https://www.zhihu.com/question/38869928
随手写的,轻喷
Changelog:
- 应评论区要求支持 #000 这样的三位 hex color
- 应评论区要求支持 gamma correction。
作者:「已注销」 链接:https://www.zhihu.com/question/38869928/answer/78527903 来源:知乎 著作权归作者所有。商业转载请联系作者获得授权,非商业转载请注明出处。 // convert #hex notation to rgb array var parseColor = function (hexStr) { return hexStr.length === 4 ? hexStr.substr(1).split('').map(function (s) { return 0x11 * parseInt(s, 16); }) : [hexStr.substr(1, 2), hexStr.substr(3, 2), hexStr.substr(5, 2)].map(function (s) { return parseInt(s, 16); }) }; // zero-pad 1 digit to 2 var pad = function (s) { return (s.length === 1) ? '0' + s : s; }; var gradientColors = function (start, end, steps, gamma) { var i, j, ms, me, output = [], so = []; gamma = gamma || 1; var normalize = function (channel) { return Math.pow(channel / 255, gamma); }; start = parseColor(start).map(normalize); end = parseColor(end).map(normalize); for (i = 0; i < steps; i++) { ms = i / (steps - 1); me = 1 - ms; for (j = 0; j < 3; j++) { so[j] = pad(Math.round(Math.pow(start[j] * me + end[j] * ms, 1 / gamma) * 255).toString(16)); } output.push('#' + so.join('')); } return output; }; // try if it works console.log(gradientColors('#00ff00', '#ff0000', 100)); // 泥萌的新需求 console.log(gradientColors('#000', '#fff', 100, 2.2));
另canvas做法