hi, u r right - not really performant in FF, developed/tested it on chrome, safari and iPad safari (which my kids love, it's mostly coded for them) so far .. will look into FF and make some performance enhancements.
i commented out a
console.log(touch.pageX);
and now the performance in FF seems to be much more smoother? can it be? it did not even get executed? strange.
It's now fast for a few seconds, then gets slow shortly after the footer loads.
after a long hard fight i made it faster (overall but especially in FF) .... the CanvasPixelArray Object (which is not an Array in Webkit ....) is a real bastard.