canvas绘制的酷炫背景图

<template>
  <div id="home">
    <canvas id="canvas" class="canvas"></canvas>
    <!-- <v-header></v-header> -->

    <div class="content">
      <!-- <sidebar></sidebar> -->
      <transition name="fade">
        <router-view></router-view>
      </transition>
    </div>
  </div>
</template>
<script>
export default {
  data () {},
  mounted () {
    var canvas = document.querySelector('canvas'),
      ctx = canvas.getContext('2d')
    canvas.width = window.innerWidth
    canvas.height = window.innerHeight
    ctx.lineWidth = 0.3
    ctx.strokeStyle = new Color(150).style

    // var mousePosition = {
    // x: 30 * canvas.width / 100,
    // y: 30 * canvas.height / 100
    // };
    var mousePosition = {
      x: canvas.width - 100,
      y: canvas.height - 60
    }

    var dots = {
      nb: 250,
      distance: 100,
      d_radius: 150,
      array: []
    }

    function colorValue (min) {
      return Math.floor(Math.random() * 255 + min)
    }

    function createColorStyle (r, g, b) {
      return 'rgba(' + r + ',' + g + ',' + b + ', 0.8)'
    }

    function mixComponents (comp1, weight1, comp2, weight2) {
      return (comp1 * weight1 + comp2 * weight2) / (weight1 + weight2)
    }

    function averageColorStyles (dot1, dot2) {
      var color1 = dot1.color,
        color2 = dot2.color

      var r = mixComponents(color1.r, dot1.radius, color2.r, dot2.radius),
        g = mixComponents(color1.g, dot1.radius, color2.g, dot2.radius),
        b = mixComponents(color1.b, dot1.radius, color2.b, dot2.radius)
      return createColorStyle(Math.floor(r), Math.floor(g), Math.floor(b))
    }

    function Color (min) {
      min = min || 0
      this.r = colorValue(min)
      this.g = colorValue(min)
      this.b = colorValue(min)
      this.style = createColorStyle(this.r, this.g, this.b)
    }

    function Dot () {
      this.x = Math.random() * canvas.width
      this.y = Math.random() * canvas.height

      this.vx = -0.5 + Math.random()
      this.vy = -0.5 + Math.random()

      this.radius = Math.random() * 2

      this.color = new Color()
    }

    Dot.prototype = {
      draw: function () {
        ctx.beginPath()
        ctx.fillStyle = this.color.style
        ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, false)
        ctx.fill()
      }
    }

    function createDots () {
      for (var i = 0; i < dots.nb; i++) {
        dots.array.push(new Dot())
      }
    }

    function moveDots () {
      for (var i = 0; i < dots.nb; i++) {
        var dot = dots.array[i]

        if (dot.y < 0 || dot.y > canvas.height) {
          dot.vx = dot.vx
          dot.vy = -dot.vy
        } else if (dot.x < 0 || dot.x > canvas.width) {
          dot.vx = -dot.vx
          dot.vy = dot.vy
        }
        dot.x += dot.vx
        dot.y += dot.vy
      }
    }

    function connectDots () {
      for (var i = 0; i < dots.nb; i++) {
        for (var j = 0; j < dots.nb; j++) {
          var i_dot = dots.array[i]
          var j_dot = dots.array[j]
          // 两个点之间的距离不能小于100
          if (
            i_dot.x - j_dot.x < dots.distance &&
            i_dot.y - j_dot.y < dots.distance &&
            i_dot.x - j_dot.x > -dots.distance &&
            i_dot.y - j_dot.y > -dots.distance
          ){            
            if (
              i_dot.x - mousePosition.x < dots.d_radius &&
              i_dot.y - mousePosition.y < dots.d_radius &&
              i_dot.x - mousePosition.x > -dots.d_radius &&
              i_dot.y - mousePosition.y > -dots.d_radius
            ) {
              ctx.beginPath()
              ctx.strokeStyle = averageColorStyles(i_dot, j_dot)
              ctx.moveTo(i_dot.x, i_dot.y)
              ctx.lineTo(j_dot.x, j_dot.y)
              ctx.stroke()
              ctx.closePath()
            }
          }
        }
      }
    }

    function drawDots () {
      for (var i = 0; i < dots.nb; i++) {
        var dot = dots.array[i]
        dot.draw()
      }
    }

    function animateDots () {
      ctx.clearRect(0, 0, canvas.width, canvas.height)
      moveDots()
      connectDots()
      drawDots()

      requestAnimationFrame(animateDots)
    }

    // ----------------------跟着鼠标动--------------------
    document.getElementById('home').addEventListener('mousemove', function (e) {
      mousePosition.x = e.pageX
      mousePosition.y = e.pageY
    })

    document.getElementById('home').addEventListener('mouseleave', function (e) {
      mousePosition.x = canvas.width / 2
      mousePosition.y = canvas.height / 2
    })
    // ----------------------跟着鼠标动--------------------
    createDots()
    requestAnimationFrame(animateDots)
  }
}
</script>
<style>
#home {
  position: relative;
  width: 100%;
  height: 100%;
  color: #fff;
  /* box-sizing: border-box; */
  overflow-x: hidden;
  background: rgba(7, 17, 27, 0.95);
}
.canvas {
  position: fixed;
  z-index: 1;
}
#home a {
  color: #fff;
  display: block;
}
.content {
  height: 100vh;
  margin-top: -16px;
  display: flex;
}

.content section {
  flex: 1;
  z-index: 11;
  margin-left: 200px;
  /* box-sizing: border-box; */
  /* padding-right: 60px; */
}

table {
  position: absolute;
  top: 100px;
  padding: 0 20px;
  width: 100%;
}
table thead tr {
  border-bottom: 2px solid #fff;
}
table tbody tr {
  border-bottom: 1px solid #fff;
}
table tr {
  height: 50px;
}
table tr td {
  text-align: center;
  cursor: pointer;
}
table tr td:last-child {
  width: 10%;
}
table tr th {
  font-weight: normal;
  cursor: pointer;
}

.search-bar {
  position: absolute;
  top: 20px;
  left: 10%;
  width: 400px;
  height: 46px;
  line-height: 46px;
}
.search-bar .input-wrap {
  float: left;
  width: 270px;
  height: 40px;
  padding: 0 15px;
  line-height: 40px;
  border: none;
  outline: none;
  font-size: 20px;
  border-radius: 20px 0 0 20px;
  background: rgba(255, 255, 255, 0.2);
  transition: all 0.8s;
}
.search-bar .input-wrap:focus {
  background: rgba(255, 255, 255, 0.8);
}
.search-bar .input-button {
  float: left;
  width: 50px;
  height: 38px;
  line-height: 38px;
  text-align: center;
  font-size: 14px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all 0.8s;
}
.search-bar .input-wrap:focus .input-botton {
  border-color: rgba(255, 255, 255, 0.8);
}

.fade-enter-active {
  transition: all 0.5s;
}
.fade-enter,
.fade-leave-active {
  opacity: 0;
  transform: rotate(-70deg) translateX(300px);
}
</style>