Getting Into the Rhythm of Chart Typography with {ragg} and {hrbragg} (a.k.a. It’s {ragg}-time}

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Horrible puns aside, hopefully everyone saw the news, earlier this week, from @thomasp85 on the evolution of modern typographic capabilities in the R ecosystem. Thomas (and some cohorts) has been working on {systemfonts}, {ragg}, and {textshaping} for quite a while now, and the — shall we say tidyglyphs ecosystem — is super-ready for prime time.

Thomas covered a seriously large amount of ground in his post, so please take some time to digest that before continuing.

Back? 👍🏽

While it is possible to mangage typographic needs with the foundry tools provided via the font-rendering package-triad, one would be hard-pressed to say that the following is “fun”, or even truly manageable coding:

library(systemfonts)

register_variant(
  name = "some-unique-prefix Inter some-style-01",
  weight = "normal",
  features = font_feature(
    poss = 1, ibly = 1, many = 1, 
    four = 1, char = 1, open = 1,
    type = 1, code = 1, spec = 1
  )
)

# remember that name

register_variant(
  name = "some-unique-prefix Inter some-style-02",
  weight = "normal",
  features = font_feature(
    poss = 1, ibly = 1, many = 1, 
    four = 1, char = 1, open = 1,
    type = 1, code = 1, spec = 1
  )
)

# remember that name 

# add a dozen more lines ...

ggplot() +
   geom_text(family = "oops-i-just-misspelled-the-family-name-*again*", ...) 

We’ve been given the power to level up our chart typography, but it’s sort of where literal typesetters (the ones who put blocks of type into a press) were and we can totally make our lives easier and charts prettier with the help of a new package — {hrbragg} https://git.rud.is/hrbrmstr/hrbragg — which is somewhat of a bridge between {ragg}, {systemfonts}, {textshaping} and a surprisingly popular package of mine: {hrbrthemes}. {hrbragg} is separate from {hrbrthemes} since this new typographic ecosystem is fairly restricted to {ragg} graphics devices (for the moment, as Thomas alluded the other day), and the new themes provided in {hrbragg} are a bit of a level-up from those in its sibling package.

Feature Management

At the heart of {systemfonts} lies the ability to tweak font features and bend them to your will. This somewhat old post shows why these tweaks exist and delves (but not too deeply) into the details of them, down to the four-letter codes that are used to represent and work with a given feature. But, what does calt mean? And, what is this tnum fellow you’ll be seeing a great deal of in R-land over the coming months? While one could leave the comfort of RStudio, VS Code, or vim to visit one of the reference links in Thomas’ package or {hrbragg}, I’ve included the most recent copy of tag-code<->full-tag-name<->short-tab-description in {hrbragg} as a usable data frame so you can treat it like the data it is!

library(systemfonts) # access to and tweaking OTFs!
library(textshaping) # lets us treat type as data
library(ragg)        # because it'll be lonely w/o the other two
library(hrbragg)     # remotes::install_git("https://git.rud.is/hrbrmstr/hrbragg.git")
library(tidyverse)   # nice printing, {ggplot2}, and b/c we'll do some font data wrangling

data("feature_dict")

feature_dict
## # A tibble: 122 x 3
##    tag   long_name                   description                                                                                             
##                                                                                                                               
##  1 aalt  Access All Alternates       Special feature: used to present user with choice all alternate forms of the character                  
##  2 abvf  Above-base Forms            Replaces the above-base part of a vowel sign. For Khmer and similar scripts.                            
##  3 abvm  Above-base Mark Positioning Positions a mark glyph above a base glyph.                                                              
##  4 abvs  Above-base Substitutions    Ligates a consonant with an above-mark.                                                                 
##  5 afrc  Alternative Fractions       Converts figures separated by slash with alternative stacked fraction form                              
##  6 akhn  Akhand                      Hindi for unbreakable.  Ligates consonant+halant+consonant, usually only for k-ss and j-ny combinations.
##  7 blwf  Below-base Forms            Replaces halant+consonant combination with a subscript form.                                            
##  8 blwm  Below-base Mark Positioning Positions a mark glyph below a base glyph                                                               
##  9 blws  Below-base Substitutions    Ligates a consonant with a below-mark.                                                                  
## 10 c2pc  Capitals to Petite Caps     Substitutes capital letters with petite caps                                                            
## # … with 112 more rows

You can also use help("opentype_typographic_features") to see an R help page with the same information. That page also has links external resource, one of which is a detailed manual of each feature with use-cases (in the event even the short-description is not as helpful as it could be).

Before one can think about using the bare-metal register_variant(..., font_feature(...)) duo, one has to know what features a particular type family supports. We can retrieve the feature codes with textshaping::get_font_features() and look them up in this data frame to get an at-a-glance view:

# old school subsetting ftw!
feature_dict[feature_dict$tag %in% textshaping::get_font_features("Inter")[[1]],]
## # A tibble: 19 x 3
##    tag   long_name                   description                                                                                                                 
##                                                                                                                                                   
##  1 aalt  Access All Alternates       Special feature: used to present user with choice all alternate forms of the character                                      
##  2 calt  Contextual Alternates       Applies a second substitution feature based on a match of a character pattern within a context of surrounding patterns      
##  3 case  Case Sensitive Forms        Replace characters, especially punctuation, with forms better suited for all-capital text, cf. titl                         
##  4 ccmp  Glyph Composition/Decompos… Either calls a ligature replacement on a sequence of characters or replaces a character with a sequence of glyphs. Provides…
##  5 cpsp  Capital Spacing             Adjusts spacing between letters in all-capitals text                                                                        
##  6 dlig  Discretionary Ligatures     Ligatures to be applied at the user's discretion                                                                            
##  7 dnom  Denominator                 Converts to appropriate fraction denominator form, invoked by frac                                                          
##  8 frac  Fractions                   Converts figures separated by slash with diagonal fraction                                                                  
##  9 kern  Kerning                     Fine horizontal positioning of one glyph to the next, based on the shapes of the glyphs                                     
## 10 locl  Localized Forms             Substitutes character with the preferred form based on script language                                                      
## 11 mark  Mark Positioning            Fine positioning of a mark glyph to a base character                                                                        
## 12 numr  Numerator                   Converts to appropriate fraction numerator form, invoked by frac                                                            
## 13 ordn  Ordinals                    Replaces characters with ordinal forms for use after numbers                                                                
## 14 pnum  Proportional Figures        Replaces numerals with glyphs of proportional width, often also onum                                                        
## 15 salt  Stylistic Alternates        Either replaces with, or displays list of, stylistic alternatives for a character                                           
## 16 subs  Subscript                   Replaces character with subscript version, cf. numr                                                                         
## 17 sups  Superscript                 Replaces character with superscript version, cf. dnom                                                                       
## 18 tnum  Tabular Figures             Replaces numerals with glyphs of uniform width, often also lnum                                                             
## 19 zero  Slashed Zero                Replaces 0 figure with slashed 0        

Most of those will not be super-useful (yet) but there are three key features that I believe one needs when picking a font for a chart:

  • One of the *ligs (because ligatures.) are so gosh darn cool, pretty, and useful)
  • tnum for tabular numbers (essential in axis value display, and more)
  • kern for sweet, sweet letterspacing, or kerning

Since I’ve just made up a rule, let’s see how many fonts I have that support said rule:

(fam <- unique(system_fonts()[["family"]])) %>% 
  get_font_features() %>% 
  set_names(fam) %>% 
  keep(~sum(c(
    any(grepl("kern", .)), 
    any(grepl("tnum", .)),
    any(grepl(".lig|liga", .)) 
    )) == 3
  ) %>% 
  names() %>% 
  sort()
##  [1] "Barlow"                 "Goldman Sans"           "Goldman Sans Condensed" "Grantha Sangam MN"     
##  [5] "Inter"                  "Kohinoor Devanagari"    "Mukta Mahee"            "Museo Slab"            
##  [9] "Neufile Grotesk"        "Roboto"                 "Roboto Black"           "Roboto Condensed"      
## [13] "Roboto Light"           "Roboto Medium"          "Roboto Thin"            "Tamil Sangam MN"       
## [17] "Trattatello"           

I do have more, but they’re on a different Mac 😎.

{hrbragg} comes with Inter, Goldman Sans, and Roboto Condensed, so let’s explore one of them — Inter — and see how we might be able to make it useful but not tedious. The supported features of Inter are above and here are the family members:

system_fonts() %>% 
  filter(family == "Inter") %>% 
  select(name, family, style, weight, width, italic, monospace)
##  A tibble: 18 x 7
##    name                   family style              weight     width  italic monospace
##                                                    
##  1 Inter-ExtraLight       Inter  Extra Light        light      normal FALSE  FALSE    
##  2 Inter-MediumItalic     Inter  Medium Italic      medium     normal TRUE   FALSE    
##  3 Inter-ExtraLightItalic Inter  Extra Light Italic light      normal TRUE   FALSE    
##  4 Inter-Bold             Inter  Bold               bold       normal FALSE  FALSE    
##  5 Inter-ThinItalic       Inter  Thin Italic        ultralight normal TRUE   FALSE    
##  6 Inter-SemiBold         Inter  Semi Bold          semibold   normal FALSE  FALSE    
##  7 Inter-BoldItalic       Inter  Bold Italic        bold       normal TRUE   FALSE    
##  8 Inter-Italic           Inter  Italic             normal     normal TRUE   FALSE    
##  9 Inter-Medium           Inter  Medium             medium     normal FALSE  FALSE    
## 10 Inter-BlackItalic      Inter  Black Italic       heavy      normal TRUE   FALSE    
## 11 Inter-Light            Inter  Light              normal     normal FALSE  FALSE    
## 12 Inter-SemiBoldItalic   Inter  Semi Bold Italic   semibold   normal TRUE   FALSE    
## 13 Inter-Regular          Inter  Regular            normal     normal FALSE  FALSE    
## 14 Inter-ExtraBoldItalic  Inter  Extra Bold Italic  ultrabold  normal TRUE   FALSE    
## 15 Inter-LightItalic      Inter  Light Italic       normal     normal TRUE   FALSE    
## 16 Inter-Thin             Inter  Thin               ultralight normal FALSE  FALSE    
## 17 Inter-ExtraBold        Inter  Extra Bold         ultrabold  normal FALSE  FALSE    
## 18 Inter-Black            Inter  Black              heavy      normal FALSE  FALSE    

Nobody. I mean, nobody wants to type eighteen+ font variant registration statements, which is why {hrbragg} comes with reconfigure_font(). Just give it the family name, the features you want supported, and it will take care of the tedium for you:

reconfigure_font(
  prefix = "hrbragg-pkg",
  family = "Inter",
  width = "normal",
  ligatures = "discretionary",
  calt = 1, tnum = 1, case = 1,
  dlig = 1, ss01 = 1, kern = 1,
  zero = 0, salt = 0
) -> customized_inter

# I'll have a proper print method for this soon

str(customized_inter, 1)
## List of 17
##  $ ultralight_italic: chr "clever-prefix Inter Thin Italic"
##  $ ultralight       : chr "clever-prefix Inter Thin"
##  $ light            : chr "clever-prefix Inter Extra Light"
##  $ light_italic     : chr "clever-prefix Inter Extra Light Italic"
##  $ normal_italic    : chr "clever-prefix Inter Light Italic"
##  $ normal_light     : chr "clever-prefix Inter Light"
##  $ normal           : chr "clever-prefix Inter Regular"
##  $ medium_italic    : chr "clever-prefix Inter Medium Italic"
##  $ medium           : chr "clever-prefix Inter Medium"
##  $ semibold         : chr "clever-prefix Inter Semi Bold"
##  $ semibold_italic  : chr "clever-prefix Inter Semi Bold Italic"
##  $ bold             : chr "clever-prefix Inter Bold"
##  $ bold_italic      : chr "clever-prefix Inter Bold Italic"
##  $ ultrabold_italic : chr "clever-prefix Inter Extra Bold Italic"
##  $ ultrabold        : chr "clever-prefix Inter Extra Bold"
##  $ heavy_italic     : chr "clever-prefix Inter Black Italic"
##  $ heavy            : chr "clever-prefix Inter Black"
##  - attr(*, "family")= chr "Inter"

The reconfigure_font() function applies the feature settings to all the family members, gives each a name with the stated prefix and provides a return value that supports autocompletion of the name in smart IDEs and practically negates the need to type out long, unique font names, like this:

ggplot() +
  geom_text(
    aes(1, 2, label = "Welcome to a <- customized -> Inter!"),
    size = 6, family = customized_inter$ultrabold
  ) +
  theme_void()

Note that we have a lovely emboldened font with clean ligatures without much work at all! (I should mention that if a prefix is not specified, a UUID is chosen instead since we don’t really care about the elongated names anymore).

While we’ve streamlined things a bit already, we can do even better.

Font-centric Themes

Just like {hrbrthemes}, {hrbragg} comes with some font/typographic-centric themes. We’ll focus on the one with Inter for the blog post. For the moment, you’ll need to install_inter() (you likely got prompted to do that if you already installed the package). This requirement will go away soon, but you’ll want to use Inter everywhere anyway, so I’d keep it installed.

Once that’s done, you’re ready to use theme_inter().

What’s that you say? Don’t we need to create a font variant first?

Would I do that to you? Never! {hrbragg} comes with a preconfigured inter_pkg font variant (which I’ll be tweaking a bit over the weekend for some edge cases) that pairs nicely with theme_inter(). Here it is in action with an old friend of ours:

ggplot() +
  geom_point(
    data = mtcars,
    aes(mpg, wt, color = factor(cyl))
  ) +
  geom_label(
    aes(
      x = 15, y = 5.48,
      label = "<- A fairly useless annotation\n       that uses the custom Inter\n          variant by default."
    ),
    label.size = 0, hjust = 0, vjust = 1
  ) +
  labs(
    x = "Fuel efficiency (mpg)", y = "Weight (tons)",
    title = "Seminal ggplot2 scatterplot example",
    subtitle = "A plot that is only useful for demonstration purposes",
    caption = "Brought to you by the letter 'g'"
  ) -> gg1

gg1 + theme_inter(grid = "XY", mode = "light") 

Wonderful kerning, a custom-built arrow due to fantastic, built-in ligatures, and spiffy tabular numbers. Gorgeous!

What was that you just asked? What’s up with that mode = "light"?. Did I forget to mention that all the {hrbragg} themes come with dark-mode support built in? My sincerest apologies. Choosing mode = "dark" will use a (configuratble) dark theme and using mode = "rstudio" (if you’re an RStudio user) will have the charts take on the IDE theme setting automagically. Here’s dark mode:

gg1 + theme_inter(grid = "XY", mode = "dark") 

The font+theme pairs automatically work and reconfigure all the ggplot2 aesthetic defaults accordingly. Since this makes heavy use of update_geom_defaults() I’ve included a (very necessary) reset_ggplot2_defaults() to get things back to normal when you need to.

Note that you can use adaptive_color() to help enable dark/light-mode color switching for your own pairings, and theme_background_color() or theme_foreground_color to utilize the (reconfigurable) default fore- and background theme colors.

Try before you buy…into using a given font

One can’t know ahead of time whether a font is going to work well, and you might want go get a feel for how a given set of family variants work for you. To that end, I’ve made it possible to preview any font you’ve reconfigured with reconfigure_font() via preview_variant(). It uses some pre-set text that exercises the key features I’ve outlined, but you can sub your own for them if you want to look at something in particular. Let’s give inter_pkg a complete look:

preview_variant(inter_pkg)

We can look at another one that we’ll create now (I did not realize this font had tabular numbers until Thomas built all these wonderful toys to play with!):

reconfigure_font(
  family = "Trattatello",
  width = "normal",
  ligatures = "discretionary",
  calt = 1, tnum = 1, case = 1,
  dlig = 1, kern = 1,
  zero = 0, salt = 0
) -> trat

preview_variant(trat)

FIN

The {hrbragg} package is not even 24 hours old yet, so there are breaking changes and many new, heh, features still to come, but please — as usual — kick the tyres and post questions, feedback, contributions, or suggestions wherever you’re most comfortable (the package is on most of the popular social coding sites).

To leave a comment for the author, please follow the link and comment on their blog: R – rud.is.

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