Hey, this was super cool!

Ages ago I had found a software that would convert an image to ascii-art, and then used another tool called posteriza to split the large image into several A4s, which I then taped together and hung on my wall. Would love to do something similar but with better tools.

Pretty cool method doing “shading.”

Unicode is a lot more concerned with what a character means vs how it displays. The box drawing characters that have codepoints are there because they were part of some device's proprietary text encoding, so it's put in a codepage somewhere so a document from that device could be used on something else given it gets converted to unicode.

Pretty unlikely they'd be into adding a new ZWJ pattern for bordering characters since it's awful given unicode's main goal is interoperability. If you copy text out of your terminal, those characters come with it and probably won't render correctly in non-terminal applications (which don't have monospaced text cells), so you'll just see the ? missing character symbol between every letter. (Possibly overstruck onto the previous character depending on handling for the ZWJ.)

I guess the other way to look at this would be "should the background colour be a unicode ZWJ pattern?"... probably not. The border (and colour) is a property of the terminal cell rather than the actual characters IMO. It's not like `X + ZWJ + LEFT-BORDER` has any unique encoded meaning. Cell attributes like the article is talking about IS the less archaic way of doing this. ZWJ patterns are a lot more archaic and cause a lot more issues. Overstrike is fine, if it's being down with cell attributes (meaning, moving the cursor overtop of a cell, and stamping a new character on it instead of replacing it. Exactly how mintty does it.)

This is not as bad an idea as it would seem, but it's never going to happen with Unicode. It could reasonably happen with a combination of NerdFonts / private area shenanigans + cell rendering on the terminal side of this to handle it.

It solves the z-index problem neatly for an individual cell as you just render in order (first underneath, second over the top). But it doesn't solve the order for adjacent cells - borders that lie between cells. At least not easily. Not an insurmountable problem.

Some perspective if you're unaware. Fonts have the unicode line drawing characters, but fonts don't align super well and so a good terminal will draw those characters with line drawing algorithms instead of as a font. I've got a WIP PR that I need to land in VSCode's that pulls in xtermjs and ghostty's line drawing stuff so that it fixes up all the existing gaps on that as an example of this problem.

Oh like a diacritic? Good idea.

How is it harder? If I understand correctly overstrike is a superset of the regluar 1-char-per-cell mode, so nothing is lost by going overstrike?

I mean X is just sitting there with an extra decade or so of modernity. (Or Wayland for something MUCH more modern) Imagine ssh-ing into a server, starting an application, and a GUI application window appears. 1990's finest technology is awaiting it's rediscovery here in 2026.

Now we are in GUI app territory which is why I don’t like this terminal proposal or even kitty gfx. The terminal should be about text processing and at most a 2d grid of cells. Once you start talking about pixel buffers replacing cell buffers I fear we have lost the plot.

Can you name one which is as lightweight and simple to use as terminal escape codes and supported by almost any platform with a screen and keyboard?

This protocol would still be used for user interfaces, but it would use a completely different approach to rendering them, I guess we could call this approach "graphical"?

If you mean your proposal adds more things, that sounds like it might be over-complicated. To solve the problem of tightly-fitting boxes around terminal text -- if you consider that to be a real problem -- overstrike sounds like a really elegant solution.

If it's not obvious how this could be achieved with overstrike, basically the idea is that you could draw text on a cell then overstrike the cell with 1/8 block characters for the 4 edges characters (U+2581 & friends) to create a border around the cell.

Edit: HN stripped the characters in question from my comment