5
--- /dev/null
+++ b/src/inventory/ui.rs
@@ -0,0 +1,93 @@
+use bevy::prelude::*;
+
+use crate::{inventory::{ActiveInventory, Inventory}, ui::{UiRoot, WindowSize}};
+
+const UI_SLOT_ASSET_PATH: &'static str = "sprites/ui/inventory_slot.png";
+
+#[derive(Component)]
+#[require(Node)]
+pub struct UiInventory;
+
+#[derive(Component)]
+#[require(Node, ImageNode)]
+pub struct UiInventorySlot(UVec2);
+
+fn ui_inventory_bundle(inventory: &Inventory, window_size: &Res<WindowSize>) -> impl Bundle {
+    let window_ratio = window_size.aspect_ratio();
+    let (width, height) = {
+        if window_ratio >= 1. {
+            (auto(), percent(100))
+        } else {
+            (percent(100), auto())
+        }
+    };
+    (
+        UiInventory,
+        Node {
+            align_self: AlignSelf::Center,
+            align_content: AlignContent::Center,
+            display: Display::Grid,
+            width,
+            height,
+            aspect_ratio: Some(inventory.size.x as f32 / inventory.size.y as f32),
+            grid_auto_columns: vec![GridTrack::percent(100. / inventory.size.x as f32)],
+            grid_auto_rows: vec![GridTrack::percent(100. / inventory.size.y as f32)],
+            ..default()
+        },
+    )
+}
+
+fn inventory_slot_bundle(x: u32, y: u32, width: u32, height: u32, image: Handle<Image>) -> impl Bundle {
+    (
+        UiInventorySlot(UVec2::new(x, y)),
+        ImageNode {
+            image,
+            image_mode: NodeImageMode::Stretch,
+            ..default()
+        },
+        Node {
+            width: percent(100.),
+            height: percent(100.),
+            grid_column: GridPlacement::start(x as i16 + 1),
+            grid_row: GridPlacement::start(y as i16 + 1),
+            ..default()
+        },
+    )
+}
+
+pub fn setup_ui_inventory(
+    mut commands: Commands,
+    asset_server: Res<AssetServer>,
+    inventory_query: Query<(&Inventory, Option<&Children>), With<ActiveInventory>>,
+    root_query: Query<Entity, With<UiRoot>>,
+    window_size: Res<WindowSize>,
+) {
+    let Ok(root) = root_query.single() else {
+        error!("Query contains more than one UiRoot");
+        return;
+    };
+    let ui_slot_image: Handle<Image> = asset_server.load(UI_SLOT_ASSET_PATH);
+    for (inventory, _children) in inventory_query {
+        let inventory_entity = commands.spawn(ui_inventory_bundle(inventory, &window_size))
+            .with_children(|commands| {
+                for x in 0..inventory.size.x {
+                    for y in 0..inventory.size.y {
+                        commands.spawn(inventory_slot_bundle(x, y, inventory.size.x, inventory.size.y, ui_slot_image.clone()));
+                    }
+                }
+            }).id();
+        commands.entity(root).add_child(inventory_entity);
+
+        // for simplicity we'll show only first inventory
+        break;
+    }
+}
+
+pub fn clear_ui_inventory(
+    mut commands: Commands,
+    inventory_query: Query<Entity, With<UiInventory>>,
+) {
+    for entity in inventory_query {
+        commands.entity(entity).despawn();
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 1e74ec8..058853f 100644
--- a/src/lib.rs
+++ b/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);
     }
 }
diff --git a/src/player.rs b/src/player.rs
index 724d6a6..902b2be 100644
--- a/src/player.rs
+++ b/src/player.rs
@@ -1,7 +1,7 @@
 use bevy::prelude::*;
 use leafwing_input_manager::prelude::*;
 
-use crate::InputAction as Action;
+use crate::{GameState, InputAction as Action, inventory::{ActiveInventory, Inventory}};
 
 #[derive(Component)]
 pub struct Player {
@@ -18,6 +18,8 @@ fn player_bundle(asset_server: &Res<AssetServer>) -> impl Bundle {
         Sprite::from_image(image),
         Transform::from_xyz(0f32, 0f32, 1f32),
         Action::default_input_map(),
+        Inventory::new(UVec2::new(12, 8)),
+        ActiveInventory,
     )
 }
 
@@ -27,15 +29,33 @@ pub fn setup_player(mut commands: Commands, asset_server: Res<AssetServer>) {
 
 pub fn handle_input(
     time: Res<Time>,
-    mut player: Query<(&Player, &ActionState<Action>, &mut Transform, &mut Sprite)>,
+    state: Res<State<GameState>>,
+    mut next_state: ResMut<NextState<GameState>>,
+    mut player: Query<(&Player, &mut ActionState<Action>, &mut Transform, &mut Sprite)>,
 ) {
     let player = player.single_mut().expect("Player should be single");
-    let (Player {speed}, action_state, mut transform, mut sprite) = player;
-    
-    let direction = action_state.clamped_value(&Action::Move);
+    match state.get() {
+        GameState::Running => {
+            let (Player {speed}, mut action_state, mut transform, mut sprite) = player;
 
-    transform.translation.x += direction * speed * time.delta_secs();
-    if direction != 0f32 {
-        sprite.flip_x = direction < 0f32;
+            if action_state.just_released(&Action::ToggleInventory) {
+                next_state.set(GameState::Inventory);
+                action_state.reset(&Action::ToggleInventory);
+            }
+            
+            let direction = action_state.clamped_value(&Action::Move);
+
+            transform.translation.x += direction * speed * time.delta_secs();
+            if direction != 0f32 {
+                sprite.flip_x = direction < 0f32;
+            }
+        },
+        GameState::Inventory => {
+            let (_, mut action_state, _, _) = player;
+            if action_state.just_released(&Action::ToggleInventory) {
+                next_state.set(GameState::Running);
+                action_state.reset(&Action::ToggleInventory);
+            }
+        },
     }
 }
diff --git a/src/ui.rs b/src/ui.rs
new file mode 100644
index 0000000..0d70e7e
--- /dev/null
+++ b/src/ui.rs
@@ -0,0 +1,39 @@
+use bevy::{prelude::*, window::WindowResized};
+
+#[derive(Component)]
+#[require(Node)]
+pub struct UiRoot;
+
+#[derive(Resource, Deref, DerefMut, Default)]
+pub struct WindowSize(Vec2);
+
+impl WindowSize {
+    pub fn aspect_ratio(&self) -> f32 {
+        self.x as f32 / self.y as f32
+    }
+}
+
+impl UiRoot {
+    pub fn new() -> impl Bundle {
+        (
+            UiRoot,
+            Node {
+                width: percent(100.),
+                height: percent(100.),
+                align_self: AlignSelf::Center,
+                justify_self: JustifySelf::Center,
+                ..default()
+            },
+        )
+    }
+}
+
+pub fn update_window_size(
+    mut resize_reader: MessageReader<WindowResized>,
+    mut window_size: ResMut<WindowSize>,
+) {
+    for event in resize_reader.read() {
+        window_size.x = event.width;
+        window_size.y = event.height;
+    }
+}