一个很小的jQuery脚本,使用线性渐变CSS函数生成动画渐变背景。
1.在文档中加载所需的jQuery JavaScript库。
- <script src="/path/to/cdn/jquery.slim.min.js"></script>
2.为渐变背景定义一组颜色。
- var colors = new Array(
- [62,35,255],
- [60,255,60],
- [255,35,98],
- [45,175,230],
- [255,0,255],
- [255,128,0]
- );
3.动画渐变背景的主要功能。
- var step = 0;
- var colorIndices = [0,1,2,3];
- var gradientSpeed = 0.002;
- function updateGradient()
- {
- if ( $===undefined ) return;
- var c0_0 = colors[colorIndices[0]];
- var c0_1 = colors[colorIndices[1]];
- var c1_0 = colors[colorIndices[2]];
- var c1_1 = colors[colorIndices[3]];
- var istep = 1 - step;
- var r1 = Math.round(istep * c0_0[0] + step * c0_1[0]);
- var g1 = Math.round(istep * c0_0[1] + step * c0_1[1]);
- var b1 = Math.round(istep * c0_0[2] + step * c0_1[2]);
- var color1 = "rgb("+r1+","+g1+","+b1+")";
- var r2 = Math.round(istep * c1_0[0] + step * c1_1[0]);
- var g2 = Math.round(istep * c1_0[1] + step * c1_1[1]);
- var b2 = Math.round(istep * c1_0[2] + step * c1_1[2]);
- var color2 = "rgb("+r2+","+g2+","+b2+")";
- $('#gradient').css({
- background: "-webkit-gradient(linear, left top, right top, from("+color1+"), to("+color2+"))"}).css({
- background: "-moz-linear-gradient(left, "+color1+" 0%, "+color2+" 100%)"});
- step += gradientSpeed;
- if ( step >= 1 )
- {
- step %= 1;
- colorIndices[0] = colorIndices[1];
- colorIndices[2] = colorIndices[3];
- colorIndices[1] = ( colorIndices[1] + Math.floor( 1 + Math.random() * (colors.length - 1))) % colors.length;
- colorIndices[3] = ( colorIndices[3] + Math.floor( 1 + Math.random() * (colors.length - 1))) % colors.length;
- }
- }
4.以给定的速度更新梯度背景。
- setInterval(updateGradient,10);