Re: [NTG-context] Calling \followtokens from with in metapost

14 Oct 2013


      On 2013–10–14 Marco Patzer wrote:
...
On 2013–10–13 Hans Hagen wrote:
...
...
inbetween the arcs, that should alsó be drawn). The text should not be
stretched but center on the top, flowing evenly distributed on each
side. This link will give you an idea:
http://www.heilsuefling.is/heilsuefling/upload/images/whp_in_general/determi...
How can this achieved?
Here is a slightly modified version of the \followtokens macro with
centres the text without stretching it to the path size.

\useMPlibrary [txt]

\unexpanded\def\followtokenscentred#1%%
  {\vbox\bgroup
   \forgetall
   \dontcomplain
   \startMPenvironment
     \doifundefined{RotFont}{\definefont[RotFont][RegularBold]}
   \stopMPenvironment
   \MPtoks\emptytoks
   \resetMPdrawing
   \startMPdrawing
     \includeMPgraphic{followtokenscentred} ;
     picture pic[] ; numeric len[], n ; n := 0 ;
   \stopMPdrawing
   \handletokens#1\with\processfollowingtoken
   \startMPdrawing
     if unknown RotPath  : path    RotPath  ; RotPath  := origin ; fi ;
     if unknown RotColor : color   RotColor ; RotColor := black  ; fi ;
     if unknown TraceRot : boolean TraceRot ; TraceRot := false  ; fi ;
     if unknown ExtraRot : numeric ExtraRot ; ExtraRot := 0      ; fi ;
     numeric al, at, pl, wid, pos ; pair ap, ad ;
     al := arclength RotPath ;
     if al=0 :
       al := len[n] + ExtraRot ;
       RotPath := origin -- (al,0) ;
     fi ;
     if al1 : (n-1) else : 1 fi) ;
     pl := 0cm;
     if TraceRot :
       draw RotPath withpen pencircle scaled 1pt withcolor blue ;
     fi ;
     for i=1 upto n :
       wid := abs(xpart urcorner pic[i] - xpart llcorner pic[i]) ;
       pos := len[i]-wid/2 + (i-1)*pl + arclength RotPath/2 - len[n]/2 ;
       at := arctime   pos of RotPath ;
       ap := point     at  of RotPath ;
       ad := direction at  of RotPath ;
       draw pic[i] shifted (-wid/2,0) rotated(angle(ad)) shifted ap
         withcolor RotColor ;
       if TraceRot :
         draw boundingbox
            pic[i] shifted (-wid/2,0) rotated(angle(ad)) shifted ap
            withpen pencircle scaled .25pt withcolor red ;
         draw ap
            withpen pencircle scaled .50pt withcolor green ;
       fi ;
     endfor ;
   \stopMPdrawing
   \MPdrawingdonetrue
   \getMPdrawing
   \resetMPdrawing
   \egroup}

\def\followtokengraphicscale#1{%%
  \startuseMPgraphic {followtokenscentred}
    path RotPath; RotPath :=  reverse halfcircle scaled #1 ;
    setbounds currentpicture to boundingbox fullcircle scaled 12cm ;
  \stopuseMPgraphic}

\starttext

\startoverlay
  {\followtokengraphicscale{10cm}%%
   \followtokenscentred{General socioeconomic cultural and environmental conditions}}
  {\followtokengraphicscale{8cm}%%
   \followtokenscentred{Living and working conditions}}
  {\followtokengraphicscale{6cm}%%
   \followtokenscentred{Social and community influences}}
  {\followtokengraphicscale{4cm}%%
   \followtokenscentred{Individual lifestyle factors}}
\stopoverlay

\stoptext

Marco