diff --git a/lib/gradient.js b/lib/gradient.js new file mode 100644 index 0000000..9252523 --- /dev/null +++ b/lib/gradient.js @@ -0,0 +1,102 @@ +/* eslint-disable */ +// 当ctx传入当前文件,const grd = ctx.createCircularGradient() 和 +// const grd = this.ctx.createLinearGradient() 无效,因此只能分开处理 +// 先分析,在外部创建grd,再传入使用就可以 + +!(function () { + + var api = { + isGradient: function(bg) { + if (bg.startsWith('linear') || bg.startsWith('radial')) { + return true; + } + return false; + }, + + doGradient: function(bg, width, height, ctx) { + if (bg.startsWith('linear')) { + linearEffect(width, height, bg, ctx); + } else if (bg.startsWith('radial')) { + radialEffect(width, height, bg, ctx); + } + }, + } + + function analizeGrad(string) { + const colorPercents = string.substring(0, string.length - 1).split("%,"); + const colors = []; + const percents = []; + for (let colorPercent of colorPercents) { + colors.push(colorPercent.substring(0, colorPercent.lastIndexOf(" ")).trim()); + percents.push(colorPercent.substring(colorPercent.lastIndexOf(" "), colorPercent.length) / 100); + } + return {colors: colors, percents: percents}; + } + + function radialEffect(width, height, bg, ctx) { + const colorPer = analizeGrad(bg.match(/radial-gradient\((.+)\)/)[1]); + const grd = ctx.createCircularGradient(0, 0, width < height ? height / 2 : width / 2); + for (let i = 0; i < colorPer.colors.length; i++) { + grd.addColorStop(colorPer.percents[i], colorPer.colors[i]); + } + ctx.setFillStyle(grd); + ctx.fillRect(-(width / 2), -(height / 2), width, height); + } + + function analizeLinear(bg, width, height) { + const direction = bg.match(/([-]?\d{1,3})deg/); + const dir = direction && direction[1] ? parseFloat(direction[1]) : 0; + let coordinate; + switch (dir) { + case 0: console.log('case 0:'); coordinate = [0, -height / 2, 0, height / 2]; break; + case 90: console.log('case 90:'); coordinate = [width / 2, 0, -width / 2, 0]; break; + case -90: console.log('case -90:'); coordinate = [-width / 2, 0, width / 2, 0]; break; + case 180: console.log('case 180:'); coordinate = [0, height / 2, 0, -height / 2]; break; + case -180: console.log('case -180:'); coordinate = [0, -height / 2, 0, height / 2]; break; + default: + let x1 = 0; + let y1 = 0; + let x2 = 0; + let y2 = 0; + if (direction[1] > 0 && direction[1] < 90) { + 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; + y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1; + x2 = -x1; + y1 = -y2; + } else if (direction[1] > -180 && direction[1] < -90) { + 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; + y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1; + x2 = -x1; + y1 = -y2; + } else if (direction[1] > 90 && direction[1] < 180) { + 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; + y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1; + x2 = -x1; + y1 = -y2; + } else { + 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; + y2 = Math.tan((90 - direction[1]) * Math.PI * 2 / 360) * x1; + x2 = -x1; + y1 = -y2; + } + coordinate = [x1, y1, x2, y2]; + break; + } + return coordinate; + } + + function linearEffect(width, height, bg, ctx) { + const param = analizeLinear(bg, width, height); + const grd = ctx.createLinearGradient(param[0], param[1], param[2], param[3]); + const content = bg.match(/linear-gradient\((.+)\)/)[1]; + const colorPer = analizeGrad(content.substring(content.indexOf(',') + 1)); + for (let i = 0; i < colorPer.colors.length; i++) { + grd.addColorStop(colorPer.percents[i], colorPer.colors[i]); + } + ctx.setFillStyle(grd); + ctx.fillRect(-(width / 2), -(height / 2), width, height); + } + + module.exports = { api } + +})(); diff --git a/lib/pen.js b/lib/pen.js index 0d49efd..1dd53b2 100644 --- a/lib/pen.js +++ b/lib/pen.js @@ -1,4 +1,5 @@ const QR = require('./qrcode.js'); +const GD = require('./gradient.js'); export default class Painter { constructor(ctx, data) { @@ -38,6 +39,8 @@ export default class Painter { // 背景填充颜色 this.ctx.setFillStyle(bg); this.ctx.fillRect(-(width / 2), -(height / 2), width, height); + } else if (GD.api.isGradient(bg)) { + GD.api.doGradient(bg, width, height, this.ctx); } else { // 背景填充图片 this.ctx.drawImage(bg, -(width / 2), -(height / 2), width, height); @@ -346,7 +349,11 @@ export default class Painter { width, height, } = this._preProcess(view); - this.ctx.setFillStyle(view.css.color); + if (GD.api.isGradient(view.css.color)) { + GD.api.doGradient(view.css.color, width, height, this.ctx); + } else { + this.ctx.setFillStyle(view.css.color); + } this.ctx.fillRect(-(width / 2), -(height / 2), width, height); this.ctx.restore(); this._doBorder(view, width, height);