Blurry GtkImage when snapshooting a widget at a bigger size

Platform
#1

Hello,

I’m using a Gtk.WidgetPaintable to take screenshots of some widgets for documentation purposes. It works perfectly when I snapshot the paintable at the same size as the widget:

Widget at scale 1

However, when I snapshot it at a bigger size (applying a scale factor to the dimensions passed to Gtk.WidgetPaintable.snapshot()), the text is clear but the image (although it is an SVG) is upscaled:

Widget at scale 2 with blurry image

Is there a way to have the GtkImage rendered at the given size?

I’m using this in a headless Weston compositor, I tried to set its scale setting to the same value but it did not seem to change anything.

#2

After further testing, the headless backend of Weston doesn’t honor the scale setting, running it nested with the Wayland backend, it works as expected:

Widget at scale 2

[EDIT: Weston 9.0.0 headless backend can be scaled.)

Still, it would be great if snapshooting the paintable at a bigger size renders a crisp image.

#3

I’m currently trying to do very similar things in C (taking screenshots of GtkWidgets headless). Is your project public and can you point to some real code? I’m mostly interested how to do it headless.

#4

Yes, my code is here, it’s in Rust: Romain / UI Shooter · GitLab

The container image is not yet updated to support scaling widgets.

#5

Thanks a lot & merci beaucoup