HiDPI Fractional Scaling on Linux/GTK

[Matthew Wallace]

I'd like to use fractional scaling in my swing application on Linux (GTK).
My application already works perfectly with fractional scaling on Windows
(Java seems to abide by the system settings) but on Linux the system
settings are ignored and setting GDK_SCALE only works for integer values.
Could anyone familiar with this outline for me the work needed to support
fractional scaling on Linux?  I'm willing to do some hacking to make this
work, but I really have no idea where to start or if it's even feasible.
Any help is greatly appreciated.