455 lines
18 KiB
Vue
455 lines
18 KiB
Vue
<template>
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<view class="cu-dialog">
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<view class="cu-bar bg-white justify-end">
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<view class="content">签名</view>
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<view class="action" @tap="_cancel">
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<text class="cuIcon-close text-red"></text>
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</view>
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</view>
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<view>
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<view class="wrapper">
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<view class="handCenter">
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<canvas
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class="handWriting"
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:disable-scroll="true"
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@touchstart="uploadScaleStart"
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@touchmove="uploadScaleMove"
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@touchend="uploadScaleEnd"
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canvas-id="handWriting"
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></canvas>
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</view>
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</view>
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</view>
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<view class="cu-bar bg-white justify-end">
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<view class="action">
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<button class="cu-btn line-green text-green" @click="retDraw">重写</button>
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<button class="cu-btn bg-green margin-left" @click="confirm" >完成</button>
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</view>
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</view>
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</view>
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</template>
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<script>
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export default {
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props: {
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imgList: {
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type: Array,
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default: function () {
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return []
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}
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}
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},
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data() {
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return {
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//手写板
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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: 'black',
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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: { top: 0, right: 0, bottom: 0, left: 0 }, //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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},
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created(){
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//手写板
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let canvasName = this.canvasName;
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let ctx = uni.createCanvasContext(canvasName);
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this.ctx = ctx;
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var query = uni.createSelectorQuery();
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query
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.select('.handCenter')
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.boundingClientRect(rect => {
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this.canvasWidth = rect.width;
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this.canvasHeight = rect.height;
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/* 将canvas背景设置为 白底，不设置 导出的canvas的背景为透明 */
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this.setCanvasBg('#fff');
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})
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.exec();
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},
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methods: {
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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.ctx;
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ctx.setFillStyle(this.lineColor); // 初始线条设置颜色
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ctx.setGlobalAlpha(this.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.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.currentPoint = currentPoint;
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// currentLine
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if (this.firstTouch) {
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this.cutArea = { top: currentPoint.y, right: currentPoint.x, bottom: currentPoint.y, left: currentPoint.x };
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this.firstTouch = false;
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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.cutArea.top) {
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this.cutArea.top = point.y;
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}
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if (point.y < 0) this.cutArea.top = 0;
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if (point.x > this.cutArea.right) {
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this.cutArea.right = point.x;
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}
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if (this.canvasWidth - point.x <= 0) {
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this.cutArea.right = this.canvasWidth;
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}
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if (point.y > this.cutArea.bottom) {
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this.cutArea.bottom = point.y;
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}
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if (this.canvasHeight - point.y <= 0) {
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this.cutArea.bottom = this.canvasHeight;
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}
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if (point.x < this.cutArea.left) {
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this.cutArea.left = point.x;
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}
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if (point.x < 0) this.cutArea.left = 0;
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this.lastPoint = this.currentPoint;
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this.currentPoint = point;
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let currentLine = this.currentLine;
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currentLine.unshift({
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time: new Date().getTime(),
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dis: this.distance(this.currentPoint, this.lastPoint),
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x: point.x,
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y: point.y
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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.lastPoint = this.currentPoint;
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this.currentPoint = point;
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let currentLine = this.currentLine;
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currentLine.unshift({
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time: new Date().getTime(),
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dis: this.distance(this.currentPoint, this.lastPoint),
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x: point.x,
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y: point.y
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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.lineSize,
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lineColor: this.lineColor
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};
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var chirography = this.chirography;
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chirography.unshift(currentChirography);
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this.chirography = chirography;
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var linePrack = this.linePrack;
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linePrack.unshift(this.currentLine);
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this.linePrack = linePrack;
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this.currentLine = [];
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},
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retDraw() {
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this.ctx.clearRect(0, 0, 700, 730);
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this.ctx.draw();
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//设置canvas背景
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this.setCanvasBg('#fff');
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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.radius;
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return;
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}
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let x0,
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x1,
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x2,
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y0,
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y1,
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y2,
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r0,
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r1,
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r2,
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len,
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lastRadius,
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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({ x: x2, y: y2 }, { x: x0, y: y0 });
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lastRadius = this.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.smoothness) break;
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}
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this.radius = Math.min((time / len) * this.pressure + this.lineMin, this.lineMax) * this.lineSize;
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line[0].r = this.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.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.radius - lastRadius) / n) * i;
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point.push({ x: x, y: y, r: r });
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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.lineColor;
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// let bethelPoint = this.bethelPoint;
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// bethelPoint = bethelPoint.push(a);
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this.bethelDraw(a, 1);
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point = [{ x: x, y: y, r: r }];
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}
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}
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this.currentLine = line;
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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,
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vy01,
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norm,
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n_x0,
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n_y0,
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vx21,
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vy21,
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n_x2,
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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({ mx: x0 + n_x0, my: y0 + n_y0, color: '#1A1A1A' });
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a.push({ c1x: x1 + n_x0, c1y: y1 + n_y0, c2x: x1 + n_x2, c2y: y1 + n_y2, ex: x2 + n_x2, ey: y2 + n_y2 });
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a.push({ c1x: x2 + n_x2 - vx21, c1y: y2 + n_y2 - vy21, c2x: x2 - n_x2 - vx21, c2y: y2 - n_y2 - vy21, ex: x2 - n_x2, ey: y2 - n_y2 });
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a.push({ c1x: x1 - n_x2, c1y: y1 - n_y2, c2x: x1 - n_x0, c2y: y1 - n_y0, ex: x0 - n_x0, ey: y0 - n_y0 });
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a.push({ c1x: x0 - n_x0 - vx01, c1y: y0 - n_y0 - vy01, c2x: x0 + n_x0 - vx01, c2y: y0 + n_y0 - vy01, ex: x0 + n_x0, ey: y0 + n_y0 });
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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.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(str,color) {
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this.selectColor = str;
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this.lineColor = color;
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},
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//完成
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confirm() {
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var _this = this;
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let img={};
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this.ctx.draw(true, () => {
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uni.canvasToTempFilePath({
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canvasId: 'handWriting',
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fileType: 'jpg',
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quality: 1, //图片质量
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destWidth:900,
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destHeight:435,
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success(res) {
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img.id='';
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img.filePath=res.tempFilePath;
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_this.retDraw();
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_this.$emit("confirm", img);
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}
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});
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});
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},
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//保存到相册
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saveCanvasAsImg() {
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uni.canvasToTempFilePath({
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canvasId: 'handWriting',
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fileType: 'png',
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quality: 1, //图片质量
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success(res) {
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// console.log(res.tempFilePath, 'canvas生成图片地址');
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uni.saveImageToPhotosAlbum({
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filePath: res.tempFilePath,
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success(res) {
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uni.showToast({
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title: '已保存到相册',
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duration: 2000
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});
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}
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});
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}
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});
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},
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//设置canvas背景色 不设置 导出的canvas的背景为透明
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//@params：字符串 color
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setCanvasBg(color) {
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/* 将canvas背景设置为 白底，不设置 导出的canvas的背景为透明 */
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//rect() 参数说明 矩形路径左上角的横坐标，左上角的纵坐标, 矩形路径的宽度, 矩形路径的高度
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//这里是 canvasHeight - 4 是因为下边盖住边框了，所以手动减了写
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this.ctx.rect(0, 0, this.canvasWidth, this.canvasHeight - 4);
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// ctx.setFillStyle('red')
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this.ctx.setFillStyle(color);
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this.ctx.fill(); //设置填充
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this.ctx.draw(); //开画
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},
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_cancel() {
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this.$emit("cancel", '');
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},
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}
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}
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</script>
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<style scoped>
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.wrapper {
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width: 100%;
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height: 24vh;
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margin: 0;
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overflow: hidden;
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display: flex;
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align-content: center;
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flex-direction: row;
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justify-content: center;
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font-size: 28rpx;
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}
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.handWriting {
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background: #fff;
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width: 100%;
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height: 100%;
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}
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.handCenter {
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border: 4rpx dashed #e9e9e9;
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flex: 5;
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overflow: hidden;
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box-sizing: border-box;
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}
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</style>
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