Shadyboy

A Nim shader toy, that is an OpenGL desktop application implemented in Nim allowing to run GLSL shaders from Shadertoy on the desktop with only little changes but potentially better performance than in the browser. Shaders can also be implemented in Nim and are translated to GLSL on-the-fly.

This is currently in alpha stage and only supports basic shadertoy.com shaders, which do not use more than one texture and no additional source files, sounds or maps.

Getting started

Build

nimble build -d:release

Run the included Nim examples

nimble run -d:release shadyboy-<name>

Run nimble examples to list available examples.

Run the included GLSL fragment shaders examples

nimble run -d:release shadyboy shaders/<name>.frag

You can also build the shadytoy program once and then use it to run the shader files:

nimble build -d:release shadyboy

And then:

./bin/shadytoy shaders/<name>.frag

Run shaders from shadertoy.com

• Find a shader you like on https://shadertoy.com, which only has one "Image" source code tab and doesn't use any textures, sounds or maps.
• Copy the shader code from the "Image" tab and save it to a file, e.g. shader.frag.
• Open the file in a source code editor and add the following code at the beginning of the file:

#version 410
precision highp float;

out vec4 fragColor;

uniform float iTime;
uniform float iFrame;
uniform vec3 iResolution;
uniform vec4 iMouse;
uniform sampler2D iChannel0;

// declare mainImage function here so we can have main at the top of the script
void mainImage(out vec4 fragColor, in vec2 fragCoord);

void main() {
    mainImage(fragColor, gl_FragCoord.xy);
}

Run the shader file with shadyboy as shown above, e.g.:

nimble run -d:release shadyboy shader.frag

Command-line Options

$ ./bin/shadyboy --help
Usage:
  shadyboy <shader>
  shadyboy (--help)

Arguments:
  <shader>              Fragment shader source path

Options:
  -x, --texture=<file>  Texture image file path
  -t, --title=<title>   Window title
  -w, --width=<px>      Window width in pixels [default: 800]
  -h, --height=<px>     Window height in pixels [default: 600]
  -v, --verbose...      Verbose output
      --help            Show help message

Interactive Controls

Control	Action
ESC / q	Quit program
F11 / f	Toggle full-screen window
SPACE	Toggle pause animation timer (iTime) and frame counter (iFrame)
Left mouse click-and-drag	Manipulate iMouse shader uniform (how does it work?)

Requirements

Building

Dependencies besides Nim, nimble and the C compiler itself are automatically resolved and installed by nimble.

• Nim 2.0+ and nimble
• opengl
• windy
• pixie
• shady
• therapist
• vmath

Runtime

• libc (dynamically linked)
• OpenGL (libGL)*
• libX11* (Linux)
• libXext* (Linux)

* Loaded dynamically via dlopen.