Re: [NTG-context] Testing the changing dimensions of boxes (in cycles) via Lua

15 Jun 2012

      On Thu, Jun 14, 2012 at 10:17 PM, Jaroslav Hajtmar  wrote:
...
Hello ConTeXist and Lua experts.
In a my Lua project I need to determine the changing dimensions of the TeX
\vbox through Lua.
In ConTeXt cycle, it works fine, but in the Lua cycle does not change the
dimensions of the box.
What am I doing wrong?
Thank you.
Jaroslav Hajtmar
Here is my minimal example:
--------------------------------------------------------------------
\newdimen\lsize
\def\contentofvbox{\input ward }
\def\setmybox{\setbox0=\vbox{\hsize=\lsize \contentofvbox}}
\starttext
Height of box via ConTeXt (works fine):
\setmybox
\lsize=5cm
\dorecurse{3}{%
   \lsize=\dimexpr(\lsize+7mm)
   \setmybox
   height of box: \the\ht0\par
   width of box: \the\wd0\par
\box0\par
}
\page
... and Height of box via Lua (do not working):
\setmybox
\ctxlua{
tex.dimen.lsize=5*72.27*65536/25.4
for i=1, 3 do
   tex.dimen.lsize=tex.dimen.lsize+7*72.27*65536/25.4
   context([[\setmybox]])
   local heightbox=tex.box[0].height
   local widthbox=tex.box[0].width
   heightbox=(heightbox*2.84527559067*25.4)/(72.27*65536)
   widthbox=(widthbox*2.84527559067*25.4)/(72.27*65536)
   context([[height of box:]]..heightbox.."pt\\par")
   context([[width of box:]]..widthbox.."pt\\par")
   context([[\box0\par]])
end
}
\stoptext
Try this one:

\def\setmybox{\setbox0=\vbox{\hsize=\lsize\input knuth \par}}
\newdimen\lsize
\lsize=5cm
\starttext

Height of box via ConTeXt (works fine):

\setmybox

\lsize=5cm
\dorecurse{3}{%
   \lsize=\dimexpr(\lsize+7mm)
   \setmybox
   height of box: \the\ht0\par
   width of box: \the\wd0\par
\box0\par
}

\page

... and Height of box via Lua (does it work ?):

\setmybox
\ctxlua{tex.dimen.lsize=5*72.27*65536/25.4;i=0}
\dorecurse{3}{%
\ctxlua{
--[=[ for i=1, 3 do ]=]
   i=i+1
   tex.dimen.lsize=tex.dimen.lsize+7*72.27*65536/25.4
   context([[\setmybox]])
}
\ctxlua{
   local heightbox=tex.box[0].height
   local widthbox=tex.box[0].width
   heightbox=(heightbox*2.84527559067*25.4)/(72.27*65536)
   widthbox=(widthbox*2.84527559067*25.4)/(72.27*65536)
   context(i..[[ height of box:]]..heightbox.."pt :
"..(tex.box[0].height/2^16).."pt\\par")
   context(i..[[ width of box:]]..widthbox.."pt :
"..(tex.box[0].width/2^16).."pt\\par")
   context([[\box0\par]])
--[=[ end ]=]
}
}
\stoptext
-- 
luigi

Re: [NTG-context] Testing the changing dimensions of boxes (in cycles) via Lua

luigi scarso