Android: too many state updates prior to rendering

[kkaefer]

On Android, we seem to be doing way too many state updates: I'm seeing 30+ calls to setScalePoint with minor differences, which are followed immediately with a call to update() (meaning we recalculate the style + tiles, a relatively expensive operation). We should track down the source that leads to setScalePoint being called to many times within one frame.

[tobrun]

I'm able to trace that this comes from MapGestureDetector#onScroll while we pan the map. I'm now looking into limiting the amount of updates we pass to core. This will require us to keep state of the amount of pixels scrolled in x,y and time the duration since previous moveBy.

[tobrun]

One thing I'm also noticing is that setScalePoint is called multiple times after the gesture has finished. Those updates are originating from somewhere else.

UPDATE: these occurrences come from fling, it seems that it's possible to trigger a fling gesture just by scrolling and lifting up your finger. It passes in a small x,y difference to moveBy with a duration of 350ms. The usage of duration here seems to trigger multiple calls to setScalePoint.

[tobrun]

A lot has moved since 2016, please reopen if still an issue. Closing as stale.