Wezterm support for variable weights.

[mindentropy]

Does Wezterm support variable weights? I am using Wezterm version 20240203-110809-5046fc22 on Ubuntu and trying to use JetBrainsMono[wght].ttf font. I am setting the variable font weight but nothing seems to change. Am I missing something?

[habahabahaba]

I'm on Sonoma, but here are the settings, that worked for me:

-- FONTS:
config.font = wezterm.font_with_fallback {
  'GeistMono Nerd Font',
  'JetBrainsMono Nerd Font Mono',
  'Lilex Nerd Font Mono',
  'MesloLGS Nerd Font Mono', 
  'Noto Color Emoji',
}

-- For Geist:
config.line_height = 1.03
config.font_rules = { 
  -- Bold-not-italic 
  {
      intensity = 'Bold',
      italic = false,
      font = wezterm.font_with_fallback{
        { 
          family = 'GeistMono Nerd Font',
          weight = 1000,
        },
      }
  }, 
  -- Bold-and-italic
  {
      intensity = 'Bold',
      italic = true,
      font = wezterm.font_with_fallback {
        { 
          family = 'GeistMono Nerd Font',
          weight = 'ExtraBold',
          italic = true
        }
      }
  }, 
  -- -- normal-intensity-and-not-italic
  {
      intensity = 'Normal',
      italic = false,
      font = wezterm.font_with_fallback {
        { 
          family = 'GeistMono Nerd Font',
          weight = 500,
        }
      }
  }, 
  -- half-intensity-and-italic (half-bright or dim)
  {
      intensity = 'Half',
      italic = true,
      font = wezterm.font_with_fallback {
        { 
          family = 'GeistMono Nerd Font',
          weight = 'Light',
          italic = true
        }
      }
  }, 
  -- half-intensity-and-not-italic
  {
      intensity = 'Half',
      italic = false,
      font = wezterm.font_with_fallback {
        { 
          family = 'GeistMono Nerd Font',
          weight = 'Light'
        }
      }
  }
}

[mindentropy]

@habahabahaba : I have externally downloaded "JetBrains Mono" and not using the internal one. My simple config is as follows:

config.font = wezterm.font("JetBrains Mono", {weight = 500})
config.font_size = 21
config.font_rules = {
  {
	intensity = 'Bold',
	italic = false,

	font = wezterm.font {
		family = "JetBrains Mono",
--		family = "Recursive Monospace",
--		family = "Inconsolata",
		weight = 500,
--		stretch = "Expanded"
    }
  },

  {
	intensity = 'Bold',
	italic = true,

	font = wezterm.font {
		family = "JetBrains Mono",
--		family = "Iosevka Term SS07",
--		family = "Recursive Monospace",
--		family = "Inconsolata",
		weight = 500,
		style = "Italic",
--		stretch = "Expanded"
    }
  },
}

If I change the weight to 499, I get thin font. 500 suddenly becomes thick. My understanding of variable weight is that there is a gradual increase of the weights and not drastic increase.

The below image is on 500.

The below image is on 499.

[mindentropy]

@habahabahaba :

My GUESS would be: there's no 499 variant, so it defaults to something else.

Shouldn't variable weight have a weight range?

Also, I have italic = true, and you - style = "Italic",

The rules what I have written is mentioned here -> https://wezfurlong.org/wezterm/config/lua/config/font_rules.html

[habahabahaba]

1. Unless the fonts get synthesized (which I'm not sure Wezterm can do), inside the range we can only use weights explicitely provided by the font.
2. Well, in your link: true (italic) or false (not italic)

[mindentropy]

1. Unless the fonts get synthesized (which I'm not sure Wezterm can do), inside the range we can only use weights explicitely provided by the font.

Sorry, I didn't get this. My ls-fonts shows
.local/share/fonts/JetBrains/variable/JetBrainsMono[wght].ttf

What do you mean by "weights explicitly provided by the font"? Doesn't the variable font provide these? How can I check what weights a font provides?

[habahabahaba]

I mean, for every character of every style (italic or normal) and of every weight, this specific character must exist inside your font file. If your font-file has a capital letter "G" of weight 499 the Wezterm will display it, and if such character is not there, Wezterm will fall back on something else.

[mindentropy]

@habahabahaba : I have JetBrains Mono as external font. There is built in Wezterm font too. How does Wezterm select between these two just based on the name?