ggplot geom_font_awesome

example_font_awesome.R

library(ggplot2)
source('geom_font_awesome.R')

shapes_map = c(
    setosa = 'car',
    virginica = 'ban',
    versicolor = 'star'
)

(
    ggplot(iris, aes(Sepal.Width, Petal.Width))
    + geom_font_awesome(aes(shape=Species, fill=Species))
    + scale_shape_manual(values=shapes_map)
)

geom_font_awesome.R

library(ggplot2)
library(gridtext)
library(grid)
library(fontawesome)

fa_html = Vectorize(function(icon, fill='black', size=1, export_scale=20, display_scale=10) {
    fa_png(icon, fill=fill, width=size * export_scale, height=size * export_scale)
    paste0("<img src='", icon, ".png' width='", size * display_scale, "'>")
})

draw_key_fa <- function(data, params, size) {
    richtext_grob(fa_html(
        data$shape,
        size=data$size,
        fill=data$fill
    ), use_markdown=FALSE)
}

GeomFontAwesome <- ggproto("GeomFontAwesome", Geom,
  required_aes = c("x", "y"),
  non_missing_aes = c("size", "shape", "fill"),
  default_aes = aes(
    shape = 'star', fill = "black", size = 1.5,
    alpha = NA
  ),
  draw_panel = function(data, panel_params, coord) {
    coords <- coord$transform(data, panel_params)
    ggplot2:::ggname("geom_font_awesome",
      richtext_grob(
        coords$x, coords$y,
        text = fa_html(
            coords$shape,
            size=coords$size,
            fill=alpha(coords$fill, coords$alpha)
        )
      )
    )
  },
  draw_key = draw_key_fa
)

geom_font_awesome <- function(mapping = NULL, data = NULL,
                       stat = "identity", position = "identity",
                       ...,
                       na.rm = FALSE,
                       show.legend = NA,
                       inherit.aes = TRUE) {
  layer(
    data = data,
    mapping = mapping,
    stat = stat,
    geom = GeomFontAwesome,
    position = position,
    show.legend = show.legend,
    inherit.aes = inherit.aes,
    params = list(
      na.rm = na.rm,
      ...
    )
  )
}