On Tue, 18 Jan 2011, Verhaag, G.C.H.M. wrote:
Hi,
I wanted to try (using ConTeXt minimals MkIV) the example on page 228 of the
MetaFun manual, dealing with typesetting in MetaPost.
I haven't look at the metapost manual ... but
The code is given as:
\resetMPdrawing
\startMPdrawing
picture pic[] ;
numeric wid[], len[], pos[], n ;
wid[0] := len[0] := pos[0] := n := 0 ;
\stopMPdrawing
\def\whatever#1%
{\appendtoks#1\to\MPtoks
\setbox\MPbox=\hbox{\bfd\the\MPtoks}%
\startMPdrawing
n := n + 1 ; len[n] := \the\wd\MPbox ;
\stopMPdrawing
\startMPdrawing[-]
pic[n] := textext("\bfd\setstrut\strut#1") ;
pic[n] := pic[n] shifted - llcorner pic[n] ;
\stopMPdrawing}
\handletokens MetaPost is Fun!\with\whatever
But is won't run. The following message is generated:
The actual error message said
! Undefined control sequence.
\@@toks ->\MPtoks
So add
\newtoks\MPtoks
After which you get
! Undefined control sequence.
\whatever ...endtoks #1\to \MPtoks \setbox \MPbox
so add
\newbox\MPbox
After that the file compiles but you get an empty image. There are two
things missing in the code. First you don't tell actually draw the
metapost drawing. for that, add
\MPdrawingdonetrue \getMPdrawing \resetMPdrawing
Still an empty page. Again the pic[n] is calculated but never drawn. So
add
draw p[n] shifted (n*1cm,0) ;
(or perhaps along a more sophisticated path),
and now you have a working example:
\newtoks\MPtoks
\newbox\MPbox
\resetMPdrawing
\startMPdrawing
picture p[] ;
numeric wid[], len[], pos[], n ;
wid[0] := len[0] := pos[0] := n := 0 ;
\stopMPdrawing
\def\whatever#1%
{\appendtoks#1\to\MPtoks
\setbox\MPbox=\hbox{\bfd\the\MPtoks}%
\startMPdrawing
n := n + 1 ; len[n] := \the\wd\MPbox ;
p[n] := textext("\bfd\setstrut\strut#1") ;
p[n] := p[n] shifted - llcorner p[n] ;
draw p[n] shifted (n*1cm,0) ;
\stopMPdrawing}
\starttext
\handletokens MetaPost is Fun!\with\whatever
\MPdrawingdonetrue \getMPdrawing \resetMPdrawing
\stoptext
You could also have just used the macros from meta-txt:
\useMPlibrary[txt]
\startMPdefinitions
newpath RotPath ;
RotPath = fullcircle scaled 3cm ;
\stopMPdefinitions
\starttext
\followtokens{Metapost is fun \quad}
\stoptext
@Hans: Perhaps we can have a more ConTeXtist interface to this macro:
\definetextonepath
[whatever]
[color=...,
style=...,
mp=..., % path specification
]
\whatever{Metapost is fun}
Aditya
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the
Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
