image2d/src/library/calculate/color.js

🍇 使用ECMAScript绘制二维图片。Drawing Two-Dimensional Pictures Using ECMAScript.

import getStyle from '../../core/get-style';
import { REGEXP } from '../../core/config';
import image2D from '../../image2D';

// 把颜色统一转变成rgba(x,x,x,x)格式
// 返回数字数组[r,g,b,a]
export let formatColor = function (color) {
    let colorNode = document.getElementsByTagName('head')[0];
    colorNode.style['color'] = color;
    let rgba = getStyle(colorNode, 'color');
    let rgbaArray = rgba.replace(/^rgba?\(([^)]+)\)$/, '$1').split(new RegExp('\\,' + REGEXP.whitespace));
    return [+rgbaArray[0], +rgbaArray[1], +rgbaArray[2], rgbaArray[3] == undefined ? 1 : +rgbaArray[3]];
};

// 获取一组随机色彩
export let getRandomColors = function (num, alpha) {
    if (!(alpha && alpha >= 0 && alpha <= 1)) alpha = 1;
    let temp = [];
    for (let flag = 1; flag <= num; flag++) {
        temp.push('rgba(' + (Math.random(1) * 230 + 20).toFixed(0) + ',' + (Math.random(1) * 230 + 20).toFixed(0) + ',' + (Math.random(1) * 230 + 20).toFixed(0) + ',' + alpha + ')');
    }
    return temp;
};

// 获取一组循环色彩
export let getLoopColors = function (num, alpha) {
    if (!(alpha && alpha >= 0 && alpha <= 1)) alpha = 1;
    // 颜色集合
    let colorList = [
        'rgba(84,112,198,' + alpha + ")", 'rgba(145,204,117,' + alpha + ")",
        'rgba(250,200,88,' + alpha + ")", 'rgba(238,102,102,' + alpha + ")",
        'rgba(115,192,222,' + alpha + ")", 'rgba(59,162,114,' + alpha + ")",
        'rgba(252,132,82,' + alpha + ")", 'rgba(154,96,180,' + alpha + ")",
        'rgba(234,124,204,' + alpha + ")"
    ];

    let colors = [];

    // 根据情况返回颜色数组
    if (num <= colorList.length) {
        // 这种情况就不需要任何处理
        return colorList;
    } else {
        // 如果正好是集合长度的倍数
        if (num % colorList.length == 0) {
            // 将颜色数组循环加入后再返回
            for (let i = 0; i < (num / colorList.length); i++) {
                colors = colors.concat(colorList);
            }
        } else {
            for (let j = 1; j < (num / colorList.length); j++) {
                colors = colors.concat(colorList);
            }
            // 防止最后一个颜色和第一个颜色重复
            if (num % colorList.length == 1) {
                colors = colors.concat(colorList[4]);
            } else {
                for (let k = 0; k < num % colorList.length; k++) {
                    colors = colors.concat(colorList[k]);
                }
            }
        }
    }

    // 返回结果
    return colors;
};