turn embedded pngs in svg to webps

base64_png_to_webp.R

library(tidyverse)
library(base64enc)
library(webp)
library(png)

compress_svg <- function(file) {
  text <- read_lines(file) |>
    paste(collapse = "\n")
  
  # Remove mask
  text <- text |>
    stringr::str_remove_all("\\s*<mask.*>[\\s\\S]*?</mask>")
  
  # remove mask atribute in <g>
  text <- text |>
    stringr::str_remove_all(" mask=\"url\\(#\\w*\\)\"")
  
  # turn embedded pngs to webp
  base64_png_to_webp <- function(image) {
    tmp_png <- tempfile()
    tmp_webp <- tempfile()
    tmp_base64 <- tempfile()
    
    writeLines(image, tmp_base64)
    base64decode(file = tmp_base64, output = tmp_png)
    write_webp(readPNG(tmp_png), tmp_webp)
    base64encode(tmp_webp)
  }
  text <- stringr::str_replace_all(text, "(?<=, )(.*?)(?=\")", base64_png_to_webp)
  text <- stringr::str_replace_all(text, "png;base64", "webp;base64")
  
  write_lines(text, file)  
}

fs::dir_map("assets/", compress_svg)