html5 canvas实现跟随鼠标旋转的箭头
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<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <title>canvas实现跟随鼠标旋转的箭头</title> <style> *{padding: 0;margin: 0} </style> </head> <body> <canvas width="500" height="500" style="border: 1px solid #555; display: block;margin: 0 auto;"></canvas> <script> var arrow=function () { this.x=0; this.y=0; this.color="#f90" this.rolation=0; } var canvas=document.querySelector('canvas') var ctx=canvas.getContext('2d'); arrow.prototype.draw=function (ctx) { ctx.save(); ctx.translate(this.x,this.y); ctx.rotate(this.rolation) ctx.fillStyle=this.color; ctx.beginPath(); ctx.moveTo(0, 15); ctx.lineTo(-50, 15); ctx.lineTo(-50, -15); ctx.lineTo(0,-15); ctx.lineTo(0,-35); ctx.lineTo(50,0); ctx.lineTo(0,35); ctx.closePath() ctx.fill(); ctx.restore(); } var Arrow=new arrow(); Arrow.x=canvas.width/2; Arrow.y=canvas.height/2;
var c_x,c_y; //相对于canvas坐标的位置； var isMouseDown=false; Arrow.draw(ctx) canvas.addEventListener('mousedown',function(e) { isMouseDown=true; },false) canvas.addEventListener('mousemove',function(e) { if(isMouseDown==true){ （编辑：焦作站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |