samples
samples copied to clipboard
flutter
Veggieseasons sample drops frames while scrolling
I noticed that the veggieseasons sample app drops below 60fps while scrolling through the veggies on the home screen. I get an average of around 20ms/frame GPU time and max GPU time of around 30 ms/frame. So it only runs about 50fps, which seems like a small deviation but on a fixed refresh display it leads to micro stuttering.
Test Setup:
Flutter 1.7.4 release build.
I turned on the performance overlay by adding to showPerformanceOverlay: true to the CupertinoApp widget.
I testest both on a Galaxy S8 with Android 9.0
and a iPad 6th generation running iOS 12.3.1
Both had similar frame times.
I know that these are not fastest devices but it is just a simple list after all and I would expect scrolling to be smooth.
I've done some more testing and it's probably obvious but, disabling the blur CupertinoSliverNavigationBar by selecting an opaque color solves the problem, but is not really what I want.
I would assume that the blur functionality in Skia is already well optimized, but then again, it isn't a problem in native iOS apps.
The scrolling was smooth in 1.5.x and has since regressed. https://github.com/flutter/flutter/issues/36064
As noted in the other issue, I've tested this with the veggieseasons app specifically
Video with performance overlay of the two versions:
Screencast v.1.7.8+hotfix.4 (youtube) Screencast v.1.5.8 (youtube)
CC: @HansMuller
Clearly we needed our own issue tracker for the samples for a while now.
I don't have an iOS hardware device on me today, but I'll try to verify if this problem still exists with the current SDK early next week.
