Initial commit

js/FilmGrainPass.js

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+/**
+ * @author rezmason
+ */
+
+THREE.FilmGrainPass = function (blurMagnitude, ditherMagnitude) {
+  this.shader = {
+    uniforms: {
+      tDiffuse: { value: null },
+      blurMagnitude: { value: blurMagnitude },
+      ditherMagnitude: { value: ditherMagnitude }
+    },
+
+    vertexShader: `
+      varying vec2 vUv;
+      void main() {
+        vUv = uv;
+        gl_Position = vec4( position, 1.0 );
+      }
+    `,
+
+    fragmentShader: `
+      #define PI 3.14159265359
+
+      uniform sampler2D tDiffuse;
+      uniform float blurMagnitude;
+      uniform float ditherMagnitude;
+      varying vec2 vUv;
+
+      highp float rand( const in vec2 uv ) {
+        const highp float a = 12.9898, b = 78.233, c = 43758.5453;
+        highp float dt = dot( uv.xy, vec2( a,b ) ), sn = mod( dt, PI );
+        return fract(sin(sn) * c);
+      }
+
+      vec3 dithering( vec3 color1, vec3 color2 ) {
+        float difference = pow(length(color1 - color2), 0.1);
+        return color1 + vec3( -1, 0.5, 0.5 ) * ditherMagnitude * difference * mix( -1.0, 1.0, rand( gl_FragCoord.xy ) );
+      }
+
+      void main() {
+        vec4 sample = texture2D( tDiffuse, vUv );
+        vec4 blurSum = vec4( 0.0 );
+
+        blurSum += texture2D( tDiffuse, vUv + vec2(-blurMagnitude, -blurMagnitude) ) * 0.25;
+        blurSum += texture2D( tDiffuse, vUv + vec2( blurMagnitude, -blurMagnitude) ) * 0.25;
+        blurSum += texture2D( tDiffuse, vUv + vec2(-blurMagnitude,  blurMagnitude) ) * 0.25;
+        blurSum += texture2D( tDiffuse, vUv + vec2( blurMagnitude,  blurMagnitude) ) * 0.25;
+
+        gl_FragColor = vec4(dithering(blurSum.rgb, sample.rgb), 1.0);
+      }
+    `
+  };
+
+  THREE.ShaderPass.call(this, this.shader);
+};
+
+THREE.FilmGrainPass.prototype = Object.assign( Object.create( THREE.Pass.prototype ), {
+  constructor: THREE.FilmGrainPass,
+  render: THREE.ShaderPass.prototype.render
+});