Hi Gerben,
Changing the macro header to this will work:
vardef SampleText (expr t)(text c) =
or you can use the answer from stackexchange, same approach.
BTW Hans would like people to use “withtransparency” instead as that is a
newer, more flexible approach (but that would also need the above change,
or a split into multiple parameters).
Taco
> On 9 Apr 2020, at 09:04, Gerben Wierda <gerben.wie...@rna.nl> wrote:
>
> Nobody?
>
>> On 8 Apr 2020, at 12:20, Gerben Wierda <gerben.wie...@rna.nl> wrote:
>>
>> I would like to use the result of transparent() straight in my macros, so I
>> can pass the colors with transparency using a single parameter. That should
>> be possible if I understand the MetaFun manual (where I’ve copy-pasted this
>> example from):
>>
>> \starttext
>> \startMPpage[instance=doublefun]
>>
>> vardef SampleText (expr t, c) =
>> save p ; picture p ;
>> p := image (draw t infont "\truefontname{Regular}") ;
>> draw (p shifted (- xpart center p,0)) scaled 5 withcolor c;
>> enddef ;
>> SampleText ("Much Of This" , transparent(1, .5, red )) ;
>> SampleText ("Functionality" , transparent(1, .5, green)) ;
>> SampleText ("Was Written" , transparent(1, .5, blue )) ;
>> SampleText ("While Listening", transparent(1, .5, cmyk(1,0,0,0))) ;
>> SampleText ("To the CD's Of" , transparent(1, .5, cmyk(0,1,0,0))) ;
>> SampleText ("Tori Amos" , transparent(1, .5, cmyk(0,0,1,0))) ;
>>
>> \stopMPpage
>> \stoptext
>>
>> But it results in:
>>
>> system > files > jobname 'testcolor', input './testcolor', result
>> 'testcolor'
>> fonts > latin modern fonts are not preloaded
>> languages > language 'en' is active
>> open source > level 2, order 3, name './testcolor.tex'
>> fonts > preloading latin modern fonts (second stage)
>> fonts > 'fallback modern-designsize rm 12pt' is loaded
>> metapost > initializing instance 'doublefun:1' using format 'metafun'
>> and method 'double'
>> metapost > loading 'metafun' as
>> '/usr/local/context-osx-64/tex/texmf-context/metapost/context/base/mpiv/metafun.mpxl'
>> using method 'double'
>> metapost > initializing number mode 'double'
>> metapost log >
>> metapost log > loading metafun, including plain.mp version 1.004 for
>> metafun iv and xl
>> metapost log >
>> metapost log > ! Missing ')' has been inserted.
>> metapost log > <to be read again>
>> metapost log > withprescript
>> metapost log > transparent->(1)withprescript
>> metapost log >
>> "tr_alternative="&decimal.transparency_alternat...
>> metapost log > <*> ... ("Much Of This" , transparent(1, .5, red )
>> metapost log > ) ;
>> SampleText ("Functiona...
>> metapost log >
>> backend > xmp > using file
>> '/usr/local/context-osx-64/tex/texmf-context/tex/context/base/mkiv/lpdf-pdx.xml'
>> pages > flushing realpage 1, userpage 1, subpage 1
>> close source > level 2, order 3, name './testcolor.tex'
>> close source > level 1, order 3, name 'cont-yes.mkiv'
>>
>> For me, it is not about passing colour on to ConTeXt to typeset text, these
>> are colors that normally would be drawn with “withcolor ca withtransparency
>> (method,factor)” but that requires the passing of many more parameters and a
>> lot more work in coding.
>>
>> Does transparent() maybe produce a string that looks like “ca
>> withtransparency (method,factor)” so something only usable in draw/fill/etc
>> statements? But in that case how does that work without scantokens to parse
>> the string?
>>
>> Is there a way I can do this without having twice the parameters (and I have
>> to pass multiple colours) in my macros everywhere?
>>
>> Thanks,
>>
>> G
>> ___________________________________________________________________________________
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>> the Wiki!
>>
>> maillist : ntg-context@ntg.nl /
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>
> ___________________________________________________________________________________
> 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://context.aanhet.net
> archive : https://bitbucket.org/phg/context-mirror/commits/
> wiki : http://contextgarden.net
> ___________________________________________________________________________________
Taco Hoekwater
Elvenkind BV
___________________________________________________________________________________
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
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