Some Ghost refactoring

interface/ghost/ghost.gd

@@ -1,8 +1,27 @@
 extends Area2D
 class_name Ghost
-
 ## Ghost previewing the instantiation of a scene.
 
+
+## Color to modulate this with if the body currently isn't overlapping anything.
+@export var valid_color: Color = Color.WHITE
+
+## Color to modulate this with if the body currently is overlapping something.
+@export var invalid_color: Color = Color.RED
+
+
+## The [Instantiator] to use to spawn the ghosted item.
+@onready var instantiator: Instantiator = $Instantiator
+
+## The [OverlapChecker] to use to see if a solid block is overlapping the ghost.
+@onready var overlap_checker: OverlapChecker = $OverlapChecker
+
+## The [PlaceableAreaChecker] to use to see if the ghost is currently inside the placeable area.
+@onready var placeable_area_checker: PlaceableAreaChecker = $PlaceableAreaChecker
+
+## The [OverlapFreer] to use to delete the [PhysicsBody2D] behind the ghost before instantiation.
+@onready var overlap_freer: OverlapFreer = $OverlapFreer
+
 ## The [CollisionShape2D] to use to check for placement checks.
 ##
 ## MUST consist of a [RectangleShape2D].
@@ -27,19 +46,6 @@ class_name Ghost
 		if preview_sprite:
 			preview_sprite.texture = value
 
-## Whether the ghost can be placed at the current location of the ghost.
-##
-## Computed by checking if [placement_shape] overlaps any entity and is inside the [PlacementArea] of the [Bottle].
-var can_place: bool:
-	get: 
-		return can_place
-	set(value):
-		can_place = value
-		if value:
-			preview_sprite.modulate = Color(1.0, 1.0, 1.0, 0.5)
-		else:
-			preview_sprite.modulate = Color(1.0, 0.0, 0.0, 0.5)
-
 
 func _ready():
 	collision_mask = collision_mask_prevent_placement | collision_mask_delete_placement
@@ -51,37 +57,22 @@ func _physics_process(_delta: float):
 	update_can_place()
 
 
+var can_place: bool:
+	get:
+		return can_place
+	set(value):
+		can_place = value
+		modulate = valid_color if value else invalid_color
+
+
 ## Update the value of [can_place].
 # DIRTY HACK: Relies on the placeable area being perfectly surrounded by solid bodies.
-func update_can_place():
-	var no_overlapping_bodies: bool = true
-	var overlapping_bodies = get_overlapping_bodies()
-	for body in overlapping_bodies:
-		if body is TileMap:
-			no_overlapping_bodies = false
-		elif body is PhysicsBody2D:
-			var body_prevents_placement = bool(body.collision_layer & collision_mask_prevent_placement)
-			no_overlapping_bodies = no_overlapping_bodies and not body_prevents_placement
+func update_can_place() -> void:
+	can_place = overlap_checker.is_overlapping_with == null and placeable_area_checker.is_overlapping_with != null
 
-	var is_in_placeable_area: bool = false
-	var overlapping_areas = get_overlapping_areas()
-	for area in overlapping_areas:
-		if area is PlaceableArea:
-			is_in_placeable_area = true
-	
-	can_place = no_overlapping_bodies and is_in_placeable_area
-
-
-## The [PackedScene] that this node should instantiate.
-@export var scene_to_instantiate: PackedScene
-
-## The [Node] instatiated scenes should be added as children to.
-@export var target: Node
-
-## Emitted when the [materialize] function has finished executing.
-signal materialized(node: Node)
 
 func materialize():
+	# Compatibility stub for Instantiator
 	if not can_place:
 		return null
 	var overlapping_bodies = get_overlapping_bodies()
@@ -89,9 +80,6 @@ func materialize():
 		if body is PhysicsBody2D:
 			if body.collision_layer & collision_mask_delete_placement:
 				body.queue_free()
-	var instantiated = scene_to_instantiate.instantiate()
-	instantiated.global_position = global_position
-	instantiated.rotation = rotation
-	target.add_child(instantiated)
-	materialized.emit(instantiated)
-	return instantiated
+	var inst = instantiator.instantiate()
+	# TODO: Remove this
+	return inst

interface/ghost/ghost.tscn

@@ -1,8 +1,12 @@
-[gd_scene load_steps=4 format=3 uid="uid://qtk4tm6l367w"]
+[gd_scene load_steps=8 format=3 uid="uid://qtk4tm6l367w"]
 
 [ext_resource type="Script" path="res://interface/ghost/ghost.gd" id="1_1bq64"]
 [ext_resource type="PackedScene" uid="uid://c3p0jdf7416ac" path="res://converters/full_converter_shape.tscn" id="2_bo8dp"]
-[ext_resource type="PackedScene" uid="uid://cgpjm06hleokk" path="res://interface/ghost/precise_placement.tscn" id="3_70ahv"]
+[ext_resource type="PackedScene" uid="uid://cgpjm06hleokk" path="res://interface/ghost/precise_touch_placer.tscn" id="3_70ahv"]
+[ext_resource type="PackedScene" uid="uid://dhrtfpyfsdf3f" path="res://interface/ghost/instantiator.tscn" id="4_f7fmh"]
+[ext_resource type="PackedScene" uid="uid://cm3gvvcsh8i7a" path="res://interface/overlap_checker.tscn" id="5_twds7"]
+[ext_resource type="PackedScene" uid="uid://bu3alsb2ufaxu" path="res://interface/ghost/overlap_freer.tscn" id="6_y1rxa"]
+[ext_resource type="PackedScene" uid="uid://blk5uc5ta7nwq" path="res://interface/placeable_area_checker.tscn" id="7_wemqm"]
 
 [node name="Ghost" type="Area2D"]
 collision_layer = 0
@@ -19,4 +23,12 @@ scale = Vector2(2.5, 2.5)
 modulate = Color(1, 1, 1, 0.5)
 z_index = 10
 
-[node name="PrecisePlacement" parent="." instance=ExtResource("3_70ahv")]
+[node name="PreciseTouchPlacer" parent="." instance=ExtResource("3_70ahv")]
+
+[node name="Instantiator" parent="." instance=ExtResource("4_f7fmh")]
+
+[node name="OverlapChecker" parent="." instance=ExtResource("5_twds7")]
+
+[node name="OverlapFreer" parent="." instance=ExtResource("6_y1rxa")]
+
+[node name="PlaceableAreaChecker" parent="." instance=ExtResource("7_wemqm")]

interface/ghost/instantiator.gd

@@ -0,0 +1,27 @@
+extends Node
+class_name Instantiator
+
+
+## The [PackedScene] that this node should instantiate.
+@export var scene_to_instantiate: PackedScene
+
+## The [Node] instantiated scenes should be attached to.
+@export var container: Node
+
+
+## The [Node2D] instantiated scenes should get properties from.
+@onready var target: Node2D = get_parent()
+
+
+func instantiate():
+	var inst = scene_to_instantiate.instantiate()
+	inst.global_position = target.global_position
+	inst.rotation = target.rotation
+	container.add_child(inst)
+	instantiated.emit(inst)
+	# TODO: Remove this
+	return inst
+
+
+## Emitted when the [instantiate] function has finished executing.
+signal instantiated(new_scene: Node)

interface/ghost/instantiator.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://dhrtfpyfsdf3f"]
+
+[ext_resource type="Script" path="res://interface/ghost/instantiator.gd" id="1_waf2e"]
+
+[node name="Instantiator" type="Node"]
+script = ExtResource("1_waf2e")

interface/ghost/overlap_freer.gd

@@ -0,0 +1,37 @@
+extends Node
+class_name OverlapFreer
+
+
+## Layers to consider when checking overlap with [PhysicBody2D].
+@export_flags_2d_physics var overlap_mask: int
+
+## Whether [TileMap]s should be considered in collisions or not.
+##
+## Their [collision_layer]s are always ignored.
+@export var overlap_with_tilemap: bool = false
+
+
+## The [Area2D] this script should act on.
+@onready var target: Area2D = get_parent()
+
+
+## Get all bodies overlapping the [target].
+func get_all_overlapping_bodies() -> Array[Node2D]:
+	var bodies: Array[Node2D] = []
+	for body in target.get_overlapping_bodies():
+		if body is TileMap:
+			if overlap_with_tilemap:
+				bodies.append(body)
+		elif body is PhysicsBody2D:
+			if body.collision_layer & overlap_mask:
+				bodies.append(body)
+	return bodies
+
+## Emitted when a body is about to be [queue_free]d.
+signal body_queueing_free(body: Node2D)
+
+## Queue free all overlapping bodies.
+func area_queue_free() -> void:
+	for body in get_all_overlapping_bodies():
+		body_queueing_free.emit(body)
+		body.queue_free()

interface/ghost/overlap_freer.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://bu3alsb2ufaxu"]
+
+[ext_resource type="Script" path="res://interface/ghost/overlap_freer.gd" id="1_vr3yj"]
+
+[node name="OverlapFreer" type="Node"]
+script = ExtResource("1_vr3yj")

interface/ghost/precise_touch_placer.gd

@@ -1,5 +1,5 @@
 extends Node
-class_name PrecisePlacement
+class_name PreciseTouchPlacer
 
 
 ## The degrees to rotate by when rotation is quantized.

interface/ghost/precise_touch_placer.tscn

@@ -1,6 +1,6 @@
 [gd_scene load_steps=2 format=3 uid="uid://cgpjm06hleokk"]
 
-[ext_resource type="Script" path="res://interface/ghost/precise_placement.gd" id="1_e7b5h"]
+[ext_resource type="Script" path="res://interface/ghost/precise_touch_placer.gd" id="1_e7b5h"]
 
-[node name="PrecisePlacement" type="Node"]
+[node name="PreciseTouchPlacer" type="Node"]
 script = ExtResource("1_e7b5h")

interface/overlap_checker.gd

@@ -0,0 +1,45 @@
+extends Node
+class_name OverlapChecker
+
+
+## Layers to consider when checking overlap with [PhysicBody2D].
+@export_flags_2d_physics var overlap_mask: int
+
+## Whether [TileMap]s should be considered in collisions or not.
+##
+## Their [collision_layer]s are always ignored.
+@export var overlap_with_tilemap: bool = true
+
+
+## The [Area2D] this script should act on.
+@onready var target: Area2D = get_parent()
+
+
+## What the [target] object is currently overlapping with.
+var is_overlapping_with: Node2D = null
+
+
+## Get the first body overlapping the [target].
+func get_first_overlapping_body() -> Node2D:
+	for body in target.get_overlapping_bodies():
+		if body is TileMap:
+			if overlap_with_tilemap:
+				return body
+		elif body is PhysicsBody2D:
+			if body.collision_layer & overlap_mask:
+				return body
+	return null
+
+## Update the [is_overlapping_with] variable.
+func _update_is_overlapping_with() -> void:
+	var current_overlap = get_first_overlapping_body()
+	if current_overlap != is_overlapping_with:
+		overlap_changing.emit(current_overlap)
+	is_overlapping_with = current_overlap
+
+## Emitted when the value of [is_overlapping_with] changes because of [_update_is_overlapping_with].
+signal overlap_changing(to: Node2D)
+
+## Calculate overlap on every physics frame.
+func _physics_process(_delta):
+	_update_is_overlapping_with()

interface/overlap_checker.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://cm3gvvcsh8i7a"]
+
+[ext_resource type="Script" path="res://interface/overlap_checker.gd" id="1_s3ksv"]
+
+[node name="OverlapChecker" type="Node"]
+script = ExtResource("1_s3ksv")

interface/placeable_area_checker.gd

@@ -0,0 +1,31 @@
+extends Node
+class_name PlaceableAreaChecker
+
+
+## The [Area2D] this script should act on.
+@onready var target: Area2D = get_parent()
+
+
+## What the [target] object is currently overlapping with.
+var is_overlapping_with: PlaceableArea = null
+
+
+## Get the first [PlaceableArea] overlapping the [target].
+func get_first_overlapping_placeable_area() -> PlaceableArea:
+	for area in target.get_overlapping_areas():
+		if area is PlaceableArea:
+			return area
+	return null
+
+## Emitted when the value of [is_overlapping_with] changes because of [_update_is_overlapping_with].
+signal overlap_changing(to: PlaceableArea)
+
+func _update_is_overlapping_with() -> void:
+	var current_overlap = get_first_overlapping_placeable_area()
+	if current_overlap != is_overlapping_with:
+		overlap_changing.emit(current_overlap)
+	is_overlapping_with = current_overlap
+
+## Calculate overlap on every physics frame.
+func _physics_process(_delta):
+	_update_is_overlapping_with()

interface/placeable_area_checker.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://blk5uc5ta7nwq"]
+
+[ext_resource type="Script" path="res://interface/placeable_area_checker.gd" id="1_yyb05"]
+
+[node name="PlaceableAreaChecker" type="Node"]
+script = ExtResource("1_yyb05")