Team:Central Calgary/shaders/HorizontalBlurShader.js

/**

* @author zz85 / http://www.lab4games.net/zz85/blog
*
* Two pass Gaussian blur filter (horizontal and vertical blur shaders)
* - described in http://www.gamerendering.com/2008/10/11/gaussian-blur-filter-shader/
*   and used in http://www.cake23.de/traveling-wavefronts-lit-up.html
*
* - 9 samples per pass
* - standard deviation 2.7
* - "h" and "v" parameters should be set to "1 / width" and "1 / height"
*/

THREE.HorizontalBlurShader = {

uniforms: {

"tDiffuse": { type: "t", value: null }, "h": { type: "f", value: 1.0 / 512.0 }

},

vertexShader: [

"varying vec2 vUv;",

"void main() {",

"vUv = uv;", "gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",

"}"

].join("\n"),

fragmentShader: [

"uniform sampler2D tDiffuse;", "uniform float h;",

"varying vec2 vUv;",

"void main() {",

"vec4 sum = vec4( 0.0 );",

"sum += texture2D( tDiffuse, vec2( vUv.x - 4.0 * h, vUv.y ) ) * 0.051;", "sum += texture2D( tDiffuse, vec2( vUv.x - 3.0 * h, vUv.y ) ) * 0.0918;", "sum += texture2D( tDiffuse, vec2( vUv.x - 2.0 * h, vUv.y ) ) * 0.12245;", "sum += texture2D( tDiffuse, vec2( vUv.x - 1.0 * h, vUv.y ) ) * 0.1531;", "sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y ) ) * 0.1633;", "sum += texture2D( tDiffuse, vec2( vUv.x + 1.0 * h, vUv.y ) ) * 0.1531;", "sum += texture2D( tDiffuse, vec2( vUv.x + 2.0 * h, vUv.y ) ) * 0.12245;", "sum += texture2D( tDiffuse, vec2( vUv.x + 3.0 * h, vUv.y ) ) * 0.0918;", "sum += texture2D( tDiffuse, vec2( vUv.x + 4.0 * h, vUv.y ) ) * 0.051;",

"gl_FragColor = sum;",

"}"

].join("\n")

};