What is Shaders
Shaders are efficient graphics filters that can greatly improve the rendering of old games. They can also be used to replicate the look and feel of old CRT monitors. You can even stack them to create your own effect. The possibilities are infinite.
RetroArch is shipped with a lot of shaders. There is an overwhelming array of them and we can't show all of them on this page.
Here are a few common examples:
Shaders can also be used to display the handheld border:
Shader languages and shader presets
Shaders are small programs, and they are written in specific programming languages. RetroArch supports 3 of these languages:
- CG: Old, deprecated format.
- GLSL: Shader format available to OpenGL.
- Slang: New and recommended shader format, when available. Compatible with Vulkan, Direct3D 10/11/12, OpenGL Core, WiiU and Metal renderers.
Depending on your platform and the way you have configured RetroArch, you need to use one of these shader types.
RetroArch is also able to stack these shaders to create a combined effect. These complex effects are saved with a special extension:
.cpg for CG
.glslp for GLSL
.slangp for Slang
The shader presets can also have parameters. This means that you can tweak them to fit your needs. You can watch our
Shader showcase videos on YouTube.
Shader Presets are combinations of one or more shaders. They can be loaded via Quick Menu -> Shaders -> Load Shader Preset and if you want to keep the shader in-between play sessions, you can save them as an "automatic" preset via Quick Menu -> Shaders -> Save -> Save Global/Core/Directory/Game Preset.
Global presets are automatically applied in any content for any core, while the Core presets are applied in any content for that specific core. Directory presets apply to all content in a certain folder and Game presets apply just to one game. Note that directory and game presets are also core specific.
If more than one automatic presets exist that could be applied, the most specific one wins out, so for example, if both a global and a game preset exists, the game preset will be used.
You can also save custom non-automatic shader presets via Quick Menu -> Shaders -> Save -> Save Shader Preset As, so if you create your "perfect" combination of shaders you can recall this at any time with Load Shader Preset then continue on to save it as an automatic preset. This will save time if using the same preset for multiple games or cores.
By default automatic presets will save to under /presets/"name-of-core"/"name-of-core/directory/game".glslp|slangp|cgp or presets/global.glslp|slangp|cgp in the shader directory while custom presets are saved in the base shader directory. The shader directoy can be changed via Settings -> Directory -> Video Shader.
There are plenty of user created default presets that come bundled with the RetroArch installation and these can be updated from Main Menu -> Online Updater -> Update Glsl|Slang|Cg Shaders (you can find these presets in the shaders_glsl|slang|cg subfolders of your shader directory)
[h2]Editing Shader Presets[/h2]
You can edit shader presets or build your own using these tools:
- Shader Passes: The number of shader passes to use.
For every shader pass you can configure:
- Shader #N: Path to a shader. All shaders must be of the same type (i.e. .glsl, .slang, or .cg).
- Shader #N Filter: Hardware filter used for scaling. "Don't Care" uses Settings -> Video -> Bilinear Scale.
- Shader #N Scale: Scale for this pass. The scale factor accumulates, i.e. 2x for first pass and 2x for second pass will give you a 4x total scale. The last pass in the chain then is streched to fullscreen using the Settings -> Video -> Bilinear Scale filter setting. Note: If the preset uses scaling methods which are not simple, (i.e. source scaling, same scaling factor for X/Y), the scaling factors displayed might not be correct.
Apply Changes: After changing shader settings, use this to apply changes. Changing shader settings is a somewhat expensive operation so it has to be done explicitly.
Shader Parameters: Shows the list of all tweakable shader parameters, which are previewed "live", i.e. without the need of hitting Apply Changes
Shader Parameters: Shows the list of all tweakable shader parameters, which are previewed "live", i.e. without the need of hitting Apply Changes
[h2]"Reference" Presets[/h2]
Presets can use a #reference "" directive, which will act as if the preset with the given path was loaded instead.
From the shader menu you can create such reference presets by first loading any shader preset and then immediately saving it as an automatic shader preset. If any changes were made to the menu preset, it'll be saved as a copy like usual.
If you make changes and still want a automatic preset to point to it, you can first save it as a custom preset and then immediately save an automatic preset. This allows you to change your custom preset without having to resave the automatic one every time.
Note that custom saved presets are always saved as copies and automatic presets cannot point to automatic presets. This is so we never get references to references (which are not supported).
[h2]Converting Cg shaders to GLSL[/h2]
In some cases, Cg shaders cannot be supported. This goes for OpenGL ES drivers, and when EGL OpenGL contexts are used (KMS mode for instance). Using Nvidia's
cgc compiler, you can convert Cg shaders to GLSL shaders with the
cg2glsl tool developed by us
here. It can convert single shaders as well as whole folder structures in batch. 100% compatibility is not guaranteed, but almost all shaders should work fine. Cg presets (.cgp) are not converted at the moment, but converting them is as simple as copying over the .cgp, rename it to .glslp and replace references to .cg files to .glsl.
If you have further questions you can find me on Discord with gadsby#6752
Don't forget to join our Steam Group! https://steamcommunity.com/groups/libretro
https://www.retroarch.com
https://docs.libretro.com/
