How can I duplicate my desktop and show it side-by-side on a single screen?

I have a custom VR device I'm testing and I'm looking to do something which should be simple with my desktop monitor settings. Essentially I want to go from a regular desktop, this:

To having this screen repeated side-by-side split down the middle, like this:

And it's literally just a real-time copy of the desktop.

For reference, I am using a 800 x 480 display, in case that's relevant.

Ideally I would like to put my computer permanently into this display mode, so that every time it boots up it's like this automatically.

2 Answers

Most of what I am writing will be coming from this SU question, or more specifically this answer.

Since you are using raspbian, you're going to have to use FakeXRandr, which has FakeXinerama built-in:

Download FakeXRandr from this link. Unzip the archive,cd ~/Downloads/fakexrandr-master and run

sudo make
sudo make install
sudo apt-get install xorg-dev libglu1-mesa-dev build-essential python3-gi python-gi-dev python-gi-cairo

You will now have the tool fakexrandr-manage available to use. Launch that from terminal, and you will see the following GUI to configure your monitor setup:

One post suggest this (Refer this link: (virtual) split screen on Ubuntu)

As far as I know you can only split your screen for two windows at a time. Either one on the left and one on the right, Or one on the top and one the bottom. And there are shortcuts associated for these actions which are:

For vertical split:

Ctrl + Win + ←→

For horizontal split:

Ctrl + Win + ↑↓

In in case this does not work As You have not mentioned you are using Ubuntu 16.04 or 18.04. You can refer this post "(virtual) split screen on Ubuntu" & "" Here FakeXRandR is suggested for 18.04.