webgl实现canvas背景渐变动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：背景

代码描述：js结合webgl实现一个canvas背景渐变颜色更换柔和的动画效果代码

下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开

<!DOCTYPE html>
<html lang="en">

<head>

    <meta charset="UTF-8">





    <style>
        html,body {
          margin:0;
          padding:0;
          width:100%;
           height:100%;
        }
        #gradient-canvas {
          width:100%;
          height:100%;
          --gradient-color-1: #ef008f; 
          --gradient-color-2: #6ec3f4; 
          --gradient-color-3: #7038ff;  
          --gradient-color-4: #ffba27;
        }
    </style>



</head>

<body>
    <canvas id="gradient-canvas" data-js-darken-top data-transition-in>
          <!--
            Remove data-js-darken-top to keep the same brightness in the upper part of the canvas
          -->
        </canvas>



    <script>
        /*
        *   Stripe WebGl Gradient Animation
        *   All Credits to Stripe.com
        *   ScrollObserver functionality to disable animation when not scrolled into view has been disabled and 
        *   commented out for now.
        *   https://kevinhufnagl.com
        */
        
        
        //Converting colors to proper format
        function normalizeColor(hexCode) {
          return [(hexCode >> 16 & 255) / 255, (hexCode >> 8 & 255) / 255, (255 & hexCode) / 255];
        }["SCREEN", "LINEAR_LIGHT"].reduce((hexCode, t, n) => Object.assign(hexCode, {
          [t]: n }),
        {});
        
        //Essential functionality of WebGl
        //t = width
        //n = height
        class MiniGl {
          constructor(canvas, width, height, debug = false) {
            const _miniGl = this,
            debug_output = -1 !== document.location.search.toLowerCase().indexOf("debug=webgl");
            _miniGl.canvas = canvas, _miniGl.gl = _miniGl.canvas.getContext("webgl", {
              antialias: true }),
            _miniGl.meshes = [];
            const context = _miniGl.gl;
            width && height && this.setSize(width, height), _miniGl.lastDebugMsg, _miniGl.debug = debug && debug_output ? function (e) {
              const t = new Date();
              t - _miniGl.lastDebugMsg > 1e3 && console.log("---"), console.log(t.toLocaleTimeString() + Array(Math.max(0, 32 - e.length)).join(" ") + e + ": ", ...Array.from(arguments).slice(1)), _miniGl.lastDebugMsg = t;
            } : () => {}, Object.defineProperties(_miniGl, {
              Material: {
                enumerable: false,
                value: class {
                  constructor(vertexShaders, fragments, uniforms = {}) {
                    const material = this;
                    function getShaderByType(type, source) {
                      const shader = context.createShader(type);
                      return context.shaderSource(shader, source), context.compileShader(shader), context.getShaderParameter(shader, context.COMPILE_STATUS) || console.error(context.getShaderInfoLog(shader)), _miniGl.debug("Material.compileShaderSource", {
                        source: source }),
                      shader;
                    }
                    function getUniformVariableDeclarations(uniforms, type) {
                      return Object.entries(uniforms).map(([uniform, value]) => value.getDeclaration(uniform, type)).join("\n");
                    }
                    material.uniforms = uniforms, material.uniformInstances = [];
        
                    const prefix = "\n              precision highp float;\n            ";
                    material.vertexSource = `\n              ${prefix}\n              attribute vec4 position;\n              attribute vec2 uv;\n              attribute vec2 uvNorm;\n              ${getUniformVariableDeclarations(_miniGl.commonUniforms, "vertex")}\n              ${getUniformVariableDeclarations(uniforms, "vertex")}\n              ${vertexShaders}\n            `,
                    material.Source = `\n              ${prefix}\n              ${getUniformVariableDeclarations(_miniGl.commonUniforms, "fragment")}\n              ${getUniformVariableDeclarations(uniforms, "fragment")}\n              ${fragments}\n            `,
                    material.vertexShader = getShaderByType(context.VERTEX_SHADER, material.vertexSource),
                    material.fragmentShader = getShaderByType(context.FRAGMENT_SHADER, material.Source),
                    material.program = context.createProgram(),
                    context.attachShader(material.program, material.vertexShader),
                    context.attachShader(material.program, material.fragmentShader),
                    context.linkProgram(material.program),
                    context.getProgramParameter(material.program, context.LINK_STATUS) || console.error(context.getProgramInfoLog(material.program)),
                    context.useProgram(material.program),
                    material.attachUniforms(void 0, _miniGl.commonUniforms),
                    material.attachUniforms(void 0, material.uniforms);
                  }
                  //t = uniform
                  attachUniforms(name, uniforms) {
                    //n  = material
                    const material = this;
                    void 0 === name ? Object.entries(uniforms).forEach(([name, uniform]) => {
                      material.attachUniforms(name, uniform);
                    }) : "array" == uniforms.type ? uniforms.value.forEach((uniform, i) => material.attachUniforms(`${name}[${i}]`, uniform)) : "struct" == uniforms.type ? Object.entries(uniforms.value).forEach(([uniform, i]) => material.attachUniforms(`${name}.${uniform}`, i)) : (_miniGl.debug("Material.attachUniforms", {
                      name: name,
                      uniform: uniforms }),
                    material.uniformInstances.push({
                      uniform: uniforms,
                      location: context.getUniformLocation(material.program, name) }));
        
                  }} },
        
        
              Uniform: {
                enumerable: !1,
                value: class {
                  constructor(e) {
                    this.type = "float", Object.assign(this, e);
                    this.typeFn = {
                      float: "1f",
                      int: "1i",
                      vec2: "2fv",
                      vec3: "3fv",
                      vec4: "4fv",
                      mat4: "Matrix4fv" }[
                    this.type] || "1f.........完整代码请登录后点击上方下载按钮下载查看