% --- start of displayed preamble in the book --- input hatching; % star macro defined as above % --- end of displayed preamble in the book --- % graphic converted to gray in book using 'color2gray' vardef star(expr n) = for i_:=0 upto 2n-1: if odd i_: 1/2 fi (right rotated (180*(i_/n))) -- endfor cycle enddef; defaultfont:="ptmr8r"; warningcheck:=0; beginfig(1) path p; p:=star(10) xscaled 30mm yscaled 20mm rotated 20; interim hatch_match:=0; hatchoptions(withcolor blue dashed evenly scaled 2); hatchfill p withcolor .75white withcolor (20,6bp,-.5bp); hatchoptions(withcolor (blue+green) dashed evenly shifted (3/2bp,0)); hatchfill p withcolor (110,6bp,-.5bp); endfig; end;