//鼠标移动 展现光片
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style> body { margin: 0; overflow: hidden; } #canvas { background: #000; } </style> </head> <body> <canvas></canvas> <script> var canvas = document.getElementById('canvas'); var context = canvas.getContext('2d'); var circleList = []; canvas.width = window.innerWidth; canvas.height = window.innerHeight; canvas.addEventListener('mousemove', function (e) { // 将对象push到数组中，画出来的彩色小点可以看作每一个对象中记录着信息 然后存在数组中 circleList.push(new Circle(e.clientX, e.clientY)); }) //取x到y之间随机数：Math.round(Math.random()*(y-x)+x) 包括y function random(min, max) { return Math.round(Math.random() * (max - min) + min); } function Circle(x, y) { this.x = x; this.y = y; this.vx = (Math.random() - 0.5) * 3; //随机出来一个正数，或者负数。乘3是为了让速度变得大一点 this.vy = (Math.random() - 0.5) * 3; this.color = 'rgb(' + random(0, 255) + ',' + random(0, 255) + ',' + random(0, 255) + ')'; this.a = 1; // 初始透明度 this.draw(); } Circle.prototype = { draw() { context.beginPath(); context.fillStyle = this.color; context.globalCompositeOperation = 'lighter'; context.globalAlpha = this.a; //全局透明度 context.arc(this.x, this.y, 30, 0, Math.PI * 2, false); context.fill(); this.update(); }, update() { // 根据速度更新每一个小圆的位置 this.x += this.vx; this.y += this.vy; this.a *= 0.98; } } function render() { //把原来的内容区域清除掉 context.clearRect(0, 0, canvas.width, canvas.height); circleList.forEach(function (ele, i) { ele.draw(); if (ele.a < 0.05) { circleList.splice(i, 1); } }); requestAnimationFrame(render); //动画，会根据浏览器的刷新频率更新动画 } render(); </script> </body> </html>
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
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