"Transparent" flag doesnt make the window transparent

[ababen1]

Godot version

v4.0.stable.official [92bee43ad]

System information

windows 10

Issue description

the transparent flag doesn't make the window have transperant background

Steps to reproduce

add a window node and turn on "transparent"

Minimal reproduction project

project.zip

[KoBeWi]

You also need to enable transparent_bg under Viewport.

[ababen1]

oh ok I see, thanks what does "transpernt" do then? how is it different then transparent_bg?

[Sauermann]

On Linux X11 Xfce, the combination Window.transparent == true + Viewport.transparent_bg == true + Project setting embed_subwindows == false leads to windows that are not transparent. Not sure if this is a X11-limitation or a Godot bug.

[KoBeWi]

Likely a limitation, see the description of transparent.

[akien-mga]

CC @bruvzg

[bruvzg]

Seems to be working fine with both embedded and native windows. But window should be borderless and Transparent BG should be enabled in the window Viewport properties, also for the native windows Allow per-pixel transparancy should be enabled in the project settings.

[Sauermann]

On Windows 10, I have tested the following combination:

Project Settings:

• per_pixel_transparency/allowed == true
• embed_subwindows == false

For a native non-Main-Window:

• Window.transparent == true
• Window.borderless == true
• Viewport.transparent_bg == true

The created secondary native window doesn't have a transparent background.

With project setting embed_subwindows == true, the secondary window has a transparent background.

MRP: GodotPlaygroundWindow.zip