GTK WIP support for Windows Pointer input

This WIP PR would bring GTK support pressure and tilt input for Surface-like devices. Dropping a link here in case anyone might have insights which might help get this over the line.

Additionally it would open the door for touch input on Windows devices, which has been something I’ve wanted to contribute to MyPaint for a while now. When this lands, are there any blockers for updating the version of GTK MyPaint uses?

Can’t offer any insights or help regarding the patch, but I can say that unless the next version of gtk suddenly removes GtkAction, there probably won’t be any major blockers for supporting it. The windows builds are always made against the latest versions of the libraries in MSYS2, so whenever Gtk3 is updated there, it is also updated in the builds.