使用html,css,js 实现烟花效果
时间: 2023-05-28 11:07:51 浏览: 122
好的,以下是使用HTML、CSS和JavaScript实现烟花效果的示例代码:
HTML 代码:
```
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>烟花效果</title>
<style>
canvas {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
<script src="firework.js"></script>
</body>
</html>
```
CSS 代码:
上面的 HTML 代码中已经包含了 CSS 样式。
JavaScript 代码:
```
// 定义常量
const GRAVITY = 0.05;
const FRICTION = 0.99;
// 获取 canvas 元素
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// 设置 canvas 大小
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
// 烟花类
class Firework {
constructor() {
// 随机生成烟花发射的位置和角度
this.x = Math.random() * canvas.width;
this.y = canvas.height;
this.angle = Math.random() * Math.PI * 2;
// 随机生成烟花的颜色
this.color = `rgb(${Math.random() * 255}, ${Math.random() * 255}, ${Math.random() * 255})`;
// 烟花的速度和加速度
this.velocity = {
x: Math.sin(this.angle) * 5,
y: Math.cos(this.angle) * 5
};
this.gravity = {
x: 0,
y: GRAVITY
};
// 记录烟花是否已经爆炸
this.exploded = false;
// 烟花爆炸后的粒子
this.particles = [];
}
// 更新烟花的状态
update() {
// 如果烟花没有爆炸
if (!this.exploded) {
// 更新烟花的速度和位置
this.velocity.x *= FRICTION;
this.velocity.y *= FRICTION;
this.velocity.y -= this.gravity.y;
this.x += this.velocity.x;
this.y -= this.velocity.y;
// 如果烟花到达顶部,则触发爆炸效果
if (this.velocity.y >= 0) {
this.explode();
}
} else {
// 更新烟花粒子的位置和透明度
for (let i = 0; i < this.particles.length; i++) {
this.particles[i].velocity.x *= FRICTION;
this.particles[i].velocity.y *= FRICTION;
this.particles[i].velocity.y += this.gravity.y;
this.particles[i].x += this.particles[i].velocity.x;
this.particles[i].y += this.particles[i].velocity.y;
this.particles[i].alpha -= 0.01;
}
// 移除已经消失的烟花粒子
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