Aditya Mahajan wrote:
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
Hi,
Okay, that makes things more clear, but couldn't find this in the
manual! Maybe it is very obvious to someone more familiar with METAPOST.
Well, I also tried the nice macro example on page 232 of the MetaFun
manual by Hans, and got of course the same problems. But after I added the
\newtoks\MPtoks
\newbox\MPbox
definitions to the file, it worked!
Also the Inkscape alternative is very useful, thanks for helping me out!
Regards,
Gerard
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