Simple. Switch to VIM. Or, just write GTK code from scratch directly in the IDE.
It's not too hard. I currently use Swing in Java, all written from scratch - no IDEs to be found. I've also dabbled around with simple GTK+ apps. They aren't as easy, nor as efficient, to work with as the standard Java toolkit, but you get used to it.
I switched back to Swing because I wanted as few dependencies as possible.
So--I'm still missing something. Are you saying that the way to get good font rendering in IntelliJ is to write GTK+ apps? It sounds like you misread the OP.
Ah, I see. I'm sorry about that, but I don't think that there's a solution to fix Swing font rendering in IntelliJ itself. Unless, of course, you dive into the source code.
It's not too hard. I currently use Swing in Java, all written from scratch - no IDEs to be found. I've also dabbled around with simple GTK+ apps. They aren't as easy, nor as efficient, to work with as the standard Java toolkit, but you get used to it.
I switched back to Swing because I wanted as few dependencies as possible.