add shaking when changing configuring state

scripts/game_key.gd

@@ -103,6 +103,9 @@ func _unhandled_input(event: InputEvent) -> void:
 	if event.is_action_pressed("reset_animations"):
 		_reset_animations()
 		return
+	if event.is_action_pressed("toggle_configuring"):
+		_shake(0.1)
+		return
 
 	if event is not InputEventKey:
 		return
@@ -326,6 +329,22 @@ func _animate_position() -> Vector3:
 	return new_position
 
 
+func _shake(force: float) -> void:
+	_pos_sod.set_y(
+		(
+			position
+			+ (
+				Vector3(
+					randf_range(-force, force),
+					randf_range(-force, force),
+					randf_range(-force, force)
+				)
+				* keyboard.key_size
+			)
+		)
+	)
+
+
 func _animate_light(delta: float) -> void:
 	if _is_pressed:
 		_light_timer = _light_fade_time

scripts/second_order_dynamics.gd

@@ -49,3 +49,7 @@ func process(t: float, x: Vector3, xd: Vector3 = Vector3.INF) -> Vector3:
 	_y = _y + t * _yd
 	_yd = _yd + t * (x + _k3 * xd - _y - _k1 * _yd) / k2_stable
 	return _y
+
+
+func set_y(y: Vector3) -> void:
+	_y = y