[messages] [Module Design] Best way to implement a rotating wheel chart?

Broadsword56 ginaworks4u at gmail.com
Sat Aug 1 04:23:59 CEST 2015

Suggestions welcome...

I'm trying to decide the best way to implement a rotating wheel chart in
my Vassal module.

It's one of those two-piece gizmos -- know as whiz wheels or volvelles
-- where you rotate one wheel and read a result through a diecut window
in the top wheel. (Great collection of vintage volvelle images here:

I've made a top piece image and a bottom piece image, and since Vassal
supports transparency in png files, the shape and windows are no
problem.  The version I've been working with uses the two parts of the
wheel as two stacked playing pieces, with pivot and rotate traits. I set
them up as an At Start Stack on a background map board. And I set the
stack vertical/horizontal offsets to 0, so the wheel would look like one
gizmo and not be skewed.

Result so far, I can manipulate the separate inner and outer pieces of
the wheel chart -- it looks very cool, but it feels very fiddly, having
to click and double-click so much on the top or bottom to manipulate the
inner or outer wheel. You have to unstack the pieces to rotate the top
or bottom wheel independently. When you double-click to unstack, It's
not intuitive to tell which piece you've got selected, and of course
when the pieces are stacked the entire gizmo is locked and doesn't
rotate at all. Bottom line: an unsatisfying clickfest.

Can anyone think of a better way to implement this, using either
better/different piece properties, or using some entirely different
Vassal capability that is better suited for this purpose?

Read this topic online here:

More information about the messages mailing list