Someone made a port of Doom that runs in a PDF

I'm just...

https://github.com/ading2210/doompdf

Same person got Linux working inside a PDF document

An entire kernel and OS running in a PDF. What a time to be alive

https://github.com/ading2210/linuxpdf

@cypnk can this Linux in a PDF also run a PDF viewer?

@dfaulkner
"It's PDF viewers the whole way down!"
@cypnk

@xinit @dfaulkner @cypnk

And we thought Conways Game of Life implementing and/or/not gates was cool, because you could, in theory, build up a computer to to run Life.

Now we've got PDF Inception, where, like the movie, we realize that time runs slower the more VMs you run inside each other.

And we thought Conways Game of Life implementing and/or/not gates was cool, because you could, in theory, build up a computer to to run Life.

In theory?



CC: @xinit@mastodon.coffee @dfaulkner@mastodon.social @cypnk@masto.hackers.town

@cypnk i see your "doom/linux running in PDF" and raise you "Pokémon running in a font" https://www.coderelay.io/fontemon.html

@cypnk

Very cool.
Also terrifying.

Raises serious questions about using PDF as a document format.

I guess my big question is how many PDF viewers are defaulted to run this kind of code in a PDF?

One would hope that most have this turned off by default?
🤨

@TerryHancock @cypnk

PDF is descended from Postscript (with extras to make it device-independent).

Postscript is a programming language (in the stack-based Forth-like family) and is Turing-complete.

This was ALWAYS going to happen eventually.

(There is no way to turn off the language functionality in PDF without stopping it from displaying documents at all.)

@cypnk I mean, cool but… why?

@Wrewdison @cypnk To show that it can be done. So that when some time in the future it's actually useful or necessary for something like a PDF to have its own inbuilt operating system, there's already knowledge out there somewhere of how to do it and maybe someone who hears of the problem will have the transferable skills to solve it.

It's like learning a bit of Latin. Nobody actually speaks the language, but it comes in very useful in the "what does this bizarre word mean?" section of pub quizzes.

@Daveosaurus @Wrewdison @cypnk No. Linux, even a massively stripped down Linux, is not a practical OS to run on the castrated JavaScript inside Acrobat.

@yacc143 @Daveosaurus @cypnk Kinda what I was thinking. Like.. ok it runs but... why? I mean a viable response is "because I wanted to" - or "because I could" - but it doesn't make my question any less valid.

@Wrewdison
Yeah, it's a bit like the Linux port to the 4004 which made in a way sense (the moon lander computer is an iconic step), but it was a) obviously unusable (week long booting into init) and b) not a real port, it was actually an implementation of a MIPS emulator on 4004.

It was basically a "look I can cross the Atlantic by swimming, I'm the greatest". No even if that happens it will not start a trend for Atlantic crossings.
@Daveosaurus @cypnk

@yacc143 @Wrewdison @Daveosaurus @cypnk porting Linux to something by emulating some other ISA is liking swimming across the atlantic in a pool on a boat...

@Wrewdison
But to answer your question why, ego.

It's basically why many stupid only seldom useful things are done.
@Daveosaurus @cypnk