支持背景渐变色
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heidao
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12c6422b0e
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a1460da565
126
lib/gradient.js
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126
lib/gradient.js
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@ -0,0 +1,126 @@
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/* eslint-disable */
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// 当ctx传入当前文件，const grd = ctx.createCircularGradient() 和
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// const grd = this.ctx.createLinearGradient() 无效，因此只能分开处理
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// 先分析，在外部创建grd，再传入使用就可以
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!(function () {
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var api = {
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toPoint: function(percent) {
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let str = percent.replace('%', '');
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str /= 100;
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return str;
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},
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analizeRadial: function(bg, width, height) {
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let count = 0;
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const coordinate = bg.match(/(?:(\d{1,3})[,])/g);
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const colors = bg.match(/((?:#(?:\w{6}|\w{3}))|(?:rgba[(](?:(?:\d{1,3})\W\s){3}\d[)]))/g);
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const status = bg.match(/\d{1,3}[%]/g);
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for (let i = 0; i < colors.length; i++) {
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if (colors[i].startsWith('rgba')) {
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count += 3;
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}
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}
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const length = coordinate.length - count;
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switch (length) {
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case 3: radialParams.coordinate = [coordinate[0].replace(',', ''), coordinate[1].replace(',', ''), coordinate[2].replace(',', '')]; break;
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case 2: radialParams.coordinate = [coordinate[0].replace(',', ''), coordinate[1].replace(',', ''), Math.sqrt(width * width / 4 + height * height / 4)]; break;
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case 1: radialParams.coordinate = [0, 0, coordinate[0].replace(',', '')]; break;
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default: radialParams.coordinate = [0, 0, Math.sqrt(width * width / 4 + height * height / 4)]; break;
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}
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radialParams.colors = colors;
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radialParams.status = status;
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return radialParams.coordinate;
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},
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radialEffect: function(width, height, grd, ctx) {
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if (radialParams.status && radialParams.status[0] && radialParams.status.length === radialParams.colors.length) {
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for (let i = 0; i < radialParams.colors.length; i++) {
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grd.addColorStop(this.toPoint(radialParams.status[i]), radialParams.colors[i]);
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}
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} else {
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for (let i = 0; i < radialParams.colors.length; i++) {
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grd.addColorStop(i / (radialParams.colors.length - 1), radialParams.colors[i]);
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}
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}
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ctx.setFillStyle(grd);
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ctx.fillRect(-(width / 2), -(height / 2), width, height);
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},
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analizeLinear: function(bg, width, height) {
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const direction = bg.match(/([-]?\d{1,3})deg/);
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const colors = bg.match(/((?:#(?:\w{6}|\w{3}))|(?:rgba[(](?:(?:\d{1,3})\W\s){3}\d[)]))/g);
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const status = bg.match(/\d{1,3}[%]/g);
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const dir = direction && direction[1] ? parseFloat(direction[1]) : 0;
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switch (dir) {
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case 0: console.log('case 0:'); linearParams.coordinate = [0, -height / 2, 0, height / 2]; break;
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case 90: console.log('case 90:'); linearParams.coordinate = [width / 2, 0, -width / 2, 0]; break;
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case -90: console.log('case -90:'); linearParams.coordinate = [-width / 2, 0, width / 2, 0]; break;
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case 180: console.log('case 180:'); linearParams.coordinate = [0, height / 2, 0, -height / 2]; break;
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case -180: console.log('case -180:'); linearParams.coordinate = [0, -height / 2, 0, height / 2]; break;
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default:
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console.log('default:');
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let x1 = 0;
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let y1 = 0;
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let x2 = 0;
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let y2 = 0;
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if (direction[1] > 0 && direction[1] < 90) {
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x1 = (width / 2) - ((width / 2) * Math.tan((90 - direction[1]) * Math.PI * 2 / 360) - height / 2) * Math.sin(2 * (90 - direction[1]) * Math.PI * 2 / 360) / 2;
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y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1;
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x2 = -x1;
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y1 = -y2;
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} else if (direction[1] > -180 && direction[1] < -90) {
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x1 = -(width / 2) + ((width / 2) * Math.tan((90 - direction[1]) * Math.PI * 2 / 360) - height / 2) * Math.sin(2 * (90 - direction[1]) * Math.PI * 2 / 360) / 2;
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y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1;
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x2 = -x1;
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y1 = -y2;
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} else if (direction[1] > 90 && direction[1] < 180) {
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x1 = (width / 2) + (-(width / 2) * Math.tan((90 - direction[1]) * Math.PI * 2 / 360) - height / 2) * Math.sin(2 * (90 - direction[1]) * Math.PI * 2 / 360) / 2;
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y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1;
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x2 = -x1;
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y1 = -y2;
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} else {
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x1 = -(width / 2) - (-(width / 2) * Math.tan((90 - direction[1]) * Math.PI * 2 / 360) - height / 2) * Math.sin(2 * (90 - direction[1]) * Math.PI * 2 / 360) / 2;
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y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1;
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x2 = -x1;
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y1 = -y2;
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}
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linearParams.coordinate = [x1, y1, x2, y2];
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break;
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}
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linearParams.colors = colors;
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linearParams.status = status;
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return linearParams.coordinate;
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},
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linearEffect: function(width, height, grd, ctx) {
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if (linearParams.status && linearParams.status[0] && linearParams.status.length === linearParams.colors.length) {
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for (let i = 0; i < linearParams.colors.length; i++) {
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grd.addColorStop(this.toPoint(linearParams.status[i]), linearParams.colors[i]);
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}
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} else {
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for (let i = 0; i < linearParams.colors.length; i++) {
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grd.addColorStop(i / (linearParams.colors.length - 1), linearParams.colors[i]);
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}
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}
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ctx.setFillStyle(grd);
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ctx.fillRect(-(width / 2), -(height / 2), width, height);
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},
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}
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const linearParams = {
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coordinate: [],
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colors: [],
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status: [],
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}
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const radialParams = {
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coordinate: [],
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colors: [],
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status: [],
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}
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module.exports = { api }
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})();
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@ -1,4 +1,5 @@
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const QR = require('./qrcode.js');
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const GD = require('./gradient.js');
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export default class Painter {
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constructor(ctx, data) {
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@ -38,6 +39,14 @@ export default class Painter {
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// 背景填充颜色
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this.ctx.setFillStyle(bg);
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this.ctx.fillRect(-(width / 2), -(height / 2), width, height);
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} else if (bg.startsWith('linear')) {
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const param = GD.api.analizeLinear(bg, width, height);
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const grd = this.ctx.createLinearGradient(param[0], param[1], param[2], param[3]);
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GD.api.linearEffect(width, height, grd, this.ctx);
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} else if (bg.startsWith('radial')) {
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const param = GD.api.analizeRadial(bg, width, height);
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const grd = this.ctx.createCircularGradient(param[0], param[1], param[2]);
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GD.api.radialEffect(width, height, grd, this.ctx);
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} else {
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// 背景填充图片
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this.ctx.drawImage(bg, -(width / 2), -(height / 2), width, height);
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