COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	% halftone font with 33 levels of gray, characters "0" (white) to "P" (black)
C00004 ENDMK
C⊗;
% halftone font with 33 levels of gray, characters "0" (white) to "P" (black)
% this is a kluge to use the APS font on the imagen for proofreading

if mode≠imagen: errmessage "Please set mode=imagen"; fi

pair p[]; % the pixels in order (first p0 becomes black, then p1, etc)
p0=(0,0);
p6=(0,-1);
p12=(1,0);
p18=(0,1);
p24=(-1,0);

for i=0 step 6 until 24:
 p[i+1]=p[i+2]=p[i+3]=p[i+4]=p[i+5]=p[i];
 endfor

p30=p31=p29;

mode_setup;
designsize:=64/10.00288; % that's 64 APS pixels

def makebox(text t)= enddef; % shut off boxes

picture prevchar;

prevchar=nullpicture;
for i=0 upto 32:
 beginchar(i+ASCII"0",designsize/8,designsize/16,0);
 currentpicture:=prevchar;
 if i>0: fill unitsquare shifted p[i-1]; fi
 prevchar:=currentpicture;
 endchar;
 endfor

font_quad=designsize/8;
end