Re: followtokens

[Hans Hagen <pragma@wxs.nl>]

Alexandre Billon wrote:

> Dear all,
>
> I am quite new to context (but love it) and i am trying tind a way to 
> typeset texts "properly kerned" in such a way that the characters be 
> all rotated with tiny randomized angle (strange project indeed). I 
> tried to do it by writing a macro inspired by \followtokens. I have 
> two questions :
>
> 1. It works but just for text within a single line :  I have no clue 
> how  to manage the line breaking, and I have to admit that I don't 
> know eanough TeX ConTeXt to find out.
>
> 2. In playing with the macro followtoken I happened to write two files 
> with no apparent significant difference (I mean for me) but which give 
> quite different results : one properly kerned, and another that is 
> not. Could someone explain me what's happening here ? (files attached)
>
\startMPenvironment[global]
    \definefont[RotFont][RegularBold]
\stopMPenvironment

\def\whatever#1%
  {\appendtoks#1\to\MPtoks
   \setbox\MPbox=\hbox{\RotFont\setstrut\strut\the\MPtoks}%
   \startMPdrawing
        n := n + 1 ; len[n] := \the\wd\MPbox ;
   \stopMPdrawing
   \startMPdrawing[-]
        pic[n] := btex \RotFont\setstrut\strut#1 etex ;
   \stopMPdrawing}

\def\funnywriting#1%
  {\bgroup
   \resetMPdrawing
   \startMPdrawing
        picture pic[] ;
        numeric wid[], len[], pos[], n ;
        wid[0] := len[0] := pos[0] := n := 0 ;
   \stopMPdrawing
   \handletokens#1\with\whatever
   \startMPdrawing
        for i=1 upto n :
            wid[i] := abs(xpart lrcorner pic[i] - xpart llcorner pic[i]) ;
            pos[i] := len[i]-wid[i] ;
            pic[i] := pic[i] rotatedaround(origin, -10 randomized 20) ;
            pic[i] := pic[i] shifted (pos[i],0) ;
            draw pic[i];
        endfor ;
   \stopMPdrawing
   \MPdrawingdonetrue
   \getMPdrawing
   \resetMPdrawing
   \egroup}

\starttext
    \funnywriting{La vie est belle}
\stoptext

watch the rotatedaround: you have to provide a pair as first argument 
(so both your files failed)

Hans