Best way to limit window size?

[dhardy]

Kas uses an algorithm to determine window size from its contents. As you can guess, someone managed to break this by stuffing too much content in the window, thus trying to open a very large window (succeeds) and create a backing texture (fails somewhere around 16000 pixels, presumably a 16k texture size limit).

What's the correct approach to limit this to something sane?

• A hard-coded maximum?
• Query the maximum supported texture size? Applying this is hard to do since Wayland does not really support specification of window size in physical pixels.
• Limit to the maximum monitor size? This isn't possible to do correctly: MonitorHandle::scale_factor does not use fractional factor on Wayland #3183

[kchibisov]

There's a https://wayland.app/protocols/xdg-shell#xdg_toplevel:event:configure_bounds created just for that, it's not supported by all the compositors, but that's exactly why it exists.

[kchibisov]

Limit to the maximum monitor size? This isn't possible to do correctly: #3183

This is possible to do correctly by limiting PhysicalSize if you take the monitor resolution, because it's physical and use it. Since what you want to limit is buffer sizes, not the window sizes, given that you're getting a texture error. Also, some drivers expose the maximum size of the texture, so you can limit by that.

[dhardy]

by limiting PhysicalSize

Constructing a Wayland window using PhysicalSize does not work correctly: the result is too big. Does this mean I should always resize afterwards?

[kchibisov]

Hm, I think I can change that to actually work with modern compositors.

[dhardy]

That's #2275 BTW.

[kchibisov]

yeah, but I can't really fix it for all setups, only for new protocol.

[kchibisov]

#3185 for window sizes, but generally, you could have a different texture limit.