手写毛笔字效果-手机版

来源：互联网发布：菏泽学院教务网络编辑：程序博客网时间：2024/04/28 13:54
<!doctype html><html lang="en"><head><meta charset="UTF-8" /><meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" /><meta name="viewport" content="width=400"><title> canvas手写毛笔字效果 </title><style type="text/css">body {margin: 0;padding: 0;background-color: #999999;}h1 {text-align: center;}#canvasId {background-color: #FFFFcc;}.button {width: 100px;height: 40px;}</style></head><body><h1>手写毛笔字效果-手机版</h1><canvas id="canvasId" width="400" height="400"></canvas><br /><input type="button" value="全部清除" class="button" onclick="hw.clear();" /><input type="button" value="清除最后一笔" class="button" onclick="hw.historyBack();" /><script type="text/javascript">function Handwriting(id) {this.canvas = document.getElementById(id);this.ctx = this.canvas.getContext("2d");this.ctx.fillStyle = "rgba(0,0,0,0.25)";this.canvas.addEventListener("touchstart", this.downEvent.bind(this), false);this.canvas.addEventListener("touchmove", this.moveEvent.bind(this), false);this.canvas.addEventListener("touchend", this.upEvent.bind(this), false);this.canvas.addEventListener("contextmenu", function(e){ e.preventDefault() }, false);//this.canvas.onmousedown = this.downEvent.bind(this);//this.canvas.onmousemove = this.moveEvent.bind(this);//this.canvas.onmouseup = this.upEvent.bind(this);//this.canvas.onmouseout = this.upEvent.bind(this);this.moveFlag = false;this.upof = {};this.radius = 0;this.has = [];this.startOf = null;this.lineMax = 30;this.lineMin = 3;this.linePressure = 1;this.smoothness = 80;this.history = [];}Handwriting.prototype.clear = function () {this.history = [];this.ctx.clearRect(0,0,this.canvas.width,this.canvas.height);}Handwriting.prototype.historyBack = function () {this.history.pop();this.ctx.clearRect(0,0,this.canvas.width,this.canvas.height);for (var i = 0; i < this.history.length; i++) {var h = this.history[i];for (var j = 0; j < h.length; j+=3) {this.ctx.beginPath();this.ctx.arc(h[j],h[j+1],h[j+2],0,2*Math.PI,true);this.ctx.fill();}}}Handwriting.prototype.downEvent = function (e) {this.moveFlag = true;this.has = [];this.history.push([]);this.upof = this.getXY(e);this.startOf = this.upof;}Handwriting.prototype.moveEvent = function (e) {if (!this.moveFlag)return;e.preventDefault();var of = this.getXY(e);var up = this.upof;var ur = this.radius;this.has.unshift({time:new Date().getTime() ,dis:this.distance(up,of)});var dis = 0;var time = 0;for (var n = 0; n < this.has.length-1; n++) {dis += this.has[n].dis;time += this.has[n].time-this.has[n+1].time;if (dis>this.smoothness)break;}var or = Math.min(time/dis*this.linePressure+this.lineMin , this.lineMax) / 2;this.radius = or;this.upof = of;if (dis<7)return;if (this.startOf) {up = this.startOf;ur = or;this.startOf = null;}var len = Math.ceil(this.distance(up,of)/2);for (var i = 0; i < len; i++) {var x = up.x + (of.x-up.x)/len*i;var y = up.y + (of.y-up.y)/len*i;var r = ur + (or-ur)/len*i;this.ctx.beginPath();this.ctx.arc(x,y,r,0,2*Math.PI,true);this.ctx.fill();this.history[this.history.length-1].push(x,y,r);}}Handwriting.prototype.upEvent = function (e) {this.moveFlag = false;}Handwriting.prototype.getXY = function (e) {var x = e.touches[0].clientX;var y = e.touches[0].clientY;//var x = e.clientX;//var y = e.clientY;return {x : x - this.canvas.offsetLeft + (document.body.scrollLeft || document.documentElement.scrollLeft),y : y - this.canvas.offsetTop  + (document.body.scrollTop || document.documentElement.scrollTop)}}Handwriting.prototype.distance = function (a,b) {var x = b.x-a.x , y = b.y-a.y;return Math.sqrt(x*x+y*y);}var hw = new Handwriting("canvasId");hw.lineMax = 40;hw.lineMin = 5;hw.linePressure = 3.1;hw.smoothness = 100;</script></body></html>
在线演示：https://js-game.github.io/Handwriting/handwriting.html
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