System 6 graphical glitches

[Sgeo]

https://system6.app is unusable

Chrome 109

[mihaip]

Looks OK to me:

This is with Chrome 109.0.5414.119 on macOS 12.6.2 on an M1 MacBook Pro. Where are you running it?

[Sgeo]

Windows 10 with a nVidia GeForce RTX 2070.

Just remembered that I had the ANGLE backend set to OpenGL. Changing it to Default resolves the problem.

[mihaip]

Thanks for confirming. System 6/Mini vMac ends up using the "dirty rect" option of putImageData, which perhaps is buggy in that implementation.

[terminalgt]

im getting this kind of graphic glitch
chrome os 105
Screen recording 2023-02-15 11.41.37 AM.webm

[mihaip]

@terminalgt I don't currently have access to a Chrome OS device. If you visit chrome://flags, do you have a setting for "ANGLE Graphics Backend", and if so, what is it set to?

[Sgeo]

Glitching on Chrome on my Pixel 7. As far as I can tell, there is no ANGLE setting on here.

Interestingly, after taking a screenshot and editing, things seem to improve, as though a repaint helped

[that-ben]

This makes me happy that I use Firefox and not Chrome. Wow :P

[mihaip]

Will look into detecting this and disabling the dirty rect optimization in that case, since it seems to be pretty common on Android and ChromeOS devices.