Load a Shader From a File

Experimental

Visuals are experimental. Expect breaking changes to shaders, operators and the visuals window.

A shader longer than a few lines is easier to write in its own .glsl file, where your editor’s GLSL support works on it. In VSCode, install a GLSL extension such as Shader languages support.

Load the file

use "std/visuals" as gfx;

let v = gfx.load_shader("plasma", "shaders/plasma.glsl");
v >> screen;
PLAY;

The path is relative to the .non file that runs the line. The file holds the same GLSL you would put in a string: #version 300 es, a precision, and an out vec4.

With a visuals window open, a compile error in the shader is marked in the .glsl file, on the line you wrote.

Reload it after an edit

Nothing watches the file. After you save it, run the gfx.load_shader line again: the file is read again, and the visual named plasma takes the new shader, keeping its wiring and its bound uniforms.

Share GLSL between shaders

A shader’s source is a string, so build it from parts. load_file reads a file as a string, with the same relative path:

use "std/visuals" as gfx;

let lib = load_file("shaders/lib.glsl");   // #version, precision and shared functions
let v = gfx.Visual("plasma", lib + load_file("shaders/plasma-main.glsl"));
v >> screen;

A shader built with gfx.Visual has no file of its own, so its compile errors are marked on the >> screen line, and the message gives the line number within the whole string.

Related

• load_shader — the function in the reference
• Your First Shader — writing a shader, from the start