%%%%
%%%% This file belongs to the ROEX package.
%%%%
%%% draw write_preamble write_postamble find_BB set_BB fill_C draw_C
%%% draw fix_fill_cmyk fix_draw_cmyk
% RO-07.MF, ``LOGO OF JOURNAL OF ALGORITHMS'':
%  Another example excerpted from The \MF{}book, pages 137 thru 139;
%  |penstroke| is redefined in such a way that instead of creating a bitmap
%  picture, it stores respective curves; two points were moved, |z.a8l| and
%  |z.a8r| (see comments with a remark ``intrusion''), in order to avoid
%  partially overlaping paths, as ROEX does not cope with such data.
% ---
input mftoeps; eps_mode_setup; input roex; tracingremoving:=1;
% ---
def penstroke text t =
 forsuffixes e = l,r: path_.e:=t; endfor
 if cycle path_.l: R[incr R.num]:=path_.l.t_; R[incr R.num]:=path_.r.t_;
 else: R[incr R.num]:=path_.l -- reverse path_.r -- cycle; fi
 enddef;
% ---
beginchar("0",29mm#,25mm#,0);
 path R[\\]; R.num:=0;
%
 thick#:=2mm#; thin#:=5/4mm#;
 define_whole_blacker_pixels(thick,thin);
 forsuffixes $=a,b,c: transform $;
  forsuffixes e=l,r: path $e,$'e; numeric t$[\\]e;
  endfor
 endfor
 penpos1(thick,0); penpos2(thick,90); penpos3(thick,180); penpos4(thick,270);
 penpos5(thick,0); penpos6(thick,90); penpos7(thick,180); penpos8(thick,270);
 x2=x4=x6=x8=.5[x5,x7]=.5w; x1r=w; x3r=0;
 x5-x7=y6-y8;
 y1=y3=y5=y7=.5[y6,y8]=.5h; y2r=h; y4r=0;
 y6r=.75h;
 forsuffixes e=l,r: a.e=b'e=c'e=superellipse (z1e,z2e,z3e,z4e,.75);
  a'e=b.e=c.e=superellipse (z5e,z6e,z7e,z8e,.72);
 endfor
 penpos a1(thin,0); penpos a5(whatever,-90); penpos a9(thin,180);
 x.a1l-x.a9l=1/3(x5l-x7l); x.a5=.5w; y.a1=y.a9; y.a5r=4/7h;
 x.a3l=x.a1l; x.a3r=x.a1r; x.a4r=1/6[x.a3r,x1l]; x0=.5w; y0=.52h;
 x.a6l+x.a4l=x.a6r+x.a4r=x.a7l+x.a3l=
  x.a7r+x.a3r=x.a9+x.a1=w;
 y.a3r=y.a4r=y.a6r=y.a7r=.2[y2l,y0]; y.a3l=y.a4l=y.a6l=y.a7l=y.a3r-thin;
 z.a4l=z.a4r+(thin,0) rotated(angle(z.a4r-z.a5r)+90)+whatever*(z.a4r-z.a5r);
 z.a4l-z.a5l=whatever*(z.a4r-z.a5r);
 z=a.r intersectionpoint (z0--(w,0));
 y.a1-y.a5=length(z-z0);
 b=identity shifted (0,y0-y.a1) rotatedaround(z0,90-angle(z0-(w,0)));
 c=b reflectedabout (z2,z4);
 for n=1,3,4,5,6,7,9: forsuffixes e=l,,r: forsuffixes $=b,c:
  z$[n]e=z.a[n]e transformed $;
 endfor endfor endfor
 forsuffixes e=l,r: forsuffixes $=a,b,c:
% intrusion: the primed entries are stored for further use (see below)
  z$2e'=$l intersectionpoint (z$1e--z$3e);
  z$8e'=$l intersectionpoint (z$9e--z$7e);
% end of intrusion
  z$2e=$r intersectionpoint (z$1e--z$3e);
  z$8e=$r intersectionpoint (z$9e--z$7e);
  t$1e=xpart($e intersectiontimes (z$1l--z$3l));
  t$9e=xpart($e intersectiontimes (z$9l--z$7l));
  t$4e=xpart($'e intersectiontimes (z$5r--z$4l));
  t$6e=xpart($'e intersectiontimes (z$5r--z$6l));
 endfor endfor
 penstroke subpath(t.a9e,t.b6e) of a.e;
 penstroke subpath(t.b4e,t.c4e) of b'e;
 penstroke subpath(t.c6e,t.a1e+8) of c'e;
 penstroke subpath(t.a6e,t.b9e) of a'e;
 penstroke subpath(t.b1e,t.c1e) of b.e;
 penstroke subpath(t.c9e,t.a4e+8) of c.e;
% intrusion: correction of offending nodes, i.e., |z.a8l|, |z.a8r|,
% |z.a8l|, and |z.a8r|
 x.a8l:=x.a8l'; x.a8r:=x.a8r'; y.a8l:=y.a8l'; y.a8r:=y.a8r'+(y2r-y2);
 x.a2l:=x.a2l'; x.a2r:=x.a2r'; y.a2l:=y.a2l'; y.a2r:=y.a2r'+(y2r-y2);
% end of intrusion
 forsuffixes $=a,b,c:
%  |penlabels($1,$2,$3,$4,$5,$6,$7,$8,$9);|
  penstroke z$2e--z$3e--z$4e--z$5e--z$6e--z$7e--z$8e;
 endfor
% |penlabels(range 0 thru 8);|
 vardef touch_path expr p = pos_turn p enddef;
 remove_overlap (make_list(1,R.num)R) () R;
 find_BB make_list(1,R.num)R;
 write_preamble jobname;
 fix_fill_cmyk 0,0,0,1/6; 
 fill_C make_list(1,R.num)R;
 fix_line_width 1/10pt;
 for i:=1 upto R.num:
  fix_draw_cmyk if check_turn R[i]>0: 0,1,1,0 else: 1,1,0,0 fi; 
  draw_C R[i];
  if proofing>0:
   for j:=0 upto length(R[i])-1:
    makelabel(decimal(j) & "/" & decimal(i),point j of R[i]);
   endfor
  fi
 endfor
 write_postamble;
endchar;
end.
%%\end