点击页面出现动态变化彩带背景

变化彩带特效是基础canavs进行编写，点击网站页面时，就会出现不同角度的折痕变化，适合作为网页浅色背景的页面使用，对于喜欢折腾网站的小伙伴可以试试。

效果图如下：

使用步骤：

1，在网页需要使用的地方添加canvas标签代码

2，添加处理canvas绘制的js代码

      <script>
      document.addEventListener('touchmove', function(e) {
          e.preventDefault()
      })
      var c = document.getElementsByTagName('canvas')[0],
          x = c.getContext('2d'),
          pr = window.devicePixelRatio || 1,
          w = window.innerWidth,
          h = window.innerHeight,
          f = 90,
          q,
          m = Math,
          r = 0,
          u = m.PI * 2,
          v = m.cos,
          z = m.random
      c.width = w * pr
      c.height = h * pr
      x.scale(pr, pr)
      x.globalAlpha = 0.6
   
      function i() {
          x.clearRect(0, 0, w, h)
          q = [{ x: 0, y: h * .7 + f }, { x: 0, y: h * .7 - f }]
          while (q[1].x < w + f) d(q[0], q[1])
      }
      function d(i, j) {
          x.beginPath()
          x.moveTo(i.x, i.y)
          x.lineTo(j.x, j.y)
          var k = j.x + (z() * 2 - 0.25) * f,
              n = y(j.y)
          x.lineTo(k, n)
          x.closePath()
          r -= u / -50
          x.fillStyle = '#' + (v(r) * 127 + 128 << 16 | v(r + u / 3) * 127 + 128 << 8 | v(r + u / 3 * 2) * 127 + 128).toString(16)
          x.fill()
          q[0] = q[1]
          q[1] = { x: k, y: n }
      }
      function y(p) {
          var t = p + (z() * 2 - 1.1) * f
          return (t > h || t < 0) ? y(p) : t
      }
      document.onclick = i
      document.ontouchstart = i
      i()
      </script>
      <script>
      document.addEventListener('touchmove', function(e) {
          e.preventDefault()
      })
      var c = document.getElementsByTagName('canvas')[0],
          x = c.getContext('2d'),
          pr = window.devicePixelRatio || 1,
          w = window.innerWidth,
          h = window.innerHeight,
          f = 90,
          q,
          m = Math,
          r = 0,
          u = m.PI * 2,
          v = m.cos,
          z = m.random
      c.width = w * pr
      c.height = h * pr
      x.scale(pr, pr)
      x.globalAlpha = 0.6
   
      function i() {
          x.clearRect(0, 0, w, h)
          q = [{ x: 0, y: h * .7 + f }, { x: 0, y: h * .7 - f }]
          while (q[1].x < w + f) d(q[0], q[1])
      }
      function d(i, j) {
          x.beginPath()
          x.moveTo(i.x, i.y)
          x.lineTo(j.x, j.y)
          var k = j.x + (z() * 2 - 0.25) * f,
              n = y(j.y)
          x.lineTo(k, n)
          x.closePath()
          r -= u / -50
          x.fillStyle = '#' + (v(r) * 127 + 128 << 16 | v(r + u / 3) * 127 + 128 << 8 | v(r + u / 3 * 2) * 127 + 128).toString(16)
          x.fill()
          q[0] = q[1]
          q[1] = { x: k, y: n }
      }
      function y(p) {
          var t = p + (z() * 2 - 1.1) * f
          return (t > h || t < 0) ? y(p) : t
      }
      document.onclick = i
      document.ontouchstart = i
      i()
      </script>
	    <script>
	    document.addEventListener('touchmove', function(e) {
	        e.preventDefault()
	    })
	    var c = document.getElementsByTagName('canvas')[0],
	        x = c.getContext('2d'),
	        pr = window.devicePixelRatio || 1,
	        w = window.innerWidth,
	        h = window.innerHeight,
	        f = 90,
	        q,
	        m = Math,
	        r = 0,
	        u = m.PI * 2,
	        v = m.cos,
	        z = m.random
	    c.width = w * pr
	    c.height = h * pr
	    x.scale(pr, pr)
	    x.globalAlpha = 0.6
	 
	    function i() {
	        x.clearRect(0, 0, w, h)
	        q = [{ x: 0, y: h * .7 + f }, { x: 0, y: h * .7 - f }]
	        while (q[1].x < w + f) d(q[0], q[1])
	    }
	    function d(i, j) {
	        x.beginPath()
	        x.moveTo(i.x, i.y)
	        x.lineTo(j.x, j.y)
	        var k = j.x + (z() * 2 - 0.25) * f,
	            n = y(j.y)
	        x.lineTo(k, n)
	        x.closePath()
	        r -= u / -50
	        x.fillStyle = '#' + (v(r) * 127 + 128 << 16 | v(r + u / 3) * 127 + 128 << 8 | v(r + u / 3 * 2) * 127 + 128).toString(16)
	        x.fill()
	        q[0] = q[1]
	        q[1] = { x: k, y: n }
	    }
	    function y(p) {
	        var t = p + (z() * 2 - 1.1) * f
	        return (t > h || t < 0) ? y(p) : t
	    }
	    document.onclick = i
	    document.ontouchstart = i
	    i()
	    </script>