canvas实现小球连线效果

浏览其它浏览器页面的时候看到一个小球动态效果，就自己写了一个，如下图
过程也很简单
封装个随机数
声明一个绘制小球的类
更新小球位置
监听鼠标移动更新小球位置
完整代码
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>阁下</title>
    <style>
        html,
        body {
            margin: 0;
            padding: 0;
            height: 100%;
            box-sizing: border-box;
        }
        #canvas {
            background-color: rgb(0, 0, 0);
        }
    </style>
</head>

<body>
    <canvas id="canvas"></canvas>
    <script>
        var canvas = document.getElementById("canvas");
        var ctx = canvas.getContext("2d");
        var xZou=0,yZou=0;

        function resizeFn(){
            canvas.width = window.innerWidth;
            canvas.height = window.innerHeight;
        }
        resizeFn();

        // 随机数
        function getRandom(min,max){
            return Math.floor(Math.random() * (max + 1 -min) + min);
        }

        class Point {
            constructor(){
                this.r = 10;//小球半径
                this.x = getRandom(0,canvas.width - this.r);//小球x坐标
                this.y = getRandom(0,canvas.height - this.r);//小球y坐标
                this.xSpeed = getRandom(-3,3);//x轴速度
                this.ySpeed = getRandom(-3,3);//y轴速度
                this.speed = 50;//小球跟随鼠标移动速度
                this.temp = 0;//小球是否跟随鼠标移动 0 不移动 1 移动

                this.flag = null;
            }
            // 绘制单个小球
            draw(){
                if(this.flag){
                    if(this.temp == 1){
                        //缓慢移动
                        this.x = this.x + (xZou - this.x) / this.speed;
                        this.y = this.y + (yZou - this.y) / this.speed;
                    }else{
                        //超出屏幕返回
                        if(this.x <= this.r || this.x >= canvas.width - this.r) this.xSpeed *= -1;
                        if(this.y <= this.r || this.y >= canvas.height - this.r) this.ySpeed *= -1;
                        this.x = this.x + this.xSpeed;
                        this.y = this.y + this.ySpeed;
                    }
                }
                // 绘制小球
                ctx.beginPath();
                ctx.arc(this.x,this.y,this.r,0,2 * Math.PI,false);
                ctx.fillStyle = "rgba(200,200,200,.6)";
                ctx.fill();
                this.flag = true;
            }
        }

        // 更新
        class Update {
            //list 小球数量 distance 小球之间连线最大距离
            constructor(list = 50,distance = 200){
                this.arr = new Array(list).fill(0).map(() => new Point());
                this.distance = distance;
            }
            draw(){
                window.requestAnimationFrame(() => this.draw());
                ctx.clearRect(0,0,canvas.width,canvas.height);
                for(let i = 0;i<this.arr.length;i++){

                    //根据小球和鼠标的距离判断是否大于distance
                    let l = Math.sqrt((this.arr[i].x - xZou) ** 2 + (this.arr[i].y - yZou) ** 2);
                    if(l > this.distance){
                        this.arr[i].temp = 0;
                    }else{
                        this.arr[i].temp = 1;
                    }

                    // 绘制小球
                    this.arr[i].draw();

                    for(let j = i + 1;j<this.arr.length;j++){
                       let d = Math.sqrt((this.arr[i].x - this.arr[j].x) ** 2 + (this.arr[i].y - this.arr[j].y) ** 2);
                       if(d > this.distance) continue;

                        // 绘制线
                       ctx.beginPath();
                       ctx.moveTo(this.arr[i].x,this.arr[i].y);
                       ctx.lineTo(this.arr[j].x,this.arr[j].y);
                       ctx.strokeStyle = `rgba(255,255,255,0.3)`;
                       ctx.stroke();
                    }
                }
            }
        }

        canvas.addEventListener('mousemove',function(e){
            xZou = e.clientX;
            yZou = e.clientY;
        })

        const update = new Update();
        update.draw();
    </script>
</body>

</html>
canvas实现小球连线效果

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