It depends. Skia can either be used as software or GPU renderer.
GPU AA rendering can slightly differs when using MSAA. When MSAA is turned on, Skia has different path renderer strategies (that could be CPU-based, like SDF, or GPU-based using coverage counting). In that case (msaa turned off), AA result should be identical on all platforms, at the cost of performance.
Having looked at Skia against a lot of different OS/GPU/driver combinations, I would be surprised to see bit identical results from GPU rendering except perhaps across different nvidia cards. I wouldn't even necessarily expect identical results in replicated runs on the same machine.
Worth keeping in mind that what Skia's GPU backend decides to do depends on GPU features, and sometimes on GPU workarounds. There's no guaranteed way to force it to render identically on all platforms short of something like swiftshader.
hey thanks for answering! You're one of the main skia contributor right?
I thought GrGlCaps was supposed to fallback most of the time to equivalents. Also thought that golden images baseline where pixel tested against a large set of different hardware.
But yeah, Skia blacklists MSAA for Intel GPU, so if you opt-in for sampling, you're not guaranted it's going to be enabled and therefore observe differences
you can force CPU only and also disable MSAA on the GPU renderer.
Enabling the GPU renderer doesn't guarantee that everything will be generated on the GPU. Skia can still decide to rasterize a path on the CPU before uploading it on the GPU.
It depends. Skia can either be used as software or GPU renderer.
GPU AA rendering can slightly differs when using MSAA. When MSAA is turned on, Skia has different path renderer strategies (that could be CPU-based, like SDF, or GPU-based using coverage counting). In that case (msaa turned off), AA result should be identical on all platforms, at the cost of performance.