Filters4Processing

A growing collection of pixel shaders ported to Processing to be used with the filter() function. Most of these shaders come from the excellent Shadertoy by Iñigo Quilez.

Note: This repository focuses on filters. If you want to port any other type of shader from Shadertoy to Processing, check out this other repository Shadertoy2Processing

Filters

Gaussian blur

Original shader by Callum Hay: http://callumhay.blogspot.com/2010/09/gaussian-blur-shader-glsl.html

Barrel Blur Chroma

Original shader by hornet: https://www.shadertoy.com/view/XssGz8

Barrel & Pincushion

Original shader by SanchYESS: https://www.shadertoy.com/view/4s2GRR

Bicubic Filter

Original shader by inigo quilez - iq/2013 (CC BY-NC-SA 3.0)

Bilateral Filter (denoise)

Original shader by mrharicot: https://www.shadertoy.com/view/4dfGDH

Contrast, Saturation, Brightness

Original shader by Romain Dura: http://mouaif.wordpress.com/?p=94

Dithering

Original shader by RavenWorks: https://www.shadertoy.com/view/Xs23zW

Edge filter

Original shader by Ken Slade: https://www.shadertoy.com/view/ldsSWr

Metaballs

Uses the blur shader by Callum Hay: http://callumhay.blogspot.com/2010/09/gaussian-blur-shader-glsl.html

Droste

Original shader by ArKano22: http://www.gamedev.net/topic/590070-glsl-droste/ (adapted by @monkstone)

Usage

This is a minimal example showing how to import a shader file in Processing and use it as a filter.

Note: Some shaders require additional uniforms. For details, refer to the example sketches included.

// Create an image object
PImage  myImage;

// Create a shader object
PShader myFilter;

void setup() {

  size( 512, 512, P2D );

  // Import the image file
  myImage  = loadImage( "texture.jpg" );

  // Import the shader file
  myFilter = loadShader( "shader.glsl" );

  // Pass the size of the window to the shader
  myFilter.set("sketchSize", float(width), float(height));

}

void draw() {

  // Draw the image on the scene
  image( myImage, 0, 0 );

  // Apply the shader to the scene
  filter( myFilter );

}

Notes about porting filters from Shadertoy

Shadertoy and Processing both have their own quirks when it comes to shader programming. We need to make some changes in order to make Shadertoy code work with Processing.

Replace: void mainImage( out vec4 fragColor, in vec2 fragCoord ) -> void main( void )

Replace all:

• iChannel0 -> texture
• fragCoord -> gl_FragCoord
• fragColor -> gl_FragColor

There is more to it than this but these tips should cover most basic filters.

Now go dig for some shaders and help us extend the library of filters available for Processing!

Acknowledgments

Thanks to all the Shadertoy contributors for their hard work. This collection wouldn't exist without them. Thanks to Andres Colubri for his work on the Processing Shader API.

License

All shaders from Shadertoy belong to there respective authors. Unless otherwise specified in the shader file, they are licensed under Creative Commons (CC BY-NC-SA 3.0)