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.

Filters

Gaussian blur

Barrel Blur Chroma

Barrel & Pincushion

Bicubic Filter

Bilateral Filter (denoise)

Contrast, Saturation, Brightness

Dithering

Edge filter

Metaballs

Droste

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 );

  // Applie 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!

Note: It is possible to port other types of shaders, but this repository focuses on filters.

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)