drag and drop

src/animation/transform.rs

@@ -15,6 +15,6 @@ impl AnimatedTransform {
 
 pub fn transform_animation(query: Query<(&mut Transform, &AnimatedTransform)>) {
     for (mut transform, anim_transform) in query {
-        transform.translation = transform.translation.lerp(anim_transform.translation, 0.5);
+        transform.translation = transform.translation.lerp(anim_transform.translation, 0.25);
     }
 }

src/card/drag.rs

@@ -1,4 +1,68 @@
 use bevy::prelude::*;
 
+use crate::{animation::transform::AnimatedTransform, card::Hand};
+
 #[derive(Component)]
 pub struct DraggableCard;
+
+#[derive(Component)]
+pub struct DraggedCard;
+
+#[derive(Resource)]
+pub struct MousePosition(pub Vec3);
+
+pub fn mouse_position_system(
+    mut mouse: ResMut<MousePosition>,
+    window: Single<&Window>,
+    camera: Single<(&Camera, &GlobalTransform)>,
+) {
+    if let Some(Ok(mouse_pos)) = window
+        .cursor_position()
+        .and_then(|viewport_pos| Some(camera.0.viewport_to_world_2d(camera.1, viewport_pos)))
+    {
+        mouse.0 = Vec3 {
+            x: mouse_pos.x,
+            y: mouse_pos.y,
+            z: 0.,
+        }
+    }
+}
+
+pub fn card_drag_start(
+    event: On<Pointer<DragStart>>,
+    mut commands: Commands,
+    card_query: Query<(), With<DraggableCard>>,
+    dragged_option: Option<Single<&DraggedCard>>,
+) {
+    if dragged_option.is_some() {
+        return;
+    }
+    if let Err(_) = card_query.get(event.entity) {
+        return;
+    }
+
+    commands
+        .entity(event.entity)
+        .insert(DraggedCard)
+        .remove_parent_in_place();
+}
+
+pub fn card_drag(
+    _: On<Pointer<Drag>>,
+    mut card_transform: Single<&mut AnimatedTransform, With<DraggedCard>>,
+    mouse_pos: Res<MousePosition>,
+) {
+    card_transform.translation = mouse_pos.0;
+}
+
+pub fn card_drag_end(
+    _: On<Pointer<DragEnd>>,
+    mut commands: Commands,
+    dragged: Single<Entity, With<DraggedCard>>,
+    hand: Single<Entity, With<Hand>>,
+) {
+    commands
+        .entity(dragged.entity())
+        .remove::<DraggedCard>()
+        .set_parent_in_place(hand.entity());
+}

src/card/mod.rs

@@ -1,5 +1,6 @@
 use crate::animation::transform::AnimatedTransform;
 use bevy::prelude::*;
+use drag::*;
 
 pub mod drag;
 
@@ -26,6 +27,11 @@ impl Plugin for CardPlugin {
             .add_systems(Update, card_arrange)
             .add_observer(card_add)
             .add_observer(card_clear);
+        app.insert_resource(MousePosition(Vec3::new(0., 0., 0.)))
+            .add_systems(PreUpdate, mouse_position_system)
+            .add_observer(card_drag_start)
+            .add_observer(card_drag)
+            .add_observer(card_drag_end);
     }
 }
 
@@ -42,19 +48,18 @@ fn hand_setup(mut commands: Commands, asset_server: Res<AssetServer>) {
 }
 
 fn card_arrange(
-    query: Query<(Entity, &mut AnimatedTransform, &Sprite, &ChildOf), With<Card>>,
+    mut query: Query<(&mut AnimatedTransform, &Sprite), With<Card>>,
     hand: Single<(Entity, &Children), With<Hand>>,
     assets: Res<Assets<Image>>,
 ) {
     let cards_amount = hand.1.len();
-    for (entity, mut transform, sprite, child_of) in query {
-        if child_of.parent() != hand.0 {
+    for (index, card) in hand.1.iter().enumerate() {
+        let Ok((mut transform, sprite)) = query.get_mut(card) else {
             continue;
-        }
+        };
         let size = assets.get(&sprite.image).unwrap().size_f32();
         let left_boundary = -size.x * (cards_amount as f32) / 2.0 + size.x / 2.0;
-        transform.translation.x =
-            left_boundary + size.x * (hand.1.iter().position(|x| x == entity).unwrap_or(0) as f32);
+        transform.translation.x = left_boundary + size.x * index as f32;
         transform.translation.y = size.y / 2.0;
     }
 }
@@ -71,6 +76,8 @@ fn card_add(
         AnimatedTransform::from_xyz(0., 0., 0.),
         Card,
         ChildOf(hand.entity()),
+        DraggableCard,
+        Pickable::default(),
     ));
 }
 

src/dev_tools/mod.rs

@@ -18,13 +18,16 @@ impl Plugin for DevToolsPlugin {
 
 fn setup_debug_menu(mut commands: Commands) {
     let root = commands
-        .spawn(Node {
-            width: percent(100.),
-            height: percent(100.),
-            align_items: AlignItems::Start,
-            justify_content: JustifyContent::End,
-            ..default()
-        })
+        .spawn((
+            Node {
+                width: percent(100.),
+                height: percent(100.),
+                align_items: AlignItems::Start,
+                justify_content: JustifyContent::End,
+                ..default()
+            },
+            Pickable::IGNORE,
+        ))
         .id();
     let panel = commands
         .spawn((