2022跨年烟花代码（七）HTML5五彩烟花动画特效
HTML5五彩烟花动画特效
html代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>HTML5 Canvas五彩烟花动画特效</title>
<style>
*{
padding: 0;
margin: 0;
}
</style>
</head>
<body>
<div id="example"></div>
<script type="text/javascript" src="js/jquery.min.js"></script>
<script type="text/javascript" src="js/firework.js"></script>
<script type="text/javascript">
$(function(){
$("#example").fireworks({
width: "100%",
height: "100%"
});
});
</script>
</body>
</html>
firework.js代码
(function ($) {
$.fn.fireworks = function(options){
options = options || {};
options.width = options.width || $(this).width();
options.height = options.height || $(this).height();
var fireworksField = this,
SCREEN_WIDTH = options.width,
SCREEN_HEIGHT = options.height,
rockets = [],
particles = [];
var canvas = document.createElement("canvas");
canvas.style.width = SCREEN_WIDTH + 'px';
canvas.style.height = SCREEN_HEIGHT + 'px';
canvas.width = SCREEN_WIDTH;
canvas.height = SCREEN_HEIGHT;
canvas.style.position = 'absolute';
canvas.style.top = '0px';
canvas.style.left = '0px';
var context = canvas.getContext('2d');
var mousePos = {};
var gravity = 0.05;
var raf;
$(fireworksField).append(canvas);
document.onmousemove = mouseMove;
setInterval(launch, 2000);
//setInterval(loop, 20);
raf = window.requestAnimationFrame(loop);
function mouseMove(ev){
ev = ev || window.event;
mousePos = mousePosition(ev);
}
function mousePosition(ev){
if(ev.pageX || ev.pageY){
return {x:ev.pageX, y:ev.pageY};
}
return {
x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
y:ev.clientY + document.body.scrollTop - document.body.clientTop
};
}
function launch() {
if (rockets.length < 10) {
var rocket = new Rocket(SCREEN_WIDTH/2);
rocket.v.x = Math.random() * 6 - 3;
rocket.v.y = Math.random() * -30 -4;
rocket.color = Math.floor(Math.random() * 360 / 10) * 10;
rockets.push(rocket);
}
}
function loop () {
var existRockets = [];
var existParticles = [];
if (SCREEN_WIDTH != window.innerWidth) {
canvas.width = SCREEN_WIDTH = window.innerWidth;
}
if (SCREEN_HEIGHT != window.innerHeight) {
canvas.height = SCREEN_HEIGHT = window.innerHeight;
}
context.fillStyle = "rgba(0,0,0,0.05)";
context.fillRect(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
//context.save();
for (var i = 0; i < rockets.length; i ++) {
rockets[i].update();
rockets[i].render(context);
//explosion rules
//1.above the 4/5 screen
//2.close to the mouse
//3.1% random chance above the 1/2 screen
var distance = Math.sqrt(Math.pow(mousePos.x - rockets[i].pos.x, 2) + Math.pow(mousePos.y - rockets[i].pos.y, 2));
var randomChance = (rockets[i].pos.y < SCREEN_HEIGHT/2)? (Math.random() * 100 <= 1) : false;
if (rockets[i].pos.y < SCREEN_HEIGHT/5 || distance <= 50 || randomChance) {
rockets[i].explode();
}else{
existRockets.push(rockets[i]);
}
}
rockets = existRockets;
for (var i = 0; i < particles.length; i ++) {
particles[i].update();
if (particles[i].exist()) {
particles[i].render(context);
existParticles.push(particles[i]);
}
}
particles = existParticles;
//context.restore();
raf = window.requestAnimationFrame(loop);
}
//the particles object
function Particle (pos) {
this.pos = {
x : pos? pos.x:0,
y : pos? pos.y:0
};
this.v = {
x : 0,
y : 0
};
this.resistance = 0.005;
this.size = 5;
this.shrink = 0.99;
this.alpha = 1;
this.fade = 0.97;
this.color = "";
}
Particle.prototype.update = function () {
this.v.x += this.resistance;
this.v.y -= this.resistance;
//gravity
this.v.y += gravity;
this.pos.x += this.v.x;
this.pos.y += this.v.y;
this.size *= this.shrink;
this.alpha *= this.fade;
}
Particle.prototype.render = function () {
var x = this.pos.x,
y = this.pos.y,
r = this.size/2;
var gradient = context.createRadialGradient(x, y, 0.1, x, y, r);
gradient.addColorStop(0, "rgba(255, 255, 255, "+ this.alpha +")");
gradient.addColorStop(0.9, "hsla(" + this.color + ", 100%, 50%, 1)");
gradient.addColorStop(1, "rgba(0, 0, 0, 1)");
context.fillStyle = gradient;
context.beginPath();
context.arc(x, y, r, 0, 2 * Math.PI, true);
context.closePath();
context.fill();
}
Particle.prototype.exist = function () {
if (this.alpha >= 0.02 && this.size > 0.8) {
return true;
}else{
return false;
}
}
//the rocket object
function Rocket (x) {
Particle.apply(this, [{
x : x,
y : SCREEN_HEIGHT
}]);
}
(function () {
var Super = function () {};
Super.prototype = Particle.prototype;
Rocket.prototype = new Super();
})();
Rocket.prototype.constructor = Rocket;
Rocket.prototype.update = function () {
this.pos.x += this.v.x;
this.pos.y += this.v.y;
}
Rocket.prototype.render = function (context) {
var x = this.pos.x,
y = this.pos.y,
r = this.size/2;
var gradient = context.createRadialGradient(x, y, 0.1, x, y, r);
gradient.addColorStop(0, "#ffff00");
gradient.addColorStop(1, "rgba(0, 0, 0, 1)");
context.fillStyle = gradient;
context.beginPath();
context.arc(x, y, r, 0, 2 * Math.PI, true);
context.closePath();
context.fill();
}
Rocket.prototype.explode = function () {
var count = getGaussianDistributionNumber(240, 20);
for (var i = 0; i <= count; i++) {
var particle = new Particle(this.pos);
var angle = Math.random() * Math.PI * 2;
var speed = getGaussianDistributionNumber(2.5, 0.3);
particle.size = 3;
particle.v.x = Math.cos(angle) * speed;
particle.v.y = Math.sin(angle) * speed;
particle.color = this.color;
particles.push(particle);
}
}
function getGaussianDistributionNumber (mean, std_dev) {
var U1 = -Math.random() + 1;
var U2 = -Math.random() + 1;
var R = Math.sqrt(-2 * Math.log(U2));
var a = 2 * Math.PI * U1;
var Z = R * Math.cos(a);
return mean + (Z * std_dev);
}
}
}(jQuery));
jquery.min.js代码
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