Grappling Hook: Improve handling of loops

Prevent connecting to the immediate previous area. For this, add an
array of excluded areas to the hook control.

Check if the area that is about to be connected has a control that is
connected. In that case, given that there is a single grappling hook in
the game, consider that a loop was created. Pass a new is_loop boolean
parameter to the hooked function of group hook_listeners. This allows
removing the string when a loop is formed, and additionally playing a
blink animation. And also improves the "all hooked" puzzle.

Author: manuq

scenes/game_elements/characters/player/components/player_hook.gd

@@ -102,14 +102,27 @@ func _new_hook_string() -> Line2D:
 ## Called when the area was hooked.
 ## [br][br]
 ## Part of group hook_listener.
-func hooked(_new_hooked_to: HookableArea) -> void:
+func hooked(_new_hooked_to: HookableArea, is_loop: bool) -> void:
 	var p: Vector2 = _new_hooked_to.anchor_point.global_position
 	if not hook_string:
 		hook_string = _new_hook_string()
 	hook_string.add_point(p, 0)
 	areas_hooked.append(_new_hooked_to)
 	if not _new_hooked_to.hook_control:
 		pull_string()
+	if is_loop:
+		# Play a blink animation and then remove the string:
+		var tween: Tween = create_tween()
+		tween.tween_property(hook_string, "modulate:a", 0.0, 0.1).set_trans(
+			Tween.TransitionType.TRANS_LINEAR
+		)
+		tween.tween_property(hook_string, "modulate:a", 1.0, 0.1).set_trans(
+			Tween.TransitionType.TRANS_LINEAR
+		)
+		tween.set_loops(8)
+		tween.play()
+		await tween.finished
+		remove_string()
 
 
 ## Called when a throw has hit a wall.

scenes/game_elements/props/all_hooked/components/all_hooked.gd

@@ -47,9 +47,9 @@ func released(area: HookableArea) -> void:
 ## Called when the area was hooked.
 ## [br][br]
 ## Part of group hook_listener.
-func hooked(area: HookableArea) -> void:
+func hooked(area: HookableArea, is_loop: bool) -> void:
 	if area not in areas_to_hook:
 		return
 	areas_hooked.append(area)
-	if areas_hooked.size() >= areas_to_hook.size() + 1:
+	if is_loop and areas_hooked.size() >= areas_to_hook.size() + 1:
 		all_hooked.emit()

scenes/game_elements/props/hook_control/components/hook_control.gd

@@ -52,6 +52,14 @@ enum State {
 ## This will be used only until user input is pressed.
 @export_range(0, 360, 1, "radians_as_degrees") var initial_hook_angle: float
 
+## The area to which this control is attached, if any.
+@export var hook_area: HookableArea
+
+## Exclude these areas from connecting.
+## This is used for excluding the immediate previous area, preventing a string
+## that goes from A to B, and then immediately from B to A.
+@export var exclude_areas: Array[HookableArea]
+
 ## The are currently hooked by this control.
 var hooked_to: HookableArea
 
@@ -123,13 +131,18 @@ func _get_hook_angle() -> float:
 
 func _throw() -> void:
 	if ray_cast_2d.is_colliding():
-		if ray_cast_2d.get_collider() is HookableArea:
+		if _can_connect():
 			hooked_to = ray_cast_2d.get_collider() as HookableArea
+			var is_loop := false
 			if hooked_to.hook_control:
-				hooked_to.hook_control.state = State.AIMING
-				hooked_to.hook_control.initial_hook_angle = _get_hook_angle()
+				is_loop = is_instance_valid(hooked_to.hook_control.hooked_to)
+				if not is_loop:
+					hooked_to.hook_control.state = State.AIMING
+					hooked_to.hook_control.initial_hook_angle = _get_hook_angle()
+					if hook_area:
+						hooked_to.hook_control.exclude_areas.append(hook_area)
 				state = State.DISABLED
-			get_tree().call_group(&"hook_listener", &"hooked", hooked_to)
+			get_tree().call_group(&"hook_listener", &"hooked", hooked_to, is_loop)
 		else:
 			release()
 			var wall_point := ray_cast_2d.get_collision_point()
@@ -147,12 +160,19 @@ func _throw() -> void:
 ## If an area is hooked, disconnect it.
 func release() -> void:
 	if hooked_to:
+		if hooked_to.hook_control:
+			hooked_to.hook_control.exclude_areas.erase(hook_area)
 		get_tree().call_group(&"hook_listener", &"released", hooked_to)
 		hooked_to = null
 
 
 func _can_connect() -> bool:
-	return ray_cast_2d.is_colliding() and ray_cast_2d.get_collider() is HookableArea
+	if not ray_cast_2d.is_colliding():
+		return false
+	var area := ray_cast_2d.get_collider() as HookableArea
+	if not area:
+		return false
+	return area not in exclude_areas
 
 
 func _set_state(new_state: State) -> void:
@@ -180,6 +200,7 @@ func _process(_delta: float) -> void:
 	rotation = _get_hook_angle()
 	sprite_2d.modulate = Color.WHITE if _can_connect() else Color(Color.WHITE, 0.5)
 	if hooked_to:
+		# Currently the control can be hooked to a single area.
 		return
 	if state != State.AIMING_PAUSED and pressing_throw_action and not throw_failed_while_pressing:
 		_throw()

scenes/game_elements/props/hookable_area/components/hookable_area.gd

@@ -31,7 +31,8 @@ extends Area2D
 const HOOKABLE_LAYER = 13
 
 ## Optional control to make this area a connection.
-@export var hook_control: HookControl
+@export var hook_control: HookControl:
+	set = _set_hook_control
 
 ## The exact point to attach the string.
 @export var anchor_point: Marker2D
@@ -56,3 +57,8 @@ func _set(property: StringName, _value: Variant) -> bool:
 	if property == "collision_layer":
 		update_configuration_warnings()
 	return false
+
+
+func _set_hook_control(new_hook_control: HookControl) -> void:
+	hook_control = new_hook_control
+	hook_control.hook_area = self

scenes/game_elements/props/hookable_needle/hookable_needle.tscn

@@ -29,8 +29,9 @@ debug_color = Color(0.689707, 0.288376, 1, 0.42)
 [node name="Marker2D" type="Marker2D" parent="HookableArea"]
 position = Vector2(0, -48)
 
-[node name="HookControl" parent="HookableArea" instance=ExtResource("3_te154")]
+[node name="HookControl" parent="HookableArea" node_paths=PackedStringArray("hook_area") instance=ExtResource("3_te154")]
 position = Vector2(0, -48)
+hook_area = NodePath("..")
 
 [node name="CollisionShape2D" type="CollisionShape2D" parent="."]
 rotation = -1.5708

scenes/quests/lore_quests/quest_002/2_grappling_hook/components/grappling_hook_needles.gd

@@ -15,10 +15,6 @@ func _ready() -> void:
 
 
 func _award() -> void:
-	# Remove the loop:
-	var player: Player = get_tree().get_first_node_in_group("player")
-	player.get_node("%PlayerHook").remove_string()
-
 	# Show and enable the button items so the player can start picking them:
 	for c in award_buttons.get_children():
 		c.process_mode = Node.PROCESS_MODE_INHERIT