Is trackpad pinch easy to add?

[amit777]

Hi, I was wondering if it would be easy to add trackpad pinch support. I believe it is just wheel event with Ctrl key modified. It seems like 2-finger touch is more complicated so it seems you have solved the harder problem!

[sandstrom]

I think we have trackpad double-tap to zoom support.

Don't know if pinch is easy to add. I didn't write the library initially, just helping out maintaining.

I think at this point the easiest may be a fairly big rewrite (v2) built around pointer events (#114) would be a good idea.