WIP: Remember threads between quest playthroughs

scenes/dev/dev_archipelago.tscn

@@ -206,6 +206,7 @@ position = Vector2(0, 64)
 
 [node name="TemplateElder" parent="OnTheGround/Elders" unique_id=1625796178 node_paths=PackedStringArray("abandon_point") instance=ExtResource("11_ui3i3")]
 position = Vector2(481, 1107)
+quest_directory = "res://scenes/dev/level_design/"
 abandon_point = NodePath("SpawnPoint")
 
 [node name="SpawnPoint" parent="OnTheGround/Elders/TemplateElder" unique_id=1656237801 instance=ExtResource("18_elr7o")]

scenes/dev/level_design/optional_threads/optional_threads.dialogue

@@ -0,0 +1,13 @@
+# SPDX-FileCopyrightText: The Threadbare Authors
+# SPDX-License-Identifier: MPL-2.0
+~ start
+if optional_collectible_item:
+	Ulysses Thriftweed: If you go East, you can get out of here.
+	Ulysses Thriftweed: If you go through the cave up North, there's another thread you can collect first, if you're feeling brave.
+else:
+	Ulysses Thriftweed: I hope now you've learned to stop picking your nose.
+=> END
+
+~ wow
+Ulysses Thriftweed: You run THAT fast?
+=> END

scenes/dev/level_design/optional_threads/optional_threads.dialogue.import

@@ -0,0 +1,16 @@
+[remap]
+
+importer="dialogue_manager"
+importer_version=15
+type="Resource"
+uid="uid://b1ywwu7aese02"
+path="res://.godot/imported/optional_threads.dialogue-f583759440f80634b369fea5863492be.tres"
+
+[deps]
+
+source_file="res://scenes/dev/level_design/optional_threads/optional_threads.dialogue"
+dest_files=["res://.godot/imported/optional_threads.dialogue-f583759440f80634b369fea5863492be.tres"]
+
+[params]
+
+defaults=true

scenes/dev/level_design/optional_threads/optional_threads.gd

@@ -0,0 +1,32 @@
+# SPDX-FileCopyrightText: The Threadbare Authors
+# SPDX-License-Identifier: MPL-2.0
+extends Node2D
+
+@export var dark_sky_color: Color
+var _tween: Tween
+
+@onready var cave_lighting: Area2D = %CaveLighting
+@onready var canvas_modulate: CanvasModulate = %CanvasModulate
+@onready var optional_collectible_item: CollectibleItem = %OptionalCollectibleItem
+
+
+func _ready() -> void:
+	optional_collectible_item.tree_exiting.connect(func() -> void: optional_collectible_item = null)
+	cave_lighting.body_entered.connect(_on_cave_lighting_body_entered)
+	cave_lighting.body_exited.connect(_on_cave_lighting_body_exited)
+
+
+func _adjust_modulation(target: Color) -> void:
+	if _tween:
+		_tween.kill()
+
+	_tween = create_tween()
+	_tween.tween_property(canvas_modulate, "color", target, 0.5)
+
+
+func _on_cave_lighting_body_entered(_body: Node2D) -> void:
+	_adjust_modulation(dark_sky_color)
+
+
+func _on_cave_lighting_body_exited(_body: Node2D) -> void:
+	_adjust_modulation(Color.WHITE)

scenes/dev/level_design/optional_threads/optional_threads.gd.uid

@@ -0,0 +1 @@
+uid://b4muk3fixh36l

scenes/dev/level_design/optional_threads/quest.tres

@@ -0,0 +1,11 @@
+[gd_resource type="Resource" script_class="Quest" format=3 uid="uid://pdpqinul8nu5"]
+
+[ext_resource type="Script" uid="uid://dts1hwdy3phin" path="res://scenes/menus/storybook/components/quest.gd" id="1_cjuqo"]
+
+[resource]
+script = ExtResource("1_cjuqo")
+title = "Optional Threads"
+description = "Shows how to add an optional thread to a scene."
+first_scene = "uid://cplmo457h47p8"
+threads_to_collect = 2
+metadata/_custom_type_script = "uid://dts1hwdy3phin"

scenes/game_elements/characters/npcs/elder/components/elder.gd

@@ -61,8 +61,8 @@ func _ready() -> void:
 	animated_sprite_2d.connect("frame_changed", _on_frame_changed)
 
 	if GameState.quest:
-		GameState.quest.inventory.item_collected.connect(_update_dialogue_title)
-		GameState.quest.inventory.item_consumed.connect(_update_dialogue_title)
+		GameState.quest.inventory.item_collected.connect(_update_dialogue_title.unbind(1))
+		GameState.quest.inventory.item_consumed.connect(_update_dialogue_title.unbind(1))
 	_update_dialogue_title()
 
 
@@ -105,7 +105,7 @@ func congratulate_player() -> void:
 	await DialogueManager.dialogue_ended
 
 
-func _update_dialogue_title(_item: InventoryItem = null) -> void:
+func _update_dialogue_title() -> void:
 	if eternal_loom and eternal_loom.is_item_offering_possible():
 		talk_behavior.title = "go_to_loom"
 	elif not _quests:

scenes/game_elements/fx/dither/dither.gdshader

@@ -0,0 +1,17 @@
+// Copyright 2024 KingToot
+// SPDX-License-Identifier: CC0-1.0
+// https://godotshaders.com/shader/dithering-screen-door-transparency/
+shader_type canvas_item;
+
+uniform float intensity: hint_range(0.0, 1.0, 0.05) = 0.0;
+
+const mat4 THRESHOLD_MATRIX = mat4(
+		vec4(1.0 / 17.0,  9.0 / 17.0,  3.0 / 17.0, 11.0 / 17.0),
+		vec4(13.0 / 17.0,  5.0 / 17.0, 15.0 / 17.0,  7.0 / 17.0),
+		vec4(4.0 / 17.0, 12.0 / 17.0,  2.0 / 17.0, 10.0 / 17.0),
+		vec4(16.0 / 17.0,  8.0 / 17.0, 14.0 / 17.0,  6.0 / 17.0));
+
+void fragment() {
+	vec2 uv = UV / TEXTURE_PIXEL_SIZE;
+	COLOR.a *= step(0.0, THRESHOLD_MATRIX[int(uv.x) % 4][int(uv.y) % 4] - intensity);
+}

scenes/game_elements/fx/dither/dither.gdshader.uid

@@ -0,0 +1 @@
+uid://cj250ayvmpwf3

scenes/game_elements/fx/dither/dither.tres

@@ -0,0 +1,8 @@
+[gd_resource type="ShaderMaterial" format=3 uid="uid://dlnyw2c84jxlj"]
+
+[ext_resource type="Shader" uid="uid://cj250ayvmpwf3" path="res://scenes/game_elements/fx/dither/dither.gdshader" id="1_xv4rv"]
+
+[resource]
+resource_local_to_scene = true
+shader = ExtResource("1_xv4rv")
+shader_parameter/intensity = 0.0

scenes/game_elements/props/collectible_item/collectible_item.tscn

@@ -2,6 +2,7 @@
 
 [ext_resource type="Script" uid="uid://be7lr8ty24cix" path="res://scenes/game_elements/props/collectible_item/components/collectible_item.gd" id="1_7ff3m"]
 [ext_resource type="Script" uid="uid://du8wfijr35r35" path="res://scenes/game_elements/props/interact_area/interact_area.gd" id="2_1kegn"]
+[ext_resource type="Material" uid="uid://dlnyw2c84jxlj" path="res://scenes/game_elements/fx/dither/dither.tres" id="4_hhgm5"]
 [ext_resource type="AudioStream" uid="uid://bhgpds38q0j4r" path="res://assets/third_party/sounds/collectibles/MemoryCollectable.ogg" id="5_hhgm5"]
 [ext_resource type="AudioStream" uid="uid://38xwdjm46478" path="res://assets/third_party/sounds/collectibles/CollectibleAppear.ogg" id="5_oh62b"]
 
@@ -311,7 +312,7 @@ metadata/_custom_type_script = "uid://du8wfijr35r35"
 
 [node name="CollisionShape2D" type="CollisionShape2D" parent="InteractArea" unique_id=1121983883]
 shape = SubResource("CircleShape2D_ghwae")
-debug_color = Color(0.600391, 0.54335, 0, 0.42)
+debug_color = Color(0.6, 0.545, 0, 0.42)
 
 [node name="Marker" type="Marker2D" parent="InteractArea" unique_id=1961850851]
 position = Vector2(0, -48)
@@ -322,6 +323,7 @@ libraries/ = SubResource("AnimationLibrary_8dm1m")
 [node name="Sprite2D" type="Sprite2D" parent="." unique_id=1620327010]
 visible = false
 modulate = Color(1, 1, 1, 0)
+material = ExtResource("4_hhgm5")
 
 [node name="CollectedSound" type="AudioStreamPlayer" parent="." unique_id=420528907]
 unique_name_in_owner = true

scenes/game_elements/props/collectible_item/components/collectible_item.gd

@@ -31,6 +31,16 @@ extends SceneLink
 ## The dialogue title from where [member collected_dialogue] will start.
 @export var dialogue_title: StringName = ""
 
+var _ghost := false:
+	set(new_value):
+		_ghost = new_value
+		# TODO: effect is ugly
+		var sm := sprite_2d.material as ShaderMaterial
+		sm.set_shader_parameter("intensity", 0.25 if _ghost else 0.0)
+# Key in GameState.quest.facts which, if present, indicates that this item was
+# previously collected on the current run.
+var _fact_key: String
+
 @onready var interact_area: InteractArea = $InteractArea
 @onready var animation_player: AnimationPlayer = $AnimationPlayer
 @onready var sprite_2d: Sprite2D = $Sprite2D
@@ -82,6 +92,21 @@ func _ready() -> void:
 	if Engine.is_editor_hint():
 		return
 
+	# Collected in current run through this quest?
+	# TODO: if TaggedItem was constructed here we could put a workaround for
+	# use_unique_path not working there.
+	_fact_key = "%s:%s:collected" % [owner.scene_file_path, owner.get_path_to(self, true)]
+	if GameState.quest.facts.get(_fact_key, false):
+		# We assume any side-effects from collecting it have also been saved.
+		queue_free()
+		return
+
+	# Collected in previous run? TODO: supposedly quest.inventory is populated
+	# from global.inventory when starting quest so only the latter check should
+	# be needed
+	if GameState.global.inventory.has(item, self) or GameState.quest.inventory.has(item, self):
+		_ghost = true
+
 	interact_area.interaction_started.connect(self._on_interacted)
 
 
@@ -111,13 +136,15 @@ func _on_interacted(player: Player, _from_right: bool) -> void:
 	animation_player.play("collected")
 	await animation_player.animation_finished
 
-	GameState.quest.inventory.add_collected_item(item)
+	if not _ghost:
+		GameState.quest.inventory.add_collected_item(item, self)
 
 	if collected_dialogue:
 		DialogueManager.show_dialogue_balloon(collected_dialogue, dialogue_title, [self, player])
 		await DialogueManager.dialogue_ended
 
 	interact_area.end_interaction()
+	GameState.quest.facts[_fact_key] = true
 	queue_free()
 
 	if next_scene:

scenes/game_elements/props/eternal_loom/components/eternal_loom.gd

@@ -43,8 +43,8 @@ func show_retelling_dialogue() -> void:
 
 
 func _has_magical_thread_of_type(type: InventoryItem.ItemType) -> bool:
-	for item: InventoryItem in GameState.quest.inventory.items:
-		if item.type == type:
+	for ci: TaggedItem in GameState.quest.inventory.items:
+		if ci.item.type == type:
 			return true
 	return false
 
@@ -92,7 +92,7 @@ func on_offering_succeeded() -> void:
 
 	loom_offering_animation_player.play(&"loom_offering")
 	await loom_offering_animation_player.animation_finished
-	GameState.quest.inventory.clear_inventory()
+	GameState.global.inventory.merge(GameState.quest.inventory)
 
 	if load_error != OK:
 		on_rewoven_finished()
@@ -121,6 +121,8 @@ func is_item_offering_possible() -> bool:
 	if not GameState.quest:
 		return false
 
+	return true
+
 	if GameState.quest.quest.threads_to_collect <= 0:
 		return false
 

scenes/globals/game_state/game_state.gd

@@ -137,6 +137,9 @@ func set_quest(new_quest: Quest) -> void:
 		quest_player_state = PlayerState.new()
 
 	quest = QuestState.new(new_quest, quest_player_state)
+	quest.inventory.items = global.inventory.items.filter(
+		func(i: TaggedItem) -> bool: return i.quest_path == new_quest.resource_path
+	)
 
 
 ## Guess which quest the given scene is part of, and set [member quest]

scenes/globals/game_state/global_state.gd

@@ -45,6 +45,8 @@ signal helper_changed
 
 @export var helper: HelperCharacterState
 
+@export var inventory: InventoryState = InventoryState.new()
+
 ## Quests that were started & abandoned without being completed, keyed by
 ## [member Resource.resource_path] of each [Quest].
 ## Captures the [QuestState] and [PerSceneState] at point, so that the player

scenes/globals/game_state/inventory/tagged_item.gd

@@ -0,0 +1,35 @@
+# SPDX-FileCopyrightText: The Threadbare Authors
+# SPDX-License-Identifier: MPL-2.0
+class_name TaggedItem
+extends Resource
+## An [InventoryItem] that knows where it came from
+
+@export var item: InventoryItem
+@export var quest_path: String
+@export var source_scene: String
+## TODO: construct unique node path here...
+@export var source_node: NodePath
+
+
+static func make(an_item: InventoryItem, quest: Quest, a_source_node: Node = null) -> TaggedItem:
+	var ci := new()
+	ci.item = an_item
+	ci.quest_path = quest.resource_path if quest else ""
+	if a_source_node:
+		ci.source_scene = a_source_node.owner.scene_file_path
+		# TODO: use_unique_path doesn't work when called on the target's owner.
+		# Reported as https://github.com/godotengine/godot/issues/122411. If
+		# eventually fixed, remove the condition and just keep the else branch.
+		if a_source_node.unique_name_in_owner:
+			ci.source_node = "%" + a_source_node.name
+		else:
+			ci.source_node = a_source_node.owner.get_path_to(a_source_node, true)
+	return ci
+
+
+func matches(that: TaggedItem) -> bool:
+	return (
+		self.item == that.item
+		and self.source_scene == that.source_scene
+		and self.source_node == that.source_node
+	)

scenes/globals/game_state/inventory/tagged_item.gd.uid

@@ -0,0 +1 @@
+uid://cvmcbvc6skodh

scenes/globals/game_state/inventory_state.gd

@@ -5,27 +5,55 @@ class_name InventoryState
 extends Resource
 
 ## Emitted when a new item is collected and added to [member items].
-signal item_collected(item: InventoryItem)
+signal item_collected(item: TaggedItem)
 
 ## Emitted when a item is consumed, causing it to be removed from
 ## [member items].
-signal item_consumed(item: InventoryItem)
+signal item_consumed(item: TaggedItem)
 
 ## Collected threads. Modify with [member add_collected_item] and
 ## [member clear_inventory].
-@export var items: Array[InventoryItem]
+@export var items: Array[TaggedItem]
 
 
-## Add the [InventoryItem] to [member items].
-func add_collected_item(item: InventoryItem) -> void:
-	items.append(item)
-	item_collected.emit(item)
+## Move all items from [param other] to this inventory.
+func merge(other: InventoryState) -> void:
+	for ci: TaggedItem in other.items:
+		if not _has(ci):
+			_add(ci)
+	other.clear_inventory()
+
+
+## Returns true if the inventory contains [param item],
+## collected in the current quest (TODO), specifically from [param source_node]
+## (if provided).
+func has(item: InventoryItem, source_node: Node = null) -> bool:
+	# TODO: should the caller make the TaggedItem instead?
+	return _has(TaggedItem.make(item, GameState.quest.quest, source_node))
+
+
+## Add [param item] to [member items], tagging it as having been collected in
+## the current quest from [param source_node].
+func add_collected_item(item: InventoryItem, source_node: Node = null) -> void:
+	_add(TaggedItem.make(item, GameState.quest.quest, source_node))
+
+
+func _has(ci: TaggedItem) -> bool:
+	return items.find_custom(ci.matches) >= 0
+
+
+func _add(ci: TaggedItem) -> void:
+	if _has(ci):
+		return
+
+	items.append(ci)
+	item_collected.emit(ci)
 	emit_changed()
 
 
-## Remove all [InventoryItem]s from [member items].
+## Remove all items from [member items].
 func clear_inventory() -> void:
-	for item: InventoryItem in items.duplicate():
-		items.erase(item)
-		item_consumed.emit(item)
+	for ci: TaggedItem in items.duplicate():
+		items.erase(ci)
+		item_consumed.emit(ci)
 	emit_changed()