%D \module
%D   [       file=meta-lua,
%D        version=2012.07.23,
%D          title=\METAPOST\ Integrated Graphics,
%D       subtitle=Templates,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

%D Don't use this code yet. I use it in some experimental rendering of graphics
%D based on output from database queries. It's not that pretty but will be
%D considered when the (similar) lmx code is redone. Also, dropping the print
%D variant makes it nicer. This experiment is part of playing with several template
%D mechanisms. (Also see trac-lmx.)
%D
%D Note for myself: see if the (bar)chart code use in q2p can use this kind of
%D magic. Basically we then need a channel to data.

\writestatus{loading}{MetaPost Library Graphics / Templates}

\registerctxluafile{meta-lua}{}

\continueifinputfile{meta-lua.mkiv}

\starttext

% conforming btex ... etex

\startbuffer[test-a]
    blua for i=1,100,5 do elua
        draw fullcircle scaled (blua p(i) elua * cm) withcolor green withpen pencircle scaled 4 ;
    blua end elua

    blua for i=1,100,10 do elua
        draw fullcircle scaled (blua p(i) elua * cm) withcolor red withpen pencircle scaled 2 ;
    blua end elua
\stopbuffer

\startMPpage[offset=10pt]
    input "mpstemplate://buffer?name=test-a" ;
\stopMPpage

% conforming lmx

\startbuffer[test-b]
    <?lua for i=1,100,5 do ?>
        draw fullcircle scaled (<?lua p(i) ?> * cm) withcolor green withpen pencircle scaled 4 ;
    <?lua end ?>

    <?lua for i=1,100,10 do ?>
        draw fullcircle scaled (<?lua p(i) ?> * cm) withcolor red withpen pencircle scaled 2 ;
    <?lua end ?>
\stopbuffer

\startMPpage[offset=10pt]
    input "mpstemplate://buffer?name=test-b" ;
\stopMPpage

\startMPpage[offset=10pt]
    picture p[] ; % we can't input nested
    input "mpstemplate://buffer?name=test-a&method=metapost" ;
    p[1] := currentpicture ; currentpicture := nullpicture ;
    input "mpstemplate://buffer?name=test-b&method=xml" ;
    p[2] := currentpicture ; currentpicture := nullpicture ;
    draw p[1] ysized 3cm ;
    draw p[2] ysized 4cm shifted (4cm,0) ;
\stopMPpage

% a mixture (using a wrapped input)

\startMPpage[offset=10pt]
    draw image (loadfile("mpstemplate://buffer?name=test-a&method=metapost")) ysized 3cm shifted (4cm,0cm) ;
    draw image (loadfile("mpstemplate://buffer?name=test-b&method=xml"))      ysized 3cm shifted (0cm,4cm) ;
    draw loadimage      ("mpstemplate://buffer?name=test-a&method=metapost")  ysized 4cm shifted (4cm,4cm) ;
    draw loadimage      ("mpstemplate://buffer?name=test-b&method=xml")       ysized 4cm shifted (0cm,0cm) ;
\stopMPpage

% conforming myself

\startluacode
    context.startMPpage { offset = "10pt" }
        for i=1,100,5 do
            context("draw fullcircle scaled (%s * cm) withcolor green withpen pencircle scaled 4 ;",i)
        end
        for i=1,100,10 do
            context("draw fullcircle scaled (%s * cm) withcolor red withpen pencircle scaled 2 ;",i)
        end
    context.stopMPpage()
\stopluacode

\stoptext