--- /dev/null
+prologues:=1;\r
+outputtemplate:="%j.mps";\r
+beginfig(1);\r
+pickup pencircle scaled(3bp);\r
+draw fullcircle scaled(38);\r
+draw (0,-19)--(0,19);\r
+draw (0,0)--((0,-19) rotated(45));\r
+draw (0,0)--((0,-19) rotated(-45));\r
+r:=17pt/(xpart(urcorner(currentpicture))-xpart(ulcorner(currentpicture)));\r
+picture pic;\r
+pic:=currentpicture;\r
+currentpicture:=nullpicture;\r
+drawoptions();\r
+draw pic scaled(r);\r
+z0=.5*urcorner(currentpicture)+.5*ulcorner(currentpicture);\r
+z1=.5*lrcorner(currentpicture)+.5*llcorner(currentpicture);\r
+draw (z0+(10.5,2));\r
+draw (z1-(10.5,2));\r
+clip currentpicture to ((z0-(8.5pt,0))--(z0+(8.5pt,0))--(z1+(8.5pt,0))--(z1-(8.5pt,0))--cycle);\r
+endfig;\r
+end;\r