Name

       kitten-choose-fonts - kitten Documentation

Overview

       Terminal  aficionados  spend all day staring at text, as such, getting text rendering just
       right is very important. kitty has extremely  powerful  facilities  for  fine-tuning  text
       rendering.  It  supports  OpenType features to select alternate glyph shapes, and Variable
       fonts to control the weight or spacing of a font precisely. You can also select which font
       is  used  to render particular unicode codepoints and you can modify font metrics and even
       adjust the gamma curves used for rendering text onto the background color.

       The first step is to select the font faces kitty will use for rendering regular, bold  and
       italic  text.  kitty  comes  with  a  convenient UI for choosing fonts, in the form of the
       choose-fonts kitten. Simply run:

          kitten choose-fonts

       and follow the on screen prompts.

       First, choose the family you want, the list of families can be easily filtered by typing a
       few  letters  from  the family name you are looking for. The family selection screen shows
       you a preview of how the family looks.

       Once you select a family by pressing the Enter key, you are shown  previews  of  what  the
       regular,  bold and italic faces look like for that family. You can choose to fine tune any
       of the faces. Start with fine-tuning the regular face by pressing the  R  key.  The  other
       styles will be automatically adjusted based on what you select for the regular face.

       You can choose a specific style or font feature by clicking on it. A precise value for any
       variable axes can be selected using the slider, in the screenshot above, the font supports
       precise  weight  adjustment.  If  you are lucky the font designer has included descriptive
       names for font features, which will be displayed, if not, consult the documentation of the
       font to see what each feature does.

The font specification syntax

       If  you  don't  like  the  choose fonts kitten or simply want to understand and write font
       selection options into kitty.conf yourself, read on.

       There  are  four  font  face  selection  keys:  font_family,  bold_font,  italic_font  and
       bold_italic_font.  Each  of these supports the syntax described below. Their values can be
       of three types, either a font family name, the  keyword  auto  or  an  extended  key=value
       syntax for specifying font selection precisely.

       If  a  font  family name is specified kitty will use Operating System APIs to search for a
       matching font. The keyword auto means kitty will choose a font  completely  automatically,
       typically  this  is  used  for  automatically  selecting  bold/italic  variants  once  the
       font_family is set. The bold and italic variants will then automatically use the same  set
       of features as the main face.

       To  specify  font face selection more precisely, a key=value syntax is used.  First, let's
       look at a few examples:

          # Select by family only, actual face selection is automatic
          font_family family="Fira Code"
          # Select an exact face by Postscript name
          font_family postscript_name=FiraCode
          # Select an exact face by family with features and variable weight
          font_family family=SourceCodeVF variable_name=SourceCodeUpright features="+zero cv01=2" wght=380

       The following are the known keys, any other keys are names of variable axes, that is, they
       are used to set the variable value for some font characteristic.

       family A font family name. A family typically has multiple actual font faces, such as bold
              and italic variants. One or more of the faces can even be variable,  allowing  fine
              tuning of font characteristics.

       style  A  style name to choose a particular font from a given family. Useful only with the
              family key, when no more precise methods for face selection are specified. Can also
              be used to specify a named variable style for variable fonts.

       postscript_name
              The  actual  postscript  name  for  a font face. This allows selecting a particular
              variant  within  a  font  family.  But  note  that  postscript  names  are  usually
              insufficient for selecting variable fonts.

       full_name
              This  can be used to select a particular font face in a family. However, it is less
              precise than postscript_name and should not generally be used.

       variable_name
              Some families with  variable  fonts  actually  contain  multiple  font  files.  For
              example, a family could have variable weights with one font file containing upright
              variable weight faces and another containing italic  variable  weight  faces.  Well
              designed  fonts  use  a  variable name to distinguish between such files. Should be
              used in conjunction with family to select a particular variable font file.

       features
              A space separated list of OpenType font features  to  enable/disable  or  select  a
              value  of, for this font. Consult the documentation for the font family to see what
              features it supports and their effects. The exact syntax for specifying features is
              documented by HarfBuzz

       system This  can  be used to pass an arbitrary string, usuall a family or full name to the
              OS font selection APIs. Should not be used in conjunction with any other  keys.  Is
              the same as specifying just the font name without any keys.

       In  addition  to  these  keys,  any  four  letter key is treated as the name of a variable
       characteristic of the font. It's value is used to set the value for the name.

Author

       Kovid Goyal

Copyright

       2024, Kovid Goyal