Not really smooth: Doom can be played in a PDF file

Not really smooth: Doom can be played in a PDF file 45 comments

Image: DoomPDF

A really popular sport among developers is the attempt to make the legendary first-person shooter Doom run on platforms that look as strange as possible. After vending machines, robot lawn mowers and thermostats, Doom is now found in a file format: DoomPDF allows you to photograph monsters in the form of a PDF file.

This is made possible because the PDF format also supports Javascript, as explained by programmer ading2210, who published the code behind the DoomPDF project on Github. “C code can be compiled to run in a PDF using an older version of Emscripten that targets asm.js instead of WebAssembly,” the developer writes. The biggest challenge was getting a frame buffer fast enough.

Instead of assigning a single text field to each of the game’s 320 x 200 pixels, which was not feasible, a separate text field is used per line. Graphics are implemented as 6-color monochrome output using various ASCII characters. While this is enough to detect something and make Doom basically playable, the refresh rate is very slow, at 80ms per frame.

If you want to try DoomPDF, you can access the file via the URL doompdf.pages.dev/doom.pdf. A Chromium-based browser is recommended for this. The game can be controlled using the mouse using an on-screen keyboard or directly using the keyboard. However, it’s not fun because of the slow reactions.

Doom worked on the most unlikely devices

id Software’s 30-year-old first-person shooter has been able to run in strange environments since the source code was released. Well-known examples include ports of Doom on ATMs, refrigerators, and calculators. But the developers didn’t even stop at medical devices and robot lawn mowers.

Although Doom is the best example of this kind of gimmick, other classics are also made playable in unfamiliar environments. For example, the strategy game Civilization can be played in an Excel spreadsheet.

Topics: Action Games Doom First Person Shooter Games PDF Source: The Register