Interaction sequence for wall switch

src/player/player.gd

@@ -40,7 +40,12 @@ func get_spray() -> Spray:
 
 
 func _physics_process(delta: float) -> void:
-	player_hud.select_interactive(interact_ray.get_collider() as Interactive)
+	# Will be null if no valid interactor is selected.
+	var interactive: Interactive = interact_ray.get_collider() as Interactive
+	player_hud.select_interactive(interactive)
+
+	if interactive and Input.is_action_just_pressed("interact"):
+		interactive.activate()
 
 	if Input.is_action_pressed("fire"):
 		get_spray().fire()

src/props/interactive.gd

@@ -1,6 +1,12 @@
 class_name Interactive extends StaticBody3D
 ## Props the player can interact with.
 
-signal activate
+signal activated
 
-@export var disabled := false
+@export var enabled := false
+
+
+func activate() -> void:
+	if enabled:
+		activated.emit()
+	# TODO: bonk

src/props/wall_switch/wall_switch.gd

@@ -1 +1,45 @@
 extends Node3D
+
+signal cleared
+signal activated
+
+const CLEAR_THRESHOLD := 2750
+
+@export var enabled := false
+
+@onready var animation_player: AnimationPlayer = %AnimationPlayer
+@onready var light_animation: AnimationPlayer = %LightAnimation
+@onready var gunk_body: GunkBody = %GunkBody
+@onready var interactive: Interactive = %Interactive
+
+
+func _ready() -> void:
+	if enabled:
+		enable()
+
+
+func enable() -> void:
+	enabled = true
+
+	# Clear off the rest of the gunk
+	gunk_body.clear_all()
+	light_animation.play("success")
+	interactive.enabled = true
+
+
+func _on_gunk_body_painted() -> void:
+	if not enabled:
+		var clear_total := gunk_body.get_clear_total()
+		if clear_total >= CLEAR_THRESHOLD:
+			enable()
+
+
+func _activate() -> void:
+	animation_player.play("activate")
+	activated.emit()
+	# Disable while animation is playing
+	interactive.enabled = false
+
+
+func _animation_finished(_anim_name: StringName) -> void:
+	interactive.enabled = true

src/ui/hud/player_hud.gd

@@ -1,6 +1,6 @@
 class_name PlayerHUD extends Control
 
-const TRANSITION_TIME := 0.05
+const TRANSITION_TIME := 0.06
 
 const COLOR_VISIBLE := Color("#ffffffee")
 const COLOR_DISABLED := Color("#cccccc44")
@@ -29,9 +29,9 @@ func _to_invisible(element: Control) -> void:
 
 func select_interactive(prop: Interactive) -> void:
 	if prop:
-		if prop.disabled:
-			_to_disabled(interact_hud)
-		else:
+		if prop.enabled:
 			_to_visible(interact_hud)
+		else:
+			_to_disabled(interact_hud)
 	else:
 		_to_invisible(interact_hud)

src/world/gunk_body/gunk_body.gd

@@ -1,6 +1,8 @@
 class_name GunkBody extends StaticBody3D
 ## StaticBody3D with an associated "gunkable" mesh.
 
+signal painted
+
 const CONTINUITY_LIMIT := 128
 const BUFFER_LIMIT := 3
 const FACE_EPSILON := 0.01
@@ -35,6 +37,15 @@ func _ready() -> void:
 	meshtool.create_from_surface(mesh, 0)
 
 
+func clear_all() -> void:
+	mask_control.queue_draw(
+		func() -> void:
+			mask_control.draw_rect(
+				Rect2(0, 0, mask_control.size.x, mask_control.size.y), MASK_COLOR
+			)
+	)
+
+
 ## Get the precise number of gunk pixels cleared from this image.
 ##
 ## This will use a cached result unless the mask has been painted since the last calculation.
@@ -184,3 +195,4 @@ func _process(_delta: float) -> void:
 
 func _on_mask_painted() -> void:
 	_clear_total_dirty = true
+	painted.emit()