js实现canvas彩色图案背景效果代码-html代码-BFW代码库

js实现canvas彩色图案背景效果代码

代码语言：html

所属分类：背景

代码描述：js实现canvas彩色图案背景效果代码，点击可更换。

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 () {

  const RADIUSMIN = 0.1;
  const RADIUSMAX = 0.2;

  let rndSeed = Math.random();

  let canv, ctx; // canvas and context
  let maxx, maxy; // canvas dimensions
  let nbx, nby;
  let uiv;
  let grid;
  let rndStruct;
  let lRef;
  let mouse;

  // for animation
  let events;

  // 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 mPIS2 = Math.PI / 2;
  const mPIS3 = Math.PI / 3;
  const m2PI = Math.PI * 2;
  const m2PIS3 = Math.PI * 2 / 3;
  const msin = Math.sin;
  const mcos = Math.cos;
  const matan2 = Math.atan2;

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

  const rac3 = msqrt(3);
  const rac3s2 = rac3 / 2;

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

  /* based on a function found at https://www.grc.com/otg/uheprng.htm
  and customized to my needs
  
  use :
    x = Mash('1213'); // returns a resettable, reproductible pseudo-random number generator function
    x = Mash();  // like line above, but uses Math.random() for a seed
    x();         // returns pseudo-random number in range [0..1[;
    x.reset();   // re-initializes the sequence with the same seed. Even if Mash was invoked without seed, will generate the same sequence.
    x.seed;      // retrieves the internal seed actually used. May be useful if no seed or non-string seed provided to Mash
                 be careful : this internal seed is a String, even if it may look like a number. Changing or omitting any single digit will produce a completely different sequence
    x.intAlea(min, max) returns integer in the range [min..max[ (or [0..min[ if max not provided)
    x.alea(min, max) returns float in the range [min..max[ (or [0..min[ if max not provided)
  */

  /*	============================================================================
  	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
  	============================================================================
  */
  /* seed may be almost anything not evaluating to false */
  function Mash(seed) {
    let n = 0xefc8249d;
    let intSeed = (seed || Math.random()).toString();

    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;.........完整代码请登录后点击上方下载按钮下载查看