[luatex] Dimensions of subboxes

[Eduardo Ochs]

On Mon, 25 Apr 2022 at 03:26, Patrick Gundlach <patrick at gundla.ch> wrote:
> (...)


Hi Patrick!

The trick with coroutines looked like overkill, but there were some
very useful comments... I followed some links, and got the solution
below. If I send these lines to a shell,


cd /tmp/emlua/tex/
cat > a.tex <<'---'
\setbox0\hbox{\hbox{$a$}\hbox{$b$}\hbox{$p$}\hbox{$q$}}
\directlua{dofile "edrxlib.lua"}
\directlua{dofile "Repl1.lua"}
\directlua{REPL = EdrxRepl.new(); print(); REPL:repl()}
\bye
---

luatex a.tex
  adj = 2^16
  print(tex.box[0])
  print(tex.box[0].width)
  print(tex.box[0].width / adj)
  for hlist in node.traverse_id(node.id"hlist", tex.box[0].list) do
    local wd = hlist.width  / adj
    local ht = hlist.height / adj
    local dp = hlist.depth  / adj
    print(format("wd: %.3f  ht: %.3f  dp: %.3f", wd, ht, dp))
  end


Then the log of my interaction with luatex is this:


This is LuaTeX, Version 1.12.0 (TeX Live 2020)
 restricted system commands enabled.
(./a.tex
>>>   adj = 2^16
>>>   print(tex.box[0])
<node    nil <    387 >    nil : hlist 2>
>>>   print(tex.box[0].width)
1273476
>>>   print(tex.box[0].width / adj)
19.431701660156
>>>   for hlist in node.traverse_id(node.id"hlist", tex.box[0].list) do
...     local wd = hlist.width  / adj
...     local ht = hlist.height / adj
...     local dp = hlist.depth  / adj
...     print(format("wd: %.3f  ht: %.3f  dp: %.3f", wd, ht, dp))
...   end
wd: 5.286  ht: 4.306  dp: 0.000
wd: 4.292  ht: 6.944  dp: 0.000
wd: 5.031  ht: 4.306  dp: 1.944
wd: 4.823  ht: 4.306  dp: 1.944
>>>


So: problem solved! Thanks! =)
  Eduardo Ochs
  http://angg.twu.net/