Mojca Miklavec wrote:
> On Wed, Dec 3, 2008 at 4:25 PM, Hans Hagen <[EMAIL PROTECTED]> wrote:
>> Mojca Miklavec wrote:
>>> Hello,
>>>
>>> A while back I wrote this dirty code (read as: hack) in attachment
>>> that allows multiple optional parameters in metapost functions, for
>>> example:
>>>
>>> draw_text("text");
>>> draw_text(angle(30),"text");
>>> draw_text(angle(30),align(right),"text");
>>> draw_text(align(center),"text");
>>>
>>> The code compiles fine with mkii, but not with mkiv. I would be
>>> grateful for any hints about how to fix this.
>>>
>>> I get the error:
>>>
>>> mplib | mp terminal: ! Missing `,' has been inserted.
>>> <to be read again>
>>> ,
>>> textext->...etextext(SUFFIX2)(rawtextext((EXPR3)),
>>>
>>> origin)else:thetextext(SUF...
>>>
>>> dummy->begingroup(TEXT2)
>>> endgroup
>>> gp_put_text->...tt)=tt.enddef;pict:=dummy((TEXT1))
>>>
>>> ;let,=@;endgroup;draw(gp_t...
>>> <*> ...m, 1cm), angle(30), textext.drt("rotated"))
>>> ; ;
>>> ! An expression can't begin with `;'.
>>> <inserted text>
>>> 0
>>> <to be read again>
>>> ,
>>> textext->...etextext(SUFFIX2)(rawtextext((EXPR3)),
>>>
>>> origin)else:thetextext(SUF...
>>>
>>> Thanks a lot,
>>> Mojca
>>>
>>> (The code is taken out of
>>> http://dl.contextgarden.net/modules/t-gnuplot/metapost/context/third/gnuplot/mp-gnuplot.mp
>>> and I'm slowly plucking up my courage to port the code to mkiv.)
>> \startMPcode
>> def fuzzy(expr a, b, c) =
>> draw image(
>> draw textext(c) ;
>> currentpicture := currentpicture rotatedaround(center
>> currentpicture,b) shifted a ;
>> ) ;
>> enddef ;
>>
>> fuzzy((1cm,1cm), 30, "rotated") ;
>> \stopMPcode
>
> But what if I wanted the angle to be an optional parameter? (More in
> the sense that if I decide to add some more parameters later, the old
> code would still work.)
>
> Is there any special reason why the old code doesn't work on mkiv?
> I have found one possible explanation, though I'm not sure about that:
>
> This works:
>
> picture a; a := \sometxt{rotated};
> gp_put_text((1cm, 1cm), angle(30), a);
>
> but this doesn't:
>
> gp_put_text((1cm, 1cm), angle(30), \sometxt{rotated});
>
> What does metapost see in mkiv when one puts \sometxt there? Maybe
> that explains the problem.
\long\def\sometxt#1#{\dosometxt{#1}} % grab optional [args]
\long\def\dosometxt#1#2%
{textext.drt("\ifcsname @@st@@#1\endcsname\csname
@@st@@#1\endcsname{#2}\else#2\fi")}
so, it sees textext.drt("somestring")
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
| www.pragma-pod.nl
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