I’ll give some background first.
I have a 3440x1440 monitor, which is very nice for the desktop, but a little too much for some of the newer AAA games. Unfortunately, the EDID info only gives me 3440x1440 (in a whole bunch of refresh rates) and three low res modes (1024x768, 800x600 and 640x480), which are all not right for games.
I tried adding modelines through xrandr, but while --newmode works fine, --addmode always fails with a “BadMatch” error. Even if I try copy the values from the active mode exactly! Since I haven’t fiddled with modelines since the CRT days, I have no idea what could be blocking this. Could the driver be causing this?
Technically, I don’t really want a different resolution. I would be happy to have a cropped version of the display with black borders. This way the screen remains unscaled, which is a big plus for me. I can easily make this happen nvidia-settings or xrandr by messing about with viewportin/viewportout (or equivalent settings). The big problem with this is
- Software doesn’t appear to understand that the framebuffer is smaller than the screen
- It won’t appear in the screen modes list as a valid fullscreen mode, so it remains unselectable.
Ideally I would like to “create” a screenmode (for instance 1920x1080) mapped onto 3440x1440 with black borders that is selectable is games as a fullscreen mode. Is there any way to make this happen?