[canucker2016]

Yes, from 2023 Jul 21 blog entry, https://medium.com/@wartelski/impeller-rendering-engine-is-i... :

"Impeller is a new Flutter rendering engine that the Flutter team claims solves the early-onset jank problem. It is designed as a replacement for Skia, with the goal of enabling better animations and addressing the jank issue, while also potentially providing support for 3D, which was not previously possible with Skia, as it exclusively supports 2D. Unlike Skia, Impeller compiles shaders during the build process instead of at runtime.

In Flutter 3.10, Impeller replaces Skia engine and becomes the primary rendering engine on iOS."

[charcircuit]

>Unlike Skia, Impeller compiles shaders during the build process instead of at runtime.

This wouldn't work on most platforms as graphic driver updates can break compatibility with previously compiled shaders.

[jsheard]

There's often multiple compilation steps, first compiling some application specific representation down to HLSL/GLSL/MSL source code, then compiling that down to DXIL/SPIRV/Metal bytecode, and then handing that off to the driver for compilation to native code. The first two steps at least can be done ahead of time, the bytecode is stable.

Metal and CUDA actually let you AOT compile native binaries since they have relatively few hardware targets to support, with a fallback to compiling bytecode to native at runtime for forwards compatibility.

[incrudible]

The bytecode compilation doesn't really matter, it's still gonna jank. Maybe not as badly, but it will. The only way to get rid of jank is to cache not the bytecode and not even the native code, but the PSOs. Realistically, that is only possible on the target machine, unless you have a ginormous farm of machines representing all the permutations of hardware and drivers. That's basically what Steam does with its mass of users.

The alternative is to just not have that many shader permutations, and potentially take a performance hit from that. This seems to be the strategy that Impeller is following.

[SleepyMyroslav]

I have not seen shipping prebuilt PSOs outside of game console platforms. Typically games that care do on device caching if any. Unfortunately, lots of projects just take shader hitches as given.

[kaba0]

Could you please tell me what PSOs are? I am not sure I found the proper abbreviation.

[perlclutcher]

PSO = Pipeline State Object