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);