The documentation for lua-visual-debug is a little sparse. Can someone interpret the boxes/lines/colors that lua-visual-debug produces?

  • 3
    Patrick Gundlach promised to improve the documentation when I asked him in the chat.
    – egreg
    Commented Apr 6, 2012 at 9:03
  • Give me a few hours... If someone enhances the documentation, I'll add a 100 bounty to the question.
    – topskip
    Commented Apr 6, 2012 at 9:44
  • A new package (documentation update) is on its way to ctan/texlive.
    – topskip
    Commented Apr 6, 2012 at 21:05
  • Patrick - I apologize if this sounded like a criticism. In all honesty I figured the lack of documentation was a reflection of how little i know about luatex. thanks for the package...
    – dfc
    Commented Apr 7, 2012 at 0:17
  • 5
    I didn't take that as criticism, the lack of that part in the documentation was obvious and therefore it sucked. No way put this in nice words. I saw your question as "hey someone is actually using the package and you've always wanted to enhance the doc". So I am grateful for the question.
    – topskip
    Commented Apr 7, 2012 at 7:10

1 Answer 1


lua-visual-debug detail

  1. A vertical glue. Beginning and end are marked with a small tick. At the mark 1 two vertical glues are connected.
  2. A horizontal glue.
  3. A negative kern. Positive kerns are yellow.
  4. A possible hyphenation point.
  5. Horizontal and vertical boxes are drawn with a border.
  6. Penalties are marked with a square. A penalty of 10,000 is marked with a blank square, a penalty less than 10,000 is filled with a gray square (that will improve in the future, currently it is grayness of penalty / 10000).

A strut box (zero width box) is marked with a red rule:


  • After the "Hello" word in the second image, there is a blue "dotted" line. It looks like the violet "dotted" line in the first image (2: A horizontal glue) - but does it also have the same meaning? The blue in first image is "4. A possible hyphenation point.", but that cannot be the meaning of the blue line after the "Hello" on second image. Can you please clarify? Thanks!
    – sdaau
    Commented Jun 20, 2012 at 2:35
  • 1
    @sdaau this blue dotted line is a glue and has the same meaning as 2) a horizontal glue. I don't know where the different colors come from.
    – topskip
    Commented Jun 20, 2012 at 8:43
  • Many thanks for clarifying, @PatrickGundlach - cheers!
    – sdaau
    Commented Jun 20, 2012 at 10:59

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .