Extracted bounding box debug draw logic to component

src/world/generation/layer/grid_layer/bounded_grid_debug_view.gd

@@ -0,0 +1,49 @@
+@tool
+class_name BoundedGridDebugView extends Node3D
+## Helper component that draws the AABB of a bounded grid in the editor
+
+@export var debug_color := Color("#a486006b"):
+	set(value):
+		debug_color = value
+		if box:
+			_set_debug_box_color(debug_color)
+
+var mesh_instance: MeshInstance3D
+var box: BoxMesh
+var material: StandardMaterial3D
+
+@onready var target: BoundedGridLayer = get_parent()
+
+
+func _ready() -> void:
+	# Don't want these during runtime
+	if not Engine.is_editor_hint():
+		queue_free()
+
+	# Initialize box drawing components
+	if not mesh_instance:
+		mesh_instance = MeshInstance3D.new()
+		add_child(mesh_instance)
+	if not box:
+		box = BoxMesh.new()
+	if not material:
+		material = StandardMaterial3D.new()
+	mesh_instance.mesh = box
+	box.material = material
+	material.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
+	material.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	_set_debug_box_color(debug_color)
+	_set_debug_box_shape(target.bounding_box)
+
+
+func _set_debug_box_color(color: Color) -> void:
+	material.albedo_color = color
+
+
+func _set_debug_box_shape(aabb: AABB) -> void:
+	mesh_instance.position = aabb.position + aabb.size / 2
+	box.size = aabb.size
+
+
+func _process(_delta: float) -> void:
+	_set_debug_box_shape(target.bounding_box)

src/world/generation/layer/grid_layer/bounded_grid_debug_view.gd.uid

@@ -0,0 +1 @@
+uid://r74iif2we4bu

src/world/generation/layer/grid_layer/bounded_grid_layer.gd

@@ -1,4 +1,3 @@
-@tool
 class_name BoundedGridLayer extends GridLayer
 ## A layer that generates tiles in a locally-constrained grid.
 
@@ -6,33 +5,15 @@ class_name BoundedGridLayer extends GridLayer
 ##
 ## Note that only feature handles are checked to be within the bounding box.
 ## The Y component of this AABB is not used.
-@export var bounding_box: AABB:
-	set(value):
-		bounding_box = value
-		if _debug_box:
-			_set_debug_box_shape(bounding_box)
-
-@export_group("Debug Draw")
-@export var draw_debug := true
-@export var debug_color := Color("#a486006b"):
-	set(value):
-		debug_color = value
-		if _debug_box:
-			_set_debug_box_color(debug_color)
-
-var _debug_meshinstance: MeshInstance3D
-var _debug_box: BoxMesh
+@export var bounding_box: AABB
 
 
 func _ready() -> void:
-	if Engine.is_editor_hint():
-		_init_debug_draw()
-	else:
-		var grid := _plane_size()
-		for lod in WorldGen.LOD_LIST:
-			for i in grid.x:
-				for j in grid.y:
-					_generation_grid[lod][Vector2(i, j)] = false
+	var grid := _plane_size()
+	for lod in WorldGen.LOD_LIST:
+		for i in grid.x:
+			for j in grid.y:
+				_generation_grid[lod][Vector2(i, j)] = false
 
 
 func _generate(lod: WorldGen.LOD) -> bool:
@@ -77,28 +58,3 @@ func local_to_world(local_pos: Vector2) -> Vector3:
 func world_to_local(world_pos: Vector3) -> Vector2:
 	var rel_pos := world_pos * global_transform - bounding_box.position
 	return Vector2(rel_pos.x / grid_size.x, rel_pos.z / grid_size.y)
-
-
-#region debug draw
-func _init_debug_draw() -> void:
-	_debug_box = BoxMesh.new()
-	var mat := StandardMaterial3D.new()
-	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
-	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
-	_debug_box.material = mat
-	_debug_meshinstance = MeshInstance3D.new()
-	_debug_meshinstance.mesh = _debug_box
-	add_child(_debug_meshinstance)
-	_set_debug_box_color(debug_color)
-	_set_debug_box_shape(bounding_box)
-
-
-func _set_debug_box_color(color: Color) -> void:
-	var mat := _debug_box.material as StandardMaterial3D
-	mat.albedo_color = color
-
-
-func _set_debug_box_shape(aabb: AABB) -> void:
-	_debug_meshinstance.position = aabb.position + aabb.size / 2
-	_debug_box.size = aabb.size
-#endregion

src/world/generation/layer/metro_grid_layer/metro_grid_layer.gd

@@ -1,4 +1,3 @@
-@tool
 extends BoundedGridLayer
 ## Procedural cityscape generation
 

src/world/generation/layer/metro_grid_layer/metro_grid_layer.tscn

@@ -1,8 +1,9 @@
-[gd_scene load_steps=4 format=3 uid="uid://cwygxhknl2h8r"]
+[gd_scene load_steps=5 format=3 uid="uid://cwygxhknl2h8r"]
 
 [ext_resource type="Script" uid="uid://d25t2340sdrox" path="res://src/world/generation/layer/metro_grid_layer/metro_grid_layer.gd" id="1_ng6r6"]
 [ext_resource type="PackedScene" uid="uid://cgvg7n525g18l" path="res://src/world/generation/feature/metro/metro_empty.tscn" id="2_47xjc"]
 [ext_resource type="PackedScene" uid="uid://beno0v5dxtwqs" path="res://src/world/generation/feature/metro/metro_construct_simple/metro_construct_simple.tscn" id="3_woad2"]
+[ext_resource type="Script" uid="uid://r74iif2we4bu" path="res://src/world/generation/layer/grid_layer/bounded_grid_debug_view.gd" id="4_woad2"]
 
 [node name="MetroGridLayer" type="Node3D"]
 script = ExtResource("1_ng6r6")
@@ -10,3 +11,7 @@ empty_scene = ExtResource("2_47xjc")
 simple_construct_scene = ExtResource("3_woad2")
 grid_size = Vector2(64, 64)
 generated_lods = 6
+
+[node name="BoundedGridDebugView" type="Node3D" parent="."]
+script = ExtResource("4_woad2")
+metadata/_custom_type_script = "uid://r74iif2we4bu"