RetroArch shaders

Leaf includes a small, curated set of GLSL shader presets for RetroArch games. Nothing switches on by itself. A fresh install shows the original picture until you pick a preset.

Shaders only affect games running through RetroArch. Standalone emulators like DraStic, PPSSPP, Mupen64Plus, and Flycast have their own video settings.

Load a bundled preset

1. Launch a game that uses RetroArch.
2. Press MENU, then open RetroArch Settings.
3. Open Quick Menu → Shaders and turn Video Shaders on.
4. Choose Load Preset.
5. Open leaf-recommended/ and pick a .glslp preset.
6. Choose Apply Changes to see it.

There are nine to choose from:

• Sharp Pixels keeps pixel art crisp at any scale, with no CRT effect. A good first choice if you are not sure what you want.
• Subtle Scanlines adds light scanlines without much of the usual darkening. Suits NES, SNES, Mega Drive, PC Engine, and PlayStation.
• GBA Color tames colors that were authored for the original Game Boy Advance screen, which look oversaturated on a modern panel. GBA games only.
• GBC Color does the same for the softer response of a Game Boy Color screen. GBC games only.
• Game Boy LCD, Game Boy Color LCD, and Game Boy Advance LCD go further than the color presets. Each simulates the handheld’s actual display, with a faint backing texture and a cheap pixel grid tuned per system.
• Sharp Shimmerless is the one to reach for when a game lands on an awkward non-integer scale and scrolling starts to shimmer.
• CRT Lite applies a mild aperture mask and softened scanlines. Aimed at 8-bit, 16-bit, and PlayStation-era games.

All nine passed Leaf’s visual checks and a 60-second performance test on the MLP1, but a couple carry caveats worth knowing before you save one.

GBA Color is cleared for 60 Hz, and for 120 Hz as long as Black Frame Insertion is off. That is not really the shader’s doing: mGBA drops below full speed at 120 Hz with BFI even when no shader is running at all, so keep those two apart regardless.

CRT Lite also wants BFI off. A PlayStation test with both enabled fell to around 50 fps, against full speed at 60 Hz and 120 Hz with BFI off.

Both of those results were measured at 120 Hz. Black Frame Insertion is also available at 100 Hz for 50fps (PAL) games, which asks for fewer frames per second and so should be easier on a core, but these shaders have not been tested there - if a PAL game with a shader runs short of full speed, turn BFI off first.

Worth remembering generally: scanlines and BFI each cost you some brightness, and using both costs more.

Going further

The leaf-bundled/ folder holds the qualified advanced presets the recommended ones are built from. Everything there loads and renders correctly, but that is a lower bar than the recommended set clears, and it says nothing about how a given preset performs on a particular core or game.

The bundle also carries a few candidates kept traceable to where they came from:

• PT SkyWalker541, a low-power handheld LCD and pixel-transparency shader with Game Boy, Game Boy Color, and Game Boy Advance modes.
• Sharp Shimmerless, built for sharp non-integer scaling without shimmer on small screens.
• CRT Hyllian Fast and CRT Lottes Fast, two lightweight CRT options.

The first three cleared testing against real game content and are what the recommended presets are made from. CRT Lottes Fast did not. It loads safely enough, but it managed only about 34 fps on Leaf’s deliberately lightweight test scene, so it stays in the advanced folder. Treat that as a warning about the folder in general: try a preset on demanding content before you save it globally.

Download the full RetroArch collection

RetroArch’s Online Updater → Update GLSL Shaders downloads the complete official libretro GLSL collection. It appears under shaders_glsl/ beside Leaf’s two folders. The download is much larger and changes independently of Leaf, so those presets have not passed Leaf’s MLP1 performance or visual checks.

The folders have separate owners:

• leaf-recommended/ and leaf-bundled/ are refreshed by Leaf updates.
• shaders_glsl/ is refreshed by RetroArch’s updater.
• custom/ is yours.

Leaf updates preserve the updater and custom folders. Updating GLSL shaders does not overwrite Leaf’s pinned, tested dependencies.

Add your own shaders

Custom shader files go on the primary SD card, under:

.umrk/mlp1/retroarch/.config/retroarch/shaders/custom/

Booting from a single card, that is:

/mnt/sdcard/.umrk/mlp1/retroarch/.config/retroarch/shaders/custom/

With two cards in, Linux may mount the Leaf card at /media/sdcard1 instead, so treat the relative .umrk/.../shaders/custom/ path as the real answer and do not hardcode a mount point.

Keep each preset’s folder structure as you found it. A .glslp file often points at .glsl passes, LUT images, or other presets sitting next to it. Leaf already points Settings → Directory → Video Shaders at the parent shaders/ directory, so normally you only need to return to Quick Menu → Shaders → Load Preset and open custom/.

Leaf’s RetroArch build reads GLSL: .glslp presets and .glsl passes. Slang/Vulkan (.slangp, .slang) and Cg (.cgp, .cg) packs will not work. And because .umrk starts with a dot, macOS and Linux file managers hide it by default, so turn on hidden files before going looking for it.

One directory to leave alone: .system/leaf/platforms/mlp1/shaders/ is Leaf’s manifest-validated source bundle and is replaced on every update. The browser, updater collection, and personal shaders all live in durable .umrk/ state.

Saving and removing a shader

Once a preset looks right, Quick Menu → Shaders → Save Preset keeps it for the current game, the content directory, the core, or all RetroArch content. Pick the narrowest scope that does the job. A global preset has to suit systems with wildly different resolutions, and it will usually end up looking worse or running slower on some of them.

To go back to the plain image, open Quick Menu → Shaders, turn Video Shaders off, and save at the same scope you saved the preset at. Saving at a different scope leaves the original in place.

Fugazi and manual presets

Fugazi works by writing an automatic global CRT preset. Applying or clearing a look there rewrites that one preset, and leaves the bundled shaders and anything in your custom directory untouched.

So if a preset you chose by hand keeps reappearing after a relaunch, Fugazi probably has a global look applied. Clear it there first.

If the preset browser is empty

No items on an older Leaf release just means that release predates the shader bundle. Update Leaf, or put your own GLSL files in the custom directory above.

If it is still empty after updating, check Settings → Directory → Video Shaders. It should point to the durable .umrk/mlp1/retroarch/.config/retroarch/shaders/ root, not directly to one of its child folders. Fully exit and relaunch the game as well, which gives Leaf a chance to refresh that directory if two SD cards have swapped mount points. Failing all that, Settings → System → Reset RetroArch Config restores the default shader directory, but it resets your other RetroArch settings too, so try fixing the directory by hand first.