js实现的牛顿摆效果

2024-05-06 16:17:58

字体：大中小

来源：转载

供稿：网友

本文给大家分享的是使用javascript实现牛顿排球的特效，非常不错，这里推荐给大家，有相同需求的小伙伴能够参考下。

牛顿摆是一个1960年代发明的桌面演示装置，五个质量相同的球体由吊绳固定，彼此紧密排列。又叫：牛顿摆球、动量守恒摆球、永动球、物理撞球、碰碰球等。

(function(window,undefined){

window.None || (window.None = {});

//重力加速度

var G=9.8;

var PI=Math.PI;

//帧频

var FPS=48;

/*

//IE角度转换

function rorateIt(node,deg){

//取得末变形前矩形的中点

var rect = node.getBoundingClientRect(),

cx1 = (rect.right - rect.left) / 2, // center x

cy1 = (rect.bottom - rect.top) / 2, // center y

deg2rad = Math.PI / 180,//角度转弧度

rad = deg * deg2rad ,

cos = Math.cos(rad),

sin = Math.sin(rad);

var ident = "DXImageTransform.Microsoft.Matrix";

node.style.filter = "progid:"+ident +"(M11='1.0',sizingmethod='auto expand')";

//http://www.satzansatz.de/cssd/onhavinglayout.html

if(!node.currentStyle.hasLayout){//在IE7中，如果没有获得hasLayout，滤镜会失效

node.style.writingMode = "tb-rl";

}

var filter = node.filters.item(ident);

// +-------+-------+

// | M11 | M12 |

// +-------+-------+

// | M21 | M22 |

// +-------+-------+

filter.M11 = cos;

filter.M12 = -sin;

filter.M21 = sin;

filter.M22 = cos;

//取得当前中心

rect = node.getBoundingClientRect();

var cx = (rect.right - rect.left) / 2;

var cy = (rect.bottom - rect.top) / 2;

//调整此元素的坐标系，实现CSS3 transform-origin的功能

node.style.marginLeft = cx1 - cx + "px";

node.style.marginTop = cy1 - cy + "px";

}

*/

//外部函数引用

//是否IE

function isIE(){

return navigator.userAgent.indexOf("MSIE")>-1;

}

//获取当前样式

function returnStyle(obj,styleName){

var myObj = typeof obj == "string" ? document.getElementById(obj) : obj;

if(document.all){

return eval("myObj.currentStyle." + styleName);

} else {

return eval("document.defaultView.getComputedStyle(myObj,null)." + styleName);

}

}

//外部函数引用

//图片方法

var img=function(src){

var img=new Image();

img.src=src;

return img;

}

//方向类，以垂直向下为0度逆时针为正

var face=function(deg,rad){

//0-360

this.unit='deg';

if(rad)deg=180/PI*deg;

this.deg=deg;

this.rad=PI/180*this.deg;

}

//矢量类

var vector=function(size,fx){

var cstrct=this.constructor;

this.size=size;

this.face=fx||new face(0);

fx=this.face;

this.toHv=function(){

var h=new cstrct(Math.sin(fx.rad)*size,90);

var v=new cstrct(Math.cos(fx.rad)*size,0);

return [h,v];

}

}

//继承，obj:需要从矢量继承的对象,arg:arguments

vector.extend=function(obj,arg){

vector.apply(obj,arg);

}

//矢量合并方法

vector.merger=function(arrvector){

if(arguments.length>1)arrvector=arguments;

var cstrct=arrvector[0].constructor;

var i=0,ilav=arrvector.length;

var sum=[0,0];

for(;i<ilav;i++){

var hv=arrvector[i].toHv();

sum[0]+=hv[0].size;

sum[1]+=hv[1].size;

}

var size=Math.sqrt(sum[0]*sum[0]+sum[1]*sum[1]);

var fa=new face(Math.atan(sum[0]/sum[1]),'rad');

return new cstrct(size,fa);

}

//力类,参数为大小和方向

var force=function(size,face){

this.unit='N';

//继承自矢量

vector.apply(this,arguments);

}

//加速度类

var a=function(size,face){

this.unit='m/s^2';

vector.extend(this,arguments);

}

//速度类

var speed=function(size,face){

this.unit='m/s';

vector.extend(this,arguments);

}

//刚体类,参数(body:IMG对象,m为质量)

var rigid=function(body,m){

//一般情况下body为一个img对象，所以暂且只有正方形或长方形两种形式

this.body=body;

this.m=m; //质量

this.focus=(this.body instanceof Image)?point(this.body.width/2,this.body.height/2):point(this.body.style.width/2,this.body.style.height/2);

this.axis=point(0,0); //轴心位置(point对象)

this.force=new force(0);

this.a=new a(this.force.size/this.m,this.force.face);

this.speed=new speed(0);

//设置，可重新设置上面所有参数

this.set=function(prop,value){

this[prop]=value;

}

this.addForce=function(f){

return this.force=vector.merger(f,this.force);

}

//旋转

this.rotate=function(face,axis){

axis=axis||this.axis||this.focus;

//cx1=returnStyle(this.body,"left");

//cy1=returnStyle(this.body,"left");

var rect=this.body.getBoundingClientRect(),

//cx1=rect.left+axis.x,

//cy1=rect.top+axis.y,

cx1 = (rect.right - rect.left) / 2,

cy1 = (rect.bottom - rect.top) / 2,

rad=face.rad,

cos = Math.cos(rad),

sin = Math.sin(rad);

if(isIE()){

var ident = "DXImageTransform.Microsoft.Matrix";

this.body.style.filter = "progid:"+ident +"(M11='1.0',sizingmethod='auto expand')";

if(!returnStyle(this.body,"hasLayout")){//在IE7中，如果没有获得hasLayout，滤镜会失效

this.body.style.writingMode = "tb-rl";

}

var filter = this.body.filters.item(ident);

filter.M11 = cos;

filter.M12 = -sin;

filter.M21 = sin;

filter.M22 = cos;

}

rect = this.body.getBoundingClientRect();

//var cx=rect.left+axis.x;

//var cy=rect.top+axis.y;

var cx = (rect.right - rect.left) / 2;

var cy = (rect.bottom - rect.top) / 2;

//调整此元素的坐标系，实现CSS3 transform-origin的功能

this.body.style.left=parseInt(this.body.style.left,10) + cx1 - cx + "px";

this.body.style.top=parseInt(this.body.style.top,10) + cy1 - cy + "px";

//CSS3

var sdeg="rotate("+face.deg+"deg)";

var paxis=axis.x+"px "+axis.y+"px";

this.body.style.transformOrigin=paxis;

this.body.style.MozTransformOrigin=paxis;

this.body.style.WebkitTransformOrigin=paxis;

this.body.style.OTransformOrigin=paxis;

this.body.style.WebkitTransform=sdeg;

this.body.style.MozTransform=sdeg;

this.body.style.OTransform=sdeg;

this.body.style.transform=sdeg;

}

}

//刚体组合

rigid.merger=function(){

}

//无弹性绳子类

var rope=function(body,length,maxForce){

this.body=body;

this.length=length;

this.maxForce=maxForce || Infinity || Number.MAX_VALUE;

}

//组合体类

var comb=function(arrObject){

}

//单摆类

var pendulum=function(ripe,rigid){

}

//类单摆

var likePend=function(rigid,fa,time){//刚体,初始角度,摆动频率

var self=this;

this.rigid=rigid;

this.body=this.rigid.body;

this.axis=this.rigid.axis;

this.dom=this.rigid.dom;

this.m=this.rigid.m;

this.rad=fa?fa.rad:fa=new face(PI/6,'rad');

//摆动

//角度30

var fx=fa.rad;

//角度平方根

var m=Math.sqrt(fx);

//摆动时间1秒

var atime=time||0.5;

var fnum=FPS*atime;

//单位增量

var fm=m/fnum;

//i:角度平方根到0

var i=-m,tid;

var g=new a(G);

var t=1000/FPS;

//o:{s:1,f:30,t:0,fun:callback} :s:(-1,1)速度增加还是减小,f:从多少度,t:到多少度,fun:摆完后运行的函数

this.swing=function(o,fun){

/* var asps=g.size*Math.cos(PI/2-fx)/(24*24*self.m);

var fss=new force(asps,new face(fx-PI/2));

this.rigid.force=fss;

var a=this.rigid.a;

//单位时间内速度的增量

var a1=Math.acos((asps+this.rigid.speed.size)/2)

this.rigid.speed=new speed(a1,new face(fx-PI/2));

a2=a1*2;*/

//{s:-1,inc:1}

o=o||{s:1};

var y=-o.s*i*i+fx*o.s;

if(i>=m){

self.rigid.rotate(new face(0),self.axis);

clearTimeout(tid);

i=-m;

if(fun)fun();

return;

}

var f=new face(y,'rad');

self.rigid.rotate(f,axis=self.axis);

i+=fm;

tid=setTimeout(function(){self.swing.call(self,o,fun)},t);

}

this.moveTo=function(p){

self.body.style.left=p.x+"px";

self.body.style.top=p.y+"px";

}

}

//世界

None.world=function(param){

//param:{force:[多个force对象]}

this.param=param||{};

this.config={

//全局外力

g:new a(G),

className:'',

width:'100%',

height:'100%',

left:0,

top:-200,

arrNav:['about','myWork','site','other','myTools'],

imgW:60,

imgN:5,

sDeg:5,

hitSound:'sounds/hit.wav',

vol:0.1

}

this.init();

};

None.world.prototype={

//初始化

dom:{},

init:function(){

var c=this.config;

var p=this.param;

//dom

var dom=document.createElement("div");

dom.className=c.className;

dom.style.position="absolute";

dom.style.width=p.width||c.width;

dom.style.height=p.height||c.height;

dom.style.left=(p.left||c.left) +"px";

dom.style.top=(p.top||c.top) +"px";

this.dom=dom;

document.body.appendChild(this.dom);

},

//添加一个刚体

addRigid:function(rigid,p){

if(!(rigid instanceof Array)){

rigid=[rigid];

}

if(!p)p=[point(0,0)];

if(!(p instanceof Array))p=[p];

for(var i=0,rl=rigid.length;i<rl;i++){

p[i]=p[i] || p[0];

rigid[i].body.style.position="absolute";

rigid[i].body.style.left=p[i].x+"px";

rigid[i].body.style.top=p[i].y+"px";

this.dom.appendChild(rigid[i].body);

}

},

//添加一个外作用力

addForce:function(){

},

start:function(){

var p=this.param,

c=this.config;

var shit=p.hitSound||c.hitSound;

var sndHit=new None.sounds(shit);

sndHit.volume=p.vol||c.vol;

var w=document.documentElement.offsetWidth;

var imgWidth=p.imgW||c.imgW;//图片宽度

var imgNum=p.imgN||c.imgN; //图片数量

var jd=p.sDeg||c.sDeg; //最大角度

var es=p.arrNav||c.arrNav;

var time=p.time||c.time;

var basex=w/2-imgWidth*imgNum/2;

var jiaodu=new face(jd);

var rig=[],ball=[],pend=[],axis=point(imgWidth/2,0);

for(var i=0,el=es.length;i<el;i++){

rig[i]=document.getElementById(es[i]);

ball[i]=new rigid(rig[i],1);

ball[i].set("axis",axis);

pend[i]=new likePend(ball[i],jiaodu,time);

}

this.addRigid(pend);

resize();

if(!isIE())swing();

window.onresize=resize;

function hit(v){

sndHit.play();

}

function swing(){

var runfun=arguments.callee;

var last=pend.length-1;

if(p.hitSound)hit(0);

pend[0].swing({s:1},function(){

if(p.hitSound)hit(1);

pend[last].swing({s:-1},runfun);

});

}

function resize(){

var w=document.documentElement.offsetWidth;

var basex=w/2-imgWidth*imgNum/2;

var n=pend.length;

for(var i=0;i<n;i++){

pend[i].moveTo(point(basex+imgWidth*i,0));

}

}

}

};

})(window);