HTML代碼
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
html {
height: 100%
}
body {
margin: 0;
height: 100%;
background:
}
canvas {
display: block;
width: 100%;
height: 100%;
}
.body_content {
position: absolute;
top: 30%;
left: 20%;
height: 20%;
background: palevioletred;
width: 20%;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
<script src="./index.js"></script>
</body>
</html>
JS代碼
class Circle {
constructor(x, y) {
this.x = x;
this.y = y;
this.r = Math.random() * 10;
this._mx = Math.random();
this._my = Math.random();
}
drawCircle(ctx) {
ctx.beginPath();
ctx.arc(this.x, this.y, this.r, 0, 360)
ctx.closePath();
ctx.fillStyle = 'rgba(204, 204, 204, 0.3)';
ctx.fill();
}
drawLine(ctx, _circle) {
let dx = this.x - _circle.x;
let dy = this.y - _circle.y;
let d = Math.sqrt(dx * dx + dy * dy)
if (d < 150) {
ctx.beginPath();
ctx.moveTo(this.x, this.y);
ctx.lineTo(_circle.x, _circle.y);
ctx.closePath();
ctx.strokeStyle = 'rgba(204, 204, 204, 0.3)';
ctx.stroke();
}
}
move(w, h) {
this._mx = (this.x < w && this.x > 0) ? this._mx : (-this._mx);
this._my = (this.y < h && this.y > 0) ? this._my : (-this._my);
this.x += this._mx / 2;
this.y += this._my / 2;
}
}
class currentCirle extends Circle {
constructor(x, y) {
super(x, y);
}
drawCircle(ctx) {
ctx.beginPath();
this.r = 8;
ctx.arc(this.x, this.y, this.r, 0, 360);
ctx.closePath();
ctx.fillStyle = 'rgba(255, 77, 54, 0.6)'
ctx.fill();
}
}
window.requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
let canvas = document.getElementById('canvas');
let ctx = canvas.getContext('2d');
let w = canvas.width = canvas.offsetWidth;
let h = canvas.height = canvas.offsetHeight;
let circles = [];
let current_circle = new currentCirle(0, 0);
let draw = function() {
ctx.clearRect(0, 0, w, h);
for (let i = 0; i < circles.length; i++) {
circles[i].move(w, h);
circles[i].drawCircle(ctx);
for (j = i + 1; j < circles.length; j++) {
circles[i].drawLine(ctx, circles[j]);
}
}
if (current_circle.x) {
current_circle.drawCircle(ctx);
for (var k = 1; k < circles.length; k++) {
current_circle.drawLine(ctx, circles[k]);
}
}
requestAnimationFrame(draw);
}
let init = function(num) {
for (var i = 0; i < num; i++) {
circles.push(new Circle(Math.random() * w, Math.random() * h));
}
draw();
}
window.addEventListener('load', init(60));
window.onmousemove = function(e) {
e = e || window.event;
current_circle.x = e.clientX;
current_circle.y = e.clientY;
}
window.onmouseout = function() {
current_circle.x = null;
current_circle.y = null;
};
最終效果
![動態粒子背景]()
