UI Fonts on (some) applications are unreadably small

Question

I recently launched a game that decided to set my resolution to 800x600, go fullscreen, and then freeze. After force-killing the game, to my joy, I was met with a panning 800x600 desktop, and had to re-learn how to use xrandr so I could set my desktop back to a reasonable resolution.

But it seems that the ghost of that game still lingers on my system, as I just noticed that two of my frequently-used programs are suddenly impossible to comprehend. It's hard to describe with words, so how about some screenshots:

dmenu and gimp are rendering their UI so small that it's incomprehensible. What's perplexing is that the window manager (DWM, normal font) is rendering that same font just fine. And other programs (like st and xfe) also are working fine.

I have no idea what to do. Fonts are not my strong suit, and I'm afraid that if I reboot, the issue won't resolve itself and my window manager will join the tiny fonts club. I don't know what GTK+ uses for UI fonts, but dmenu uses Xft (X11). How can I make my UI readable again?

Answer 1

I forgot that I posted this question. I actually did end up finding a solution, which I put in a shell script aptly named unfuckdesktop:

$ cat unfuckdesktop
#!/bin/sh
mon=DVI-I-1
xrandr --output $mon --scale 1x1 --panning 0x0 --mode 1920x1080

Replace DVI-I-1 with whatever xrandr (without arguments) spits back.

$ xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
DVI-I-0 disconnected primary (normal left inverted right x axis y axis)
DVI-I-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 544mm x 303mm
   1920x1080     60.00*+ 239.76   143.98   119.98    59.94    50.00    60.00    50.04
   1600x900      60.00
   1280x1024     75.02    60.02
   1280x720      59.94    50.00
   1152x864      75.00
   1024x768      75.03    60.00
   800x600       75.00    60.32
   ...

Note where it says "connected"

DVI-I-1 connected 1920x1080+0+0

That said, when I executed this, it fixed the small text. It was a while ago, so I don't remember exactly which parameter it was, but it's probably --scale 1x1.

It's also possible that I didn't put it in there. I'm pretty sure that I did, since that problem plagued me for a good while, but if you're experiencing tiny-text and the above solution doesn't work, you can also try --dpi.

xrandr --output $mon --dpi 90

IIRC, the last time I messed with my DPI settings, I set it to 90.