js实现可编辑的雪花效果代码-html代码-BFW代码库

js实现可编辑的雪花效果代码

代码语言：html

所属分类：其他

代码描述：js实现可编辑的雪花效果代码

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;
}

button {
  display: block;
  z-index: 10;
  position: absolute;
  left: 1em;
  cursor: pointer;
}

#controls {
  top: 1em;
}

#setfern {
  top: 3em;
}

#setsierp {
  top: 5em;
}
</style>


  
</head>

<body translate="no">
  <button type="button" id="controls">edit</button>
<button type="button" id="setfern">fern</button>
<button type="button" id="setsierp">Sierpiński</button>
  
      <script >
let canv, ctx; // canvas and context
let fgCanv, fgCtx;
let maxx, maxy; // canvas dimensions
let fern;
let xc, yc, radius;
let controls = true;
let animFernState = 0;

const captureRadius = 10;

// for animation
let messages;

// 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;

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

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 randomSign() {
  // -1 or +1
  return mrandom > 0.5 ? -1 : 1;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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
}

//------------------------------------------------------------------------
function drawFigure(point, figureIndex, color, lineWidth) {
  fgCtx.beginPath();
  fgCtx.strokeStyle = color;
  fgCtx.lineWidth = lineWidth;
  switch (figureIndex) {
    case 0: // cross
      fgCtx.moveTo(point.x - 3, point.y);
      fgCtx.lineTo(point.x + 3, point.y);
      fgCtx.moveTo(point.x, point.y - 3);
      fgCtx.lineTo(point.x, point.y + 3);
      break;
    case 1: // x
      fgCtx.moveTo(point.x - 2, point.y - 2);
      fgCtx.lineTo(point.x + 2, point.y + 2);
      fgCtx.moveTo(point.x - 2, point.y + 2);
      fgCtx.lineTo(point.x + 2, point.y - 2);
      break;
    case 2: // o
      fgCtx.arc(point.x, point.y, 2, 0, m2PI);
      break;}

  fgCtx.stroke();
} // drawFigure

//------------------------------------------------------------------------
// POINT
//------------------------------------------------------------------------
// class Point
function Point(x, y) {
  this.x = x;
  this.y = y;
} // function Point

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

Point.prototype.draw = function (color) {
  // hope this.index has been defined!
  // black background (thick line)
  drawFigu.........完整代码请登录后点击上方下载按钮下载查看