Editor splash screen is massive on Wayland compared to X11

[Calinou]

Tested versions

• Reproducible in: 4.3.dev cae7599

System information

Godot v4.3.dev (cae7599) - Fedora Linux 39 (KDE Plasma) - Wayland - GLES3 (Compatibility) - NVIDIA GeForce RTX 4090 (nvidia; 545.29.06) - 13th Gen Intel(R) Core(TM) i9-13900K (32 Threads)

Issue description

The splash screen is rescaled to match the window size, which makes it look massive on a 4K display:

This doesn't occur on X11 where the splash screen remains pixel-perfect. My Wayland display scale is 100%, and so is the editor scale.

Ideally, we should scale the splash screen according to the OS scale factor (or the editor scale factor) on both X11 and Wayland.

Steps to reproduce

Use a Wayland session, enable the Prefer Wayland editor setting then restart the editor.

Minimal reproduction project (MRP)

N/A

[Riteo]

So, this is a fun one.

Basically, if the wp_viewport extension is available, it turns it on to allow for fractional scaling.

That has the fun (and intended) side effect of removing the explicit bond between buffers and windows, stretching the poor little splash to a full-screen window.

With the extension disabled/missing, you'd see the lil' buffer in a huge window.

IMO, the fix would be to properly (re?)render the splash on resize, somehow.

(BTW, there is a hack to force a proper window resize before rendering, but that wouldn't change the fact that a resize would squishy squash the buffer)