Character Controller and basic stuff (#46)

Issue:
==============
Closes #6

What was done:
==============
* Added camera, animation and game related modules.
* Makes the camera follow the player.
* Added a dragon spritesheet for the player.
* Added input management for player movement via mouse.
* Added a placeholder background image.
* Fixed some noisy WGPU console warnings.
* Added build optimizations for third party crates.
* Fixed a few minor issues.
* Added a few convenience functions.
* Updated all dependencies in Cargo.lock.

Cargo.toml

@@ -23,3 +23,6 @@ bevy = { version = "0.12.0", default-features = false, features = [
     "vorbis",
     "x11",
 ] }
+
+[profile.dev.package."*"]
+opt-level = 3

src/animation.rs

@@ -0,0 +1,49 @@
+use bevy::prelude::*;
+
+pub struct AnimationPlugin;
+
+impl Plugin for AnimationPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Update, animate_sprite);
+    }
+}
+
+#[derive(Component)]
+pub struct AnimationIndices {
+    first: usize,
+    last: usize,
+}
+
+impl AnimationIndices {
+    pub fn new(first: usize, last: usize) -> Self {
+        Self { first, last }
+    }
+}
+
+#[derive(Component, Deref, DerefMut)]
+pub struct AnimationTimer(Timer);
+
+impl AnimationTimer {
+    pub fn from_seconds(secs: f32) -> Self {
+        Self(Timer::from_seconds(secs, TimerMode::Repeating))
+    }
+}
+
+fn animate_sprite(
+    time: Res<Time>,
+    mut query: Query<(
+        &AnimationIndices,
+        &mut AnimationTimer,
+        &mut TextureAtlasSprite,
+    )>,
+) {
+    for (indices, mut timer, mut sprite) in &mut query {
+        if timer.tick(time.delta()).just_finished() {
+            sprite.index = if sprite.index == indices.last {
+                indices.first
+            } else {
+                sprite.index + 1
+            };
+        }
+    }
+}

src/camera.rs

@@ -0,0 +1,28 @@
+use bevy::prelude::*;
+
+use crate::game::Player;
+
+pub struct CameraPlugin;
+
+impl Plugin for CameraPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, setup_camera);
+
+        app.add_systems(Update, update_camera.run_if(any_with_component::<Player>()));
+    }
+}
+
+fn setup_camera(mut commands: Commands) {
+    commands.spawn(Camera2dBundle::default());
+}
+
+fn update_camera(
+    mut camera_query: Query<&mut Transform, With<Camera2d>>,
+    player_query: Query<&Transform, (With<Player>, Without<Camera2d>)>,
+) {
+    let player_transform = player_query.single();
+    let mut camera_transform = camera_query.single_mut();
+
+    camera_transform.translation.x = player_transform.translation.x;
+    camera_transform.translation.y = player_transform.translation.y;
+}

src/game/mod.rs

@@ -0,0 +1,5 @@
+mod player;
+mod plugin;
+
+pub use player::Player;
+pub use plugin::GamePlugin;

src/game/player.rs

@@ -0,0 +1,26 @@
+use bevy::prelude::*;
+
+use crate::animation::{AnimationIndices, AnimationTimer};
+
+#[derive(Component)]
+pub struct Player;
+
+pub(super) fn spawn_player(mut commands: Commands, asset_server: Res<AssetServer>) {
+    let texture = asset_server
+        .get_handle("textures/dragon.png")
+        .unwrap_or_default();
+    let texture_atlas = TextureAtlas::from_grid(texture, Vec2::new(191., 161.), 12, 1, None, None);
+    let texture_atlas_handle = asset_server.add(texture_atlas);
+
+    commands.spawn((
+        Player,
+        SpriteSheetBundle {
+            sprite: TextureAtlasSprite::new(0),
+            texture_atlas: texture_atlas_handle.clone(),
+            transform: Transform::from_translation(Vec2::ZERO.extend(1.)),
+            ..default()
+        },
+        AnimationIndices::new(0, 2),
+        AnimationTimer::from_seconds(0.2),
+    ));
+}

src/game/plugin.rs

@@ -0,0 +1,23 @@
+use bevy::prelude::*;
+
+use crate::AppState;
+
+use super::player::spawn_player;
+
+pub struct GamePlugin;
+
+impl Plugin for GamePlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(OnEnter(AppState::InGame), (draw_background, spawn_player));
+    }
+}
+
+fn draw_background(mut commands: Commands, asset_server: Res<AssetServer>) {
+    let texture = asset_server
+        .get_handle("textures/background.png")
+        .unwrap_or_default();
+    commands.spawn(SpriteBundle {
+        texture,
+        ..default()
+    });
+}

src/input.rs

@@ -0,0 +1,72 @@
+use std::f32::consts::FRAC_PI_2;
+
+use bevy::{ecs::system::SystemParam, prelude::*, window::PrimaryWindow};
+
+use crate::{game::Player, playing};
+
+pub struct InputPlugin;
+
+impl Plugin for InputPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Update, mouse_input.run_if(playing()));
+    }
+}
+
+#[derive(Resource)]
+struct CursorWorldPosition(Option<Vec2>);
+
+#[derive(SystemParam)]
+struct CursorWorldPositionChecker<'w, 's> {
+    window_query: Query<'w, 's, &'static Window, With<PrimaryWindow>>,
+    camera_query: Query<'w, 's, (&'static Camera, &'static GlobalTransform), With<Camera2d>>,
+}
+
+impl CursorWorldPositionChecker<'_, '_> {
+    pub fn cursor_world_position(&self) -> Option<Vec2> {
+        let window = self.window_query.single();
+
+        window.cursor_position().and_then(|cursor_position| {
+            let (camera, camera_transform) = self.camera_query.single();
+            camera.viewport_to_world_2d(camera_transform, cursor_position)
+        })
+    }
+}
+
+fn mouse_input(
+    mouse_input: ResMut<Input<MouseButton>>,
+    cursor_world_position_checker: CursorWorldPositionChecker,
+    mut query: Query<&mut Transform, With<Player>>,
+    mut gizmos: Gizmos,
+) {
+    if mouse_input.pressed(MouseButton::Right) {
+        if let Some(cursor_position) = cursor_world_position_checker.cursor_world_position() {
+            let mut player_transform = query.single_mut();
+            let player_position = player_transform.translation.truncate();
+            let cursor_to_player_vector = cursor_position - player_position;
+            let cursor_distance_to_player = cursor_position.distance(player_position);
+            let velocity_rate = cursor_distance_to_player.min(300.) / 300.;
+
+            if cursor_to_player_vector != Vec2::ZERO {
+                let direction = cursor_to_player_vector.normalize();
+
+                player_transform.translation.x += direction.x * 15. * velocity_rate;
+                player_transform.translation.y += direction.y * 15. * velocity_rate;
+
+                if direction != Vec2::ZERO {
+                    let angle = (direction).angle_between(Vec2::X);
+
+                    if angle.is_finite() {
+                        // FIXME: Rotate the image sprite to always face right?
+                        // FRAC_PI_2 is subtracted to offset the 90 degree rotation from the X axis the sprite has.
+                        player_transform.rotation = Quat::from_rotation_z(-angle - FRAC_PI_2);
+                    }
+                }
+            }
+
+            #[cfg(debug_assertions)]
+            {
+                gizmos.line_2d(player_position, cursor_position, Color::YELLOW);
+            }
+        }
+    }
+}

src/main.rs

@@ -1,14 +1,71 @@
-use audio::AudioPlugin;
-use bevy::prelude::*;
-use textures::TexturesPlugin;
+use animation::AnimationPlugin;
+use audio::{audio_assets_loaded, AudioPlugin};
+use bevy::{
+    prelude::*,
+    render::{
+        settings::{Backends, RenderCreation, WgpuSettings},
+        RenderPlugin,
+    },
+};
+use camera::CameraPlugin;
+use game::GamePlugin;
+use input::InputPlugin;
+use textures::{texture_assets_loaded, TexturesPlugin};
 
+mod animation;
 mod audio;
+mod camera;
+mod game;
+mod input;
 mod textures;
 
 fn main() {
     let mut app = App::new();
 
-    app.add_plugins((DefaultPlugins, AudioPlugin, TexturesPlugin));
+    app.add_plugins((
+        // FIXME: Remove setting the backend explicitly to avoid noisy warnings
+        // when https://github.com/gfx-rs/wgpu/issues/3959 gets fixed.
+        DefaultPlugins.set(RenderPlugin {
+            render_creation: RenderCreation::Automatic(WgpuSettings {
+                backends: Some(Backends::DX12),
+                ..default()
+            }),
+        }),
+        AnimationPlugin,
+        AudioPlugin,
+        CameraPlugin,
+        GamePlugin,
+        InputPlugin,
+        TexturesPlugin,
+    ));
+
+    app.add_state::<AppState>();
+
+    app.add_systems(
+        Update,
+        handle_asset_load.run_if(assets_loaded().and_then(run_once())),
+    );
 
     app.run();
 }
+
+#[derive(Clone, Debug, Default, Hash, PartialEq, Eq, States)]
+pub enum AppState {
+    #[default]
+    Setup,
+    InGame,
+}
+
+pub fn playing() -> impl Condition<()> {
+    IntoSystem::into_system(in_state(AppState::InGame))
+}
+
+fn handle_asset_load(mut state: ResMut<NextState<AppState>>) {
+    #[cfg(debug_assertions)]
+    info!("Assets loaded successfully.");
+    state.set(AppState::InGame);
+}
+
+fn assets_loaded() -> impl Condition<()> {
+    texture_assets_loaded().and_then(audio_assets_loaded())
+}