效果
源代码
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<style>
html, body{
width: 100%;
height: 100%;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #101010;
}
.container{
position: absolute;
width: 500px;
height: 500px;
top: 50%;
left: 50%;
margin-top: -250px;
margin-left: -250px;
}
canvas{
position: absolute;
top: 0;
left: 0;
}
</style>
</HEAD>
<BODY>
<div id="jsi-fireworks-container" class="container"></div>
<script src="https://cdn.bootcss.com/jquery/1.12.4/jquery.min.js"></script>
<script>
var RENDERER = {
LEAF_INTERVAL_RANGE : {
min : 100, max : 200},
FIREWORK_INTERVAL_RANGE : {
min : 20, max : 200},
SKY_COLOR : 'hsla(210, 60%, %luminance%, 0.2)',
STAR_COUNT : 100,
init : function(){
this.setParameters();
this.reconstructMethod();
this.createTwigs();
this.createStars();
this.render();
},
setParameters : function(){
this.$container = $('#jsi-fireworks-container');
this.width = this.$container.width();
this.height = this.$container.height();
this.distance = Math.sqrt(Math.pow(this.width / 2, 2) + Math.pow(this.height / 2, 2));
this.contextFireworks = $('<canvas />').attr({
width : this.width, height : this.height}).appendTo(this.$container).get(0).getContext('2d');
this.contextTwigs = $('<canvas />').attr({
width : this.width, height : this.height}).appendTo(this.$container).get(0).getContext('2d');
this.twigs = [];
this.leaves = [new LEAF(this.width, this.height, this)];
this.stars = [];
this.fireworks = [new FIREWORK(this.width, this.height, this)];
this.leafInterval = this.getRandomValue(this.LEAF_INTERVAL_RANGE) | 0;
this.maxFireworkInterval = this.getRandomValue(this.FIREWORK_INTERVAL_RANGE) | 0;
this.fireworkInterval = this.maxFireworkInterval;
},
reconstructMethod : function(){
this.render = this.render.bind(this);
},
getRandomValue : function(range){
return range.min + (range.max - range.min) * Math.random();
},
createTwigs : function(){
this.twigs.push(new TWIG(this.width, this.height, 0, 0, Math.PI * 3 / 4, 0));
this.twigs.push(new TWIG(this.width, this.height, this.width, 0, -Math.PI * 3 / 4, Math.PI));
this.twigs.push(new TWIG(this.width, this.height, 0, this.height, Math.PI / 4, Math.PI));
this.twigs.push(new TWIG(this.width, this.height, this.width, this.height, -Math.PI / 4, 0));
},
createStars : function(){
for(var i = 0, length = this.STAR_COUNT; i < length; i++){
this.stars.push(new STAR(this.width, this.height, this.contextTwigs, this));
}
},
render : function(){
requestAnimationFrame(this.render);
var maxOpacity = 0,
contextTwigs = this.contextTwigs,
contextFireworks = this.contextFireworks;
for(var i = this.fireworks.length - 1; i >= 0; i--){
maxOpacity = Math.max(maxOpacity, this.fireworks[i].getOpacity());
}
contextTwigs.clearRect(0, 0, this.width, this.height);
contextFireworks.fillStyle = this.SKY_COLOR.replace('%luminance', 5 + maxOpacity * 15);
contextFireworks.fillRect(0, 0, this.width, this.height);
for(var i = this.fireworks.length - 1; i >= 0; i--){
if(!this.fireworks[i].render(contextFireworks)){
this.fireworks.splice(i, 1);
}
}
for(var i = this.stars.length - 1; i >= 0; i--){
this.stars[i].render(contextTwigs);
}
for(var i = this.twigs.length - 1; i >= 0; i--){
this.twigs[i].render(contextTwigs);
}
for(var i = this.leaves.length - 1; i >= 0; i--){
if(!this.leaves[i].render(contextTwigs)){
this.leaves.splice(i, 1);
}
}
if(--this.leafInterval == 0){
this.leaves.push(new LEAF(this.width, this.height, this));
this.leafInterval = this.getRandomValue(this.LEAF_INTERVAL_RANGE) | 0;
}
if(--this.fireworkInterval == 0){
this.fireworks.push(new FIREWORK(this.width, this.height, this));
this.maxFireworkInterval = this.getRandomValue(this.FIREWORK_INTERVAL_RANGE) | 0;
this.fireworkInterval = this.maxFireworkInterval;
}
}
};
var TWIG = function(width, height, x, y, angle, theta){
this.width = width;
this.height = height;
this.x = x;
this.y = y;
this.angle = angle;
this.theta = theta;
this.rate = Math.min(width, height) / 500;
};
TWIG.prototype = {
SHAKE_FREQUENCY : Math.PI / 300,
MAX_LEVEL : 4,
COLOR : 'hsl(120, 60%, 1%)',
renderBlock : function(context, x, y, length, level, angle){
context.save();
context.translate(x, y);
context.rotate(this.angle + angle * (level + 1));
context.scale(this.rate, this.rate);
context.beginPath();
context.moveTo(0, 0);
context.lineTo(0, -length);
context.stroke();
context.fill();
if(level == this.MAX_LEVEL){
length = length / (1 - level / 10);
context.save();
context.beginPath();
context.scale(1 - level / 10, 1 - level / 10);
context.moveTo(0, -length);
context.quadraticCurveTo(30, -length - 20, 0, -length - 80);
context.quadraticCurveTo(-30, -length - 20, 0, -length);
context.stroke();
context.fill();
context.restore();
context.restore();
}else{
for(var i = -1; i <= 1; i += 2){
context.save();
context.translate(0, -40);
context.rotate((Math.PI / 3 - Math.PI / 20 * level) * i);
context.scale(1 - level / 10, 1 - level / 10);
context.beginPath();
context.moveTo(0, 0);
context.lineTo(0, -length * 0.8);
context.quadraticCurveTo(30, -length * 0.8 - 20, 0, -length * 0.8 - 80);
context.quadraticCurveTo(-30, -length * 0.8 - 20, 0, -length * 0.8);
context.stroke();
context.fill();
context.restore();
}
context.restore();
level++;
this.renderBlock(context, x + 40 * Math.sin(this.angle + angle * level), y - 40 * Math.cos(this.angle + angle * level) , length, level, angle);
}
},
render : function(context){
context.fillStyle = this.COLOR;
context.strokeStyle = this.COLOR;
context.lineWidth = 3;
this.renderBlock(context, this.x, this.y, 40, 0, Math.PI / 48 * Math.sin(this.theta));
this.theta += this.SHAKE_FREQUENCY;
this.theta %= Math.PI * 2;
}
};
var LEAF = function(width, height, renderer){
this.width = width;
this.height = height;
this.renderer = renderer;
this.init();
};
LEAF.prototype = {
OFFSET : 100,
VELOCITY_Y : 3,
COLOR : 'hsl(120, 60%, 1%)',
init : function(){
this.x = this.renderer.getRandomValue({
min : 0, max : this.width});
this.y = -this.OFFSET;
this.vx = this.renderer.getRandomValue({
min : 0, max : 1}) * (this.x <= this.width / 2 ? 1 : -1);
this.vy = this.VELOCITY_Y;
this.rate = this.renderer.getRandomValue({
min : 0.4, max : 0.8});
this.theta = this.renderer.getRandomValue({
min : 0, max : Math.PI * 2});
this.deltaTheta = this.renderer.getRandomValue({
min : -Math.PI / 300, max : Math.PI / 300});
},
render : function(context){
context.save();
context.filleStyle = this.COLOR;
context.translate(this.x, this.y);
context.rotate(this.theta);
context.scale(this.rate, this.rate);
context.beginPath();
context.moveTo(0, 0);
context.quadraticCurveTo(30, -20, 0, -80);
context.quadraticCurveTo(-30, -20, 0, 0);
context.fill();
context.restore();
this.x += this.vx * this.rate;
this.y += this.vy * this.rate;
this.theta += this.deltaTheta;
this.theta %= Math.PI * 2;
return this.y <= this.height + this.OFFSET && this.x >= -this.OFFSET && this.x <= this.width + this.OFFSET;
}
};
var STAR = function(width, height, context, renderer){
this.width = width;
this.height = height;
this.renderer = renderer;
this.init(context);
};
STAR.prototype = {
RADIUS_RANGE : {
min : 1, max : 4},
COUNT_RANGE : {
min : 100, max : 1000},
DELTA_THETA : Math.PI / 30,
DELTA_PHI : Math.PI / 50000,
init : function(context){
this.x = this.renderer.getRandomValue({
min : 0, max : this.width});
this.y = this.renderer.getRandomValue({
min : 0, max : this.height});
this.radius = this.renderer.getRandomValue(this.RADIUS_RANGE);
this.maxCount = this.renderer.getRandomValue(this.COUNT_RANGE) | 0;
this.count = this.maxCount;
this.theta = 0;
this.phi = 0;
this.gradient = context.createRadialGradient(0, 0, 0, 0, 0, this.radius);
this.gradient.addColorStop(0, 'hsla(220, 80%, 100%, 1)');
this.gradient.addColorStop(0.1, 'hsla(220, 80%, 80%, 1)');
this.gradient.addColorStop(0.25, 'hsla(220, 80%, 50%, 1)');
this.gradient.addColorStop(1, 'hsla(220, 80%, 30%, 0)');
},
render : function(context){
context.save();
context.globalAlpha = Math.abs(Math.cos(this.theta));
context.translate(this.width / 2, this.height / 2);
context.rotate(this.phi);
context.translate(this.x - this.width / 2, this.y - this.height / 2);
context.beginPath();
context.fillStyle = this.gradient;
context.arc(0, 0, this.radius, 0, Math.PI * 2, false);
context.fill();
context.restore();
if(--this.count == 0){
this.theta = Math.PI;
this.count = this.maxCount;
}
if(this.theta > 0){
this.theta -= this.DELTA_THETA;
}
this.phi += this.DELTA_PHI;
this.phi %= Math.PI / 2;
}
};
var FIREWORK = function(width, height, renderer){
this.width = width;
this.height = height;
this.renderer = renderer;
this.init();
};
FIREWORK.prototype = {
COLOR : 'hsl(%hue, 80%, 60%)',
PARTICLE_COUNT : 300,
DELTA_OPACITY : 0.01,
RADIUS : 2,
VELOCITY : -3,
WAIT_COUNT_RANGE : {
min : 30, max : 60},
THRESHOLD : 50,
DELTA_THETA : Math.PI / 10,
GRAVITY : 0.002,
init : function(){
this.setParameters();
this.createParticles();
},
setParameters : function(){
var hue = 256 * Math.random() | 0;
this.x = this.renderer.getRandomValue({
min : this.width / 8, max : this.width * 7 / 8});
this.y = this.renderer.getRandomValue({
min : this.height / 4, max : this.height / 2});
this.x0 = this.x;
this.y0 = this.height + this.RADIUS;
this.color = this.COLOR.replace('%hue', hue);
this.status = 0;
this.theta = 0;
this.waitCount = this.renderer.getRandomValue(this.WAIT_COUNT_RANGE);
this.opacity = 1;
this.velocity = this.VELOCITY;
this.particles = [];
},
createParticles : function(){
for(var i = 0, length = this.PARTICLE_COUNT; i < length; i++){
this.particles.push(new PARTICLE(this.x, this.y, this.renderer));
}
},
getOpacity : function(){
return this.status == 2 ? this.opacity : 0;
},
render : function(context){
switch(this.status){
case 0:
context.save();
context.fillStyle = this.color;
context.globalCompositeOperation = 'lighter';
context.globalAlpha = (this.y0 - this.y) <= this.THRESHOLD ? ((this.y0 - this.y) / this.THRESHOLD) : 1;
context.translate(this.x0 + Math.sin(this.theta) / 2, this.y0);
context.scale(0.8, 2.4);
context.beginPath();
context.arc(0, 0, this.RADIUS, 0, Math.PI * 2, false);
context.fill();
context.restore();
this.y0 += this.velocity;
if(this.y0 <= this.y){
this.status = 1;
}
this.theta += this.DELTA_THETA;
this.theta %= Math.PI * 2;
this.velocity += this.GRAVITY;
return true;
case 1:
if(--this.waitCount <= 0){
this.status = 2;
}
return true;
case 2:
context.save();
context.globalCompositeOperation = 'lighter';
context.globalAlpha = this.opacity;
context.fillStyle = this.color;
for(var i = 0, length = this.particles.length; i < length; i++){
this.particles[i].render(context, this.opacity);
}
context.restore();
this.opacity -= this.DELTA_OPACITY;
return this.opacity > 0;
}
}
};
var PARTICLE = function(x, y, renderer){
this.x = x;
this.y = y;
this.renderer = renderer;
this.init();
};
PARTICLE.prototype = {
RADIUS : 1.5,
VELOCITY_RANGE : {
min : 0, max : 3},
GRAVITY : 0.02,
FRICTION : 0.98,
init : function(){
var radian = Math.PI * 2 * Math.random(),
velocity = (1 - Math.pow(Math.random(), 6)) * this.VELOCITY_RANGE.max,
rate = Math.random();
this.vx = velocity * Math.cos(radian) * rate;
this.vy = velocity * Math.sin(radian) * rate;
},
render : function(context, opacity){
context.beginPath();
context.arc(this.x, this.y, this.RADIUS, 0, Math.PI * 2, false);
context.fill();
this.x += this.vx;
this.y += this.vy;
this.vy += this.GRAVITY;
this.vx *= this.FRICTION;
this.vy *= this.FRICTION;
}
};
$(function(){
RENDERER.init();
});
</script>
</BODY>
</HTML>