Hi again, I've taken a look at the Sine Behavior code. If I'm not wrong, it should be enough to add following code to add a Reset action:
edittime.js
<font color=blue>AddAction(5, af_none, "Reset", "", "{my} <b>Reset</b>", "Reset the wave function.", "ResetWave");</font>
runtime.js
<font color=blue>Acts.prototype.ResetWave = function (){this.i = 0;};</font>
I've tested it. It works as expected. On Reset, the Sine function starts at 0. Maybe you could test it too, and it could be added to the next C2 issue??