%D \module
%D   [       file=meta-imp-clock,
%D        version=2021.01.21,
%D          title=\METAPOST\ Graphics,
%D       subtitle=Demo Clock Font,
%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 This is just a demo of defining a font in \METAPOST. The rendering as well as definitions
%D are delayed till we actually need the glyph. A crazy examples made in crazy times.

\startMPcalculation{simplefun}

    % the 0 in getparameterdefault makes sure we convert to a number

    picture DemoClocks[];

    vardef ClockCircle =
        image(draw fullcircle scaled 10 ;)
    enddef ;

    vardef ClockPoints =
        image (
            for i=1 upto 12 :
                draw (0,5) rotated ((360 * i) / 12) withpen pencircle scaled 1 ;
            endfor ;
        )
    enddef ;

    vardef ClockTicks =
        image (
            for i=1 upto 12 :
                draw ((0,4.5)--(0,5.5)) rotated ((360 * i) / 12) ;
            endfor ;
        )
    enddef ;

    vardef ClockCenter =
        image (
            draw origin withpen pencircle scaled 1 ;
        )
    enddef ;

    vardef ClockHour =
        image(
            draw (origin -- (0,4)) rotated (
              - 360 * (getparameterdefault "mpsfont" "hour"   0) / 12
              - 360 * (getparameterdefault "mpsfont" "minute" 0) / (60 * 12)

        ) )
    enddef ;

    vardef ClockMinute =
        image(
            draw (origin -- (0,5)) rotated (
              - 360 * (getparameterdefault "mpsfont" "minute" 0) / 60
            )
        )
    enddef ;

    vardef DemoClock =
        composeglyph(DemoClocks) ;
    enddef ;

    lmt_registerglyphs [
        name     = "clock",
        units    = 10,
        width    = 10,
        height   = 10,
        depth    = 0,
    ] ;

    lmt_registerglyph [
        category = "clock",
    ] ;

\stopMPcalculation

% \startluacode
%     metapost.metafonts.clock = { }
% \stopluacode

\continueifinputfile{meta-imp-clock.mkxl}

% \enableexperiments[fonts.compact]

\nopdfcompression

\setuplayout[tight]

\setupbodyfont[dejavu]

\definefontfeature[clock][metapost=clock,metafont=clock]

\definefont[ClockFont][Serif*clock]

\starttext

\protected\def\MyClock#1#2%
  {\begingroup
   \ClockFont
   \iffontchar\font\privatecharactercode{CLOCK:#1:#2}\else
     % We could move this out to a helper \MyClockMake{#1}{#2} but normally
     % it's efficient enough. (If we trace a lot it matters more.)
     \setmetaglyph {
       category {clock}
       name     {CLOCK:#1:#2}
       code     {DemoClock}
       hour     {#1}
       minute   {#2}
       shapes   {
            { shape {ClockCircle}  color {darkred}    }
            { shape {ClockTicks}   color {middlegray} }
          % { shape {ClockBullets} color {middlegray} }
            { shape {ClockHour}    color {darkgreen}  }
            { shape {ClockMinute}  color {darkblue}   }
            { shape {ClockCenter}  color {middlegray} }
       }
     }%
   \fi
   \setalternate{\twodigits{#1}:\twodigits{#2}}% cut'n'paste in acrobat
   \privatecharacter{CLOCK:#1:#2}%
   \endgroup}

\dorecurse{8}{
    \begingroup
        \glyphxscale \numexpr 1000+#100\relax
        \glyphyscale \glyphxscale
        \veryraggedright
        \dostepwiserecurse{0}{60}{1}{
            \MyClock{3}{##1}\hskip\zeropoint plus \onepoint\allowbreak% space
        }
        \blank
    \endgroup
}
\stoptext