question about MPpositiongraphic

question about MPpositiongraphic

[Thomas A. Schmitz]

Hi all,

first, best wishes for the New Year to all of you - may 2009 bring  
peace and fortune and world domination for ConTeXt!

And my little question - trivial for the resident experts, I guess,  
but I can't find a solution: I want to write a little macro that will  
allow me to place a thin curved line under letters (metrical symbol  
for synizesis). Now that metafun is so fast in mkiv, I thought I'd use  
a MPpositiongraphic for that purpose, but my problem is that I can't  
make the graphic really local - when it is used more than once in a  
document, Metafin uses the last values for all occurrences. I tried  
grouping and the "save" command, but to no avail. Here's an example  
that shows the problem:

\startMPpositiongraphic{placesynizesis}
      StartPage ;
      begingroup ; save a ;
      initialize_box(\MPpos{\MPvar{self}}) ;
      numeric a ; a = ExHeight/6 ;
      z1 = llxy ;
      z2 = lrxy ;
      z3 = 1/2[z1,z2] ;
      z4 = ((x1 + 2a),(y1 - 2a)) ;
      z5 = (x3, (y3 - 4a)) ;
      z6 = ((x2 - 2a),(y2 - 2a)) ;
      path syn ; syn := z4 .. z5 .. z6 ;
      pickup pencircle scaled a ;
      draw syn ;
      anchor_box(\MPanchor{\MPvar{self}}) ;
      endgroup ;
      StopPage ;
\stopMPpositiongraphic%
\setMPpositiongraphic{POS}{placesynizesis}

\define[1]\synizesis
   {\hpos{POS}{#1}}

\starttext

\switchtobodyfont[25pt]

test: \synizesis{au} and \synizesis{aeiou}

\stoptext

Any solution to this conundrum?

All best

Thomas
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Re: question about MPpositiongraphic

[Wolfgang Schuster]

Am 03.01.2009 um 15:02 schrieb Thomas A. Schmitz:

> Hi all,
>
> first, best wishes for the New Year to all of you - may 2009 bring  
> peace and fortune and world domination for ConTeXt!
>
> And my little question - trivial for the resident experts, I guess,  
> but I can't find a solution: I want to write a little macro that  
> will allow me to place a thin curved line under letters (metrical  
> symbol for synizesis). Now that metafun is so fast in mkiv, I  
> thought I'd use a MPpositiongraphic for that purpose, but my problem  
> is that I can't make the graphic really local - when it is used more  
> than once in a document, Metafin uses the last values for all  
> occurrences. I tried grouping and the "save" command, but to no  
> avail. Here's an example that shows the problem:
>
> \startMPpositiongraphic{placesynizesis}
>     StartPage ;
>     begingroup ; save a ;
>     initialize_box(\MPpos{\MPvar{self}}) ;
>     numeric a ; a = ExHeight/6 ;
>     z1 = llxy ;
>     z2 = lrxy ;
>     z3 = 1/2[z1,z2] ;
>     z4 = ((x1 + 2a),(y1 - 2a)) ;
>     z5 = (x3, (y3 - 4a)) ;
>     z6 = ((x2 - 2a),(y2 - 2a)) ;
>     path syn ; syn := z4 .. z5 .. z6 ;
>     pickup pencircle scaled a ;
>     draw syn ;
>     anchor_box(\MPanchor{\MPvar{self}}) ;
>     endgroup ;
>     StopPage ;
> \stopMPpositiongraphic%
> \setMPpositiongraphic{POS}{placesynizesis}
>
> \define[1]\synizesis
>  {\hpos{POS}{#1}}
>
> \starttext
>
> \switchtobodyfont[25pt]
>
> test: \synizesis{au} and \synizesis{aeiou}
>
> \stoptext
>
> Any solution to this conundrum?

\newcount\synizesisnumber

\define[1]\synizesis
  {\advance\synizesisnumber\plusone
   \setMPpositiongraphic{POS-\number\synizesisnumber}{placesynizesis}
   \hpos{POS-\number\synizesisnumber}{#1}}

Wolfgang

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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: question about MPpositiongraphic

[Thomas A. Schmitz]

On Jan 3, 2009, at 3:26 PM, Wolfgang Schuster wrote:

> \newcount\synizesisnumber
>
> \define[1]\synizesis
> {\advance\synizesisnumber\plusone
>  \setMPpositiongraphic{POS-\number\synizesisnumber}{placesynizesis}
>  \hpos{POS-\number\synizesisnumber}{#1}}
>
> Wolfgang

Wow - so simple, and so efficient! Wolfgang, you were my hero in 2008,  
and you'll be my hero in 2009!

Thanks a lot!

Thomas
___________________________________________________________________________________
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  : https://foundry.supelec.fr/projects/contextrev/
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___________________________________________________________________________________