https://github.com/user-attachments/assets/f7fd0b61-ae9d-443c-b0ed-82120da5fe03

rdoom

{rdoom} is a playable version of Doom for R. This package includes the demo game, but it should also work with the game .wad file for DoomI, DoomII and related games.

This is a technical demonstration for the rendering speed and interactivity of tigerfb.

{tigerfb} is a cross-platform framebuffer for R which enables realtime, interactive graphical displays in R with mouse & keyboard input.

It uses:

• doomgeneric as the game engine. A fork of the original Doom source code.
• {tigerfb} as the framebuffer for R
• {nara} for fast native raster image support
• {audio} for playing sound effects

This code should run on macos, linux and windows platforms (but has only been extensively tested on macos).

Suggested way to run this on all platforms:

install.packages(c('nara'))                # Backend render surface
install.packages(c('audio'))               # Sound support
pak::pkg_install('coolbutuseless/tigerfb') # Framebuffer
pak::pkg_install('coolbutuseless/rdoom')   # This doom engine

# Run with the demo WAD file
rdoom::doom()

Quirks

Mouse control

The mouse control is a bit awkward. This doom engine is expecting that the mouse movement delta between frames is always available. However the framebuffer library being used by {tigerfb} only supports reading the mouse cursor position on the screen. This means that when the mouse hits the edge of the screen, the movement input will fail.

Fix: the best interim fix I implemented is that mouse movement in the bottom fraction of the screen does not act as input to the game. This means you can re-centre the mouse by moving it low-down on the screen.

Cheat Codes

Most cheat codes won’t work directly because of the way keyboard handling is coordinated between the doom engine and the frame buffer provided by {tigerfb}

To enter a cheat code, such as iddqd, you need to do the following:

1. Press F9 to temporarily disable control via the keyboard
2. Type i, d, d, q, d
3. Press F10 to re-enable the keyboard controls

Audio

For sound effects, {rdoom} exploits the fact that the {audio} package can play sound asynchronously.

The downside of the {audio} package is that it only does basic additive sound mixing, so when multiple sounds play at the same time, the combined magnitude exceeds the limit of the audio device and clipping makes it all sound awful.

To workaround this, all audio samples have been scaled to a lower volume, and there is a minimum 0.1 second window between sound triggers.

This means that sound may be softer than expected, and when many sounds are triggered to play simultaneously some of them will just go missing.