475 lines
14 KiB
JavaScript
475 lines
14 KiB
JavaScript
import Toast from '@vant/weapp/toast/toast';
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Component({
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/**
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* 组件的属性列表
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*/
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properties: {
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show: false
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},
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/**
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* 组件的初始数据
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*/
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data: {
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imgList: [],
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//签名
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canvasName: 'handWriting',
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ctx: '',
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canvasWidth: 0,
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canvasHeight: 0,
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transparent: 1, // 透明度
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selectColor: '#fff',
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lineColor: '#1A1A1A', // 颜色
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lineSize: 1.5, // 笔记倍数
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lineMin: 0.5, // 最小笔画半径
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lineMax: 4, // 最大笔画半径
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pressure: 1, // 默认压力
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smoothness: 60, //顺滑度，用60的距离来计算速度
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currentPoint: {},
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currentLine: [], // 当前线条
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firstTouch: true, // 第一次触发
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radius: 1, //画圆的半径
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cutArea: {
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top: 0,
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right: 0,
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bottom: 0,
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left: 0
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}, //裁剪区域
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bethelPoint: [], //保存所有线条 生成的贝塞尔点；
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lastPoint: 0,
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chirography: [], //笔迹
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currentChirography: {}, //当前笔迹
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linePrack: [] //划线轨迹 , 生成线条的实际点
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},
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attached() {
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let canvasName = this.data.canvasName
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let ctx = wx.createCanvasContext(canvasName, this)
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this.setData({
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ctx: ctx
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})
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var query = this.createSelectorQuery();
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query.select('.container').boundingClientRect(rect => {
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this.setData({
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canvasWidth: rect.width,
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canvasHeight: rect.height
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})
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}).exec();
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},
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/**
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* 组件的方法列表
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*/
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methods: {
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ViewImage(e) {
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let files = [];
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files.push(e.currentTarget.dataset.url)
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wx.previewImage({
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urls: files,
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current: e.currentTarget.dataset.url
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});
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},
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// 笔迹开始
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uploadScaleStart(e) {
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if (e.type != 'touchstart') return false;
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let ctx = this.data.ctx;
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ctx.setFillStyle(this.data.lineColor); // 初始线条设置颜色
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ctx.setGlobalAlpha(this.data.transparent); // 设置半透明
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let currentPoint = {
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x: e.touches[0].x,
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y: e.touches[0].y
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}
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let currentLine = this.data.currentLine;
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currentLine.unshift({
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time: new Date().getTime(),
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dis: 0,
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x: currentPoint.x,
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y: currentPoint.y
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})
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this.setData({
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currentPoint,
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// currentLine
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})
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if (this.data.firstTouch) {
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this.setData({
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cutArea: {
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top: currentPoint.y,
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right: currentPoint.x,
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bottom: currentPoint.y,
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left: currentPoint.x
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},
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firstTouch: false
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})
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}
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this.pointToLine(currentLine);
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},
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// 笔迹移动
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uploadScaleMove(e) {
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if (e.type != 'touchmove') return false;
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if (e.cancelable) {
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// 判断默认行为是否已经被禁用
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if (!e.defaultPrevented) {
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e.preventDefault();
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}
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}
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let point = {
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x: e.touches[0].x,
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y: e.touches[0].y
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}
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//测试裁剪
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if (point.y < this.data.cutArea.top) {
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this.data.cutArea.top = point.y;
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}
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if (point.y < 0) this.data.cutArea.top = 0;
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if (point.x > this.data.cutArea.right) {
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this.data.cutArea.right = point.x;
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}
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if (this.data.canvasWidth - point.x <= 0) {
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this.data.cutArea.right = this.data.canvasWidth;
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}
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if (point.y > this.data.cutArea.bottom) {
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this.data.cutArea.bottom = point.y;
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}
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if (this.data.canvasHeight - point.y <= 0) {
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this.data.cutArea.bottom = this.data.canvasHeight;
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}
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if (point.x < this.data.cutArea.left) {
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this.data.cutArea.left = point.x;
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}
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if (point.x < 0) this.data.cutArea.left = 0;
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this.setData({
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lastPoint: this.data.currentPoint,
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currentPoint: point
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})
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let currentLine = this.data.currentLine
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currentLine.unshift({
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time: new Date().getTime(),
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dis: this.distance(this.data.currentPoint, this.data.lastPoint),
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x: point.x,
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y: point.y
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})
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// this.setData({
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// currentLine
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// })
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this.pointToLine(currentLine);
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},
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// 笔迹结束
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uploadScaleEnd(e) {
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if (e.type != 'touchend') return 0;
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let point = {
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x: e.changedTouches[0].x,
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y: e.changedTouches[0].y
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}
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this.setData({
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lastPoint: this.data.currentPoint,
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currentPoint: point
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})
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let currentLine = this.data.currentLine
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currentLine.unshift({
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time: new Date().getTime(),
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dis: this.distance(this.data.currentPoint, this.data.lastPoint),
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x: point.x,
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y: point.y
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})
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// this.setData({
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// currentLine
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// })
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if (currentLine.length > 2) {
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var info = (currentLine[0].time - currentLine[currentLine.length - 1].time) / currentLine.length;
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//$("#info").text(info.toFixed(2));
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}
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//一笔结束，保存笔迹的坐标点，清空，当前笔迹
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//增加判断是否在手写区域；
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this.pointToLine(currentLine);
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var currentChirography = {
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lineSize: this.data.lineSize,
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lineColor: this.data.lineColor
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};
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var chirography = this.data.chirography
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chirography.unshift(currentChirography);
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this.setData({
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chirography
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})
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var linePrack = this.data.linePrack
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linePrack.unshift(this.data.currentLine);
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this.setData({
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linePrack,
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currentLine: []
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})
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},
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retDraw() {
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this.data.linePrack = []
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this.data.chirography = []
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this.data.ctx.clearRect(0, 0, 680, 300)
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this.data.ctx.draw()
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this.hideModal()
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},
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//画两点之间的线条；参数为:line，会绘制最近的开始的两个点；
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pointToLine(line) {
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this.calcBethelLine(line);
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return;
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},
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//计算插值的方式；
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calcBethelLine(line) {
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if (line.length <= 1) {
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line[0].r = this.data.radius;
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return;
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}
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let x0, x1, x2, y0, y1, y2, r0, r1, r2, len, lastRadius, dis = 0,
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time = 0,
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curveValue = 0.5;
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if (line.length <= 2) {
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x0 = line[1].x
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y0 = line[1].y
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x2 = line[1].x + (line[0].x - line[1].x) * curveValue;
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y2 = line[1].y + (line[0].y - line[1].y) * curveValue;
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//x2 = line[1].x;
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//y2 = line[1].y;
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x1 = x0 + (x2 - x0) * curveValue;
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y1 = y0 + (y2 - y0) * curveValue;;
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} else {
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x0 = line[2].x + (line[1].x - line[2].x) * curveValue;
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y0 = line[2].y + (line[1].y - line[2].y) * curveValue;
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x1 = line[1].x;
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y1 = line[1].y;
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x2 = x1 + (line[0].x - x1) * curveValue;
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y2 = y1 + (line[0].y - y1) * curveValue;
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}
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//从计算公式看，三个点分别是(x0,y0),(x1,y1),(x2,y2) ；(x1,y1)这个是控制点，控制点不会落在曲线上；实际上，这个点还会手写获取的实际点，却落在曲线上
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len = this.distance({
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x: x2,
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y: y2
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}, {
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x: x0,
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y: y0
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});
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lastRadius = this.data.radius;
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for (let n = 0; n < line.length - 1; n++) {
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dis += line[n].dis;
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time += line[n].time - line[n + 1].time;
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if (dis > this.data.smoothness) break;
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}
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this.setData({
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radius: Math.min(time / len * this.data.pressure + this.data.lineMin, this.data.lineMax) * this.data.lineSize
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});
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line[0].r = this.data.radius;
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//计算笔迹半径；
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if (line.length <= 2) {
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r0 = (lastRadius + this.data.radius) / 2;
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r1 = r0;
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r2 = r1;
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//return;
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} else {
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r0 = (line[2].r + line[1].r) / 2;
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r1 = line[1].r;
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r2 = (line[1].r + line[0].r) / 2;
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}
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let n = 5;
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let point = [];
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for (let i = 0; i < n; i++) {
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let t = i / (n - 1);
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let x = (1 - t) * (1 - t) * x0 + 2 * t * (1 - t) * x1 + t * t * x2;
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let y = (1 - t) * (1 - t) * y0 + 2 * t * (1 - t) * y1 + t * t * y2;
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let r = lastRadius + (this.data.radius - lastRadius) / n * i;
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point.push({
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x: x,
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y: y,
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r: r
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});
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if (point.length == 3) {
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let a = this.ctaCalc(point[0].x, point[0].y, point[0].r, point[1].x, point[1].y, point[1].r, point[2].x, point[2].y, point[2].r);
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a[0].color = this.data.lineColor;
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// let bethelPoint = this.data.bethelPoint;
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// bethelPoint = bethelPoint.push(a);
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this.bethelDraw(a, 1);
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point = [{
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x: x,
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y: y,
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r: r
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}];
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}
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}
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this.setData({
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currentLine: line
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})
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},
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//求两点之间距离
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distance(a, b) {
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let x = b.x - a.x;
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let y = b.y - a.y;
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return Math.sqrt(x * x + y * y);
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},
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ctaCalc(x0, y0, r0, x1, y1, r1, x2, y2, r2) {
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let a = [],
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vx01, vy01, norm, n_x0, n_y0, vx21, vy21, n_x2, n_y2;
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vx01 = x1 - x0;
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vy01 = y1 - y0;
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norm = Math.sqrt(vx01 * vx01 + vy01 * vy01 + 0.0001) * 2;
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vx01 = vx01 / norm * r0;
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vy01 = vy01 / norm * r0;
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n_x0 = vy01;
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n_y0 = -vx01;
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vx21 = x1 - x2;
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vy21 = y1 - y2;
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norm = Math.sqrt(vx21 * vx21 + vy21 * vy21 + 0.0001) * 2;
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vx21 = vx21 / norm * r2;
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vy21 = vy21 / norm * r2;
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n_x2 = -vy21;
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n_y2 = vx21;
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a.push({
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mx: x0 + n_x0,
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my: y0 + n_y0,
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color: "#1A1A1A"
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});
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a.push({
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c1x: x1 + n_x0,
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c1y: y1 + n_y0,
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c2x: x1 + n_x2,
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c2y: y1 + n_y2,
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ex: x2 + n_x2,
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ey: y2 + n_y2
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});
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a.push({
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c1x: x2 + n_x2 - vx21,
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c1y: y2 + n_y2 - vy21,
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c2x: x2 - n_x2 - vx21,
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c2y: y2 - n_y2 - vy21,
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ex: x2 - n_x2,
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ey: y2 - n_y2
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});
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a.push({
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c1x: x1 - n_x2,
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c1y: y1 - n_y2,
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c2x: x1 - n_x0,
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c2y: y1 - n_y0,
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ex: x0 - n_x0,
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ey: y0 - n_y0
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});
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a.push({
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c1x: x0 - n_x0 - vx01,
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c1y: y0 - n_y0 - vy01,
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c2x: x0 + n_x0 - vx01,
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c2y: y0 + n_y0 - vy01,
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ex: x0 + n_x0,
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ey: y0 + n_y0
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});
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a[0].mx = a[0].mx.toFixed(1);
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a[0].mx = parseFloat(a[0].mx);
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a[0].my = a[0].my.toFixed(1);
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a[0].my = parseFloat(a[0].my);
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for (let i = 1; i < a.length; i++) {
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a[i].c1x = a[i].c1x.toFixed(1);
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a[i].c1x = parseFloat(a[i].c1x);
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a[i].c1y = a[i].c1y.toFixed(1);
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a[i].c1y = parseFloat(a[i].c1y);
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a[i].c2x = a[i].c2x.toFixed(1);
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a[i].c2x = parseFloat(a[i].c2x);
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a[i].c2y = a[i].c2y.toFixed(1);
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a[i].c2y = parseFloat(a[i].c2y);
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a[i].ex = a[i].ex.toFixed(1);
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a[i].ex = parseFloat(a[i].ex);
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a[i].ey = a[i].ey.toFixed(1);
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a[i].ey = parseFloat(a[i].ey);
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}
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return a;
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},
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bethelDraw(point, is_fill, color) {
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let ctx = this.data.ctx;
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ctx.beginPath();
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ctx.moveTo(point[0].mx, point[0].my);
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if (undefined != color) {
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ctx.setFillStyle(color);
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ctx.setStrokeStyle(color);
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} else {
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ctx.setFillStyle(point[0].color);
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ctx.setStrokeStyle(point[0].color);
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}
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for (let i = 1; i < point.length; i++) {
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ctx.bezierCurveTo(point[i].c1x, point[i].c1y, point[i].c2x, point[i].c2y, point[i].ex, point[i].ey);
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}
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ctx.stroke();
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if (undefined != is_fill) {
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ctx.fill(); //填充图形 ( 后绘制的图形会覆盖前面的图形, 绘制时注意先后顺序 )
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}
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ctx.draw(true)
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},
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selectColorEvent(event) {
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var color = event.currentTarget.dataset.colorValue;
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var colorSelected = event.currentTarget.dataset.color;
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this.setData({
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selectColor: colorSelected,
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lineColor: color
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})
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},
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subCanvas() {
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var _this = this;
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// let ctx = this.data.ctx;
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// ctx.fillStyle='#FFFFFF';
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// ctx.fillRect(0, 0, 680, 300)
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// this.data.ctx.draw(true, function () {
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wx.canvasToTempFilePath({
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canvasId: 'handWriting',
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fileType: 'png',
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quality: 1,
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destWidth: this.data.canvasHeight,
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destHeight: this.data.canvasWidth,
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success(res) {
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if (_this.data.linePrack.length == 0) {
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Toast.loading({
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type: 'fail',
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message: '签名无效',
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selector: '#van-toast',
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zIndex: 99999999,
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});
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return
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}
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wx.getImageInfo({
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src: res.tempFilePath,
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success: (msg) => {
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let height = msg.height / 2
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let width = msg.width / 2
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let canvas = wx.createCanvasContext('handWriting1', _this);
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canvas.translate(height / 2, width / 2)
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canvas.rotate(270 * Math.PI / 180)
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canvas.drawImage(res.tempFilePath, -width / 2, -height / 2, width, height);
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canvas.draw(false, () => {
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wx.canvasToTempFilePath({
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canvasId: 'handWriting1',
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fileType: 'png',
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quality: 1,
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destWidth: _this.data.canvasWidth,
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destHeight: _this.data.canvasHeight,
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success(vas) {
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let imgList = _this.data.imgList;
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imgList.splice(0, _this.data.imgList.length);
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let img = {};
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img.id = '';
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img.filePath = vas.tempFilePath;
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imgList.push(img)
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_this.setData({
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imgList: [...imgList]
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})
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_this.triggerEvent('subCanvas', imgList[0].filePath)
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_this.retDraw();
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}
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}, _this)
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})
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}
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})
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}
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}, _this);
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// });
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},
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hideModal(e) {
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this.triggerEvent('hideModal')
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},
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}
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}) |