glsl-dither

Bayer matrix dithering in GLSL. Originally sourced from @oosmoxiecode's C64 Shader Demo, which in turn was based on the implementation in this article.

Usage

Each dithering function takes two arguments:

• pos: the position of the current pixel – you can use gl_FragCoord.xy directly in most cases.
• brightness: the current pixel's brightness, either as a float or a vec3|vec4 color directly.

The returned value will be the same type as the brightness parameter.

dither8x8(vec2 pos, vec3|vec4|float brightness)

Dither using a 8x8 matrix.

dither4x4(vec2 pos, vec3|vec4|float brightness)

Dither using a 4x4 matrix.

dither2x2(vec2 pos, vec3|vec4|float brightness)

Dither using a 2x2 matrix.

precision mediump float;

uniform sampler2D uTexture;
varying vec2 vUv;

// Use any of the following:
#pragma glslify: dither = require(glsl-dither)
#pragma glslify: dither = require(glsl-dither/8x8)
#pragma glslify: dither = require(glsl-dither/4x4)
#pragma glslify: dither = require(glsl-dither/2x2)

void main() {
  vec4 color = texture2D(uTexture, vUv);
  gl_FragColor = dither(gl_FragCoord.xy, color);
}

License

MIT. See LICENSE.md for details.