canvas实现点击换色的漩涡动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：动画

代码描述：canvas实现点击换色的漩涡动画效果代码

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>
body {
  font-family: Arial, Helvetica, "Liberation Sans", FreeSans, sans-serif;
  background-color: #000;
  margin: 0;
  padding: 0;
  border-width: 0;
  cursor: pointer;
}
</style>




</head>

<body >

  
      <script  >
"use strict";

window.addEventListener("load", function () {
  let canv, ctx; // canvas and context
  let maxx, maxy; // canvas dimensions

  // for animation
  let messages;
  let cent;
  let mouse = {};

  // shortcuts for Math.
  const mrandom = Math.random;
  const mfloor = Math.floor;
  const mround = Math.round;
  const mceil = Math.ceil;
  const mabs = Math.abs;
  const mmin = Math.min;
  const mmax = Math.max;

  const mPI = Math.PI;
  const m2PI = Math.PI * 2;
  const msin = Math.sin;
  const mcos = Math.cos;
  const matan2 = Math.atan2;

  const mhypot = Math.hypot;
  const msqrt = Math.sqrt;

  //------------------------------------------------------------------------

  function alea(mini, maxi) {
    // random number in given range
    if (typeof maxi == "undefined") return mini * mrandom(); // range 0..mini
    return mini + mrandom() * (maxi - mini); // range mini..maxi
  }

  // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  function intAlea(mini, maxi) {
    // random integer in given range (mini..maxi - 1 or 0..mini - 1)
    //
    if (typeof maxi == "undefined") return mfloor(mini * mrandom()); // range 0..mini - 1
    return mini + mfloor(mrandom() * (maxi - mini)); // range mini .. maxi - 1
  }

  //-----------------------------------------------------------------------------
  /* returns a function which returns a random number in the range 0..1
            for a given seed, the returned function will always return the same value for the same argument.
            Values returned by the returned function seem uncorrelated for two different arguments.
            */

  function getRandomFunction(seed) {
    /*	============================================================================
                    This is based upon Johannes Baagoe's carefully designed and efficient hash
                    function for use with JavaScript.  It has a proven "avalanche" effect such
                    that every bit of the input affects every bit of the output 50% of the time,
                    which is good.	See: http://baagoe.com/en/RandomMusings/hash/avalanche.xhtml
                    ============================================================================
                */
    let n = 0xefc8249d;
    mash((seed || Math.random()).toString());
    let nSeed = n;

    return x => {
      n = nSeed;
      return mash(x + "a");
    };

    function mash(data) {
      if (data) {
        data = data.toString();
        for (var i = 0; i < data.length; i++) {
          n += data.charCodeAt(i);
          var h = 0.02519603282416938 * n;
          n = h >>> 0;
          h -= n;
          h *= n;
          n = h >>> 0;
          h -= n;
          n += h * 0x100000000; // 2^32
        }
        return (n >>> 0) * 2.3283064365386963e-10; // 2^-32
      } else n = 0xefc8249d;
    }
  } // getRandomFunction

  function getNoiseFunction(period, min, max, randomf) {
    // randomf must return a value in range 0..1 - always the same value for the same argument
    // if no randomf is provided, getRandomFunction() will be used (without argument)
    // period MUST be != 0
    // may be used with seed invoking getNoiseFunction (period, min, max, getRandomFunction(seed))

    let frand = randomf || getRandomFunction();
    let desync = frand(1.234);
    return x => {
      x /= period;
      x += desync;
      let kx = mfloor(x);
      let fx = x - kx;
      let v0 = frand(kx);
      let v1 = frand(kx + 1);
      fx = (-2 * fx + 3) * fx * fx; // range 0..1
      return min + (max - min) * (v1 * fx + v0 * (1 - fx));
    };
  }

  // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  function arrayShuffle(array) {
    /* randomly changes the order of items in an array
                   only the order is modified, not the elements
                */
    let k1, temp;
    for (let k = array.length - 1; k >= 1; --k) {
      k1 = intAlea(0, k + 1);
      temp = array[k];
      array[k] = array[k1];
      array[k1] = temp;
    } // for k
    return array;
  } // arr.........完整代码请登录后点击上方下载按钮下载查看