very smooth my end, and a huge difference to the original… that not the case on your end? 
can you screen shot the app? I feel like you dont have the right apk (ie, does it have a “header” and “footer” button?)
Its not so easy to see the jitter in the video but…
Is that slow like it was before (before batching)? Maybe its the video but it looks fairly smooth… Before (without batching) the list would barely move for me when i scrolled.
I would say its quite similar to virtual=true before the batching rework… And my phone is pretty fast too… But its strange… because in html5 on the same phone its smoooth…
Will do a test app with an fps counter and check…
just building two apks… batching and no batching… i knew i decided to put it as a flag for a good reason! 
Its not easy to see the jitter in the video because it is 30 fps…
So i’ve added a fps counter and its pretty obvious then… the framerate jumps up and down from 30 to 60 fps…
but it only happens when scrolling… steady 60fps when not moving the list…
OK, couple of things… how are you adding the FPS counter? Is it something simple i can just plug into my app, also here are the apks:
- http://haxeui.org/shared/app-nobatch-debug.apk (no batching)
- http://haxeui.org/shared/app-batch-debug.apk (with batching)
How do they compare to each other? Also, ignore the red buttons… was playing with something else 
Ok, will test them!
Here is a test app with fps counter … see what you get:
https://www.dropbox.com/s/5no8wqcfc85938m/app-debug.apk?dl=0
Fps counter is very simple:
class Fps
{
static var deltaTime : Float;
static var lastTime : Float;
static public var fps : Int;
static public function update():Int
{
var currentTime = Scheduler.time();
deltaTime = currentTime - lastTime;
lastTime = currentTime;
var nFps = 1.0 / deltaTime;
if (Math.isFinite(nFps))
fps = Math.round(nFps);
return fps;
}
}Well, ok… In your test apps no-batching drops lots of frames… while the batching one is smoother. That being said - it still drops some frames, making the scroll jitter… like in my test
Maybe this is a Kha AndroidNative issue ? I mean, should there be any reason that html5 is smooth while native jitters? …on the same device…
Yeah, its weird… And as you say, html5 on the same device is snappy(er)
EDIT: i wonder if its glScissor on android native… i mean, thats all i cant think it might be
Hm… yeah… but on the other hand shouldnt the framerate be consistent? Why is it only happening when scrolling? And in my performance tests i was able to scroll lots of texts and graphics in smooth 60fps on AndroidNative, are you doing something special during rendering / update?
where are you calling that update in your FPS counter? Going to add something like that into haxeui-kha as it seems useful
anywhere really, like in the update once pr frame
honestly, im at a bit of a loss now… Ive tried profiling the APK in android studio but it all looks pretty normal there (have you tried the same?). FYI, ive added an FPS counter to haxeui-kha now if you need it
EDIT: there is no gpu profiler in android studio - but im not sure if that is a bottleneck or not
Nice, fps counter is useful.
Hm… Hard to say… Im sure something is going on… Will try to investigate a bit on my end too, see if i can make some sense of it…
Maybe Robert has some insight here?
Just a thought, is it possible to make the scroll logic run in its own thread? In case the issue is not GPU bound?
It seems very much related to the scroll and not the actual drawing - since i presume you render all the elements on screen each frame even if the scroll is not moving?.. Because the framerate is good when the scroll is static…
[edit: actually it seems the framerate drop when items leave or enter the screen only… Very small movements up / down does not cause frame drops here]