% negative pseudo-halftone font with 65 sizes of square dots
mode_setup;
w#:=2.5pt#; font_quad:=w#; designsize:=8w#;

for i=0 upto 64: beginchar(i+ASCII"0",w#,w#,0);
 r#:=sqrt(.9w#*(1-i/80)); define_pixels(r);
 fill unitsquare scaled r shifted(.5w,.5h); endchar;
 endfor
end.