js实现炫酷三角canvas背景动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：背景

代码描述：js实现炫酷三角canvas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">



</head>
<body>

<script>


class Utils {
  // random number.
  static randomNumber(min, max) {
    return Math.floor(Math.random() * (max - min + 1) + min);
  }
  // random color rgb.
  static randomColorRGB() {
    return (
      "rgb(" +
      this.randomNumber(0, 255) +
      ", " +
      this.randomNumber(0, 255) +
      ", " +
      this.randomNumber(0, 255) +
      ")"
    );
  }
  // random color hsl.
  static randomColorHSL(hue, saturation, lightness) {
    return (
      "hsl(" +
      hue +
      ", " +
      saturation +
      "%, " +
      lightness +
      "%)"
    );
  }
  // gradient color.
  static gradientColor(ctx, cr, cg, cb, ca, x, y, r) {
    const col = cr + "," + cg + "," + cb;
    const g = ctx.createRadialGradient(x, y, 0, x, y, r);
    g.addColorStop(0, "rgba(" + col + ", " + (ca * 1) + ")");
    g.addColorStop(0.5, "rgba(" + col + ", " + (ca * 0.5) + ")");
    g.addColorStop(1, "rgba(" + col + ", " + (ca * 0) + ")");
    return g;
  }
   // create multiple array
  static createMultipleArray(number_one, number_two) {
    let num_one = number_one;
    let num_two = number_two;
    let arr = new Array(num_one);
    for (let i = 0; i < num_one; i++) {
      arr[i] = new Array(num_one);
      for (let j = 0; j < num_two; j++) {
        arr[i][j] = 0;
      }
    }
    return arr;
  }
  // framerate
  static calcFPS() {
    const now = (+new Date());
    const fps = 1000 / (now - lastTime);
    lastTime = now;
    return fps.toFixed();
  }
}

/*
* File Name / vector2d.js
* Referenced / O'Reilly Programming HTML5 Canvas
* Author / Toshiya Marukubo
* Twitter / https://twitter.com/toshiyamarukubo
*/

class Vector2d {
  constructor(x, y) {
    this.vx = x;
    this.vy = y;
  }

  scale(scale) {
    this.vx *= scale;
    this.vy *= scale;
  }

  add(v, x, y) {
    if (v instanceof Vector2d) {
      return new Vector2d(this.vx + v.vx, this.vy + v.vy);
    } else {
      this.vx += x;
      this.vy += y;
    }
  }
  
  mult(num) {
    return new Vector2d(this.vx * num, this.vy * num);
  }

  sub(v, x, y) {
    if (v instanceof Vector2d) {
      return new Vector2d(this.vx - v.vx, this.vy - v.vy);
    } else {
      this.vx -= x;
      this.vy -= y;
    }
  }
  
  dist(v) {
    return Math.sqrt(Math.pow(v.vx - this.vx, 2) + Math.pow(v.vy - this.vy, 2));
  }
  
  fromAngle(radian) {
    this.vx = Math.cos(radian);
    this.vy = Math.sin(radian);
  }

  negate() {
    this.vx = -this.vx;
    this.vy = -this.vy;
  }

  length() {
    return Math.sqrt(this.vx * this.vx + this.vy * this.vy);
  }

  lengthSquared() {
    return this.vx * this.vx + this.vy * this.vy;
  }

  normalize() {
    let len = Math.sqrt(this.vx * this.vx + this.vy * this.vy);
    if (len) {
      this.vx /= len;
      this.vy /= len;
    }
    return len;
  }

  rotate(angle) {
    let vx = this.vx;
    let vy = this.vy;
    let cosVal = Math.cos(angle);
    let sinVal = Math.sin(angle);
    this.vx = vx * cosVal - vy * sinVal;
    this.vy = vx * sinVal + vy * cosVal;
  }

  toString() {
    return '(' + this.vx.toFixed(3) + ',' + this.vy.toFixed(3) + ')';
  }
}

/*
* File Name / collision.js
* Referenced / O'Reilly Programming HTML5 Canvas
* Author / Toshiya Marukubo
* Twitter / https://twitter.com/toshiyamarukubo
*/

class Collision {
  constructor(targetArr) {
    this.arr = targetArr;
  }

  collideAll() {
    let vec = new Vector2d(0, 0);
    let dist;
    let obj1;
    let obj2;
    let c;
    let i;
    for (c = 0; c < this.arr.length; c++) {
      obj1 = this.arr[c];
      for (i = c + 1; i < this.arr.length; i++) {
        obj2 = this.arr[i];
        vec.vx = obj2.x - obj1.x;
        vec.vy = obj2.y - obj1.y;
        dist = vec.length();
        if (dist < obj1.r + obj2.r) {
          vec.normalize();
          vec.scale(obj1.r + obj2.r - dist);
          vec.negate();
          obj1.x += vec.vx;
          obj1.y += vec.vy;
          this.bounce(obj1, obj2);
        }
      }
    }
  }

  bounce(obj1, obj2) {
    let colnAngle = Math.atan2(obj1.y - obj2.y, obj1.x - obj2.x);
    let length1 = obj1.v.length();
    let length2 = obj2.v.length();
    let dirAngle1 = Math.atan2(obj1.v.vy, obj1.v.vx);
    let dirAngle2 = Math.atan2(obj2.v.vy, obj2.v.vx);
    let newVX1 = length1 * Math.cos(dirAngle1 - colnAngle);
    let newVX2 = length2 * Math.cos(dirAngle2 - colnAngle);
    obj1.v.vy = length1 * Math.sin(dirAngle1 - colnAngle);
    obj2.v.vy = length2 * Math.sin(dirAngle2 - colnAngle);
    obj1.v.vx = ((obj1.r - obj2.r) * newVX1 + (2 * obj2.r) * newVX2) / (obj1.r + obj2.r);
    obj2.v.vx = ((obj2.r - obj1.r) * newVX2 + (2 * obj1.r) * newVX1) / (obj1.r + obj2.r);
    obj1.v.rotate(colnAngle);
    obj2.v.rotate(colnAngle);
  }
}

/*
* File Name / stopwatch.js
* Referenced / O'Reilly Programming HTML5 Canvas
* Author / Toshiya Marukubo
* Twitter / https://twitter.com/toshiyamarukubo
*/

class Stopwatch {
  constructor(time) {
    this.startTime = 0;
    this.running = false;
    this.elapsed = undefined;
  }

  start() {
    this.startTime = +new Date();
    this.elapsedTime = null;
    this.running = true;
  }

  stop() {
    this.elapsed = (+new Date()) - this.startTime;
    this.running = false;
  }

  getElapsedTime() {
    if (this.running) {
      return (+new Date()) - this.startTime;
    } else {
      return this.elapsed;
    }
  }

  isRunning() {
    return this.running;
  }

  reset() {
    this.elapsed = 0;
  }
}

/*
* File Name / animationTimer.js
* Referenced / O'Reilly Programming HTML5 Canvas
* Author / Toshiya Marukubo
* Twitter / https://twitter.com/toshiyamarukubo
*/

class AnimationTimer {
  constructor(duration, timeWarp) {
    if (duration !== undefined) this.duration = duration;
    if (timeWarp !== undefined) this.timeWarp = timeWarp;
    this.stopwatch = new Stopwatch();
  }

  start() {
    this.stopwatch.start();
  }

  stop() {
    this.stopwatch.stop();
  }

  getElapsedTime() {
    const elapsedTime = this.stopwatch.getElapsedTime();
    const percentComplete = elapsedTime / this.duration;
    if (!this.stopwatch.running) return undefined;
    if (this.timeWarp === undefined) return elapsedTime;
    return elapsedTime * (this.timeWarp(percentComplete) / percentComplete);
  }

  isRunning() {
    return this.stopwatch.running;
  }

  isOver() {
    return this.stopwatch.getElapsedTime() > this.duration;
  }

  makeEaseIn(strength) {
    return function(percentComplete) {
      return Math.pow(per.........完整代码请登录后点击上方下载按钮下载查看