https://helium-3.es/wp-content/plugins/astroidz/assets/js/shaders/HorizontalBlurShader.js?ver=1.0.1

1/**
2 * @author zz85 / http://www.lab4games.net/zz85/blog
3 *
4 * Two pass Gaussian blur filter (horizontal and vertical blur shaders)
5 * - described in http://www.gamerendering.com/2008/10/11/gaussian-blur-filter-shader/
6 *   and used in http://www.cake23.de/traveling-wavefronts-lit-up.html
7 *
8 * - 9 samples per pass
9 * - standard deviation 2.7
10 * - "h" and "v" parameters should be set to "1 / width" and "1 / height"
11 */
12
13THREE.HorizontalBlurShader = {
14
15	uniforms: {
16
17		"tDiffuse": { value: null },
18		"h":        { value: 1.0 / 512.0 }
19
20	},
21
22	vertexShader: [
23
24		"varying vec2 vUv;",
25
26		"void main() {",
27
28			"vUv = uv;",
29			"gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
30
31		"}"
32
33	].join( "\n" ),
34
35	fragmentShader: [
36
37		"uniform sampler2D tDiffuse;",
38		"uniform float h;",
39
40		"varying vec2 vUv;",
41
42		"void main() {",
43
44			"vec4 sum = vec4( 0.0 );",
45
46			"sum += texture2D( tDiffuse, vec2( vUv.x - 4.0 * h, vUv.y ) ) * 0.051;",
47			"sum += texture2D( tDiffuse, vec2( vUv.x - 3.0 * h, vUv.y ) ) * 0.0918;",
48			"sum += texture2D( tDiffuse, vec2( vUv.x - 2.0 * h, vUv.y ) ) * 0.12245;",
49			"sum += texture2D( tDiffuse, vec2( vUv.x - 1.0 * h, vUv.y ) ) * 0.1531;",
50			"sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y ) ) * 0.1633;",
51			"sum += texture2D( tDiffuse, vec2( vUv.x + 1.0 * h, vUv.y ) ) * 0.1531;",
52			"sum += texture2D( tDiffuse, vec2( vUv.x + 2.0 * h, vUv.y ) ) * 0.12245;",
53			"sum += texture2D( tDiffuse, vec2( vUv.x + 3.0 * h, vUv.y ) ) * 0.0918;",
54			"sum += texture2D( tDiffuse, vec2( vUv.x + 4.0 * h, vUv.y ) ) * 0.051;",
55
56			"gl_FragColor = sum;",
57
58		"}"
59
60	].join( "\n" )
61
62};