bytev-charts/lib/plugin/three.js/examples/js/shaders/FilmShader.js

基于echarts和JavaScript及ES6封装的一个可以直接调用的图表组件库，内置主题设计，简单快捷，且支持用户自定义配置； npm 安装方式: npm install bytev-charts 若启动提示还需额外install插件,则运行 npm install @babel/runtime-corejs2 即可;

import "core-js/modules/es.array.join.js";
console.warn("THREE.FilmShader: As part of the transition to ES6 Modules, the files in 'examples/js' were deprecated in May 2020 (r117) and will be deleted in December 2020 (r124). You can find more information about developing using ES6 Modules in https://threejs.org/docs/#manual/en/introduction/Installation.");
/**
 * 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")
};