%D \module
%D   [       file=mp-text.mpii,
%D        version=2000.07.10,
%D          title=\CONTEXT\ \METAPOST\ graphics,
%D       subtitle=text support,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
%C details.

%D Under construction.

if known context_text : endinput ; fi ;

boolean context_text ; context_text := true ;

if unknown noftexpictures :
  numeric noftexpictures ; noftexpictures := 0 ;
fi ;

if unknown texpictures[1] :
  picture texpictures[] ;
fi ;

numeric textextoffset ; textextoffset := 0 ;

% vardef textext@#(expr txt) =
%   interim labeloffset := textextoffset ;
%   noftexpictures := noftexpictures + 1 ;
%   if string txt :
%     write "% figure " & decimal charcode & " : " &
%       "texpictures[" & decimal noftexpictures & "] := btex " &
%       txt & " etex ;" to jobname & ".mpt" ;
%     if unknown texpictures[noftexpictures] :
%       thelabel@#("unknown",origin)
%     else :
%       thelabel@#(texpictures[noftexpictures],origin)
%     fi
%   else :
%     thelabel@#(txt,origin)
%   fi
% enddef ;

boolean hobbiestextext ; hobbiestextext := false ;
% string  textextstring  ; textextstring  := "" ;

% def resettextextdirective =
%   textextstring := "" ;
% enddef ;

% def textextdirective text t =
%   textextstring := textextstring & t ;
% enddef ;

vardef textext@#(expr txt) =
  save _s_ ; string _s_ ;
  interim labeloffset := textextoffset ;
  noftexpictures := noftexpictures + 1 ;
  if string txt :
    if hobbiestextext : % the tex.mp method as fallback (see tex.mp)
      write _s_ & "btex " & txt & " etex" to "mptextmp.mp" ;
      write EOF to "mptextmp.mp" ;
      scantokens "input mptextmp"
    else :
      write "% figure " & decimal charcode & " : " &
        "texpictures[" & decimal noftexpictures & "] := btex " &
        txt & " etex ;" to jobname & ".mpt" ;
      if unknown texpictures[noftexpictures] :
        thelabel@#("unknown",origin)
      else :
        thelabel@#(texpictures[noftexpictures],origin)
      fi
    fi
  else :
    thelabel@#(txt,origin)
  fi
enddef ;

string laboff_   ; laboff_   := ""      ;
string laboff_c  ; laboff_c  := ""      ;
string laboff_l  ; laboff_l  := ".lft"  ;
string laboff_r  ; laboff_r  := ".rt"   ;
string laboff_b  ; laboff_b  := ".bot"  ;
string laboff_t  ; laboff_t  := ".top"  ;

string laboff_lt ; laboff_lt := ".ulft" ;
string laboff_rt ; laboff_rt := ".urt"  ; % bugged, conflict with r
string laboff_lb ; laboff_lb := ".llft" ;
string laboff_rb ; laboff_rb := ".lrt"  ;
string laboff_tl ; laboff_tl := ".ulft" ;
string laboff_tr ; laboff_tr := ".urt"  ;
string laboff_bl ; laboff_bl := ".llft" ;
string laboff_br ; laboff_br := ".lrt"  ;

vardef textextstr(expr s, a) =
  save ss ; string ss ;
  ss := "laboff_" & a  ;
  ss := scantokens ss ;
  ss := "textext" & ss & "(" & ditto & s & ditto & ")" ;
  scantokens ss
enddef ;

pair laboff.origin ; laboff.origin = (0,0) ; % (infinity,infinity) ;
pair laboff.raw    ; laboff.raw    = (0,0) ; % (infinity,infinity) ;

laboff.origin = (0,0) ; labxf.origin := 0 ; labyf.origin := 0 ;
laboff.raw    = (0,0) ; labxf.raw    := 0 ; labyf.raw    := 0 ;

vardef thelabel@#(expr s, z) =
  save p ; picture p ;
  p = s if not picture s : infont defaultfont scaled defaultscale fi ;
%   wrong, see myway textext
%   if laboff@#<>laboff.origin :
    (p shifted (z + labeloffset*laboff@# - (labxf@#*lrcorner p +
         labyf@#*ulcorner p + (1-labxf@#-labyf@#)*llcorner p)))
%   else :
%     (p shifted z)
%   fi
enddef;

def build_parshape (expr p, offset_or_path, dx, dy,
  baselineskip, strutheight, strutdepth, topskip) =

  if unknown trace_parshape :
    boolean trace_parshape ; trace_parshape := false ;
  fi ;

  begingroup ;

  save    q, l, r, line, tt, bb,
          n, hsize, vsize, vvsize, voffset, hoffset, width, indent,
          ll, lll, rr, rrr, cp, cq, t, b ;

  path    q, l, r, line, tt, bb ;
  numeric n, hsize, vsize, vvsize, voffset, hoffset, width[], indent[] ;
  pair    ll, lll, rr, rrr, cp, cq, t, b ;

  n := 0 ; cp := center p ;

  if path offset_or_path :
    q := offset_or_path ; cq := center q ;
    voffset := dy ;
    hoffset := dx ;
  else :
    q := p ; cq := center q ;
    hoffset := offset_or_path + dx ;
    voffset := offset_or_path + dy ;
  fi ;

  hsize := xpart lrcorner q - xpart llcorner q ;
  vsize := ypart urcorner q - ypart lrcorner q ;

  q := p shifted - cp ;

  startsavingdata ;

  savedata "\global\parvoffset " & decimal voffset&"bp " ;
  savedata "\global\parhoffset " & decimal hoffset&"bp " ;
  savedata "\global\parwidth   " & decimal   hsize&"bp " ;
  savedata "\global\parheight  " & decimal   vsize&"bp " ;

  if not path offset_or_path :
    q := q xscaled ((hsize-2hoffset)/hsize)
           yscaled ((vsize-2voffset)/vsize) ;
  fi ;

  hsize := xpart lrcorner q - xpart llcorner q ;
  vsize := ypart urcorner q - ypart lrcorner q ;

  t := (ulcorner q -- urcorner q) intersection_point q ;
  b := (llcorner q -- lrcorner q) intersection_point q ;

  if xpart directionpoint t of q < 0 :
    q := reverse q ;
  fi ;

  l := q cutbefore t ;
  l := l if xpart point 0 of q < 0 : & q fi cutafter b ;

  r := q cutbefore b ;
  r := r if xpart point 0 of q > 0 : & q fi cutafter t ;

%  tt := (ulcorner q -- urcorner q) shifted (0,-topskip) ;
%  bb := (llcorner q -- lrcorner q) shifted (0,strutdepth) ;
%
%  l := l cutbefore (l intersection_point tt) ;
%  l := l cutafter  (l intersection_point bb) ;
%  r := r cutbefore (r intersection_point bb) ;
%  r := r cutafter  (r intersection_point tt) ;

  if trace_parshape :
    drawarrow p            withpen pencircle scaled 2pt withcolor red ;
    drawarrow l shifted cp withpen pencircle scaled 1pt withcolor green ;
    drawarrow r shifted cp withpen pencircle scaled 1pt withcolor blue ;
  fi ;

  vardef found_point (expr lin, pat, sig) =
    pair a, b ;
    a := pat intersection_point (lin shifted (0,strutheight)) ;
    if intersection_found :
      a := a shifted (0,-strutheight) ;
    else :
      a := pat intersection_point lin ;
    fi ;
    b := pat intersection_point (lin shifted (0,-strutdepth)) ;
    if intersection_found :
      if sig :
        if xpart b > xpart a : a := b shifted (0,strutdepth) fi ;
      else :
        if xpart b < xpart a : a := b shifted (0,strutdepth) fi ;
      fi ;
    fi ;
    a
  enddef ;

  if (strutheight+strutdepth<baselineskip) :
    vvsize := vsize ;
  else :
    vvsize := (vsize div baselineskip) * baselineskip ;
  fi ;

  for i=topskip step baselineskip until vvsize :

    line := (ulcorner q -- urcorner q) shifted (0,-i-eps) ;

    ll := found_point(line,l,true ) ;
    rr := found_point(line,r,false) ;

    if trace_parshape :
      fill (ll--rr--rr shifted (0,strutheight)--ll
        shifted (0,strutheight)--cycle) shifted cp withcolor .5white ;
      fill (ll--rr--rr shifted (0,-strutdepth)--ll
        shifted (0,-strutdepth)--cycle) shifted cp withcolor .7white ;
      draw ll shifted cp withpen pencircle scaled 2pt ;
      draw rr shifted cp withpen pencircle scaled 2pt ;
      draw (ll--rr) shifted cp  withpen pencircle scaled .5pt ;
    fi ;

    n := n + 1 ;
    indent[n] := abs(xpart ll - xpart llcorner q) ;
    width[n]  := abs(xpart rr - xpart ll) ;

    if (i=strutheight) and (width[n]<baselineskip) :
      n := n - 1 ;
      savedata "\global\chardef\parfirst=1 " ;
    fi ;

  endfor ;

  savedata "\global\parlines  " & decimal n ;
  savedata "\global\partoks{  " ;
  for i=1 upto n:
    savedata decimal indent[i]&"bp " & decimal width[i]&"bp " ;
  endfor ;
  savedata "}" ;

  stopsavingdata ;

  endgroup ;

enddef ;

vardef verbatim(expr str) =
    ditto & "\detokenize{" & str & "}" & ditto
enddef ;
