From: Roger Guay <[EMAIL PROTECTED]>
Cool, Jim. And, if you change just one line of your code in the
mouseMove handler to
"if rr is not r then"
you get an object that is constrained to move on the circle of radius
rr. This is useful if you want to build a rotary knob for example.
Roger,
Scott and I were working on a problem like the one you describe some
time ago. But the question was: Could the rotary knob be used to
*accumulate* multiple turns by following the the polar angle. The
difficulty here was that the angle as reported by RR using the atan2
function is single valued, that is it returns to the same value after
one complete revolution. How then do you record the angle *plus* the
number of revolutions?
But as the knob crosses the branch cut where the angle changes from
360 back to 0, one can detect this large discontinuity using
something like: if abs(da) > some small number then add 1 to the
counter and multiply this counter by 360, where da is the
continuously measure difference in polar angle in the mouseMove
function.
This is hard to explain. Easier to see: In the message box:
go stack url "http://home.infostations.net/jhurley/Clock.rev";
Jim
_______________________________________________
use-revolution mailing list
[email protected]
Please visit this url to subscribe, unsubscribe and manage your subscription
preferences:
http://lists.runrev.com/mailman/listinfo/use-revolution
