1. Start ST with the software renderer enabled.
2. "vid_renderer 1" in the console.
3. Start a new game.
4. Alter your display resolution in "Options -> Set Video Mode".
I'm unable to reproduce the issue in GZDoom 323, but I'm able to reproduce it in GZDoom SVN build 1215.
Spoiler: The visual glitch
Windows 7 Home Premium 64-bit
Intel Pentium Dual-Core CPU T4400 @ 2.20GHz
4,00 GB RAM
ATI Mobility Radeon HD 4500 Series (8.634.1.0)
Actually you could since this is to be tested in software mode anyway.
You've got to start with vid_renderer 0, open the console, set it to 1, then you get a message telling you it won't take effect until you restart GZDoom but don't restart, start a new game, and change the resolution.
Then you can set vid_renderer back to 0 before quitting.
Edward-san wrote:Hi, did you read this? It's about this one.
I and Gez can't reproduce what you described with latest gzdoom svn. Can you recontrol this?
So apparently the issue was fixed somewhere between r1221 and r1231. It's perhaps not too surprising given most of these revisions correspond to Graf's clean-up of the renderer code.