How to get global_position of KinematicBody2D with sync_to_physics enabled?

Question

I have a node which has a child KinematicBody2D as such:

and the script of the Holder as such

extends Node2D

onready var item = $Item

func _physics_process(delta):
    global_position.y += 3000 * delta

func _draw():
    draw_line(
        to_local(item.global_position) - Vector2(100, 0),
        to_local(item.global_position) + Vector2(100, 0),
        Color.violet
    )

In theory, the draw_line() should draw at the position of the Item (green) but I'm guessing since sync_to_physics is enabled there is some offset due to catching up?

Regardless, the problem arises that the global_position being returned is wrong due to which the line being drawn is at the wrong position:

What's more bizarre is that when I resize the window it corrects itself:

So is there a reliable way / workaround I can get the global_position of a KinematicBody2D with sync_to_physics enabled?

Edit: A continuation of the question has been asked here

Answer 1

You are getting the position correctly, and sync to physics is not the issue at hand either.

What happens is that Godot avoids calling _draw unless it knows it need to redraw. So once your _draw function ran, Godot won't call it again unless something triggers it (resize the window, for example).

You can tell Godot to call _draw again by calling queue_redraw() in Godot 4, or update in Godot 3. For example:

extends Node2D

onready var item = $Item

func _physics_process(delta):
    global_position.y += 3000 * delta
    update()

func _draw():
    draw_line(
        to_local(item.global_position) - Vector2(100, 0),
        to_local(item.global_position) + Vector2(100, 0),
        Color.violet
    )