Questions about font ligature and bold font

[miullu]

Issue 1: Safely Disabling Font Ligatures in Rio Terminal

I am trying to stably disable font ligatures in Rio Terminal. I noticed that GitHub issue #1258 regarding this topic is currently open—does this mean there is no official configuration update for it yet?

The fonts.features Option

I saw that Rio offers a fonts.features option. Since ligatures are technically font features, I assumed this would help. However, setting features = [] does not disable the connection of characters like - (as shown in the image below).

Is the features option intended for a different use case, or am I formatting it incorrectly?

---

Issue 2: Config Settings for Bold Fonts & Weights

Do you have any recommendations for configuring bold fonts in Rio?

Specifically, does the weight property inside the regular font configuration block still exist in the current syntax? For example:

regular = { family = "<string>", style = "<string>", width = "<string>", weight = <integer> }

[TheusHen]

Hi!

For the first issue, features = [] does not disable the default OpenType shaping features. In the current Rio configuration, you can explicitly disable ligatures by prefixing the feature tags with -.

For example:

[fonts]
features = ["-calt", "-liga"]

-calt disables contextual alternates and -liga disables standard ligatures. This is now supported by Rio's font shaping implementation.

So if the goal is to get completely non-ligated text, I would start with those two settings.

For the second issue, yes, the weight property is supported in the current syntax and can be configured independently for each font slot. For example:

[fonts.regular]
family = "Your Font"
weight = 400

[fonts.bold]
family = "Your Font"
weight = 700

[fonts.italic]
family = "Your Font"
weight = 400

[fonts.bold-italic]
family = "Your Font"
weight = 700

The current implementation accepts CSS-style weights from 100 to 900. On Linux/Windows it influences font-face selection, while for variable fonts it can also pin the wght axis and avoid synthetic bold.

Also, font features are not hot-reloaded, so Rio needs to be restarted after changing fonts.features.

Hope this helps!

[miullu]

It works well now. thx.

It is abnormal that rioterm only use 20 MB of memory? it now settle into a baseline of around 200 MB after active use, but i have seen 20 MB in the past i.e. when i was asking about the settings

[TheusHen]

Glad to hear it works well now! :)

Regarding the memory usage: I wouldn't be too concerned about seeing Rio settle around ~200 MB after some active use. Rio is GPU-accelerated, so memory usage can increase as graphics resources, font/glyph data, terminal state, scrollback, etc. are initialized and cached. Seeing a much lower number such as ~20 MB shortly after startup can therefore happen, but it isn't necessarily the steady-state memory footprint. The current Rio architecture includes GPU rendering and multiple rendering-related resources, so the exact usage can also vary depending on the platform and workload.

So I wouldn't consider ~200 MB by itself evidence of a memory leak. What would be more interesting is whether it keeps increasing continuously under the same workload instead of eventually reaching a stable baseline.

By the way, could I ask you a slightly selfish favor? Since this Q&A is currently marked as unanswered, would you mind creating another small Q&A discussion with the same question (or reopening/reposting it as a new one), and then I can post the answer there again so you can mark it as resolved?

I'm trying to get the GitHub Galaxy Brain badge, so I'd really appreciate it! 😂

Thanks!

[miullu]

these?

---

or this

[TheusHen]

Sure! Could you create a new Q&A discussion with the same question? Then I can post the answer there again, and you can mark that new discussion as “Close as resolved”.
I'm specifically trying to get the Galaxy Brain badge, and apparently the answer needs to be marked as the accepted/resolved answer for it to count.
Sorry for the slightly silly request, and thanks a lot!