zutty & HackNerdFontMono

zutty

Hi,

I'm trying to reproduce the experience I have with `urxvt` with `zutty` using the font "HackNerdFontMono". While I can use the font, I do have problems with it:

* The font color is the same as the background color (at least for me). Changing the colors (i.e. new "theme" in ~/.Xresources) did not have an effect.
* I do not have "Braille" symbols available (`btop` used as indicator here).
* I also want to have the special glyphs from that font. Those are not provideb by the font "Hack".

There are some screenshots with tests below. I'm sorry this is so chaotic, I worked on two different systems (wayland + xserver, not sure this makes a difference); both running NixOS.
Posting everything within the same comment would have helped to re-order but I had issues with this (besides also using two different GitHub accounts [work+personal]).

I have no clue about fonts and virtual terminals so please forgive if I'm asking/doing anything wrong/stupid here.

I have used zutty v0.16 as show here: https://github.com/NixOS/nixpkgs/pull/257156#issuecomment-2278807153

The comment below (https://gist.github.com/rolfschr/4261ea856535c6007194b2b27f3dee04?permalink_comment_id=5150931#gistcomment-5150931) shows my expected outcome.

Basic comparison is:
`urxvt -fn "xft:Hack Nerd Font Mono:size=12"` vs `zutty -font "HackNerdFontMono"`

Zutty - DejaVuSansMono

Zutty with DejaVuSansMono doesn't show braille signs in btop (CPU) and does not have the glyphs (lsd):

(Not sure the double with font error is important here.)

Zutty's default with default font 9x18

Zutty shows the braille, but no glyphs (which is fine, of course:

For a quick overview on Braille support for nerd fonts, see ryanoasis/nerd-fonts#1064 and ryanoasis/nerd-fonts#837

Zutty - HackNerdFontMono

Somehow, the font color is the same as the background (even when using a dedicated theme). The glyphs are shown (I think):

(btop is similar to DejaVuSansMono [no braille] but worse due to the same color of bg & font)

Urxvt - Hack Nerd Font Mono

Glyphs + Braille are shown. Though on another system, I had to give urxvt another (=second) font to get Braille to work (which is consistent with the Braille support for Nerd fonts, see links above). On my current machine, it (=Braille) seems to work out of the box:

Urxvt - DejaVu Sans Mono

Zutty Hack lsd (Xserver)

Zutty HackNerdFontMono lsd (Xserver)

Zutty HackNerdFontMono btop (Xserver)

Feedback from the author:

I was able to reproduce your issue with HackNerdFontMono (not showing
anything but the background). That is due to a bug which is corrected
by the below snippet - feel free to test it:

diff --git a/src/font.cc b/src/font.cc
index d3f9118..6fd73fe 100644
--- a/src/font.cc
+++ b/src/font.cc
@@ -65,6 +65,9 @@ namespace zutty
       if (c == Unicode_Replacement_Character)
          return true;

+      if (c > std::numeric_limits<uint16_t>::max ())
+         return false;
+
       return ((dwidth && wcwidth (c) == 2) ||
               (!dwidth && wcwidth (c) < 2));
    }

The author integrated this (background issue) into zutty:

https://git.hq.sig7.se/zutty.git/commit/04b2ca3b3aaa070c41583247f8112c31b6003886

As for the Braille + nerd font glyph support, one needs to find a font that contains both. Zutty will not do any magic here.