# GLSL Imports Import GLSL functions from NPM packages, your files, or URLs using `#include` — no copy-pasting shader code between nodes. `#include` works across most visual objects: [glsl](/docs/objects/glsl), [swgl](/docs/objects/swgl), [regl](/docs/objects/regl), [hydra](/docs/objects/hydra) (inside `setFunction`), and [three](/docs/objects/three) (via `await glsl` tagged template). Write a utility once, use it everywhere. ## How It Works The `#include` directive inlines GLSL source code at the include site before shader compilation. It works like the C preprocessor: resolve the path, fetch the source, paste it in. ```glsl #include void mainImage(out vec4 fragColor, in vec2 fragCoord) { float n = snoise(vec3(uv * 4.0, iTime)); fragColor = vec4(vec3(n), 1.0); } ``` This fetches the `snoise` function from the [lygia](https://lygia.xyz) shader library and makes it available in your code. No setup needed — includes are resolved automatically. ## Import Sources There are three ways to import GLSL code: ### NPM Packages Use angle brackets to import from shader libraries like lygia: ```glsl #include #include #include ``` The `.glsl` extension is optional — `` and `` are equivalent. ### Your Files Use double quotes with a `user://` path to import from your [Virtual Filesystem](/docs/virtual-filesystem) files: ```glsl #include "user://my-shaders/utils.glsl" #include "user://sdf-functions.glsl" ``` Upload `.glsl` files through the sidebar (`Ctrl/Cmd + B > Files`), then include them in any shader node. ### URLs Use double quotes with a full URL to import from anywhere on the web: ```glsl #include "https://raw.githubusercontent.com/stegu/psrdnoise/main/src/psrdnoise2.glsl" ``` URL imports are cached in memory for the session, so they only fetch once. ## Supported Objects `#include` works in five visual objects — most of them auto-preprocess your shaders, so you just write `#include` and it works: | Object | How it works | | --- | --- | | [glsl](/docs/objects/glsl) | Auto-preprocessed before shader compilation | | [swgl](/docs/objects/swgl) | Auto-preprocessed in `FP`, `VP`, and `Inc` fields | | [regl](/docs/objects/regl) | Auto-preprocessed in `frag` and `vert` fields | | [hydra](/docs/objects/hydra) | Auto-preprocessed inside `setFunction` GLSL strings | | [three](/docs/objects/three) | Use `await glsl` tagged template or `processIncludes()` | ### Hydra Usage Use `#include` inside `setFunction` to bring external GLSL into Hydra's shader pipeline: ```javascript osc() .setFunction({ type: "frag", glsl: ` #include vec4 myEffect(vec4 color, vec2 uv) { float n = snoise(vec3(uv * 4.0, time)); return vec4(vec3(n), 1.0); } `, }) .out() ``` ### Three.js Usage Three.js nodes can't auto-preprocess because Patchies doesn't control `THREE.ShaderMaterial`. Use the `await glsl` tagged template instead: ```javascript const material = new THREE.ShaderMaterial({ fragmentShader: await glsl` #include void main() { float n = snoise(vec3(vUv * 4.0, time)); gl_FragColor = vec4(vec3(n), 1.0); } `, }) ``` The `glsl` tag and `processIncludes()` function are available in all JavaScript-based visual objects. ## Try It ### Exercise — Use lygia noise in a GLSL shader 1. Create a `glsl` object (`Enter` > type `glsl`) 2. Paste this code: ```glsl #include void mainImage(out vec4 fragColor, in vec2 fragCoord) { float n = snoise(vec3(uv * 5.0, iTime * 0.5)); fragColor = vec4(vec3(n * 0.5 + 0.5), 1.0); } ``` 3. Connect to `bg.out` — you should see animated simplex noise ### Exercise — Share a utility across nodes 1. Open the sidebar (`Ctrl/Cmd + B > Files`) and create a file called `utils.glsl` 2. Add a helper function: ```glsl vec3 palette(float t) { return 0.5 + 0.5 * cos(6.28318 * (t + vec3(0.0, 0.33, 0.67))); } ``` 3. In a `glsl` object, include and use it: ```glsl #include "user://utils.glsl" void mainImage(out vec4 fragColor, in vec2 fragCoord) { fragColor = vec4(palette(uv.x + iTime * 0.2), 1.0); } ``` 4. Create a second `glsl` object and include the same file — both nodes share the function ## Nested Includes Included files can contain their own `#include` directives. Resolution is recursive up to 32 levels deep. Circular includes are detected and produce an error. ## Caching - **NPM packages** are fetched from a CDN and cached for the session - **VFS files** are re-read when changed, so edits are reflected immediately - **URLs** are cached for the session (reload the page to re-fetch) ## Licensing: Lygia Shader Library Lygia is dual licensed under the [Prosperity License](https://prosperitylicense.com/versions/3.0.0) and the [Lygia Patron License](https://lygia.xyz/license). This means that Lygia is free for non-commercial use, i.e. for personal use and usage in non-commercial organizations. For _commercial_ use, please purchase a license from the creator, Patricio Gonzalez Vivo on [GitHub Sponsors](https://github.com/sponsors/patriciogonzalezvivo). This does NOT apply to you if you do not import the Lygia package by using `#include ` in your shaders. You can still use Patchies and all its features without importing Lygia. ## See Also - [glsl](/docs/objects/glsl) — fragment shaders with Shadertoy-compatible uniforms - [swgl](/docs/objects/swgl) — SwissGL shaders - [regl](/docs/objects/regl) — WebGL with REGL - [three](/docs/objects/three) — Three.js scenes - [Virtual Filesystem](/docs/virtual-filesystem) — managing files for `user://` imports

Message	Description
`bang`	Start listening for MIDI input
`stop`	Stop listening for MIDI input
	Set device, channel, and event filter

Message	Description
	MIDI note on message
	MIDI note off message
	MIDI control change message
	MIDI program change message
	MIDI pitch bend message
	MIDI channel pressure message

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