I really like the smooth pinch-zoom of Safari using the touchpad, but the two-finger scroll on Firefox is so much better than the scrolling performance in Safari.
So I really like to use Firefox, but then I miss out on two-finger-double-tap to zoom to paragraph width, and the smooth pinch gesture zoom.
What I'm wondering is if it is possible to write a Firefox Extension to improve the update rate of the full-page zoom in Firefox that is already functioning via the touchpad pinch gesture. I feel like it is specifically programmed to zoom at certain zoom levels: 100%, 120%, 150% (these are guesses of mine) but I think it would be great if I can get some more control there to make it work more like the zoom functionality in Safari.
Also the two-finger-double-tap on a paragraph or element to zoom to it would be really awesome as well.
https://developer.mozilla.org/en/Full_page_zoom
This seems to indicate (if "full page zoom" is what I think it is) that an extension has the ability to zoom to an arbitrary scale factor, but what remains is to find out if it is possible to obtain or hook the touchpad pinch gesture.
Update: I have updated the toolkit.zoomManager.zoomValues option in about:config to include more zoom levels: .3,.5,.67,.8,.9,1,1.01,1.02,1.03,1.04,1.05,1.06,1.07,1.08,1.09,1.1,1.2,1.33,1.5,1.7,2,2.4,3
Notice how I inserted a bunch of entries between 1 and 1.1.
But it isn't switching between them any faster (why would it?) so it's less usable than before because of waiting for it to respond fast enough.
It's clear that re-rendering the page at a different zoom level requires time and in order for the zoom to be dynamic, some kind of screen capture and scale effect must be performed (which is what Safari does). I guess such a thing is probably doable but I don't think I could pull it off. :-/