played card stack can now be expanded upon hovering to see which cards were played

card_stack.gd

@@ -5,6 +5,16 @@ var _card_height: float = 0.02
 
 @export var playing_card_scene: PackedScene
 
+## Surface for allowing peeking at the played cards by hovering the mouse.
+@export var peek_surface: Area3D
+
+var _is_expanded: bool = false
+
+func _ready() -> void:
+	if peek_surface:
+		peek_surface.mouse_entered.connect(_peek_mouse_entered)
+		peek_surface.mouse_exited.connect(_peek_mouse_exited)
+
 func add_card(card: PlayingCard) -> void:
 	var height = self.get_child_count() * _card_height
 	self.add_child(card)
@@ -19,3 +29,30 @@ func add_card_by_id(card_id: int) -> void:
 func purge_cards() -> void:
 	while get_child_count() > 0:
 		remove_child(get_children()[get_child_count() - 1])
+
+func _peek_mouse_entered() -> void:
+	if get_child_count() > 1:
+		var index = 0
+		var child_count = get_child_count()
+		for child: Node3D in get_children():
+			create_tween().set_trans(Tween.TRANS_CUBIC).set_ease(Tween.EASE_OUT).tween_property(
+				child,
+				"position",
+				Vector3(0.2, index * -0.42 - (((child_count - 1) * -0.42) / 2.0), _card_height * index),
+				0.3,
+			)
+			index += 1
+		_is_expanded = true
+
+func _peek_mouse_exited() -> void:
+	if _is_expanded:
+		var index = 0
+		for child: Node3D in get_children():
+			create_tween().set_trans(Tween.TRANS_CUBIC).set_ease(Tween.EASE_OUT).tween_property(
+				child,
+				"position",
+				Vector3(0.0, 0.0, _card_height * index),
+				0.3,
+			)
+			index += 1
+		_is_expanded = false