JQ动态粒子效果
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
</head>
<!-- 注意：style和script都包含在body内部，否则会导致代码无样式效果以及js事件无法实现 -->
<body>
<div id="jsi-particle-container" class="container">
<!-- 创建画布 -->
<canvas width="100%" height="100%" style="align:center;"></canvas><!--canvas标签定义图形，必须使用脚本来绘制图形-->
</div>
<style>
html,body {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
overflow: hidden;
/*overflow属性指定如果内容溢出一个元素的框，会发生什么 其属性值hidden表示内容会被修建，并且其余内容是不可见的*/
/* overflow属性值:
visible 默认值，内容不会被修剪，会呈现在元素框之外
hidden 内容会被修剪，并且其余内容是不可见的
scroll 内容会被修剪，但是浏览器会显示滚动条以便查看其他内容
auto 若内容被修剪，则浏览器会显示滚动条
inherit 规定应该从父元素继承overflow属性的值
注意：overflow属性只工作于指定高度的块元素上
*/
}
.container{
width: 100％;
height: 100%;
margin: 0;
padding: 0;
background-color: #000000;
}
</style>
<script>
//绘制图形
var RENDERER = {
PARTICLE_COUNT : 1000,
PARTICLE_RADIUS : 1,
MAX_ROTATION_ANGLE : Math.PI / 60,
TRANSLATION_COUNT : 10000,
//函数体汇总
init : function(strategy){
this.setParameters(strategy);
this.createParticles();
this.setupFigure();
this.reconstructMethod();
this.bindEvent();
this.drawFigure();
},
//窗口响应事件，图形大小控制
setParameters : function(strategy){
this.$window = $(window);
//调用html中的样式
this.$container = $('#jsi-particle-container');
this.width = this.$container.width();
this.height = this.$container.height();
this.$canvas = $('<canvas />').attr({width : this.width, height : this.height}).appendTo(this.$container);
this.context = this.$canvas.get(0).getContext('2d');//2D动画
this.center = {x : this.width / 2, y : this.height / 2};
//rotation控制旋转 MAX_ROTATION_ANGLE随机旋转
this.rotationX = this.MAX_ROTATION_ANGLE;
this.rotationY = this.MAX_ROTATION_ANGLE;
//strategyIndex战略索引
this.strategyIndex = 0;
//translationCount动画过渡数量 影响点击颜色变化的深浅度
this.translationCount = 0;
this.theta = 0;
this.strategies = strategy.getStrategies();
this.particles = [];
},
createParticles : function(){
//循环输出
for(var i = 0; i < this.PARTICLE_COUNT; i ++){
this.particles.push(new PARTICLE(this.center));
}
},
//绑定事件bind
reconstructMethod : function(){
this.setupFigure = this.setupFigure.bind(this);//建立
this.drawFigure = this.drawFigure.bind(this);//绘制
this.changeAngle = this.changeAngle.bind(this);//改变
},
bindEvent : function(){
this.$container.on('click', this.setupFigure);//点击事件
this.$container.on('mousemove', this.changeAngle);//鼠标响应事件
},
changeAngle : function(event){
var offset = this.$container.offset(), //offset方法返回或设置匹配元素相对于文档的偏移（位置）
x = event.clientX - offset.left + this.$window.scrollLeft(),//clientX js鼠标事件
y = event.clientY - offset.top + this.$window.scrollTop();
this.rotationX = (this.center.y - y) / this.center.y * this.MAX_ROTATION_ANGLE;
this.rotationY = (this.center.x - x) / this.center.x * this.MAX_ROTATION_ANGLE;
},
setupFigure : function(){
for(var i = 0, length = this.particles.length; i < length; i++){
this.particles[i].setAxis(this.strategies[this.strategyIndex]());
}
if(++this.strategyIndex == this.strategies.length){
this.strategyIndex = 0;
}
this.translationCount = 0;
},
drawFigure : function(){
requestAnimationFrame(this.drawFigure);
this.context.fillStyle = 'rgba(0, 0, 0, 0.2)';
this.context.fillRect(0, 0, this.width, this.height);
for(var i = 0, length = this.particles.length; i < length; i++){
var axis = this.particles[i].getAxis2D(this.theta);
this.context.beginPath();
this.context.fillStyle = axis.color;
this.context.arc(axis.x, axis.y, this.PARTICLE_RADIUS, 0, Math.PI * 2, false);
this.context.fill();
}
this.theta++;
this.theta %= 360;
for(var i = 0, length = this.particles.length; i < length; i++){
this.particles[i].rotateX(this.rotationX);
this.particles[i].rotateY(this.rotationY);
}
this.translationCount++;
this.translationCount %= this.TRANSLATION_COUNT;
if(this.translationCount == 0){
this.setupFigure();
}
}
};
var STRATEGY = {
SCATTER_RADIUS :200,
CONE_ASPECT_RATIO : 4,
RING_COUNT : 8,
getStrategies : function(){
var strategies = [];
//校验
for(var i in this){
if(this[i] == arguments.callee || typeof this[i] != 'function'){
continue;
}
strategies.push(this[i].bind(this));
}
return strategies;
},
//随机数绘制图形
createSphere : function(){
var cosTheta = Math.random() * 2 - 1,
sinTheta = Math.sqrt(1 - cosTheta * cosTheta),
phi = Math.random() * 2 * Math.PI;
return {
x : this.SCATTER_RADIUS * sinTheta * Math.cos(phi),
y : this.SCATTER_RADIUS * sinTheta * Math.sin(phi),
z : this.SCATTER_RADIUS * cosTheta,
hue : Math.round(phi / Math.PI * 30)
};
},
createTorus : function(){
var theta = Math.random() * Math.PI * 2,
x = this.SCATTER_RADIUS + this.SCATTER_RADIUS / 6 * Math.cos(theta),
y = this.SCATTER_RADIUS / 6 * Math.sin(theta),
phi = Math.random() * Math.PI * 2;
return {
x : x * Math.cos(phi),
y : y,
z : x * Math.sin(phi),
hue : Math.round(phi / Math.PI * 30)
};
},
createCone : function(){
var status = Math.random() > 1 / 3,
x,
y,
phi = Math.random() * Math.PI * 2,
rate = Math.tan(30 / 180 * Math.PI) / this.CONE_ASPECT_RATIO;
if(status){
y = this.SCATTER_RADIUS * (1 - Math.random() * 2);
x = (this.SCATTER_RADIUS - y) * rate;
}else{
y = -this.SCATTER_RADIUS;
x = this.SCATTER_RADIUS * 2 * rate * Math.random();
}
return {
x : x * Math.cos(phi),
y : y,
z : x * Math.sin(phi),
hue : Math.round(phi / Math.PI * 30)
};
},
createVase : function(){
var theta = Math.random() * Math.PI,
x = Math.abs(this.SCATTER_RADIUS * Math.cos(theta) / 2) + this.SCATTER_RADIUS / 8,
y = this.SCATTER_RADIUS * Math.cos(theta) * 1.2,
phi = Math.random() * Math.PI * 2;
return {
x : x * Math.cos(phi),
y : y,
z : x * Math.sin(phi),
hue : Math.round(phi / Math.PI * 30)
};
}
};
var PARTICLE = function(center){
this.center = center;
this.init();
};
PARTICLE.prototype = {
SPRING : 0.01,
FRICTION : 0.9,
FOCUS_POSITION : 300,
COLOR : 'hsl(%hue, 100%, 50%)',//HSL值，在CSS中，可以使用色相、饱和度和明度（HSL）来指定颜色
//不太懂init : function含义
init : function(){
this.x = 0;
this.y = 0;
this.z = 0;
this.vx = 0;
this.vy = 0;
this.vz = 0;
this.color;
},
setAxis : function(axis){
this.translating = true;
this.nextX = axis.x;
this.nextY = axis.y;
this.nextZ = axis.z;
this.hue = axis.hue;
},
rotateX : function(angle){
var sin = Math.sin(angle),
cos = Math.cos(angle),
nextY = this.nextY * cos - this.nextZ * sin,
nextZ = this.nextZ * cos + this.nextY * sin,
y = this.y * cos - this.z * sin,
z = this.z * cos + this.y * sin;
this.nextY = nextY;
this.nextZ = nextZ;
this.y = y;
this.z = z;
},
rotateY : function(angle){
var sin = Math.sin(angle),
cos = Math.cos(angle),
nextX = this.nextX * cos - this.nextZ * sin,
nextZ = this.nextZ * cos + this.nextX * sin,
x = this.x * cos - this.z * sin,
z = this.z * cos + this.x * sin;
this.nextX = nextX;
this.nextZ = nextZ;
this.x = x;
this.z = z;
},
rotateZ : function(angle){
var sin = Math.sin(angle),
cos = Math.cos(angle),
nextX = this.nextX * cos - this.nextY * sin,
nextY = this.nextY * cos + this.nextX * sin,
x = this.x * cos - this.y * sin,
y = this.y * cos + this.x * sin;
this.nextX = nextX;
this.nextY = nextY;
this.x = x;
this.y = y;
},
getAxis3D : function(){
this.vx += (this.nextX - this.x) * this.SPRING;
this.vy += (this.nextY - this.y) * this.SPRING;
this.vz += (this.nextZ - this.z) * this.SPRING;
this.vx *= this.FRICTION;
this.vy *= this.FRICTION;
this.vz *= this.FRICTION;
this.x += this.vx;
this.y += this.vy;
this.z += this.vz;
return {x : this.x, y : this.y, z : this.z};
},
getAxis2D : function(theta){
var axis = this.getAxis3D(),
scale = this.FOCUS_POSITION / (this.FOCUS_POSITION + axis.z);
return {x : this.center.x + axis.x * scale, y : this.center.y - axis.y * scale, color : this.COLOR.replace('%hue', this.hue + theta)};
}
};
$(function(){
RENDERER.init(STRATEGY);
});
</script>
</body>
</html>
该代码来源于菜鸟教程的jQuery教程中的实例，其中添加了个人对于不解知识点的注释分享
另外还有关于代码中init : function(){}部分，不太理解，诚请广大码友解答