Re: [dev-context] [do we need TeXtexts in MkIV]: how to rewrite \startTeXtexts?

4 Oct 2008


      Mojca Miklavec wrote:
...
Hello,
I'm a bit "out" of programming at the moment (and not following mkiv
as deep as I should), but here's one of the old sins that keeps
preventing my module to be used in MKIV.
How can I get rid of \startTeXtexts in the following code, so that the
code will be usable by both mkii and mkiv? (Metapost code is probably
[almost] OK, but the TeX part needs some minor polishing. One could
definitely rewrite metapost code into lua, but then I would need to
take care for two paralel versions - I do not want to go there since
metapost does all the work at the moment.)
Any hinst most welcome,
    Mojca
\defineconversion
  [hans and taco]
  [H,a,n,s,\ ,\&,\ ,T,a,c,o,\ ]
\setupcolors
  [state=start]
\chardef\TeXtextcolormode\zerocount
\startTeXtexts
  \doloop{\doifelseconversionnumber{hans and taco}{\recurselevel}%
      % +500 is a hack (hopefully the plot doesn't contain more than 500 labels)
      % otherwise the points would be overwritten by labels with another \TeXtext:
      % it might need a fix in ConTeXt core
      {\TeXtext{\numexpr\recurselevel+500\relax}{\strut{\convertnumber{hans
and taco}{\recurselevel}}}}%
  {\exitloop}}%
\stopTeXtexts
\edef\numberofsymbols{1}%
\doloop{\doifelseconversionnumber{hans and taco}{\recurselevel}%
  {\edef\numberofsymbols{\recurselevel}}%
  {\exitloop}}%
\starttext
\startMPcode
color c[];
for i=1 upto \numberofsymbols:
  c[i] = ((i-1)/(\numberofsymbols-1))[red,blue];
endfor;
vardef the_number(expr n) = ((n mod \numberofsymbols) + 1) enddef;
vardef the_symbol(expr n) =
  picture pict;
  pict := sometxt(the_number(n) + 500);
  pict shifted -.5[llcorner pict,lrcorner pict]
enddef;
def draw_point(expr x, y, n) =
  draw (the_symbol(n) shifted (x,y)) withcolor c[the_number(n)];
enddef;
for i=0 upto 23:
  draw_point(0,-i*3mm,i);
endfor;
\stopMPcode
\stoptext
just make a proper tex string ... here 's'

\setupcolors[state=start]

\unexpanded\def\colored[#1]%
   {\groupedcommand
      {\definecolor[@colored@][#1]\doactivatecolor{@colored@}}
      {}}

\starttext
     \startMPcode
     vardef draw_point(expr x, y, n) =
         save s ; string s ;
         s := "\colored[r=" & decimal (n/25) & "]{" & decimal n & "}" ;
         draw (textext(s) shifted (x,y)) ;
     enddef;

     for i=0 upto 23:
         draw_point(-i*2mm,-i*3mm,i);
     endfor;
     \stopMPcode
\stoptext

i'll add \colored to the core (this is the mkiv definition)


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