feat(sprint-14): add Cake cut/reset state machine

scripts/objects/cake.gd

@@ -0,0 +1,56 @@
+## Cake — tap to cut a slice, slice auto-respawns after a delay.
+class_name Cake extends Node2D
+
+enum State { WHOLE, CUTTING, CUT, RESETTING }
+
+const CUT_DURATION: float = 0.3
+const RESET_DURATION: float = 0.3
+const RESET_DELAY: float = 3.0
+const BUTTON_HALF_WIDTH: float = 40.0
+const BUTTON_HALF_HEIGHT: float = 20.0
+
+var _state: State = State.WHOLE
+
+
+func _input(event: InputEvent) -> void:
+	if _state != State.WHOLE:
+		return
+	if not event is InputEventScreenTouch:
+		return
+	var touch: InputEventScreenTouch = event as InputEventScreenTouch
+	if not touch.pressed:
+		return
+	var local: Vector2 = to_local(touch.position)
+	if abs(local.x) > BUTTON_HALF_WIDTH or abs(local.y) > BUTTON_HALF_HEIGHT:
+		return
+	_start_cutting()
+
+
+func _start_cutting() -> void:
+	AudioManager.play_sfx("object_tap")
+	_state = State.CUTTING
+	var slice: Node2D = get_node_or_null("Slice") as Node2D
+	var tween: Tween = create_tween()
+	if slice != null:
+		tween.tween_property(slice, "modulate:a", 0.0, CUT_DURATION)
+	tween.tween_callback(_on_cut_complete)
+
+
+func _on_cut_complete() -> void:
+	_state = State.CUT
+	var tween: Tween = create_tween()
+	tween.tween_interval(RESET_DELAY)
+	tween.tween_callback(_start_reset)
+
+
+func _start_reset() -> void:
+	_state = State.RESETTING
+	var slice: Node2D = get_node_or_null("Slice") as Node2D
+	var tween: Tween = create_tween()
+	if slice != null:
+		tween.tween_property(slice, "modulate:a", 1.0, RESET_DURATION)
+	tween.tween_callback(_on_reset_complete)
+
+
+func _on_reset_complete() -> void:
+	_state = State.WHOLE

test/unit/test_cake.gd

@@ -0,0 +1,31 @@
+## Tests for Cake — state machine transitions.
+extends GutTest
+
+const CakeScript = preload("res://scripts/objects/cake.gd")
+
+var _cake: Node2D
+
+
+func before_each() -> void:
+	_cake = CakeScript.new()
+	add_child_autofree(_cake)
+
+
+func test_initial_state_is_whole() -> void:
+	assert_eq(_cake._state, CakeScript.State.WHOLE)
+
+
+func test_start_cutting_transitions_to_cutting() -> void:
+	_cake._start_cutting()
+	assert_eq(_cake._state, CakeScript.State.CUTTING)
+
+
+func test_on_cut_complete_transitions_to_cut() -> void:
+	_cake._on_cut_complete()
+	assert_eq(_cake._state, CakeScript.State.CUT)
+
+
+func test_on_reset_complete_transitions_to_whole() -> void:
+	_cake._state = CakeScript.State.RESETTING
+	_cake._on_reset_complete()
+	assert_eq(_cake._state, CakeScript.State.WHOLE)