Shaders and 3dfx

Shaders & 3dfx

EmuDOS can make games look like they did on a CRT, and can render 3dfx/Voodoo titles through your graphics card.

CRT shaders

EmuDOS runs the libretro slang shader collection — the same CRT, scanline, and monochrome-monitor shaders used by RetroArch — on the GPU via librashader.

Getting the shaders

They're a large, one-time download (the pack is big and licensed separately, so it isn't bundled):

1. Open Preferences → Downloads.
2. Find CRT shaders (just below Controller names) and click Download.

This fetches the shader pack and the librashader engine into your data folder. Once it says Installed, the shaders are ready.

Using them

• While a game is running, press the shader key (default F3, rebindable in Preferences → Hotkeys) to cycle through Off → the CRT presets, live.
• The choice is remembered per game — set it once and it comes back next launch.
• Shaders are applied on the GPU before the picture reaches the screen, so they're also captured in screenshots and video recordings.

The shader key currently cycles the whole crt category of the pack, so you may step through quite a few presets. Find one you like and it sticks.

Hardware 3dfx (Voodoo / Glide)

Many late-90s DOS games could use a 3dfx Voodoo card for hardware-accelerated 3D. EmuDOS emulates the Voodoo and can render it through hardware OpenGL for a sharp, accelerated picture.

• It's on by default. Toggle it in Preferences → General → "Hardware 3dfx (OpenGL)".
• Non-3dfx games are unaffected — they keep using the normal software path.
• If your GPU can't provide an OpenGL context, EmuDOS quietly falls back to the core's software Voodoo, so nothing breaks.

Reaching a game's 3dfx mode

Every game enables 3dfx differently:

• Built-in / auto-detect — some games (e.g. later patched releases) detect the Voodoo automatically, or offer a "3dfx" option in their own setup. Just turn it on in the game.
• Separate executable — many games ship a dedicated 3dfx build (names like *3dfx*, glide, gl*). EmuDOS floats these to the top of the program picker (right-click a game → Choose program) so they're easy to find.
• Command-line switch — for games that take a flag like -3dfx, set it under the game's launch options.

Once the game is using Glide, EmuDOS's emulated Voodoo renders it on the GPU.