Zutty - Frequently Asked Questions

A: Zutty is primarily developed and extensively tested on Linux, and (to a lesser extent) on OpenBSD.

Zutty is portable: provided that necessary prerequisites are present, it builds from source and runs without the need for any code fixes or configuration changes on default installs of recent stable versions of FreeBSD, NetBSD and OpenBSD.

Zutty will probably work on other UNIX-like systems as well; making the necessary (small) adjustments is left as an exercise to interested users. If you have a patch to make Zutty run somewhere not listed above, I want to hear from you!

If you use Windows or MacOS, I'm afraid Zutty is not going to be useful for you. I have no interest to work on making Zutty available on closed source, proprietary operating systems.

A: You need to build Zutty yourself from source code that is cryptographically signed (proven to be authentic). Or you may rely on a distro-provided package, in which case you trust them to do this verification and also prevent any tampering with the built binary.

In the source repository of Zutty, official commits for general consumption are on the master branch. As the sole publisher of commits, I started cryptographically signing all such commits with my 4096-bit RSA key, starting with commit f1d56d3 on 19 February 2022.

To inspect commit signatures, run git log --show-signature. This will show you that commits are signed using RSA key 73A89DD13935912D. That hexadecimal value is a key identifier, consisting of the last 16 digits of the signature of the key, which itself is the result of a hash function applied to the public key. If you want to verify the signatures, you will need the public key itself. Follow the previous link and download it to your computer, then run the command gpg --import pubkey.asc. Having done this once, you will be able to see the commit signatures as verified in the output of git log --show-signature.

Any unsigned commits should not be used in production and should under no circumstances be ever packaged and distributed.

Any commits to branches other than master (if they exist) should not be used other than educational or research purposes. These will not be signed.

I am getting an error like this:

E [charvdev.cc:181] Error: Compiling fragment shader:
0:1(10): error: GLSL ES 3.10 is not supported.
Supported versions are: 1.00 ES, and 3.00 ES

A: Your graphics hardware or driver is not sufficient, you need support for GLSL ES 3.1 or better.

The actual support level of the OpenGL (ES) implementation is only detectable at runtime, i.e., having the right EGL and GLES libraries to compile with (which is what the configure script is able to check) does not guarantee that the OpenGL implementation supports the required level at runtime. Note that compiling and running a dedicated test program as part of the configure phase would not solve this: the Zutty binary can be packaged, distributed and run on other machines with different graphics hardware (or the hardware of the same machine could be changed).

You could buy hardware that has sufficient support; the SBC on which I primarily run Zutty set me back the equivalent of about $50.

Alternatively, see the next question.

A: Yes. If you can tolerate higher resource usage (primarily CPU usage), you could try the llvmpipe software renderer. Note that you need a sufficiently recent version that includes support for compute shaders. Mesa 20.2.6 (present in Debian Bullseye) is ok. Please note that using Zutty with such a setup is experimental and be prepared for subpar performance.

A: As a preliminary note: Zutty does work perfectly fine with a wide range of fonts, both fixed and scalable, loadable from several font file formats (see Screenshots). However, fonts are a highly diverse bunch, so this does not mean that any random font you found on the 'net will magically work! I personally have all the fonts I could ever want, so if you insist on using a font that does not work with Zutty out of the box, it is on you to do the extra work to make that happen. Please keep this in mind.

Now to the specifics. If you get an error message like this:

E [fontpack.cc:218] Error: No Regular variant of the requested font 'Cozette'
could be identified.

In that case, Zutty is telling you that the font file selection process did not succeed in identifying a suitable font file. Please carefully read and understand the documentation on how you might make it work.

In case of certain filename endings (extensions) not recognized by Zutty, you might have to add them to the filter in src/fontpack.cc (search for .pcf.gz in fontFileFilter) and recompile. Then get ready to debug all sorts of weird issues related to this new format. You are on your own.

On the other hand, Zutty might have started up, having found suitably named font files, but you feel that the font rendering is off, for example all letters are "stuck to the ceiling" or overly wide, have wide gaps in between, or rendered with some such distortion. It is up to you to debug why it does not work like all the fonts that do. You have the source code of Zutty and all dependencies, so please do not expect me to do it for you!

If you don't have the time to do that, don't know C++, don't know how to debug, or have any other lame excuse, please do yourself a favour and use some of the well documented font alternatives known to work with Zutty.

Do not send me bug reports unless you have a well understood font loading or rendering issue due to an actual, demonstrable bug in Zutty. Complaints amounting to "Font XYZ does not work" will be discarded.

A: Zutty has been written (in the year 2020) against plain Xlib. Yeah, I know. That said, according to user reports, Zutty works fine with XWayland, so just install xorg-xwayland (if you haven't already) and you should be good to go!

A: Zutty is not necessarily better than any other program. I do not have "world domination" on my TODO list, so you are free to ignore Zutty and use another program.

That said, I believe Zutty has a number of interesting properties. It is a terminal with accurate VT support, high performance, low latency, a small codebase and is potentially compatible with a wide array of contemporary graphics hardware. This combination is, as far as I am aware, a unique proposition. You might be interested in my articles that add substance to these claims, here and here.

A: Lots of reasons! If you want any of these, Zutty is not for you, and will probably remain so in the future:

• availability on MacOS or Windows
• transparent backgrounds
• scrollbar, menu bar, interactive configuration, etc.
• ligatures
• right-to-left text
• curvy underlines and similar fancy markup
• bitmap images (SIXEL, ReGIS, …)
• overriding certain symbols / picking and mixing from different fonts

On the other hand, certain features are missing, but only due to the very limited time I can spend working on Zutty. For details, see Zutty - Omissions and limitations.

A: There is no mailing list, but you can keep track of changes to Zutty by subscribing to one of the repository feeds provided by gitweb: Atom, RSS.

A: Please see the general information on top of my code self-hosting website. However, it mostly boils down to a simple thing: use email.

A: No, you cannot do that. This is by intention, to preserve my intellectual freedom and independence, and to ensure that Zutty remains what it is: a hobby project. I want to be able to say no to (or ignore) any request, from any person – having accepted payments from someone would possibly make this awkward.

A: First of all, thank you for your interest in Zutty. If you run into issues, or have ideas on how to meaningfully improve Zutty, you are welcome to collaborate (investing a share of your own time and mental resources, as opposed to just demanding a slice of mine) to understand and solve the problem, or discuss a possible improvement. When asking for an enhancement or new feature, please motivate why you think it's important (for you, at least) and please cite prior art (what other terminals are out there already supporting it? what do the relevant standards say? etc).

I appreciate well thought-out, well written, clear feedback on what could be better, as well as high quality bug reports, and I try hard to respond to all such correspondence.

A: First of all, thank you for your interest in improving Zutty. To be honest, I am not overly interested in receiving unsolicited patches against the Zutty codebase, unless you have a clear fix to an actual (demonstrable) bug. In general, if you have ideas for improvement, try to convey them without coding them up – try to put them into well readable, concise English prose instead! If you found a bug, send me a high quality report with all the necessary details (and your analysis, if any) so I can easily reproduce and fix it. If you want to send a patch with your proposed fix, that's fine, but absolutely not a requirement!

If you do want to contribute code, make sure you have read the Contribution guide, and please note that my standards for accepting code for inclusion are very high. Your patch will be, in all likelihood, completely rewritten or ignored.

A: The IPA notation is [zuːc̟]. I'm afraid you won't be able to pronounce that, unless you happen to natively speak a language featuring the voiceless palatal plosive. If you decide to try, make sure to go for the alveolo-palatal variant. Hint: Zutty does not rhyme with kitty (or how English-speaking people commonly pronounce PuTTY).

The word zutty itself is an onomatopoetic interjection in the Hungarian language, similar in its meaning to the English whoops in referring to some sudden, quick action, but lacking the element of (often negative) surprise. This fairly obscure word is borrowed to stand for zero-cost unicode teletype.