Local Shadertoy

A program to run and develop your shadertoy shaders locally!

The project is under active development. It is possible to run shadertoy shaders, but iChannels are currently not supported.

I am adding them in future.

How to use

You need to have rust installed.

Clone this repository and run

cargo install --path .

After the installation, the shadertoy command should be available (make sure, cargo binaries are available in $PATH).

Run a shader with the command

shadertoy -s shader.glsl

Like mentioned above, shaders are compatible with the shadertoy.com style. This project supports live reloading. Happy coding!

I am new to shader programming, how can I start?

Get to know the GLSL Website. This is the ground truth to know about, but in my opinion not the most efficient way to learn shader programming.

I recommend to follow this blog and use shadertoy.com for writing your first shaders. You can also use this program to run your shadertoy shaders locally and use your favourite development environment for it.

Minimal Shader

// Frag Color is the color to paint the pixel in, fragCoord is the coordinate of the pixel to paint
void mainImage(out vec4 fragColor, in vec2 fragCoord) {
    // Just paint every pixel green
    fragColor = vec4(vec3(0., 1., 0.), 1.);
}

Official Shadertoy.com Example

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord/iResolution.xy;

    // Time varying pixel color
    vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx+vec3(0,2,4));

    // Output to screen
    fragColor = vec4(col,1.0);
}

Exposed Variables

• iResolution: A vec2 for the window width and height
• iTime: A floating point number which holds the time the program runs in seconds
• iMouse: A vec4 which holds the x and y coordinates of the mouse in the first two dimensions when clicked
• iFrame: Holds the count of the frame that will be displayed (integer)
• iFrameRate: Holds the frame rate of the window (float)