Pinch to zoom stutters and get stuck a lot

[pixelfreak]

Try pinching to zoom on iPhone/iPad. It stutters pretty badly and gets stuck a lot, meaning you can't zoom in/out again unless you let go and start pinching again.

[pixelfreak]

Trying to debug this...the touchmove event seems to stop getting triggered when it hits the next/previous zoom level. The issue also seems to be intermittent.

[pixelfreak]

I moved all the touches listener to document.body, no luck, doesn't seem to matter.

[pixelfreak]

Is there a way to not update the tiles until touchend happens? I think that might be what's causing the issue.

[pixelfreak]

The code that zooms the tiles and the one that updates them are a little convoluted. I am not familiar enough with the codebase to fix this.

[tmcw]

@pixelfreak - I'll be working on this area and addressing this in the #84 ticket. If you want to de-convolute the code, go for it.

[pixelfreak]

I did some standalone experiment and confirmed that the culprit is the map updating the tiles on touchmove. Delaying the updates until touchend solves it.

[tmcw]

@pixelfreak try the ff branch: it defers tile loading and changes the CSS transforms strategy. Currently at the cost of Firefox & IE compatibility, but that should be fixable soon.