canvas实现蓝色彩带飘动背景动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：动画

代码描述：canvas实现蓝色彩带飘动背景动画效果代码

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>
    * {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background-color: #000;
  overflow: hidden;
}

#holder {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}
</style>

</head>
<body>
<!-- partial:index.partial.html -->
<div id="holder"></div>
<!-- partial -->
  <script  >
      
      (function () {

  var pi = Math.PI;
  var pi2 = 2 * Math.PI;

  this.Waves = function (holder, options) {
    var Waves = this;

    Waves.options = extend(options || {}, {
      resize: false,
      rotation: 45,
      waves: 5,
      width: 100,
      hue: [11, 14],
      amplitude: 0.5,
      background: true,
      preload: true,
      speed: [0.004, 0.008],
      debug: false,
      fps: false,
    });

    Waves.waves = [];

    Waves.holder = document.querySelector(holder);
    Waves.canvas = document.createElement('canvas');
    Waves.ctx = Waves.canvas.getContext('2d');
    Waves.holder.appendChild(Waves.canvas);

    Waves.hue = Waves.options.hue[0];
    Waves.hueFw = true;
    Waves.stats = new Stats();

    Waves.resize();
    Waves.init(Waves.options.preload);

    if (Waves.options.resize)
      window.addEventListener('resize', function () {
        Waves.resize();
      }, false);

  };

  Waves.prototype.init = function (preload) {
    var Waves = this;
    var options = Waves.options;

    for (var i = 0; i < options.waves; i++)
      Waves.waves[i] = new Wave(Waves);

    if (preload) Waves.preload();
  };

  Waves.prototype.preload = function () {
    var Waves = this;
    var options = Waves.options;

    for (var i = 0; i < options.waves; i++) {
      Waves.updateColor();
      for (var j = 0; j < options.width; j++) {
        Waves.waves[i].update();
      }
    }
  };

  Waves.prototype.render = function () {
    var Waves = this;
    var ctx = Waves.ctx;
    var options = Waves.options;

    Waves.updateColor();
    Waves.clear();

    if (Waves.options.debug) {
      ctx.beginPath();
      ctx.strokeStyle = '#f00';
      ctx.arc(Waves.centerX, Waves.centerY, Waves.radius, 0, pi2);
      ctx.stroke();
    }

    if (Waves.options.background) {
      Waves.background();
    }

    each(Waves.waves, function (wave, i) {
      wave.update();
      wave.draw();
    });
  };

  Waves.prototype.animate = function () {
    var Waves = this;

    Waves.render();

    if (Waves.options.fps) {
      Waves.stats.log();
      Waves.ctx.font = '12px Arial';
      Waves.ctx.fillStyle = '#fff';
      Waves.ctx.fillText(Waves.stats.fps() + ' FPS', 10, 22);
    }

    window.requestAnimationFrame(Waves.animate.bind(Waves));
  };

  Waves.prototype.clear = function () {
    var Waves = this;
    Waves.ctx.clearRect(0, 0, Waves.width, Waves.height);
  };

  Waves.prototype.background = function () {
    var Waves = this;
    var ctx = Waves.ctx;

    var gradient = Waves.ctx.createLinearGradient(0, 0, 0, Waves.height);
    gradient.addColorStop(0, '#000');
    gradient.addColorStop(1, Waves.color);

    ctx.fillStyle = gradient;
    ctx.fillRect(0, 0, Waves.width, Waves.height);
  };

  Waves.prototype.resize = function () {
    var Waves = this;
    var width = Waves.holder.offsetWidth;
    var height = Waves.holder.offsetHeight;
    Waves.scale = window.devicePixelRatio || 1;
    Waves.width = width * Waves.scale;
    Waves.height = height * Waves.scale;
    Waves.canvas.width = Waves.width;
    Waves.canvas.height = Waves.height;
    Waves.canvas.style.width = width + 'px';
    Waves.canvas.style.height = height + 'px';
    Waves.radius = Math.sqrt(Math.pow(Waves.width, 2) + Math.pow(Waves.height, 2)) / 2;
    Waves.centerX = Waves.width / 2;
    Waves.centerY = Waves.height / 2;
    //Waves.radius /= 2; // REMOVE FOR FULLSREEN
  };

  Waves.prototype.updateColor = function () {
    var Waves = this;

    Waves.hue += (Waves.hueFw) ? 0.01 : -0.01;

    if (Waves.hue > Waves.options.hue[1] && Waves.hueFw) {
      Waves.hue = Waves.options.hue[1];
      Waves.Waves = false;
    } else if (Waves.hue < Waves.options.hue[0] && !Waves.hueFw) {
      Waves.hue = Waves.options.hue[0];
      Waves.Waves.........完整代码请登录后点击上方下载按钮下载查看