If a HTML5 game has another aspect ratio than that of the monitor, fullscreen screws up the aspect ratio in Firefox. #78329
Description
Godot version
v4.0.beta10.official [d0398f6]
System information
Godot v4.1.beta1 - Windows 10.0.22621 - Vulkan (Compatibility) - NVIDIA GeForce GTX 1050 (NVIDIA; 30.0.15.1123) - Intel(R) Core(TM) i5-8300H CPU @ 2.30GHz (8 Threads)
Issue description
This doesn't happen in Edge, Chrome and Chromium, so it migth be limited to Firefox.
I think I have figured out in what way the aspect ratio misbehaves:
The upper image show how fullscreen is supposed to behave: the 4:3 play area should get black borders left/right to fit the monitors 16:9 aspect ratio.
The lower image shows what happens in Firefox. The entire upper image, including black borders, is squashed horizontally to fit a 4:3 aspect ratio and then lined up against the left edge.
Here's an page for checking out the error.
https://kasper-hviid.itch.io/very-authentic-console?secret=TRfcgEgsnjf6nn7yZClK0OOQ6Kc
Steps to reproduce
Create a project with a aspect ratio different from your monitor. In the settings, under Display->Window->Stretch set Mode to Canvas_item (seems best for fullscreen). Export for web, zip the exported files, and upload the .zip file to itch.io with checkmark at [v] Fullscreen button and [v] SharedArrayBuffer support. With the Firefox browser, run the game in fullscreen.
Minimal reproduction project
N/A