tteerawat / gutenex

Native PDF generation for Elixir

Gutenex

PDF generation!

So weird that it's still a thing for murderers in horror movies to keep clippings of their crimes. PDF that shit! — Julieanne Smolinkski

What started out as a wrapper for the Erlang erlguten library has turned into a full rewrite in Elixir.

Plan

Rewriting the basic PDF functionality means:

• text
• fonts
• images
• rendering/exporting
• parsing existing PDFs
• templating
• documentation

Usage

  # Load image, get alias
  {alpaca_alias, alpaca_rendition} = Gutenex.PDF.Images.load("./test/support/images/alpaca.png")

  {:ok, pid} = Gutenex.start_link
  Gutenex.add_image(pid, alpaca_alias, alpaca_rendition)
    |> Gutenex.begin_text
    |> Gutenex.set_font("Helvetica", 48)
    |> Gutenex.text_position(40, 180)
    |> Gutenex.text_render_mode(:fill)
    |> Gutenex.write_text("ABC")
    |> Gutenex.set_font("Courier", 32)
    |> Gutenex.text_render_mode(:stroke)
    |> Gutenex.write_text("xyz")
    |> Gutenex.end_text
    |> Gutenex.move_to(400, 20)
    |> Gutenex.draw_image(alpaca_alias, %{
      translate_x: 300,
      translate_y: 500,
    })
    |> Gutenex.export("./tmp/alpaca.pdf")
    |> Gutenex.stop

Now open up that file and you should see some text near the bottom and a picture of what I believe to be an alpaca. Could also be a llama.

By default, coordinates are in units of 1/72 inch as per the PDF spec. Origin is in lower left corner of the page. This is roughly 1 point in printing terms.

  Gutenex.line_width(pid, 0.01)          # very fine line
  |> Gutenex.line({{0, 0}, {500, 500}})  # up and to the right