I've realized that doing a zoom isn't going to work out, since that
will make the text appearing on my panel, etc get bigger... I just want
to increase the dimensions of my shape.   So, I've settled on iterating
through my coordinates and adjusting the lengths of each line by a
scaling factor.   This way the shape grows to fill the panel but the
other drawn items remain the same scale.    But, this is getting pretty
challenging with non-rectangles... It's getting messy.   I'm wondering
if there is a cleaner way.    Does anyone know of any tricks for doing
coordinate scaling transforms like this?  my problems seem to mostly be
related to trying to keep the position of the first point fixed.

I am dealing with the shape as "lines" consisting of two points each.
 I go through each line and change the second point (x2 or y2
depending on the plane) to reflect the new length (multiplied by
scaling factor, eg len * 1.5).   But once I get to the underside of the
shape,  things get out of whack.