Re: metafun

[Hans Hagen <pragma@wxs.nl>]

On 3/24/2016 6:24 PM, Piotr Kopszak wrote:
> P.S.
>
> For your conveniance, the minimal example:
>
> \startMPpositiongraphic{mypos:arrow}
>     pair c[] ;
>     initialize_box(\MPpos{\MPvar{self}});
>     c[1] := cxy ;
>     initialize_box(\MPpos{\MPvar{to}});
>     c[2] := cxy ;
>     drawarrow c[1] -- c[2] withpen pencircle scaled 2bp ;
> \stopMPpositiongraphic
> \startpositionoverlay{arrow}
> \setMPpositiongraphic{X-1}{mypos:arrow}{to=X-2}
> \setMPpositiongraphic{X-2}{mypos:arrow}{to=X-3}
> \stoppositionoverlay
> \defineoverlay[arrow][\positionoverlay{arrow}]
> \setupbackgrounds[page][background=arrow]
>
>
> \starttext
>
> \section {Anchors and layers}
>
> In a previous section we saw that some \hpos{X-1}{words} were
> \hpos{X-2}{circled} and connected by an \hpos{X-3}{arrow}.
> As with most things in \CONTEXT, marking these words is separated
> from declaring what to do with those words. This paragraph is keyed
> in as:
>
> \stoptext

The interface changed a bit

\setupMPvariables
   [mpos:encircle]
   [fillcolor=lightgray,
    filloffset=0pt,
    linecolor=blue,
    lineoffset=5pt,
    linewidth=1pt]

\startMPpositiongraphic{mpos:encircle}{linecolor,fillcolor,linewidth,lineoffset}
     if unknown context_apos : input mp-apos.mpiv ; fi ;
     \MPgetposboxes{\MPvar{self}}{\MPanchorid}
     if nofposboxes = 1 :
         posboxes[1] := posboxes[1] enlarged \MPvar{lineoffset} cornered 
\MPvar{lineoffset}  ;
         fill posboxes[1] withcolor \MPvar{fillcolor} ;
         draw posboxes[1] withpen pencircle scaled \MPvar{linewidth} 
withcolor \MPvar{linecolor} ;
     fi ;
\stopMPpositiongraphic

\setupMPvariables
   [mpos:connect]
   [linecolor=red,
    lineoffset=.25ex,
    linewidth=1pt]

\startMPpositiongraphic{mpos:connect}{linecolor,lineoffset,linewidth}
     if unknown context_apos : input mp-apos.mpiv ; fi ;
     boxlinewidth  := \MPvar{linewidth} ;
     boxlineoffset := \MPvar{lineoffset} ;
     def boxlineoptions = withcolor \MPvar{linecolor} enddef ;
     \MPgetposboxes{\MPvar{from},\MPvar{to}}{\MPanchorid}
     connect_positions ;
\stopMPpositiongraphic

\starttext

     \startpositionoverlay{text-1}
 
\setMPpositiongraphic{connect-1-b}{mpos:connect}{from=connect-1-b,to=connect-1-e}
 
\setMPpositiongraphic{connect-1-e}{mpos:connect}{from=connect-1-b,to=connect-1-e}
     \stoppositionoverlay

     \startpositionoverlay{text-1}
         \setMPpositiongraphic{encircle-1}{mpos:encircle}{self=encircle-1}
     \stoppositionoverlay

     test \hpos{connect-1-b}{START}
         \dorecurse{10}{\input ward}
     \hpos{encircle-1}{\strut HERE}
         \dorecurse{10}{\input ward}
     \hpos{connect-1-e}{STOP} test

\stoptext





> 2016-03-24 18:23 GMT+01:00 Piotr Kopszak <kopszak@gmail.com>:
>> Hello list,
>>
>> The solution shown here no longer works with recent beta (indeed, it
>> probably ceased to work some time ago). How should it be corrected?
>>
>> Best
>>
>> Piotr
>>
>> 2010-10-24 0:14 GMT+02:00 Aditya Mahajan <adityam@umich.edu>:
>>> On Sat, 23 Oct 2010, Herbert Voss wrote:
>>>
>>>> It is a hard job to understand how all works ...
>>>
>>>
>>> I agree. That chapter is confusing if you do not know already how the
>>> mechanism
>>> works.
>>>
>>>> I tried to create the first example of the
>>>> documentation "Page 257 Anchors and layers",
>>>> but failed with mkii and iv. The page is created,
>>>> but without the graphical elements. Not using
>>>> \startbuffer--\stopbuffer makes no difference.
>>>
>>>
>>> You are simply setting the positions. You also need to tell ConTeXt to do
>>> something with the positions.
>>>
>>> 1. First define a position graphic that does something with the anchors that
>>> it is passed.
>>>
>>> \startMPpositiongraphic{mypos:arrow}
>>>    pair c[] ;
>>>    initialize_box(\MPpos{\MPvar{self}});
>>>    c[1] := cxy ;
>>>    initialize_box(\MPpos{\MPvar{to}});
>>>    c[2] := cxy ;
>>>    drawarrow c[1] -- c[2] withpen pencircle scaled 2bp ;
>>> \stopMPpositiongraphic
>>>
>>> cxy is the center of the box. See the defn of initialize_box in mp-core.mp
>>> for other values. I wish these were better documented.
>>>
>>> 2. Then define a position overlay that specifies the relation between the
>>> anchors.
>>>
>>> \startpositionoverlay{arrow}
>>> \setMPpositiongraphic{X-1}{mypos:arrow}{to=X-2}
>>> \setMPpositiongraphic{X-2}{mypos:arrow}{to=X-3}
>>> \stoppositionoverlay
>>>
>>>
>>> 3. Define an overlay that is mapped to MP position overlay.
>>>
>>> \defineoverlay[arrow][\positionoverlay{arrow}]
>>>
>>> 4. Hook the overlay as a page background
>>>
>>> \setupbackgrounds[page][background=arrow]
>>>
>>> 5. Then everything will work.
>>>
>>> \starttext
>>>
>>> \section {Anchors and layers}
>>>
>>> In a previous section we saw that some \hpos{X-1} {words} were
>>> \hpos{X-2}{circled} and connected by an \hpos{X-3} {arrow}.
>>> As with most things in \CONTEXT, marking these words is separated
>>> from declaring what to do with those words. This paragraph is keyed
>>> in as:
>>>
>>> \stoptext
>>>
>>> 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
>>> ___________________________________________________________________________________
>>
>>
>>
>> --
>> http://okle.pl
>
>
>


-- 

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                                           Hans Hagen | PRAGMA ADE
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