supportsOffscreenMsaa property

set supportsOffscreenMsaa (bool supported)

True, and settable so a test can be the device that answers no — gfx-20n.

The reason it is worth setting: a frame that stops multisampling because the device cannot and a frame that stops because something reads the surface buffer look identical from outside, and FrameResult.antiAliasing exists to tell them apart. A fake that could only say yes leaves half of that untested.

Implementation

set supportsOffscreenMsaa(bool supported) => _features = supported
    ? _features.union(const <DeviceFeature>[
        DeviceFeature.offscreenMultisample,
      ])
    : _features.without(const <DeviceFeature>[
        DeviceFeature.offscreenMultisample,
      ]);