The bug

If a small texture is defined for a UI element and its scaling behaviour set to "tile", the game will be incredibly laggy on the client due to it having to render a single texture file thousands of times.

How to reproduce

1. Download and apply the attached resource pack
2. Try your best to navigate the menus

Expected results

A usable experience.

Actual results

prankd

How to fix

If the texture to be tiled is sufficiently small, then pre-generate a larger version of the tiled texture and stitch this to the gui.png-atlas, then tile with this. Much less texture planes will be needed as a result while the outcome is visually identical.