upgrade-instructions.txt

As part of my efforts to package LightField, it has been necessary to relocate... well,
nearly everything in order to integrate it into the system properly.

Old Directory                                       New Directory
/home/lumen/Volumetric/model-library/               /var/lib/lightfield/model-library/
/home/lumen/Volumetric/working/                     /var/cache/lightfield/print-jobs/
/home/lumen/Volumetric/debug/                       /var/log/lightfield/
/home/lumen/Volumetric/LightField/stdio-shepherd/   /usr/share/lightfield/libexec/stdio-shepherd/
/home/lumen/Volumetric/printrun/                    /usr/share/lightfield/libexec/printrun/

To upgrade a Lumen X printer to the "new way" of doing things, I have written two scripts.

At the moment I can't get setpower--now known as set-projector-power to avoid any potential
name clashes--to build on Ubuntu, either on my printer or in my Ubuntu VM, so it will be
necessary to reuse the existing setpower binary for the meantime.

Both of the scripts MUST be run with sudo, or they will fail horribly, although they won't
mess anything up.

The first script is PrepareSystem, which undoes any symlinks from the new directories above
into /home/lumen/Volumetric, then moves any models, debug logs, and cached print jobs into
their new homes.

The second script is install-lightfield, which will build the debugging version of LightField,
install it, then reconfigure the system to automatically start X and LightField--without
GNOME--on tty1 at startup.

To start GNOME, after the system has been reconfigured:
* Press Ctrl+Alt+F2 to switch to tty2.
* Log in as user lumen.
* Run these two commands:
  * systemctl stop getty@tty1.service
    * startx
	* After exiting GNOME, run this command to return things to (the new) normal:
	  * systemctl start getty@tty1.service

	  To look at the debugging log:
	  * Press Ctrl+Alt+F2 to switch to tty2.
	  * Log in as user lumen.
	  * Change to directory /var/log/debug, the debugging logs' new home.