Remove `DamageOutOfRange` error #314

madsmtm · 2026-01-19T17:35:03Z

There is a very natural thing to do if we receive a damage rectangle outside supported bounds: Clamp it to be inside. This is also what's done by Wayland IIUC, and probably on other platforms as well, so let's do it in Softbuffer as well, and avoid the needless error case.

This also allows us to make present forward directly to present_with_damage, which is a nice internal simplification.

Finally, this exposed latent bugs with out-of-bounds damage regions on Windows, Web and X11, I've fixed those as well.

Tested on:

src/backends/wayland/mod.rs

src/backends/android.rs

src/backends/kms.rs

src/lib.rs

src/backends/web.rs

MarijnS95 · 2026-01-20T10:43:55Z

This is also what's done by Wayland IIUC

Maybe explicitly linking this portion of the documentation:

The compositor ignores the parts of the damage that fall outside of the surface.

Damage that fall outside the surface is ignored.

Makes it clearer what we're actually doing with the damage rectangles.

ids1024 · 2026-01-27T21:55:59Z

I'm not sure about other platforms, but this is definitely reasonable enough on Wayland. 👍 Using a damage_buffer with i32::MAX as the width/height is a standard/recommended way to damage the whole buffer.

madsmtm · 2026-01-27T22:07:36Z

As I understand it, -[CALayer setNeedsDisplayInRect:] also clamps out of bounds values.

(Not that we would be using it, I'm pretty sure that damage tracking is only inside AppKit and/or Core Animation itself, the compositor doesn't know about it, so it won't matter once we start using IOSurface - but it at least shows that there's another API out there which has the same behaviour).

madsmtm added the enhancement New feature or request label Jan 19, 2026

madsmtm force-pushed the madsmtm/remove-damage-out-of-range branch 2 times, most recently from 551b385 to ab88d81 Compare January 19, 2026 19:27