## UltrasoundMachine — displays a continuous heartbeat pulse on the screen.
class_name UltrasoundMachine extends Node2D

const BEAT_RISE_DURATION: float = 0.12
const BEAT_FALL_DURATION: float = 0.12
const BEAT_INTERVAL: float = 0.60
const BEAT_SCALE_PEAK: Vector2 = Vector2(1.5, 1.5)
const BEAT_SCALE_REST: Vector2 = Vector2(1.0, 1.0)


func _ready() -> void:
	_start_heartbeat_loop()


func _start_heartbeat_loop() -> void:
	var dot: Node2D = get_node_or_null("HeartbeatDot") as Node2D
	if dot == null:
		return
	var tween: Tween = create_tween()
	tween.set_loops()
	tween.tween_property(dot, "scale", BEAT_SCALE_PEAK, BEAT_RISE_DURATION)
	tween.tween_property(dot, "scale", BEAT_SCALE_REST, BEAT_FALL_DURATION)
	tween.tween_interval(BEAT_INTERVAL)