Text Sizing Protocol

[rockorager]

Kitty has recently implemented a text sizing protocol. The idea is that in a single sequence, one can specify a scale factor (integer, for larger text), a numerator + denominator (for smaller text), and explicit widths. The explicit widths are used as an alternate solution to mode 2027, and are (IMO) more robust - the application can explicitly tell a terminal how wide a given grapheme should be, as opposed to hoping they both agree.

Aside from the width portion, I think there are numerous use cases for the scaling protocol as well. I'm planning to implement this in libvaxis (width is already implemented, but I will do scaling once I have figured out a good data model for it) and it would be great for Ghostty to have support as well.

[rockorager]

More discussion here: kovidgoyal/kitty#8226

Also note: foot is implementing the width portion of the spec.

[reykjalin]

Quick demo of why this would be cool in a markdown CLI renderer. The demo just scales the size of h1, h2, and h3 headings, but I think it does a good job showing off the potential :)

out.mp4

I'm personally excited for this to use for building TUIs. Scaling certain UI elements would be really nice, e.g. making some buttons bigger, rendering different sized text in dialogs, and other things of that sort.

EDIT: Repo with demo executable I'm using here: https://github.com/reykjalin/md

[00-kat]

Somewhat relevant: there is also some chatter over at Neovim about utilising Kitty's new text sizing protocol: neovim/neovim#32539.