Sides of fullscreen map cut off on larger screens

[leumasme]

When using the fullscreen map, the map is cut off near the edges of the screen.

https://github.com/user-attachments/assets/184c31d7-2ffc-4903-bf4f-20f934072337

Using a clean IDE dev build at the current master commit 6c82a24

The grid also stops rendering in the affected area (so it seems like the tiles for that area are not loaded This only happens on my 1440p screen (2560 x 1440 pixels). The issue does not appear on my 1080p screens. The issue appears independently of my Minecraft GUI scale setting. My Windows is set to 125% system zoom (recommended for my screen based on its DPI). I have briefly tried on 100% global zoom but the issue still seems to appear. The issue appears both in fullscreen and in windowed mode. The issue does not appear in windowed mode if the window is resized to a sufficiently small width. The issue appears exagerated if the window is resized to an even wider size. The width of the actually rendered part of the map/grid in this case appears to be 2560 pixels (full width of the window here is 3103 pixels)

[leumasme]

Seems like the grid size of the fullscreen map is hardcoded to render 5x5 tiles of 512x512px each for 2560x2560 total fullscreen map resolution. This is bad in both directions

• useless work is done when the window is small, a 1080p screen only has 1080px in height so only 3 of the 5 tiles in height will ever be visible
• not enough work is done when the window is large: when panned by half a tile, the previously seen issue of the map cutting off can happen starting at a window width/height of 2304pixels. This must look terrible on a 4k screen, with only 2560/3840=66% of the screen width actually rendering the map.

[mysticdrew]

Fullscreen map initially was 5x5 tiles, because at the time 4k screens were not a thing in 1.7.10 era. This has since been remedied in 1.12.2 and beyond. I would accept, merge, and release a PR that fixes this for legacy.