Hi, On Tue, 2025-05-13 at 11:52 +0200, BALATON Zoltan wrote: > On Tue, 13 May 2025, Weifeng Liu wrote: > > Hi, > > > > On Tue, 2025-05-13 at 00:37 +0000, Kim, Dongwon wrote: > > > Hi, > > > > > > > Subject: [PATCH 8/9] ui/gtk-gl-area: Render guest content with > > > > padding in > > > > fixed-scale mode > > > > > > > > In fixed-scale mode (zoom-to-fit=false), we expect that scale > > > > should not > > > > change, meaning that if window size is larger than guest surface, > > > > padding is > > > > > > # @zoom-to-fit: Zoom guest display to fit into the host window. When > > > # turned off the host window will be resized instead. In case > > > the > > > # display device can notify the guest on window resizes > > > # (virtio-gpu) this will default to "on", assuming the guest will > > > # resize the display to match the window size then. Otherwise it > > > # defaults to "off". (Since 3.1) > > > > > > Current definition says the host window should be resized to fit the > > > size of the guest surface instead. Wouldn't padding accommodate this? > > > > > > > Yeah, window will be resized to fit the size of guest surface in fixed- > > scale mode. However, users are still allowed to resize the window to a > > larger size and this is case where padding is required, otherwise the > > fixed-scale assumption is broken. In fact, gl=off mode employs padding > > to preserve scale already but gl=on mode doesn't follow this behavior, > > which, IMO, is a defect that this patch is trying to correct. > > I think current set of switches is not enough to describe all possible > configs and this leads to inconsistency between display backends. Each > display backend has different idea on how zoom-to-fit should work now. > Maybe we need a new keep-aspect=off or similar option to make it explicit > then these can be set independently to decide if a full-screen zoom-to-fit > window should be stretched or padded. Currently it behaves differently > depending on display backend or even options of one display backend as you > say above. Fixing just one place won't solve the problem with other > backends so maybe separating this option into a new one would end this > inconsistency. I got requests from people for both padded or stretched > behaviour so it seems some prefer one or the other and just zoom-to-fit > can't set both. >
Thank you for pointing out the demand for both stretched and padded behavior — allowing users to choose their preferred display makes a lot of sense. With the changes in this patch set, we can at least ensure that all GTK-based backends behave consistently with regard to aspect ratio. I’ll follow up with a separate patch set to introduce the new keep-aspect=off (or similar) option you suggested. By the way, I’ve also been working on a “scale” option to let users specify an exact zoom level. I deliberately left it out of this patch set because I wanted to keep its scope narrowly focused on refactoring. Once this set is merged, I’ll submit the new patch set with these changes. Best regards, Weifeng > Regards, > BALATON Zoltan
