Support for borderless windowed mode
Currently there is no support for "fullscreen" windowed borderless mode.
This mode allows faster transition between the desktop and the game and also allows for 3rd party overlays like the Windows 10 Game Bar [1] (Shortcut Win+G) or the AMD Radeon overlay to show up. (To make them work in fullscreen mode other changes are needed I think).
SDL supports this, I also found some discussion about it [2]. Also see [3].
For mobile there is already something like this in the code: https://gitlab.com/xonotic/darkplaces/-/blob/div0-stable/vid_sdl.c#L2550
[2] https://discourse.libsdl.org/t/true-borderless-fullscreen-behaviour/24622/19
Edited by Cloudwalk