% pattern_rev (for PCs, written as reverse.mf) def pattern= def endchar= tracingequations:=1; cullit; picture phaseone; phaseone=currentpicture; currentpicture:=nullpicture; fill (0,-desc)--(w,-desc)--(w,cap)--(0,cap)--cycle; cullit; picture phasetwo; phasetwo=currentpicture-phaseone; currentpicture:=phasetwo; scantokens extra_endchar; chardx:=w; shipit; if displaying>0: showit; fi endgroup; enddef; enddef;