What's the best way to center a minigame on screen?

Tomkun

Hello.
I've been hard at work creating a dungeon-crawler type game and thanks to help from here I am making good progress. I am coming to a point where I am beginning to put all the pieces together and need advice.

I have a dungeon and in this dungeon are doors. The doors are separate scenes that are instanced into the correct places in the dungeon. I think this is the correct way to do it and it seems to work just fine.

Each door is locked and you need to complete a small puzzle in order to open it. I have created the puzzle in yet another scene which is then instanced from the door scene. The puzzle is essentially a scene within a scene. Once you complete the puzzle it sends a signal to the door scene and it opens. So far so good.

My problem is that I want the minigame to appear in the center of the screen yet I can't for the life of me work out how. I can center it on the door, no problem but I cannot seem to figure out how to position it in relation to the screen rather than the door.

So, I have two main questions: First is the scene-within-a-scene the normal way of doing this sort of thing and second, how can I position the minigame sub-scene in the center of the screen?!

DaveTheCoder

I don't know if this helps, but it's a Godot 4 function I wrote to center a popup dialog in the viewport.

# Compute position of a window so that it's centered in the viewport.
#
# The position of a window is its top left corner, so the centered position must
# be computed using the center of the viewport and the window size.
func compute_centered_window_position(window_size: Vector2i) -> Vector2i:
	return (Rect2i(get_tree().root.get_visible_rect()).size - window_size) / 2

Here's an example of how I use it:

var dialog := AcceptDialog.new()
dialog.dialog_text = "Hello, I am a dialog."
add_child(dialog)
dialog.show()
# dialog.size is not computed until the dialog is visible.
dialog.position = compute_centered_window_position(dialog.size)

Tomkun

DaveTheCoder

Thanks, I will try that.
When I tried to get the size of the scene before it always returned (0,0). I will try again!

DaveTheCoder

Tomkun it always returned (0,0)

You may have accessed the size before it was computed. I edited my post above and added an example.

Tomkun

Unfortunately it looks like your approach will not work in my case. I'm not sure why, but the location of the puzzle is always relative to the location of the door, not the screen.

I'm sure it's because the puzzle scene is a child of the door, but I don't see any way to override it.

razorborne

Could you do this by putting the puzzle scene as a child of a CanvasLayer?

Tomkun

I will look into that.
I have tried setting it as a child of the Root node which is a Node2D. That works, kind of, but the minigame is still not relative to the screen/window. It's as though it's a part of the map if that makes sense.
Is a canvaslayer attached to the screen?

EDIT:
OMG, this worked perfectly, thank you so much, @razorborne! And thank you, too, @DaveTheCoder!