本文实例为大家分享了js跟随鼠标移动小球的具体代码,供大家参考,具体内容如下
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<!DOCTYPE html> < html > < head > < meta charset = "utf-8" > < title ></ title > < style > canvas{ border: 1px solid #000; } </ style > </ head > < body > < canvas id = "mycanvas" width = "1500" height = "800" ></ canvas > < script > // 创建画布 var canvas = document.getElementById('mycanvas'); var ctx = canvas.getContext('2d'); // 球类 function Ball(x, y) { this.x = x; this.y = y; // 初始半径 this.r = parseInt(Math.random() * 50) + 10; this.step = parseInt(Math.random() * 5) + 0.1; // 设置随机颜色 this.color = getRandom(); // 设置随机方向 this.dx = parseInt(Math.random() * 10) - 5; this.dy = parseInt(Math.random() * 10) - 5; // 将自身对象装入数组中 ballArr.push(this); } // 在数组中删除对象 Ball.prototype.remove = function() { for (var i = 0; i < ballArr.length ; i++) { if (ballArr[i] == this) { ballArr.splice(i, 1); } } } // 更新数据 Ball.prototype.update = function () { // 更新数据 this.x += this.dx; this.y += this.dy; this.r - = this .step; // 清除数组中的小球 if (this.r <= 0) { this.remove(); } // 如果超出边界,小球继续运动 if (this.x < 0) { this.x = 1500 ; this.color = getRandom (); } else if (this.x > 1500) { this.x = 0; this.color = getRandom(); } else if (this.y < 0 ) { this.y = 800 ; this.color = getRandom (); } else if (this.y > 800) { this.y = 0; this.color = getRandom(); } } // 渲染小球 Ball.prototype.render = function() { ctx.beginPath(); ctx.arc(this.x, this.y, this.r, 0, Math.PI * 2, false); ctx.fillStyle = this.color; ctx.fill(); } // canvas 画布DOM2事件 canvas.addEventListener("mousemove", function(event) { new Ball(event.offsetX, event.offsetY); }); var ballArr = []; // 定时器进行动画渲染和更新 setInterval(function() { // 动画逻辑 // 清屏-更新-渲染 ctx.clearRect(0, 0, canvas.width, canvas.height); // 小球的更新和渲染 for (var i = 0; i < ballArr.length ; i++) { ballArr[i].update(); if (ballArr[i]) { ballArr[i].render(); } } }, 30); // 随机颜色 function getRandom() { var allType = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f" ; var allTypeArr = allType.split(","); var color = "#" ; // 拼接颜色字符串 for (var i = 0 ; i < 6; i++) { var random = parseInt (Math.random() * allTypeArr.length); color += allTypeArr[random]; } return color; } </script> </ body > </ html > |
效果
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服务器之家。
原文链接:https://blog.csdn.net/qq_35068659/article/details/113762578