How to make a square topped, round rect bottomed graphic?

[Roger Guay]

Howdy,

One of the things I remember most fondly about SuperCard was its incredible shrinker/expander polygon tool. With this tool it was a snap to surround a group of objects, for example, and the tool would then automatically generate a new polygon that fit tightly around the original group. As an option, this tool could also expand to fill a void. 

I have tried to build such tool in Rev but to no avail. I guess I am too much of an amateur!

Oh, to have such a tool in Rev/LiveCode!!

Cheers,
Roger Guay