前端学习笔记之用canvas实现鼠标追踪
用js实现鼠标追踪的效果：
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>鼠标追踪</title>
<style>
#cw {
position: fixed;
z-index: -1;
}
body {
margin: 0;
padding: 0;
background-color: rgba(0, 0, 0, 0.05);
}
</style>
</head>
<body>
<canvas id="cw"></canvas>
<script>
var cn;
var c;
var u = 10;
const m = {
x: innerWidth / 2,
y: innerHeight / 2
};
window.onmousemove = function (e) {
m.x = e.clientX;
m.y = e.clientY;
}
function gc() {
var s = "0123456789ABCDEF";
var c = "#";
for (var i = 0; i < 6; i++) {
c += s[Math.ceil(Math.random() * 15)]
}
return c
}
var a = [];
window.onload = function myfunction() {
cn = document.getElementById('cw');
c = cn.getContext('2d');
for (var i = 0; i < 10; i++) {
var r = 30;
var x = Math.random() * (innerWidth - 2 * r) + r;
var y = Math.random() * (innerHeight - 2 * r) + r;
var t = new ob(innerWidth / 2, innerHeight / 2, 5, "red", Math.random() * 200 + 20, 2);
a.push(t);
}
c.lineWidth = "2";
c.globalAlpha = 0.5;
resize();
anim()
}
window.onresize = function () {
resize();
}
function resize() {
cn.height = innerHeight;
cn.width = innerWidth;
for (var i = 0; i <99; i++) {
var r = 30;
var x = Math.random() * (innerWidth - 2 * r) + r;
var y = Math.random() * (innerHeight - 2 * r) + r;
a[i] = new ob(innerWidth / 2, innerHeight / 2, 4, gc(), Math.random() * 200 + 20, 0.02);
}
}
function ob(x, y, r, cc, o, s) {
this.x = x;
this.y = y;
this.r = r;
this.cc = cc;
this.theta = Math.random() * Math.PI * 2;
this.s = s;
this.o = o;
this.t = Math.random() * 150;
this.o = o;
this.dr = function () {
const ls = {
x: this.x,
y: this.y
};
this.theta += this.s;
this.x = m.x + Math.cos(this.theta) * this.t;
this.y = m.y + Math.sin(this.theta) * this.t;
c.beginPath();
c.lineWidth = this.r;
c.strokeStyle = this.cc;
c.moveTo(ls.x, ls.y);
c.lineTo(this.x, this.y);
c.stroke();
c.closePath();
}
}
function anim() {
requestAnimationFrame(anim);
c.fillStyle = "rgba(0,0,0,0.05)";
c.fillRect(0, 0, cn.width, cn.height);
a.forEach(function (e, i) {
e.dr();
});
}
</script>
</body>
</html>
