Automatically disable texture swizzling on incompatible graphics drivers

[anohren]

I'm not sure what's supposed to happen when launching the nightly on macOS. This is what I see:

What should I expect it to look like on macOS?

MacOS 10.14.6
Macbook air 2012, intel hd 4000

[jdm]

There are supposed to be fonts and images showing up; it loads https://servo.org/ by default. That's a surprising result!

[anohren]

Thanks. It's not easy to know what to expect the first launch when you're not familiar with how far along a project is.

Sometimes I get black raindrops that I suppose text and images would look like when travelling at lightspeed:

I downloaded the nightly a few minutes before creating this issue. I got the exact same result a few months ago when I downloaded the nightly build for the very first time, but dismissed it as not being prioritized for macOS.

[jdm]

Oh, I bet you're running into https://bugzilla.mozilla.org/show_bug.cgi?id=1570736#c32. If you launch the nightly with open ServoNightly.app --args --pref gfx.texture-swizzling.enabled=false (or whatever the .app file is called), do the fonts appear?

[anohren]

Yes, that seems to fix it. The page renders with text and images. The intel drivers are defective in this way only on macOS if I understood correctly.