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Mini Shell
Mini Shell
/**
* @author felixturner / http://airtight.cc/
*
* Bad TV Shader
* Simulates a bad TV via horizontal distortion and vertical roll
* Uses Ashima WebGl Noise: https://github.com/ashima/webgl-noise
*
* time: steadily increasing float passed in
* distortion: amount of thick distortion
* distortion2: amount of fine grain distortion
* speed: distortion vertical travel speed
* rollSpeed: vertical roll speed
*/
THREE.BadTVShader = {
uniforms: {
"tDiffuse": { type: "t", value: null },
"time": { type: "f", value: 0.0 },
"distortion": { type: "f", value: 3.0 },
"distortion2": { type: "f", value: 5.0 },
"speed": { type: "f", value: 0.2 },
"rollSpeed": { type: "f", value: 0.1 },
},
vertexShader: [
"varying vec2 vUv;",
"void main() {",
"vUv = uv;",
"gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
"}"
].join("\n"),
fragmentShader: [
"uniform sampler2D tDiffuse;",
"uniform float time;",
"uniform float distortion;",
"uniform float distortion2;",
"uniform float speed;",
"uniform float rollSpeed;",
"varying vec2 vUv;",
// Start Ashima 2D Simplex Noise
"vec3 mod289(vec3 x) {",
" return x - floor(x * (1.0 / 289.0)) * 289.0;",
"}",
"vec2 mod289(vec2 x) {",
" return x - floor(x * (1.0 / 289.0)) * 289.0;",
"}",
"vec3 permute(vec3 x) {",
" return mod289(((x*34.0)+1.0)*x);",
"}",
"float snoise(vec2 v)",
" {",
" const vec4 C = vec4(0.211324865405187, // (3.0-sqrt(3.0))/6.0",
" 0.366025403784439, // 0.5*(sqrt(3.0)-1.0)",
" -0.577350269189626, // -1.0 + 2.0 * C.x",
" 0.024390243902439); // 1.0 / 41.0",
" vec2 i = floor(v + dot(v, C.yy) );",
" vec2 x0 = v - i + dot(i, C.xx);",
" vec2 i1;",
" i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);",
" vec4 x12 = x0.xyxy + C.xxzz;",
" x12.xy -= i1;",
" i = mod289(i); // Avoid truncation effects in permutation",
" vec3 p = permute( permute( i.y + vec3(0.0, i1.y, 1.0 ))",
" + i.x + vec3(0.0, i1.x, 1.0 ));",
" vec3 m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy), dot(x12.zw,x12.zw)), 0.0);",
" m = m*m ;",
" m = m*m ;",
" vec3 x = 2.0 * fract(p * C.www) - 1.0;",
" vec3 h = abs(x) - 0.5;",
" vec3 ox = floor(x + 0.5);",
" vec3 a0 = x - ox;",
" m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );",
" vec3 g;",
" g.x = a0.x * x0.x + h.x * x0.y;",
" g.yz = a0.yz * x12.xz + h.yz * x12.yw;",
" return 130.0 * dot(m, g);",
"}",
// End Ashima 2D Simplex Noise
"void main() {",
"vec2 p = vUv;",
"float ty = time*speed;",
"float yt = p.y - ty;",
//smooth distortion
"float offset = snoise(vec2(yt*3.0,0.0))*0.2;",
// boost distortion
"offset = pow( offset*distortion,3.0)/distortion;",
//add fine grain distortion
"offset += snoise(vec2(yt*50.0,0.0))*distortion2*0.001;",
//combine distortion on X with roll on Y
"gl_FragColor = texture2D(tDiffuse, vec2(fract(p.x + offset),fract(p.y-time*rollSpeed) ));",
"}"
].join("\n")
};
Zerion Mini Shell 1.0