Re:First Impressions Using React Native
by malandrew on Monday February 09, 2015 @03:40AM
(#9020213)
Basically if you want to prevent reflowing you end up making everything a texture and that leads you to making many many CSS transform changes on every frame. 60fps is easy to hit on a modern desktop, but mobile performance requires more effort to achieve an effect that feels natural. The problem with the marshalling is that it is comparatively expensive and a blocking operation, which is not conducive to buttery smooth graphics performance on all platforms.
People attribute pauses to GC, when it's sometimes just the browser container environment acting up and there's nothing we can do about it - so it's easy to write it off as GC. Not sure about today, but 1.5 years ago (i = new Image(), i.src="http...") could block the JS thread for as much as 19ms. In a larger app, it's easy to write that off as GC, but (at least on iOS) the performance tooling is really lacking and it's tough to find the culprit.
Reflowing is a big deal, I agree.