/**
* @author alteredq / http://alteredqualia.com/
*
* Film grain & scanlines shader
*
* - ported from HLSL to WebGL / GLSL
* http://www.truevision3d.com/forums/showcase/staticnoise_colorblackwhite_scanline_shaders-t18698.0.html
*
* Screen Space Static Postprocessor
*
* Produces an analogue noise overlay similar to a film grain / TV static
*
* Original implementation and noise algorithm
* Pat 'Hawthorne' Shearon
*
* Optimized scanlines + noise version with intensity scaling
* Georg 'Leviathan' Steinrohder
*
* This version is provided under a Creative Commons Attribution 3.0 License
* http://creativecommons.org/licenses/by/3.0/
*/
THREE.FilmShader = {
uniforms: {
"tDiffuse": { value: null },
"time": { value: 0.0 },
"nIntensity": { value: 0.5 },
"sIntensity": { value: 0.05 },
"sCount": { value: 4096 },
"grayscale": { value: 1 }
},
vertexShader: [
"varying vec2 vUv;",
"void main() {",
"vUv = uv;",
"gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
"}"
].join( "\n" ),
fragmentShader: [
"#include <common>",
// control parameter
"uniform float time;",
"uniform bool grayscale;",
// noise effect intensity value (0 = no effect, 1 = full effect)
"uniform float nIntensity;",
// scanlines effect intensity value (0 = no effect, 1 = full effect)
"uniform float sIntensity;",
// scanlines effect count value (0 = no effect, 4096 = full effect)
"uniform float sCount;",
"uniform sampler2D tDiffuse;",
"varying vec2 vUv;",
"void main() {",
// sample the source
"vec4 cTextureScreen = texture2D( tDiffuse, vUv );",
// make some noise
"float dx = rand( vUv + time );",
// add noise
"vec3 cResult = cTextureScreen.rgb + cTextureScreen.rgb * clamp( 0.1 + dx, 0.0, 1.0 );",
// get us a sine and cosine
"vec2 sc = vec2( sin( vUv.y * sCount ), cos( vUv.y * sCount ) );",
// add scanlines
"cResult += cTextureScreen.rgb * vec3( sc.x, sc.y, sc.x ) * sIntensity;",
// interpolate between source and result by intensity
"cResult = cTextureScreen.rgb + clamp( nIntensity, 0.0,1.0 ) * ( cResult - cTextureScreen.rgb );",
// convert to grayscale if desired
"if( grayscale ) {",
"cResult = vec3( cResult.r * 0.3 + cResult.g * 0.59 + cResult.b * 0.11 );",
"}",
"gl_FragColor = vec4( cResult, cTextureScreen.a );",
"}"
].join( "\n" )
};
