numeric grbase; grbase:=1;	%don't read this file twice

%make reference to file in subdirectories less painful
def readfrom(expr filename) = scantokens ("input " & filename); enddef;

%we start by defining a few more font parameters:
boolean monowidth;		%are the widths of all strokes roughly the same?
boolean straight;		%are certain strokes straight?

let old_font_setup = font_setup;
def font_setup =
 define_whole_vertical_pixels(acc_ht,circ_ht,Circ_ht,iota_dp);	%accent heights
 old_font_setup;
enddef;

%Since many of our characters are composite (for instance, s+letter),
%we avoid recomputing many pictures by saving them.
%But if we're using various definitions for the same letter (as when
%running 6test.mf) we can't use this trick, so we set working_hard:=true.

boolean working_hard;			%are we to recompute letters every time?
working_hard:=false;

def this_letter =
  italcorr ital; adjust_fit(fit_params);
  if known savedpicture: currentpicture:=savedpicture; else: gen_letter; fi
  if not working_hard : picture savedpicture; savedpicture=currentpicture; fi
enddef;

%The following routines are for use with double characters.
boolean is_double; is_double:=false;
let oldendchar=endchar;

def begindoublechar(expr c,w_sharp,h_sharp,d_sharp) =
  is_double:=true; beginchar(c,w_sharp,h_sharp,d_sharp);
enddef;

def doublecharkern(expr k_sharp) =
  if not monospace: k:=hround(k_sharp*hppp); r:=r+k; charwd:=charwd+k_sharp; fi
enddef;

def middoublechar(expr w_sharp,h_sharp,d_sharp) =
  scantokens extra_endchar;
  forsuffixes e=r,l,w,charwd: numeric first.e; first.e:=e; endfor

  w:=hround(w_sharp*hppp); h:=vround(h_sharp*hppp); d:=vround(d_sharp*hppp);
  charwd:=w_sharp; charht:=max(charht,h_sharp); chardp:=max(chardp,d_sharp);
  picture first.glyph; first.glyph=currentpicture;
  clearxy; clearpen; clearit; clearpen;
enddef;

def endchar =
  if is_double :
    charwd:=first.charwd+charwd;
    picture second_glyph; second_glyph=currentpicture shifted (first.r-l,0);
    currentpicture:= first.glyph; addto currentpicture also second_glyph;
    scantokens extra_endchar;
    w:=first.w+w; r:=first.r-l+r; l:=first.l;
    chardx:=first.w+w; interim xoffset:= -l;
    if proofing>0: makebox(proofrule); fi
    shipit;
    if displaying>0: makebox(screenrule); showit; fi
    endgroup;
    is_double:=false
  else : oldendchar
  fi
enddef;

%By convention, we reserve the name z1' for the direction at z1, and so on.
%The direction at z1r is z1'r, or zdir1r.
vardef zdir[]@#= z@'@# enddef;
vardef assign_z@#(expr zz)= x@#:=xpart(zz); y@#:=ypart(zz) enddef;
vardef sgn(expr x)= if (x>0): 1 elseif (x<0): -1 else: 0 fi enddef;

vardef double_circ_stroke text t =
 forsuffixes e = l,r: path_.e:=t; endfor
 if cycle path_.l: errmessage "Beware: `stroke' isn't intended for cycles"; fi
 path_.l .. reverse path_.r .. cycle enddef;

vardef drawloop(suffix $,$$,@@,@)=
  numeric temp[], sup;
  sup=superness;
  forsuffixes e=r,l:
    path curv[]e; numeric S[]e;
    curv1e=pulled_super_arc.e($,$$)(.5superpull);
    curv2e=pulled_super_arc.e(@,@@)(.5superpull); endfor
  (S1r,S2r)=curv1r intersectiontimes curv2r;
  (temp1,S2l)=curv1r intersectiontimes curv2l;
  (S1l,temp2)=curv1l intersectiontimes curv2r;
  for i=1 upto 9:
    exitif (temp1>=S1r) and (temp2>=S2r);
    begingroup
      numeric S[]r, S[]l, temp[]; pair p;
      interim superness:=(i/10)[sup,1];
      message"change in superness required; increased to "; show superness;
      curv1r:=pulled_super_arc.r($,$$)(0);
      curv2r:=pulled_super_arc.r(@,@@)(0);
      (S1r,S2r)=curv1r intersectiontimes curv2r;
      (temp1,S2l)=curv1r intersectiontimes curv2l;
      (S1l,temp2)=curv1l intersectiontimes curv2r;
    endgroup;
  endfor;
  if S1l=-1 : S1l:=2; fi
  if S2l=-1 : S2l:=2; fi
  filldraw stroke subpath(0,S1e+eps) of curv1e; 
  filldraw stroke subpath(0,S2e+eps) of curv2e;
  filldraw subpath (S1r+eps,2) of curv1r...subpath(2,S2r+eps) of curv2r..cycle;
enddef ;

vardef gr_arc.r(suffix $,$$,$$$)(expr min,max,tilt)=
  pair center, corner;
  if (y$$$r-y$r)*(x$$$r-x$r) < 0 :	%first or third quadrant
    center=(x$$$r,y$r); corner=(x$r,y$$$r);
  else :
    center=(x$r,y$$$r); corner=(x$$$r,y$r);
  fi
  z$r{corner-z$r}...superness[center,corner]{z$$$r-z$r}...
    {z$$$r-corner}z$$$r
enddef;

vardef gr_arc.l(suffix $,$$,$$$)(expr min,max,tilt)=
  save p,q,wdth;
  pair center, corner, temp;
  numeric wdth, t, s;
  path p,q;
  if (y$$$r-y$r)*(x$$$r-x$r) < 0 :	%first or third quadrant
    center=(x$$$r,y$r); corner=(x$r,y$$$r);
    if tilt>=0 : wdth:=min; other_wdth:=max; t:=2(1-tilt);
    else : wdth:=max; other_wdth:=min; t:=-2tilt; fi
  else :
    center=(x$r,y$$$r); corner=(x$$$r,y$r);
    if tilt>=0 : wdth:=max; other_wdth:=min; t:=2(1-tilt);
    else : wdth:=min; other_wdth:=max; t:=-2tilt; fi
  fi
  p:=z$r{corner-z$r}...superness[center,corner]{z$$$r-z$r}...
    {z$$$r-corner}z$$$r;
  pos$$(wdth,angle direction t of p - 90);
  z$$r=point t of p;
  assign_z$$'l(direction t of p);
  assign_z$$'r(z$$'l);
  if other_wdth<=currentbreadth: errmessage "bad pos"; fi
  temp:=point (2-t) of p-
    (other_wdth-currentbreadth,0) rotated (angle direction (2-t) of p - 90);
  boolean k[]; k1:=false; k2:=false;
  if unknown x$l:
    k1:=true;
    assign_z$l(temp);
    assign_z$'l(direction(2-t) of p);
    if (y$$$r-y$r)*(x$$$r-x$r) < 0 :	%first or third quadrant
      y$l:=2ypart center-y$l;
      x$'l:=-x$'l;
    else:
      x$l:=2xpart center-x$l;
      y$'l:=-y$'l;
    fi
  fi
  if unknown x$$$l:
    k2:=true;
    assign_z$$$l(temp);
    assign_z$$$'l(direction(2-t) of p);
    if (y$$$r-y$r)*(x$$$r-x$r) < 0 :	%first or third quadrant
      x$$$l:=2xpart center-x$$$l;
      y$$$'l:=-y$$$'l;
    else:
      y$$$l:=2ypart center-y$$$l;
      x$$$'l:=-x$$$'l;
    fi
  fi
  q:=z$l{z$'l}...z$$l{z$$'l}...z$$$l{z$$$'l};
  if k1 :
    t := xpart(q intersectiontimes (center---z$r));
    if t=-1 : t:=0; fi
    assign_z$l(point t of q);
    assign_z$'l(direction t of q);
    assign_z$'r(corner-z$r);
    z$l+z$r=2z$;
  else: t:=0;
  fi
  if k2 :
    s := xpart(q intersectiontimes (center---z$$$r));
    if s=-1 : s:=2; fi
    assign_z$$$l(point s of q);
    assign_z$$$'l(direction s of q);
    assign_z$$$'r(z$$$r-corner);
    z$$$l+z$$$r=2z$$$;
  else: s:=2;
  fi
  subpath (t,s) of q
enddef;

vardef doodah(suffix $,$$,$$$)=
 if known x$$:
  vardef ward(expr gr)=
   sgn(xpart direction 1 of (z${zdir$}..(x$$,gr)..{zdir$$$}z$$$)) <> sgn(x$-x$$)
  enddef;
  y$$=solve ward(y$,y$$$);
 else:
  vardef ward(expr gr)=
   sgn(ypart direction 1 of (z${zdir$}..(gr,y$$)..{zdir$$$}z$$$)) <> sgn(y$-y$$)
  enddef;
  x$$=solve ward(x$,x$$$);
 fi
 (z${zdir$}..z$$..{zdir$$$}z$$$)
enddef;

forsuffixes e=r,l:
  vardef club.e(suffix $,$$,$$$)= doodah($e,$$e,$$$e) enddef; endfor

screen_rows:=600; screen_cols:=1000;

vardef alpha_tail(suffix $,$$) =
  pos$$(hair,180); top y$$=vround 4/3[bot y$l,top y$r];		%tip of hook
  rt x$$l=hround(x$+(y$$-y$)+.5hair);			%central arc is round
enddef;

vardef pi_bar =
  pos3(vstem,-90); rt x3=hround(w-.75u); top y3l=x_height;	%top right
  pos2(vstem,-90); y2=y3; x2=.25w;				%top left
  x1-.5hair=hround.75u; y1-.5hair=4/3[top y2l,bot y2r];		%tip of bar
  numeric slope; slope=angle((z2-z1)yscaled 2); pos1(hair,slope-90);
  forsuffixes e=l,r: z1'e=(z2e-z1e)yscaled 2; endfor
  filldraw circ_stroke z1e{z1'e}...z2e---z3e;		%bar
enddef;