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Texture Dithering
Just a sample to demonstrate texture-based grayscale dithering over some FBM clouds
Created by marcogomez on Tue, 28 Sep 2021 15:07:05 GMT.
#version 300 es // ╔═════════════╦════════════════╗ // ║ Marco Gomez ║ https://mgz.me ║ // ╚═════════════╩════════════════╝ precision highp float; uniform sampler2D prgm2Texture; uniform vec2 resolution; out vec4 fragColor; void main(void) { vec2 uv = gl_FragCoord.xy / resolution.xy; vec4 prgm2 = texture(prgm2Texture, uv); fragColor = prgm2; }
#version 300 es // ╔═════════════╦════════════════╗ // ║ Marco Gomez ║ https://mgz.me ║ // ╚═════════════╩════════════════╝ precision highp float; uniform sampler2D noiseTexture; uniform vec2 resolution; uniform float time; uniform float fft; out vec4 fragColor; const float PI = acos(-1.0); // π or acos(-1.0) or 180° const float TAU = PI * 2.0; // τ = π * 2 or 360° const mat2 m2 = mat2(0.80, -0.60, 0.60, 0.80); float gaussian(float z, float u, float o) { return ( 1.0 / (o * sqrt(TAU)) ) * exp(-(((z - u) * (z - u)) / (2.0 * (o * o)))); } vec3 gaussGrain(float t) { vec2 ps = vec2(1.0) / resolution.xy; vec2 uv = gl_FragCoord.xy * ps; float seed = dot(uv, vec2(12.9898, 78.233)); float noise = fract(sin(seed) * 43758.5453 + t); noise = gaussian(noise, 0.0, 0.5); return vec3(noise); } float noise(vec2 x) { vec2 p = floor(x); vec2 f = fract(x); f = f * f * (3.0 - 2.0 * f); float a = texture(noiseTexture, (p + vec2(0.5, 0.5 + fft * 0.25)) / 256.0, 0.0).x; float b = texture(noiseTexture, (p + vec2(1.5, 0.5 + fft * 0.25)) / 256.0, 0.0).x; float c = texture(noiseTexture, (p + vec2(0.5, 1.5 + fft * 0.25)) / 256.0, 0.0).x; float d = texture(noiseTexture, (p + vec2(1.5, 1.5 + fft * 0.25)) / 256.0, 0.0).x; return mix(mix(a, b, f.x), mix(c, d, f.x), f.y); } float fbm (vec2 uv) { float f = 0.0; f += 0.5000 * noise(uv); uv = m2 * uv * 2.02; f += 0.2500 * noise(uv); uv = m2 * uv * 2.03; f += 0.1250 * noise(uv); uv = m2 * uv * 2.01; f += 0.0625 * noise(uv); return f / 0.9375; } vec3 clouds(vec2 uv) { vec3 color; float t = time * 0.75; vec2 q = vec2( 0.0 ), r = vec2( 0.0 ); q.x = fbm(uv + t * 0.25); q.y = fbm(uv + vec2(1.0)); r.x = fbm(uv + q + vec2(1.7, 9.2) + 0.31 * t * 0.25); r.y = fbm(uv + q + vec2(8.3, 2.8) + 0.21 * t * 0.25); float f = fbm(uv + r); color = mix(vec3(1.0, 1.0, 1.0), vec3(0.3, 1.6, 1.6), clamp((f * f) * 2.0, 0.0, 1.0) + fft * 0.5); color = mix(color, vec3(0.4, 0.2, 0.16), clamp(length(q) + fft * 0.33, 0.0, 1.0)); color = mix(color, vec3(0.4, 0.7, 3.00), clamp(length(r.x) + fft * 0.33, 0.0, 1.0)); return color * color * color; } vec2 curve(vec2 uv) { uv *= 1.1; uv.x *= 1.0 + pow((abs(uv.y) / 5.0), 2.0); uv.y *= 1.0 + pow((abs(uv.x) / 5.0), 2.0); uv = (uv / 2.0) + 0.5; uv = uv * 0.92 + 0.08; return uv; } void main(void) { vec2 uv = gl_FragCoord.xy / resolution.y; uv.y *= (resolution.x / resolution.y) * -.0625 - 1.0; vec2 p = -1.0 + 2.0 * uv; p.x -= time * 0.0125; vec3 g = gaussGrain(time) * 0.04; vec3 col = clouds(p * 3.0) - g; fragColor = vec4(col, 1.0); }
#version 300 es // ╔═════════════╦════════════════╗ // ║ Marco Gomez ║ https://mgz.me ║ // ╚═════════════╩════════════════╝ precision highp float; uniform sampler2D ditherTexture; uniform sampler2D prgm1Texture; uniform vec2 resolution; uniform float time; out vec4 fragColor; void main(void) { vec2 uv = gl_FragCoord.xy / resolution.xy; float pixelSize = 4.0; vec2 pPixel = floor(gl_FragCoord.xy / pixelSize); vec2 pRes = floor(resolution.xy / pixelSize); vec2 pUV = pPixel / pRes; vec4 color = texture(prgm1Texture, pUV); float alpha = 1.0; vec2 tuv = gl_FragCoord.xy / 8.0; tuv *= 17.0; tuv = fract(tuv); vec4 tdither = texture(ditherTexture, tuv); vec4 lum = vec4(0.299, 0.587, 0.114, 0); float dither = dot(tdither, lum); float gs = dot(color, lum) * 0.3; gs = (gs - 0.5) * 1.2 + 0.5; vec3 col = vec3(step(dither, gs)); fragColor = vec4(col, alpha); }
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// ╔═════════════╦════════════════╗
// ║ Marco Gomez ║ https://mgz.me ║
// ╚═════════════╩════════════════╝
precision highp float;
uniform sampler2D prgm2Texture;
uniform vec2 resolution;
out vec4 fragColor;
void main(void) {
vec2 uv = gl_FragCoord.xy / resolution.xy;
vec4 prgm2 = texture(prgm2Texture, uv);
fragColor = prgm2;
}
96 fps 14ms
00:00:00.30
0.00