R/fig_convert.R

In ianhandel/figr: Tools to inject a directory of figures into md/pdf/html and refence them

#' Convert pdfs to pngs for rendering
#'
#' Given a directory will convert all pdf's to pngs's to
#' allow RMarkdown rendering to look pretty. Requires the
#' R magick package to work.
#'
#' @param dir Directory to converts
#' @param silent If FALSE converted pdf list printed
#' @return Returns a table with column of text links and text labels.
#' @export
#'

fig_convert <- function(dir, silent = TRUE) {
  if (!requireNamespace("magick", quietly = TRUE)) {
    stop(
      "Package <magick> needed for this function to work. Please install it.",
      call. = FALSE
    )
  }

  if (length(dir) > 1) {
    stop("dir should be length 1 - have you given filenames instead?")
  }

  pdfs <- fs::dir_ls(dir, glob = "*.pdf")
  purrr::walk(pdfs, convert)
  if (!silent) print(pdfs)
}

convert <- function(filename) {
  img <- magick::image_read(filename, density = 600)
  filename <- fs::path_ext_set(filename, "png")
  magick::image_write(img, filename, format = "png")
}