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

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Patrick Gundlach promised to improve the documentation when I asked him in the chat. –  egreg Apr 6 '12 at 9:03
Give me a few hours... If someone enhances the documentation, I'll add a 100 bounty to the question. –  topskip Apr 6 '12 at 9:44
A new package (documentation update) is on its way to ctan/texlive. –  topskip Apr 6 '12 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 Apr 7 '12 at 0:17
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 Apr 7 '12 at 7:10

1 Answer 1

up vote 14 down vote accepted

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:


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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 Jun 20 '12 at 2:35
@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 Jun 20 '12 at 8:43
Many thanks for clarifying, @PatrickGundlach - cheers! –  sdaau Jun 20 '12 at 10:59

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