Alright, guys. I cannot for the life of me figure this one out. What I'm trying to do is change my Xorg settings to act as if my 3 (identical) monitors are a single monitor so I can span a game across all 3.
Here are the 3 monitors I'm using with my NVIDIA GeForce RTX 2080: https://www.dell.com/en-us/shop/dell-24-gaming-monitor-s2417dg/apd/210-aizs
I was able to find this video from Jakejw93 on YouTube, which was uploaded back in 2016. From what it looks like, all he had to do was change Xinerama to "1" in his /etc/X11/xorg.conf. I can see he is running Unity in the video, so I'd assume he was on 16.04.
I figured that seemed simple enough, so I did it on my 18.04 install. I went ahead and set Xinerama to "1" in my /etc/X11/xorg.conf file, and rebooted. However, that's when trouble starts.
Upon reboot, I am greeted with just my mouse cursor on a black screen. The good thing, however, is that I can move the cursor around. Here's a (low quality) picture I took with my phone: https://imgur.com/a/m3QF94j
Here's a copy of my (modified) /etc/X11/xorg.conf: https://pastebin.com/sjK356aE ...here's my /etc/Xorg.0.log: https://pastebin.com/bWt2kYAc ...and my /etc/Xorg.1.log https://pastebin.com/DjYq7Sfc
Output of lshw: https://pastebin.com/U5WuriWz
Where would I even start with this? There isn't much documentation online about Xinerama, and I was not able to find any about NVIDIA's TwinView either.https://imgur.com/oLbpaWV
This issue was caused by the GDM3 display manager. After switching to a greeter and desktop environment that does not use GDM3 (specifically MATE), Xinerama works just fine. I was finally able to log into the Desktop.