[Groff] filling object with a pattern

[giecrilj]

I understand that I can fill pic objects with solid fill; 
but is it possible to use a pattern fill instead?  
This would be useful to draw e.g. a Venn diagram. 
I am unable to figure out how to do it e.g. with slanted lines, 
except by calculating the line segments by hand.  
I would prefer to draw them to the bounding box and have them cropped.