Neovide: Font Fallback Fails for Certain Glyphs

[shaunsingh]

Describe the bug
(continued form https://github.com/Kethku/neovide/issues/741#issuecomment-867731459)

To Reproduce
Steps to reproduce the behavior:

1. Download/install neovide
2. Set gui font to a nerd font (user is using CaskaydiaCove Nerd Font, (I believe this is Cascadia Code)
3. Open a Nerdtree buffer
4. See error

Expected behavior
Glyphs should render correctly.

Screenshots

(top terminal, bottom neovide)

Desktop (please complete the following information):

• OS: MacOS 11
• Neovide Version: Latest intel build pulled from github actions (running on an m1 machine)
• Neovim Version: 0.5.0 nightly

Please run neovide --log and paste the results here:
--not run, don't think its required for this issue

Additional context
User is using Cascadia code nerd font, but has tried it with "FiraCode, FuraCode and JetBrainsMono nerd fonts. None of them worked." I will test this on my personal machine shortly

[shaunsingh]

I can't repro this on my machine. I am using the FiraCode nerd font and the latest release of neovide built from source. I checked, and the arrow/star glyphs are included with the nerd font

[IBS27]

Which icon set do you use and which filetree is that?

[shaunsingh]

I am using the nvim-devicons, which is using the glyphs provided in the nerd font
The tree itself is nvim-tree, and the icons are defined in my personal config here: https://github.com/shaunsingh/vimrc-dotfiles/blob/a5546ba505341531234a43afe44046e9cb8636aa/.config/nvim/init.lua#L1169 (it appears blank because GitHub doesn't have the glyphs, if you paste it into a terminal it should work)

[IBS27]

I can see that you are using lua. But, my config isn't based on it.

[shaunsingh]

Lua shouldn't be an issue. If you would like to test my config, you can use

lua <<EOF 
--code goes here 
EOF 

Note that you need to install nvim-tree and nvim-devicons for this to work

[IBS27]

I tried your config. And I liked it. It worked fine except that a couple of glyphs were not working.

[shaunsingh]

could you kindly send a screenshot showing the glyphs not working

[IBS27]

It's fine. I replaced those with some very similar looking emojis from the mac emoji viewer. It works now.

[Kethku]

Ok so this is a font fallback issue. Unfortunately its niche enough that I'm not gonna make it super high priority in the short run.

[IBS27]

What about the dead keys issue? When will that be fixed?

[Kethku]

dead keys are tracked here: https://github.com/Kethku/neovide/issues/445

Wanna help out?

[IBS27]

Yeah! I can help in testing it on mac.

[IBS27]

@Kethku how do you use the .snap files? I am kinda new to all this.
I want to try out your latest commit. how do I do that?

[Kethku]

pinging @j4qfrost as I know nothing about various linux packing systems. I'm as in the dark as you

[IBS27]

Oh. So is that snap file only for linux?

[IBS27]

And I tried the latest mac build of neovide. That is the one with the new icons. The icon doesn't show.

[Kethku]

@shaunsingh I think you've been working on a better mac build. Does your new PR set the icon?

[j4qfrost]

The cargo bundle command should already set an icon for the dmg, everything's ng installs just fine for me. I have it running just fine on the Mac mini.

[j4qfrost]

@IBS27 @Kethku snap is just for Linux.

[IBS27]

@Kethku how do you insert emojis in neovide? In terminal vim I just press the fn key on mac and I get the emoji picker. But if I do the same thing in neovide it doesn't take it. The emoji feature in neovide is useless if I can't insert emojis.

[Kethku]

It's not useless as the primary use case for it was to enable linting overlays which depends on some emoji.

Is what you describe standard behavior on Mac?

[IBS27]

By what I described, what exactly do you mean?

[IBS27]

@Kethku I tried out the latest build and the dead keys issue seems to be fixed.

[IBS27]

@Kethku the icon is still not working. Can I just get the .icns file of the icon for mac as it looks weird now.

[shaunsingh]

@IBS27 Can you try cloning this: https://github.com/Kethku/neovide/pull/746, and running make dmg? That should create a .dmg build that you can open and run, with the icon.

[IBS27]

I tried it. It throws an error while building. This always happens when it starts building skia-bindings.

[fredizzimo]

I have the same problem on Windows, but I believe the description of the bug is wrong.

It doesn't seem to have anything to do with font fallbacks, it happens when using patched fonts with all the required glyphs.

Instead I'm fairly sure it's related to how colored double width glyphs are rendered. For me it happens with telescope.nvim, but only if I set the option color_devicons to true. It does not happen in nvim-tree.lua, but that's because it has a workaround in the plugin itself

This is not a unique problem to Neovide, some terminals also have the same problem, but others like Alacritty, which I'm using render the glyphs correctly.

The issue is discussed here https://github.com/nvim-telescope/telescope.nvim/issues/674, and here https://github.com/nvim-telescope/telescope.nvim/issues/358
The fix for nvim-tree (adds highlight to the space following the glyph) is here https://github.com/kyazdani42/nvim-tree.lua/pull/162