text: /**
   * Creates low-poly ribbons background effect inside a target container.
   */
  // (function (name, factory) {
  //   if (typeof window === "object") {
  //     window[name] = factory();
  //   }
  //
  // })("Ribbons", function () {
  let Factory
  
  ;(function () {
  
    try {
      var _w = window,
        _b = document.body,//返回html dom中的body节点 即<body>
        _d = document.documentElement//返回html dom中的root 节点 即<html>
    } catch (e) {
  
    }
  
  // 随机 函数
    var random = function () {
      if (arguments.length === 1) {//只有1个参数
        if (Array.isArray(arguments[0])) //从数组中提取索引
        {
          var index = Math.round(random(0, arguments[0].length - 1))
          return arguments[0][index]
        }
        return random(0, arguments[0]) // 假定是数字
      } else if (arguments.length === 2) {//两个参数范围
        return Math.random() * (arguments[1] - arguments[0]) + arguments[0]
      }
      return 0 //默认
    }
  
  // 视口属性 函数
    var screenInfo = function (e) {
      var width = Math.max(0, _w.innerWidth || _d.clientWidth || _b.clientWidth || 0),
        height = Math.max(0, _w.innerHeight || _d.clientHeight || _b.clientHeight || 0),
        scrollx = Math.max(0, _w.pageXOffset || _d.scrollLeft || _b.scrollLeft || 0) - (_d.clientLeft || 0),
        scrolly = Math.max(0, _w.pageYOffset || _d.scrollTop || _b.scrollTop || 0) - (_d.clientTop || 0)
  
      return {
        width: width,
        height: height,
        ratio: width / height,
        centerx: width / 2,
        centery: height / 2,
        scrollx: scrollx,
        scrolly: scrolly
      }
  
    }
  
  // 鼠标操作 函数
    var mouseInfo = function (e) {
      var screen = screenInfo(e),
        mousex = e ? Math.max(0, e.pageX || e.clientX || 0) : 0,
        mousey = e ? Math.max(0, e.pageY || e.clientY || 0) : 0
  
      return {
        mousex: mousex,
        mousey: mousey,
        centerx: mousex - screen.width / 2,
        centery: mousey - screen.height / 2
      }
  
    }
  
  //点对象
    var Point = function (x, y) {
      this.x = 0
      this.y = 0
      this.set(x, y)
    }
    Point.prototype = {
      constructor: Point,
  
      set: function (x, y) {
        this.x = x || 0
        this.y = y || 0
      },
      copy: function (point) {
        this.x = point.x || 0
        this.y = point.y || 0
        return this
      },
      multiply: function (x, y) {
        this.x *= x || 1
        this.y *= y || 1
        return this
      },
      divide: function (x, y) {
        this.x /= x || 1
        this.y /= y || 1
        return this
      },
      add: function (x, y) {
        this.x += x || 0
        this.y += y || 0
        return this
      },
      subtract: function (x, y) {
        this.x -= x || 0
        this.y -= y || 0
        return this
      },
      clampX: function (min, max) {
        this.x = Math.max(min, Math.min(this.x, max))
        return this
      },
      clampY: function (min, max) {
        this.y = Math.max(min, Math.min(this.y, max))
        return this
      },
      flipX: function () {
        this.x *= -1
        return this
      },
      flipY: function () {
        this.y *= -1
        return this
      }
    }
  
  //类构造函数
    Factory = function (options) {
      this._canvas = null
      this._context = null
      this._sto = null
      this._width = 0
      this._height = 0
      this._scroll = 0
      this._ribbons = []
      this._options = {
        //色带HSL饱和度
        colorSaturation: '80%',
        //色带HSL亮度量
        colorBrightness: '60%',
        //带状颜色透明度
        colorAlpha: 0.65,
        //在HSL颜色空间中循环显示颜色的速度
        colorCycleSpeed: 6,
        //从哪一侧开始Y轴 (top|min, middle|center, bottom|max, random)
        verticalPosition: 'center',
        //到达屏幕另一侧的速度
        horizontalSpeed: 200,
        //在任何给定时间，屏幕上会保留多少条彩带
        ribbonCount: 3,
        //添加笔划以及色带填充颜色
        strokeSize: 0,
        //通过页面滚动上的因子垂直移动彩带
        parallaxAmount: -0.5,
        //为每个功能区添加动画效果
        animateSections: true
      }
  
      this._onDraw = this._onDraw.bind(this)
      this._onResize = this._onResize.bind(this)
      this._onScroll = this._onScroll.bind(this)
      this.setOptions(options)
      this.init()
    }
  
  //类原型
    Factory.prototype = {
      constructor: Factory,
  
      //设置并合并 选项
      setOptions: function (options) {
        if (typeof options === 'object') {
          for (var key in options) {
            if (options.hasOwnProperty(key)) {
              this._options[key] = options[key]
            }
          }
        }
      },
  
      //初始化彩带效果
      init: function () {
        try {
          this._canvas = document.createElement('canvas')
          this._canvas.style['display'] = 'block'
          this._canvas.style['position'] = 'fixed'
          this._canvas.style['margin'] = '0'
          this._canvas.style['padding'] = '0'
          this._canvas.style['border'] = '0'
          this._canvas.style['outline'] = '0'
          this._canvas.style['left'] = '0'
          this._canvas.style['top'] = '0'
          this._canvas.style['width'] = '100%'
          this._canvas.style['height'] = '100%'
          this._canvas.style['z-index'] = '-1'
          // this._canvas.style["background-color"]="#1f1f1f";
          this._canvas.id = 'bgCanvas'
          this._onResize()
  
          this._context = this._canvas.getContext('2d')
          this._context.clearRect(0, 0, this._width, this._height)
          this._context.globalAlpha = this._options.colorAlpha
  
          window.addEventListener('resize', this._onResize)
          window.addEventListener('scroll', this._onScroll)
          document.body.appendChild(this._canvas)
        } catch (e) {
          console.warn('Canvas Context Error: ' + e.toString())
          return
        }
        this._onDraw()
      },
  
      //创建一个新的随机功能区和列表
      addRibbon: function () {
        // movement data
        var dir = Math.round(random(1, 9)) > 5 ? 'right' : 'left',
          stop = 1000,
          hide = 200,
          min = 0 - hide,
          max = this._width + hide,
          movex = 0,
          movey = 0,
          startx = dir === 'right' ? min : max,
          starty = Math.round(random(0, this._height))
  
        if (/^(top|min)$/i.test(this._options.verticalPosition)) {
          starty = 0 + hide
        } else if (/^(middle|center)$/i.test(this._options.verticalPosition)) {
          starty = this._height / 2
        } else if (/^(bottom|max)$/i.test(this._options.verticalPosition)) {
          starty = this._height - hide
        }
  
        //彩带 数据
        var ribbon = [],
          point1 = new Point(startx, starty),
          point2 = new Point(startx, starty),
          point3 = null,
          color = Math.round(random(0, 360)),
          delay = 0
  
        //渲染彩带
        while (true) {
          if (stop <= 0) break
          stop--
  
          movex = Math.round((Math.random() * 1 - 0.2) * this._options.horizontalSpeed)
          movey = Math.round((Math.random() * 1 - 0.5) * (this._height * 0.25))
  
          point3 = new Point()
          point3.copy(point2)
  
          if (dir === 'right') {
            point3.add(movex, movey)
            if (point2.x >= max) break
          } else if (dir === 'left') {
            point3.subtract(movex, movey)
            if (point2.x <= min) break
          }
          // point3.clampY( 0, this._height );
  
          ribbon.push({ //单个彩带部分
            point1: new Point(point1.x, point1.y),
            point2: new Point(point2.x, point2.y),
            point3: point3,
            color: color,
            delay: delay,
            dir: dir,
            alpha: 0,
            phase: 0
          })
  
          point1.copy(point2)
          point2.copy(point3)
  
          delay += 4
          color += this._options.colorCycleSpeed
        }
        this._ribbons.push(ribbon)
      },
  
      //绘制单个 部分
      _drawRibbonSection: function (section) {
        if (section) {
          if (section.phase >= 1 && section.alpha <= 0) {
            return true //完成
          }
          if (section.delay <= 0) {
            section.phase += 0.02
            section.alpha = Math.sin(section.phase) * 1
            section.alpha = section.alpha <= 0 ? 0 : section.alpha
            section.alpha = section.alpha >= 1 ? 1 : section.alpha
  
            if (this._options.animateSections) {
              var mod = Math.sin(1 + section.phase * Math.PI / 2) * 0.1
  
              if (section.dir === 'right') {
                section.point1.add(mod, 0)
                section.point2.add(mod, 0)
                section.point3.add(mod, 0)
              } else {
                section.point1.subtract(mod, 0)
                section.point2.subtract(mod, 0)
                section.point3.subtract(mod, 0)
              }
              section.point1.add(0, mod)
              section.point2.add(0, mod)
              section.point3.add(0, mod)
            }
          } else {
            section.delay -= 0.5
          }
  
          var s = this._options.colorSaturation,
            l = this._options.colorBrightness,
            c = 'hsla(' + section.color + ', ' + s + ', ' + l + ', ' + section.alpha + ' )'
  
          this._context.save()
  
          if (this._options.parallaxAmount !== 0) {
            this._context.translate(0, this._scroll * this._options.parallaxAmount)
          }
          this._context.beginPath()
          this._context.moveTo(section.point1.x, section.point1.y)
          this._context.lineTo(section.point2.x, section.point2.y)
          this._context.lineTo(section.point3.x, section.point3.y)
          this._context.fillStyle = c
          this._context.fill()
  
          if (this._options.strokeSize > 0) {
            this._context.lineWidth = this._options.strokeSize
            this._context.strokeStyle = c
            this._context.lineCap = 'round'
            this._context.stroke()
          }
          this._context.restore()
        }
        return false // 还没 完成
      },
  
      // 绘制彩带
      _onDraw: function () {
        //清理彩带列表
        // cleanup on ribbons list to rtemoved finished ribbons
        for (var i = 0, t = this._ribbons.length; i < t; ++i) {
          if (!this._ribbons[i]) {
            this._ribbons.splice(i, 1)
          }
        }
  
        // 绘制新彩带
        this._context.clearRect(0, 0, this._width, this._height)
  
        for (var a = 0; a < this._ribbons.length; ++a)//单个彩带
        {
          var ribbon = this._ribbons[a],
            numSections = ribbon.length,
            numDone = 0
  
          for (var b = 0; b < numSections; ++b) {
            if (this._drawRibbonSection(ribbon[b])) {
              numDone++
            }
          }
          if (numDone >= numSections) //完成
          {
            this._ribbons[a] = null
          }
        }
        //在画布上彩带的数量
        if (this._ribbons.length < this._options.ribbonCount) {
          this.addRibbon()
        }
        requestAnimationFrame(this._onDraw)
      },
  
      //更新窗口大小
      _onResize: function (e) {
        var screen = screenInfo(e)
        this._width = screen.width
        this._height = screen.height
  
        if (this._canvas) {
          this._canvas.width = this._width
          this._canvas.height = this._height
  
          if (this._context) {
            this._context.globalAlpha = this._options.colorAlpha
          }
        }
      },
  
      // 页面滚动
      _onScroll: function (e) {
        var screen = screenInfo(e)
        this._scroll = screen.scrolly
      }
    }
  })()
  
  export default Factory
  
  
  
  