Hey folks, I was reading this article about reduci...

# compose

[Vivek Modi]

Hey folks, I was reading this article about reducing overdraw in Jetpack Compose especially around Scaffold usage. It mentions that Scaffold can introduce unnecessary background layers and lead to overdraw if combined with Surface or other full-screen backgrounds.

I wanted to get your thoughts:
- How accurate is this in real-world apps?
- Is this something we should actively optimize for, or is the impact usually negligible?

Just trying to validate how much this actually matters from a performance standpoint vs being more of a theoretical concern.

Thanks!

[Chrimaeon]

Overdraw was an issue in the early days of Android AFAIK.
Also https://kotlinlang.slack.com/archives/CJLTWPH7S/p1692630677071789?thread_ts=1692608489.508949&channel=CJLTWPH7S&message_ts=1692630677.071789

[Chrimaeon]

https://kotlinlang.slack.com/archives/CJLTWPH7S/p1622446090360100

[romainguy]

A few things about overdraw:

[romainguy]

• It matters a lot less on the type of GPUs used in pretty much all Android devices today (tilers)
• Android introduced an optimization that automatically gets rid of backgrounds when they are fully covered by other opaque backgrounds
• It can still be an interesting tool indicating that your UI hierarchy might be too complicated (so it's more about complexity/layout performance, etc.)

[ursus]

Android introduced an optimization that automatically gets rid of backgrounds when they are fully covered by other opaque backgrounds

Is that a compose thing or lower level?

[romainguy]

Lower-level. It was added in Android 4.x