bytev-charts/lib/plugin/three.js/examples/js/shaders/VignetteShader.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.VignetteShader: 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.");
/**
 * Vignette shader
 * based on PaintEffect postprocess from ro.me
 * http://code.google.com/p/3-dreams-of-black/source/browse/deploy/js/effects/PaintEffect.js
 */

THREE.VignetteShader = {
  uniforms: {
    "tDiffuse": {
      value: null
    },
    "offset": {
      value: 1.0
    },
    "darkness": {
      value: 1.0
    }
  },
  vertexShader: ["varying vec2 vUv;", "void main() {", "	vUv = uv;", "	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );", "}"].join("\n"),
  fragmentShader: ["uniform float offset;", "uniform float darkness;", "uniform sampler2D tDiffuse;", "varying vec2 vUv;", "void main() {", // Eskil's vignette
  "	vec4 texel = texture2D( tDiffuse, vUv );", "	vec2 uv = ( vUv - vec2( 0.5 ) ) * vec2( offset );", "	gl_FragColor = vec4( mix( texel.rgb, vec3( 1.0 - darkness ), dot( uv, uv ) ), texel.a );",
  /*
  // alternative version from glfx.js
  // this one makes more "dusty" look (as opposed to "burned")
  	"	vec4 color = texture2D( tDiffuse, vUv );",
  "	float dist = distance( vUv, vec2( 0.5 ) );",
  "	color.rgb *= smoothstep( 0.8, offset * 0.799, dist *( darkness + offset ) );",
  "	gl_FragColor = color;",
  */
  "}"].join("\n")
};