(function(){function Asteroids(){if(!window.ASTEROIDS)
window.ASTEROIDS={enemiesKilled:0};function Vector(x,y){if(typeof x=='Object'){this.x=x.x;this.y=x.y;}else{this.x=x;this.y=y;}};Vector.prototype={cp:function(){return new Vector(this.x,this.y);},mul:function(factor){this.x*=factor;this.y*=factor;return this;},mulNew:function(factor){return new Vector(this.x*factor,this.y*factor);},add:function(vec){this.x+=vec.x;this.y+=vec.y;return this;},addNew:function(vec){return new Vector(this.x+vec.x,this.y+vec.y);},sub:function(vec){this.x-=vec.x;this.y-=vec.y;return this;},subNew:function(vec){return new Vector(this.x-vec.x,this.y-vec.y);},rotate:function(angle){var x=this.x,y=this.y;this.x=x*Math.cos(angle)-Math.sin(angle)*y;this.y=x*Math.sin(angle)+Math.cos(angle)*y;return this;},rotateNew:function(angle){return this.cp().rotate(angle);},setAngle:function(angle){var l=this.len();this.x=Math.cos(angle)*l;this.y=Math.sin(angle)*l;return this;},setAngleNew:function(angle){return this.cp().setAngle(angle);},setLength:function(length){var l=this.len();if(l)this.mul(length/l);else this.x=this.y=length;return this;},setLengthNew:function(length){return this.cp().setLength(length);},normalize:function(){var l=this.len();this.x/=l;this.y/=l;return this;},normalizeNew:function(){return this.cp().normalize();},angle:function(){return Math.atan2(this.y,this.x);},collidesWith:function(rect){return this.x>rect.x&&this.y>rect.y&&this.x<rect.x+rect.width&&this.y<rect.y+rect.height;},len:function(){var l=Math.sqrt(this.x*this.x+this.y*this.y);if(l<0.005&&l>-0.005)return 0;return l;},is:function(test){return typeof test=='object'&&this.x==test.x&&this.y==test.y;},toString:function(){return'[Vector('+this.x+', '+this.y+') angle: '+this.angle()+', length: '+this.len()+']';}};function Line(p1,p2){this.p1=p1;this.p2=p2;};Line.prototype={shift:function(pos){this.p1.add(pos);this.p2.add(pos);},intersectsWithRect:function(rect){var LL=new Vector(rect.x,rect.y+rect.height);var UL=new Vector(rect.x,rect.y);var LR=new Vector(rect.x+rect.width,rect.y+rect.height);var UR=new Vector(rect.x+rect.width,rect.y);if(this.p1.x>LL.x&&this.p1.x<UR.x&&this.p1.y<LL.y&&this.p1.y>UR.y&&this.p2.x>LL.x&&this.p2.x<UR.x&&this.p2.y<LL.y&&this.p2.y>UR.y)return true;if(this.intersectsLine(new Line(UL,LL)))return true;if(this.intersectsLine(new Line(LL,LR)))return true;if(this.intersectsLine(new Line(UL,UR)))return true;if(this.intersectsLine(new Line(UR,LR)))return true;return false;},intersectsLine:function(line2){var v1=this.p1,v2=this.p2;var v3=line2.p1,v4=line2.p2;var denom=((v4.y-v3.y)*(v2.x-v1.x))-((v4.x-v3.x)*(v2.y-v1.y));var numerator=((v4.x-v3.x)*(v1.y-v3.y))-((v4.y-v3.y)*(v1.x-v3.x));var numerator2=((v2.x-v1.x)*(v1.y-v3.y))-((v2.y-v1.y)*(v1.x-v3.x));if(denom==0.0){return false;}
var ua=numerator/denom;var ub=numerator2/denom;return(ua>=0.0&&ua<=1.0&&ub>=0.0&&ub<=1.0);}};var that=this;var isIE=!!window.ActiveXObject;var w=document.documentElement.clientWidth,h=document.documentElement.clientHeight;var playerWidth=20,playerHeight=30;var playerVerts=[[-1*playerHeight/2,-1*playerWidth/2],[-1*playerHeight/2,playerWidth/2],[playerHeight/2,0]];var ignoredTypes=['HTML','HEAD','BODY','SCRIPT','TITLE','META','STYLE','LINK','SHAPE','LINE','GROUP','IMAGE','STROKE','FILL','SKEW','PATH','TEXTPATH'];var hiddenTypes=['BR','HR'];var FPS=50;var acc=300;var maxSpeed=600;var rotSpeed=360;var bulletSpeed=700;var particleSpeed=400;var timeBetweenFire=150;var timeBetweenBlink=250;var timeBetweenEnemyUpdate=isIE?10000:2000;var bulletRadius=2;var maxParticles=isIE?20:40;var maxBullets=isIE?10:20;this.flame={r:[],y:[]};this.toggleBlinkStyle=function(){if(this.updated.blink.isActive){removeClass(document.body,'ASTEROIDSBLINK');}else{addClass(document.body,'ASTEROIDSBLINK');}
this.updated.blink.isActive=!this.updated.blink.isActive;};addStylesheet(".ASTEROIDSBLINK .ASTEROIDSYEAHENEMY","outline: 2px dotted red;");this.pos=new Vector(100,100);this.lastPos=false;this.vel=new Vector(0,0);this.dir=new Vector(0,1);this.keysPressed={};this.firedAt=false;this.updated={enemies:false,flame:new Date().getTime(),blink:{time:0,isActive:false}};this.scrollPos=new Vector(0,0);this.bullets=[];this.enemies=[];this.dying=[];this.totalEnemies=0;this.particles=[];function updateEnemyIndex(){for(var i=0,enemy;enemy=that.enemies[i];i++)
removeClass(enemy,"ASTEROIDSYEAHENEMY");var all=document.body.getElementsByTagName('*');that.enemies=[];for(var i=0,el;el=all[i];i++){if(indexOf(ignoredTypes,el.tagName.toUpperCase())==-1&&el.prefix!='g_vml_'&&hasOnlyTextualChildren(el)&&el.className!="ASTEROIDSYEAH"&&el.offsetHeight>0){el.aSize=size(el);that.enemies.push(el);addClass(el,"ASTEROIDSYEAHENEMY");if(!el.aAdded){el.aAdded=true;that.totalEnemies++;}}}};updateEnemyIndex();var createFlames;(function(){var rWidth=playerWidth,rIncrease=playerWidth*0.1,yWidth=playerWidth*0.6,yIncrease=yWidth*0.2,halfR=rWidth/2,halfY=yWidth/2,halfPlayerHeight=playerHeight/2;createFlames=function(){that.flame.r=[[-1*halfPlayerHeight,-1*halfR]];that.flame.y=[[-1*halfPlayerHeight,-1*halfY]];for(var x=0;x<rWidth;x+=rIncrease){that.flame.r.push([-random(2,7)-halfPlayerHeight,x-halfR]);}
that.flame.r.push([-1*halfPlayerHeight,halfR]);for(var x=0;x<yWidth;x+=yIncrease){that.flame.y.push([-random(2,7)-halfPlayerHeight,x-halfY]);}
that.flame.y.push([-1*halfPlayerHeight,halfY]);};})();createFlames();function radians(deg){return deg*0.0174532925;};function degrees(rad){return rad*57.2957795;};function random(from,to){return Math.floor(Math.random()*(to+1)+from);};function code(name){var table={'up':38,'down':40,'left':37,'right':39,'esc':27};if(table[name])return table[name];return name.charCodeAt(0);};function boundsCheck(vec){if(vec.x>w)
vec.x=0;else if(vec.x<0)
vec.x=w;if(vec.y>h)
vec.y=0;else if(vec.y<0)
vec.y=h;};function size(element){var el=element,left=0,top=0;do{left+=el.offsetLeft||0;top+=el.offsetTop||0;el=el.offsetParent;}while(el);return{x:left,y:top,width:element.offsetWidth||10,height:element.offsetHeight||10};};function addEvent(obj,type,fn){if(obj.addEventListener)
obj.addEventListener(type,fn,false);else if(obj.attachEvent){obj["e"+type+fn]=fn;obj[type+fn]=function(){obj["e"+type+fn](window.event);}
obj.attachEvent("on"+type,obj[type+fn]);}}
function removeEvent(obj,type,fn){if(obj.removeEventListener)
obj.removeEventListener(type,fn,false);else if(obj.detachEvent){obj.detachEvent("on"+type,obj[type+fn]);obj[type+fn]=null;obj["e"+type+fn]=null;}}
function arrayRemove(array,from,to){var rest=array.slice((to||from)+1||array.length);array.length=from<0?array.length+from:from;return array.push.apply(array,rest);};function applyVisibility(vis){for(var i=0,p;p=window.ASTEROIDSPLAYERS[i];i++){p.gameContainer.style.visibility=vis;}}
function getElementFromPoint(x,y){applyVisibility('hidden');var element=document.elementFromPoint(x,y);if(!element){applyVisibility('visible');return false;}
if(element.nodeType==3)
element=element.parentNode;applyVisibility('visible');return element;};function addParticles(startPos){var time=new Date().getTime();var amount=maxParticles;for(var i=0;i<amount;i++){that.particles.push({dir:(new Vector(Math.random()*20-10,Math.random()*20-10)).normalize(),pos:startPos.cp(),cameAlive:time});}};function setScore(){that.points.innerHTML=window.ASTEROIDS.enemiesKilled*10;};function hasOnlyTextualChildren(element){if(element.offsetLeft<-100&&element.offsetWidth>0&&element.offsetHeight>0)return false;if(indexOf(hiddenTypes,element.tagName)!=-1)return true;if(element.offsetWidth==0&&element.offsetHeight==0)return false;for(var i=0;i<element.childNodes.length;i++){if(indexOf(hiddenTypes,element.childNodes[i].tagName)==-1&&element.childNodes[i].childNodes.length!=0)return false;}
return true;};function indexOf(arr,item,from){if(arr.indexOf)return arr.indexOf(item,from);var len=arr.length;for(var i=(from<0)?Math.max(0,len+from):from||0;i<len;i++){if(arr[i]===item)return i;}
return-1;};function addClass(element,className){if(element.className.indexOf(className)==-1)
element.className=(element.className+' '+className).replace(/\s+/g,' ').replace(/^\s+|\s+$/g,'');};function removeClass(element,className){element.className=element.className.replace(new RegExp('(^|\\s)'+className+'(?:\\s|$)'),'$1');};function addStylesheet(selector,rules){var stylesheet=document.createElement('style');stylesheet.type='text/css';stylesheet.rel='stylesheet';stylesheet.id='ASTEROIDSYEAHSTYLES';try{stylesheet.innerHTML=selector+"{"+rules+"}";}catch(e){stylesheet.styleSheet.addRule(selector,rules);}
document.getElementsByTagName("head")[0].appendChild(stylesheet);};function removeStylesheet(name){var stylesheet=document.getElementById(name);if(stylesheet){stylesheet.parentNode.removeChild(stylesheet);}};this.gameContainer=document.createElement('div');this.gameContainer.className='ASTEROIDSYEAH';document.body.appendChild(this.gameContainer);this.canvas=document.createElement('canvas');this.canvas.setAttribute('width',w);this.canvas.setAttribute('height',h);this.canvas.className='ASTEROIDSYEAH';with(this.canvas.style){width=w+"px";height=h+"px";position="fixed";top="0px";left="0px";bottom="0px";right="0px";zIndex="10000";}
if(typeof G_vmlCanvasManager!='undefined'){this.canvas=G_vmlCanvasManager.initElement(this.canvas);if(!this.canvas.getContext){alert("So... you are using IE?  Sorry but at the moment WebsiteAsteroids only supports Firefox");}}else{if(!this.canvas.getContext){alert('This program does not yet support your browser. Please join me at http://github.com/erkie/erkie.github.com if you think you can help');}}
addEvent(this.canvas,'mousedown',function(e){e=e||window.event;var message=document.createElement('span');message.style.position='absolute';message.style.border='1px solid #999';message.style.background='white';message.style.color="black";message.innerHTML='Press Esc to quit';document.body.appendChild(message);var x=e.pageX||(e.clientX+document.documentElement.scrollLeft);var y=e.pageY||(e.clientY+document.documentElement.scrollTop);message.style.left=x-message.offsetWidth/2+'px';message.style.top=y-message.offsetHeight/2+'px';setTimeout(function(){try{message.parentNode.removeChild(message);}catch(e){}},1000);});var eventResize=function(){that.canvas.style.display="none";w=document.documentElement.clientWidth;h=document.documentElement.clientHeight;that.canvas.setAttribute('width',w);that.canvas.setAttribute('height',h);with(that.canvas.style){display="block";width=w+"px";height=h+"px";}};addEvent(window,'resize',eventResize);this.gameContainer.appendChild(this.canvas);this.ctx=this.canvas.getContext("2d");this.ctx.fillStyle="black";this.ctx.strokeStyle="black";if(!document.getElementById('ASTEROIDS-NAVIGATION')){this.navigation=document.createElement('div');this.navigation.id="ASTEROIDS-NAVIGATION";this.navigation.className="ASTEROIDSYEAH";with(this.navigation.style){fontFamily="Arial,sans-serif";position="fixed";zIndex="10001";bottom="10px";right="10px";textAlign="right";}
this.navigation.innerHTML="(press esc to quit) ";this.gameContainer.appendChild(this.navigation);this.points=document.createElement('span');this.points.id='ASTEROIDS-POINTS';this.points.style.font="28pt Arial, sans-serif";this.points.style.fontWeight="bold";this.points.className="ASTEROIDSYEAH";this.navigation.appendChild(this.points);}else{this.navigation=document.getElementById('ASTEROIDS-NAVIGATION');this.points=document.getElementById('ASTEROIDS-POINTS');}
setScore();if(typeof G_vmlCanvasManager!='undefined'){var children=this.canvas.getElementsByTagName('*');for(var i=0,c;c=children[i];i++)
addClass(c,'ASTEROIDSYEAH');}
var eventKeydown=function(event){event=event||window.event;that.keysPressed[event.keyCode]=true;switch(event.keyCode){case code(' '):that.firedAt=1;break;}
if(indexOf([code('up'),code('down'),code('right'),code('left'),code(' '),code('B'),code('W'),code('A'),code('S'),code('D')],event.keyCode)!=-1){if(event.preventDefault)
event.preventDefault();if(event.stopPropagation)
event.stopPropagation();event.returnValue=false;event.cancelBubble=true;return false;}};addEvent(document,'keydown',eventKeydown);var eventKeypress=function(event){event=event||window.event;if(indexOf([code('up'),code('down'),code('right'),code('left'),code(' '),code('W'),code('A'),code('S'),code('D')],event.keyCode||event.which)!=-1){if(event.preventDefault)
event.preventDefault();if(event.stopPropagation)
event.stopPropagation();event.returnValue=false;event.cancelBubble=true;return false;}};addEvent(document,'keypress',eventKeypress);var eventKeyup=function(event){event=event||window.event;that.keysPressed[event.keyCode]=false;if(indexOf([code('up'),code('down'),code('right'),code('left'),code(' '),code('B'),code('W'),code('A'),code('S'),code('D')],event.keyCode)!=-1){if(event.preventDefault)
event.preventDefault();if(event.stopPropagation)
event.stopPropagation();event.returnValue=false;event.cancelBubble=true;return false;}};addEvent(document,'keyup',eventKeyup);this.ctx.clear=function(){this.clearRect(0,0,w,h);};this.ctx.clear();this.ctx.drawLine=function(xFrom,yFrom,xTo,yTo){this.beginPath();this.moveTo(xFrom,yFrom);this.lineTo(xTo,yTo);this.lineTo(xTo+1,yTo+1);this.closePath();this.fill();};this.ctx.tracePoly=function(verts){this.beginPath();this.moveTo(verts[0][0],verts[0][1]);for(var i=1;i<verts.length;i++)
this.lineTo(verts[i][0],verts[i][1]);this.closePath();};this.ctx.drawPlayer=function(){this.save();this.translate(that.pos.x,that.pos.y);this.rotate(that.dir.angle());this.tracePoly(playerVerts);this.fillStyle="white";this.fill();this.tracePoly(playerVerts);this.stroke();this.restore();};var PI_SQ=Math.PI*2;this.ctx.drawBullets=function(bullets){for(var i=0;i<bullets.length;i++){this.beginPath();this.arc(bullets[i].pos.x,bullets[i].pos.y,bulletRadius,0,PI_SQ,true);this.closePath();this.fill();}};var randomParticleColor=function(){return(['red','yellow'])[random(0,1)];};this.ctx.drawParticles=function(particles){var oldColor=this.fillStyle;for(var i=0;i<particles.length;i++){this.fillStyle=randomParticleColor();this.drawLine(particles[i].pos.x,particles[i].pos.y,particles[i].pos.x-particles[i].dir.x*10,particles[i].pos.y-particles[i].dir.y*10);}
this.fillStyle=oldColor;};this.ctx.drawFlames=function(flame){this.save();this.translate(that.pos.x,that.pos.y);this.rotate(that.dir.angle());var oldColor=this.strokeStyle;this.strokeStyle="red";this.tracePoly(flame.r);this.stroke();this.strokeStyle="yellow";this.tracePoly(flame.y);this.stroke();this.strokeStyle=oldColor;this.restore();}
addParticles(this.pos);addClass(document.body,'ASTEROIDSYEAH');var isRunning=true;var lastUpdate=new Date().getTime();this.update=function(){var forceChange=false;var nowTime=new Date().getTime();var tDelta=(nowTime-lastUpdate)/1000;lastUpdate=nowTime;var drawFlame=false;if(nowTime-this.updated.flame>50){createFlames();this.updated.flame=nowTime;}
this.scrollPos.x=window.pageXOffset||document.documentElement.scrollLeft;this.scrollPos.y=window.pageYOffset||document.documentElement.scrollTop;if((this.keysPressed[code('up')])||(this.keysPressed[code('W')])){this.vel.add(this.dir.mulNew(acc*tDelta));drawFlame=true;}else{this.vel.mul(0.96);}
if((this.keysPressed[code('left')])||(this.keysPressed[code('A')])){forceChange=true;this.dir.rotate(radians(rotSpeed*tDelta*-1));}
if((this.keysPressed[code('right')])||(this.keysPressed[code('D')])){forceChange=true;this.dir.rotate(radians(rotSpeed*tDelta));}
if(this.keysPressed[code(' ')]&&nowTime-this.firedAt>timeBetweenFire){this.bullets.unshift({'dir':this.dir.cp(),'pos':this.pos.cp(),'startVel':this.vel.cp(),'cameAlive':nowTime});this.firedAt=nowTime;if(this.bullets.length>maxBullets){this.bullets.pop();}}
if(this.keysPressed[code('B')]){if(!this.updated.enemies){updateEnemyIndex();this.updated.enemies=true;}
forceChange=true;this.updated.blink.time+=tDelta*1000;if(this.updated.blink.time>timeBetweenBlink){this.toggleBlinkStyle();this.updated.blink.time=0;}}else{this.updated.enemies=false;}
if(this.keysPressed[code('esc')]){destroy.apply(this);return;}
if(this.vel.len()>maxSpeed){this.vel.setLength(maxSpeed);}
this.pos.add(this.vel.mulNew(tDelta));if(this.pos.x>w){window.scrollTo(this.scrollPos.x+50,this.scrollPos.y);this.pos.x=0;}else if(this.pos.x<0){window.scrollTo(this.scrollPos.x-50,this.scrollPos.y);this.pos.x=w;}
if(this.pos.y>h){window.scrollTo(this.scrollPos.x,this.scrollPos.y+h*0.75);this.pos.y=0;}else if(this.pos.y<0){window.scrollTo(this.scrollPos.x,this.scrollPos.y-h*0.75);this.pos.y=h;}
for(var i=this.bullets.length-1;i>=0;i--){if(nowTime-this.bullets[i].cameAlive>2000){this.bullets.splice(i,1);forceChange=true;continue;}
var bulletVel=this.bullets[i].dir.setLengthNew(bulletSpeed*tDelta).add(this.bullets[i].startVel.mulNew(tDelta));this.bullets[i].pos.add(bulletVel);boundsCheck(this.bullets[i].pos);var murdered=getElementFromPoint(this.bullets[i].pos.x,this.bullets[i].pos.y);if(murdered&&murdered.tagName&&indexOf(ignoredTypes,murdered.tagName.toUpperCase())==-1&&hasOnlyTextualChildren(murdered)&&murdered.className!="ASTEROIDSYEAH"){didKill=true;addParticles(this.bullets[i].pos);this.dying.push(murdered);this.bullets.splice(i,1);continue;}}
if(this.dying.length){for(var i=this.dying.length-1;i>=0;i--){try{if(this.dying[i].parentNode)
window.ASTEROIDS.enemiesKilled++;this.dying[i].parentNode.removeChild(this.dying[i]);}catch(e){}}
setScore();this.dying=[];}
for(var i=this.particles.length-1;i>=0;i--){this.particles[i].pos.add(this.particles[i].dir.mulNew(particleSpeed*tDelta*Math.random()));if(nowTime-this.particles[i].cameAlive>1000){this.particles.splice(i,1);forceChange=true;continue;}}
if(forceChange||this.bullets.length!=0||this.particles.length!=0||!this.pos.is(this.lastPos)||this.vel.len()>0){this.ctx.clear();this.ctx.drawPlayer();if(drawFlame)
this.ctx.drawFlames(that.flame);if(this.bullets.length){this.ctx.drawBullets(this.bullets);}
if(this.particles.length){this.ctx.drawParticles(this.particles);}}
this.lastPos=this.pos;setTimeout(updateFunc,1000/FPS);}
var updateFunc=function(){that.update.call(that);};setTimeout(updateFunc,1000/FPS);function destroy(){removeEvent(document,'keydown',eventKeydown);removeEvent(document,'keypress',eventKeypress);removeEvent(document,'keyup',eventKeyup);removeEvent(window,'resize',eventResize);isRunning=false;removeStylesheet("ASTEROIDSYEAHSTYLES");removeClass(document.body,'ASTEROIDSYEAH');this.gameContainer.parentNode.removeChild(this.gameContainer);};}
if(!window.ASTEROIDSPLAYERS)
window.ASTEROIDSPLAYERS=[];if(window.ActiveXObject){try{var xamlScript=document.createElement('script');xamlScript.setAttribute('type','text/xaml');xamlScript.textContent='<?xml version="1.0"?><Canvas xmlns="http://schemas.microsoft.com/client/2007"></Canvas>';document.getElementsByTagName('head')[0].appendChild(xamlScript);}catch(e){}
var script=document.createElement("script");script.setAttribute('type','text/javascript');script.onreadystatechange=function(){if(script.readyState=='loaded'||script.readyState=='complete'){if(typeof G_vmlCanvasManager!="undefined")
window.ASTEROIDSPLAYERS[window.ASTEROIDSPLAYERS.length]=new Asteroids();}};script.src="http://erkie.github.com/excanvas.js";document.getElementsByTagName('head')[0].appendChild(script);}
else window.ASTEROIDSPLAYERS[window.ASTEROIDSPLAYERS.length]=new Asteroids();})();