Lobby barrel-smash reward + roll/slam barrel destruction

Bull's boulder roll now homes on and ploughs through lobby barrels, and
the slam shockwave bursts them within its radius. HUD tallies barrels on
load and fires a confetti "WOooOoW!" + two gold bonus HP pips when the
last one breaks; gates open from run state as fights are cleared.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

hud.gd

@@ -42,6 +42,13 @@ var _ability_bar: HBoxContainer
 var _ability_panels: Array[PanelContainer] = []
 var _bull_bg: TextureRect
 
+# Lobby barrel-smash reward — tally the barrels present on load; when the last one bursts,
+# throw confetti + a "WOooOoW!" and grant the bull two yellow bonus pips. Latched so it
+# fires once per lobby visit.
+var _barrels_remaining: int = 0
+var _barrel_reward_given: bool = false
+const _BARREL_BONUS_HP: int = 2
+
 # Red damage vignette — a full-screen shader ColorRect flashed on every hit.
 const _VIGNETTE_SHADER := "res://damage_vignette.gdshader"
 var _vignette: ColorRect
@@ -90,6 +97,7 @@ func _ready() -> void:
 	_build_touch_controls()
 	_update_control_hints()
 	_find_spawner.call_deferred()
+	_watch_barrels.call_deferred()
 
 
 # On-screen joystick + ability buttons for touch devices. Self-gating: the overlay
@@ -213,6 +221,104 @@ func _find_spawner() -> void:
 	_spawner.all_defeated.connect(_on_all_defeated)
 
 
+# ── Lobby barrel-smash reward ───────────────────────────────────────────────────
+
+# Tally the barrels the current level loaded with and listen for each one bursting. Only
+# the lobby has barrels, so on every other level this simply finds none and stands down.
+func _watch_barrels() -> void:
+	var barrels := get_tree().get_nodes_in_group(&"barrel")
+	_barrels_remaining = barrels.size()
+	if _barrels_remaining == 0:
+		return
+	for barrel: Node in barrels:
+		barrel.destroyed.connect(_on_barrel_destroyed)
+
+
+func _on_barrel_destroyed() -> void:
+	_barrels_remaining -= 1
+	if _barrels_remaining > 0 or _barrel_reward_given:
+		return
+	_barrel_reward_given = true
+	# Bank the reward run-wide (capped at +2). Only heal the bull for the pips that were
+	# actually added — if it already carried the cap over from an earlier lobby, it keeps
+	# the cheer but no new health.
+	var granted := Run.add_bonus_hp(_BARREL_BONUS_HP)
+	if granted > 0 and _player != null and _player.has_method(&"grant_bonus_hp"):
+		_player.call(&"grant_bonus_hp", granted)
+	_celebrate()
+
+
+# The "cleared the lobby" flourish: a burst of confetti and a big springy "WOooOoW!".
+func _celebrate() -> void:
+	_spawn_confetti()
+	_show_wow()
+
+
+func _show_wow() -> void:
+	var wow := Label.new()
+	wow.text = "WOooOoW!"
+	wow.set_anchors_preset(Control.PRESET_CENTER)
+	wow.grow_horizontal = Control.GROW_DIRECTION_BOTH
+	wow.grow_vertical = Control.GROW_DIRECTION_BOTH
+	wow.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
+	wow.vertical_alignment = VERTICAL_ALIGNMENT_CENTER
+	wow.mouse_filter = Control.MOUSE_FILTER_IGNORE
+	wow.add_theme_font_override("font", UiFonts.title())
+	wow.add_theme_font_size_override("font_size", 96)
+	wow.add_theme_color_override("font_color", _HP_BONUS)
+	wow.add_theme_color_override("font_outline_color", Color(0.0, 0.0, 0.0, 0.9))
+	wow.add_theme_constant_override("outline_size", 8)
+	wow.pivot_offset = Vector2.ZERO
+	wow.scale = Vector2(0.2, 0.2)
+	add_child(wow)
+	# Keep the pop growing from the label's centre once it has a real size.
+	await get_tree().process_frame
+	wow.pivot_offset = wow.size * 0.5
+
+	var tw := create_tween()
+	tw.tween_property(wow, "scale", Vector2.ONE, 0.35).set_trans(Tween.TRANS_BACK).set_ease(
+		Tween.EASE_OUT)
+	tw.tween_interval(1.1)
+	tw.parallel().tween_property(wow, "modulate:a", 0.0, 0.6)
+	tw.parallel().tween_property(wow, "position:y", wow.position.y - 40.0, 0.6)
+	tw.tween_callback(wow.queue_free)
+
+
+func _spawn_confetti() -> void:
+	const _CONFETTI_COLORS: Array[Color] = [
+		Color(0.98, 0.24, 0.28),   # red
+		Color(1.00, 0.78, 0.20),   # gold
+		Color(0.30, 0.80, 0.40),   # green
+		Color(0.30, 0.62, 1.00),   # blue
+		Color(0.85, 0.40, 0.95),   # violet
+		Color(1.00, 1.00, 1.00),   # white
+	]
+	var vp := get_viewport().get_visible_rect().size
+	# One emitter per colour, raining down across the top of the screen.
+	for col: Color in _CONFETTI_COLORS:
+		var p := CPUParticles2D.new()
+		p.position = Vector2(vp.x * 0.5, -20.0)
+		p.emission_shape = CPUParticles2D.EMISSION_SHAPE_RECTANGLE
+		p.emission_rect_extents = Vector2(vp.x * 0.5, 6.0)
+		p.amount = 40
+		p.lifetime = 2.6
+		p.one_shot = true
+		p.explosiveness = 0.35
+		p.direction = Vector2(0.0, 1.0)
+		p.spread = 25.0
+		p.gravity = Vector2(0.0, 420.0)
+		p.initial_velocity_min = 120.0
+		p.initial_velocity_max = 260.0
+		p.angular_velocity_min = -360.0
+		p.angular_velocity_max = 360.0
+		p.scale_amount_min = 4.0
+		p.scale_amount_max = 8.0
+		p.color = col
+		add_child(p)
+		# Self-clean once the burst has fully fallen.
+		get_tree().create_timer(p.lifetime + 0.5).timeout.connect(p.queue_free)
+
+
 func _unhandled_input(event: InputEvent) -> void:
 	if event is InputEventKey and event.pressed and not event.echo:
 		if _game_over and event.physical_keycode in [KEY_ENTER, KEY_KP_ENTER]:
@@ -238,14 +344,12 @@ func _restart() -> void:
 	get_tree().reload_current_scene()
 
 
-# A cleared level advances the run and drops the player into the lobby hub: commit the
-# win, flag the lobby as the active level, then reload the shell so it builds the lobby.
-# (Choosing the next map node happens from the lobby via trigger areas, added later.)
+# A cleared level drops the player back into the lobby hub: bank the win (which opens the
+# gates it unlocks) and reload the shell so it rebuilds the lobby.
 func _continue_to_lobby() -> void:
 	get_tree().paused = false
 	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED
-	Run.complete_current_level()
-	Run.go_to_lobby()
+	Run.return_to_lobby()
 	get_tree().change_scene_to_file(Run.active_level().scene_path)
 
 
@@ -422,6 +526,9 @@ func _build_game_over() -> void:
 const _HP_FULL:   Color = Color(0.82, 0.16, 0.12)
 const _HP_EMPTY:  Color = Color(0.35, 0.05, 0.05)
 const _HP_SOCKET: Color = Color(0.05, 0.02, 0.02, 0.92)
+# Bonus pips (barrel-smash reward) read as bright gold-yellow so they stand apart from the
+# red life bar.
+const _HP_BONUS:  Color = Color(1.00, 0.84, 0.18)
 
 const _HP_PIP_W: float = 22.0
 const _HP_PIP_H: float = 14.0
@@ -500,10 +607,15 @@ func _on_health_changed(current: int, max_hp: int) -> void:
 	var cur := maxi(current, 0)
 	var frac := 0.0 if max_hp <= 0 else clampf(float(cur) / float(max_hp), 0.0, 1.0)
 	var lit := _HP_FULL.lerp(_HP_EMPTY, 1.0 - frac)
+	# Bonus pips sit at the high end of the bar; paint those top pips yellow when lit.
+	var bonus := 0
+	if _player != null and _player.has_method(&"get_bonus_hp"):
+		bonus = _player.call(&"get_bonus_hp")
+	var base_max := max_hp - bonus
 	for i: int in _hp_seg_fills.size():
 		var fill := _hp_seg_fills[i]
 		fill.visible = i < cur
-		fill.color   = lit
+		fill.color   = _HP_BONUS if i >= base_max else lit
 
 
 const _SLOT_SEPARATION: int = 10