started working on the camera movement

src/actions/mod.rs

@@ -1,3 +1,4 @@
+use bevy::input::mouse::MouseMotion;
 use bevy::prelude::*;
 
 use crate::actions::game_control::{get_movement, GameControl};
@@ -19,9 +20,14 @@ impl Plugin for ActionsPlugin {
 #[derive(Default, Resource)]
 pub struct Actions {
     pub player_movement: Option<Vec2>,
+    pub camera_movement: Option<Vec2>,
 }
 
-pub fn set_movement_actions(mut actions: ResMut<Actions>, keyboard_input: Res<Input<KeyCode>>) {
+pub fn set_movement_actions(
+    mut actions: ResMut<Actions>,
+    keyboard_input: Res<Input<KeyCode>>,
+    mut mouse_motion: EventReader<MouseMotion>,
+) {
     let player_movement = Vec2::new(
         get_movement(GameControl::Right, &keyboard_input)
             - get_movement(GameControl::Left, &keyboard_input),
@@ -34,4 +40,18 @@ pub fn set_movement_actions(mut actions: ResMut<Actions>, keyboard_input: Res<In
     } else {
         actions.player_movement = None;
     }
+
+    if mouse_motion.is_empty() {
+        actions.camera_movement = None;
+    } else {
+        actions.camera_movement = Some({
+            let mut camera_movement = Vec2::ZERO;
+
+            for motion in mouse_motion.iter() {
+                camera_movement += motion.delta;
+            }
+
+            camera_movement
+        });
+    }
 }

src/ball/ui.rs

@@ -1,4 +1,4 @@
-use bevy::prelude::*;
+use bevy::{prelude::*, ui::UiSystem};
 
 use crate::util::cleanup;
 use crate::GameState;
@@ -12,7 +12,12 @@ impl Plugin for BallUiPlugin {
         app.register_type::<BallUi>()
             .register_type::<BallUiBar>()
             .add_system(setup_ball_ui.in_schedule(OnEnter(GameState::Playing)))
-            .add_system(update_ball_ui.in_set(OnUpdate(GameState::Playing)))
+            .add_system(
+                update_ball_ui
+                    .run_if(in_state(GameState::Playing))
+                    .in_base_set(CoreSet::PostUpdate)
+                    .after(UiSystem::Stack),
+            )
             .add_system(cleanup::<BallUi>.in_schedule(OnEnter(GameState::Playing)));
     }
 }

src/camera.rs

@@ -0,0 +1,82 @@
+use bevy::{prelude::*, window::CursorGrabMode};
+use bevy_rapier3d::prelude::*;
+
+use crate::{actions::Actions, ball::Ball, util::cleanup, GameState};
+
+// TODO: Make this a setting if there's time left.
+const SENSITIVITY: f32 = 0.2;
+
+pub struct CameraPlugin;
+
+impl Plugin for CameraPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems((setup_camera, lock_cursor).in_schedule(OnEnter(GameState::Playing)))
+            .add_system(look_angles.in_set(OnUpdate(GameState::Playing)))
+            .add_system(cleanup::<Camera>.in_schedule(OnExit(GameState::Playing)));
+    }
+}
+
+#[derive(Component, Reflect, Clone, Copy, Debug, Default)]
+#[reflect(Component)]
+struct CameraControls {
+    pub radius: f32,
+}
+
+fn setup_camera(mut commands: Commands) {
+    commands
+        .spawn(Camera3dBundle {
+            transform: Transform::from_xyz(25., 7., 0.).looking_at(Vec3::ZERO, Vec3::Y),
+            ..default()
+        })
+        .insert(CameraControls { radius: 32. });
+}
+
+fn lock_cursor(mut windows: Query<&mut Window>) {
+    let mut window = windows.single_mut();
+
+    window.cursor.visible = false;
+    window.cursor.grab_mode = CursorGrabMode::Locked;
+}
+
+fn look_angles(
+    mut query: Query<(&mut Transform, &CameraControls)>,
+    target: Query<(Entity, &Transform), (With<Ball>, Without<CameraControls>)>,
+    actions: Res<Actions>,
+    time: Res<Time>,
+    rapier_context: Res<RapierContext>,
+) {
+    if let Ok((ball, target)) = target.get_single() {
+        let delta = actions.camera_movement.unwrap_or(Vec2::ZERO);
+        let delta = delta * SENSITIVITY * time.delta_seconds();
+
+        let (mut transform, camera_controls) = query.single_mut();
+
+        let yaw = Quat::from_rotation_y(-delta.x);
+        let pitch = Quat::from_rotation_x(-delta.y);
+
+        transform.rotation = yaw * transform.rotation;
+        transform.rotation = transform.rotation * pitch;
+
+        // TODO: Clamp y rotation
+
+        transform.rotation = transform.rotation.normalize();
+
+        let ray_direction = -transform.forward().normalize();
+
+        let camera_position = if let Some((_entity, toi)) = rapier_context.cast_ray(
+            target.translation,
+            ray_direction,
+            camera_controls.radius,
+            false,
+            QueryFilter::new().exclude_collider(ball),
+        ) {
+            let hit_point = target.translation + ray_direction * toi;
+
+            hit_point
+        } else {
+            target.translation + ray_direction * camera_controls.radius
+        };
+
+        transform.translation = camera_position;
+    }
+}

src/lib.rs

@@ -1,5 +1,6 @@
 mod actions;
 mod ball;
+mod camera;
 mod level;
 mod light;
 mod loading;
@@ -21,6 +22,7 @@ use bevy_rapier3d::{
     prelude::{NoUserData, RapierPhysicsPlugin},
     render::RapierDebugRenderPlugin,
 };
+use camera::CameraPlugin;
 use level::LevelPlugin;
 use light::LightPlugin;
 
@@ -47,6 +49,7 @@ impl Plugin for GamePlugin {
             .add_plugin(ActionsPlugin)
             .add_plugin(RapierPhysicsPlugin::<NoUserData>::default())
             .add_plugin(LevelPlugin)
+            .add_plugin(CameraPlugin)
             .add_plugin(AudioPlugin)
             .add_plugin(LightPlugin)
             .add_plugin(MenuPlugin)

src/menu.rs

@@ -1,5 +1,6 @@
 use crate::loading::FontAssets;
 use crate::GameState;
+use crate::util::cleanup;
 use bevy::prelude::*;
 
 pub struct MenuPlugin;
@@ -11,7 +12,7 @@ impl Plugin for MenuPlugin {
         app.init_resource::<ButtonColors>()
             .add_system(setup_menu.in_schedule(OnEnter(GameState::Menu)))
             .add_system(click_play_button.in_set(OnUpdate(GameState::Menu)))
-            .add_system(cleanup_menu.in_schedule(OnExit(GameState::Menu)));
+            .add_systems((cleanup_menu, cleanup::<Camera2d>).in_schedule(OnExit(GameState::Menu)));
     }
 }
 
@@ -35,10 +36,7 @@ fn setup_menu(
     font_assets: Res<FontAssets>,
     button_colors: Res<ButtonColors>,
 ) {
-    commands.spawn(Camera3dBundle {
-        transform: Transform::from_xyz(0., 6., 25.).looking_at(Vec3::new(0., 0., 0.), Vec3::Y),
-        ..default()
-    });
+    commands.spawn(Camera2dBundle::default());
     commands
         .spawn(ButtonBundle {
             style: Style {