JS1k: The JavaScript code golfing competition

O='("+b+"rfuncti111111$10if();010000011011000111for(c.){.split(;D.onk=on(t[3[F(=0ft[f.keyCo=Q(1+*C)*S="d/2+h/2stroke)/2)/ment;c.=1)]=0")eTo(f,(0,0,.get=(de]+=on 00=-1;th+(1-=smOin)]Y)*val(*s'.split('');Q='wiU(MaUF=floor;C=cos;SZ_;QZqrt}D=docu#;c=D@Ele#ById("c"widU=W=5L%height=h=3L;c=c@Context("2d"m=t=[];O _ s$10	11LL10101$L0012	1$""$"))m[O]Z[O]""X=Y=O&;E=I;rZ.2;J.56eydownG&}eyupG};Ku(f;f<W;f++a=2*f/W-1,d=X+E*a,e=I+J*a;a=F(Og=F(Y),je*e/(d*d)),kd*d/(e*e)),p,i&,l&,nAa+1-Ozj,oAg+1-Yzk;d<0iNnAO-azj}e<0lNoAY-gzk};!p;q;n<onHj;aHi}else{oHk;gHl;q&}m[a][g]>0)p&}eAg-YVle;q=)eAa-OVid;e+.01;d=h/e;a=-;i=%Stylergb?"+F(d)+")"%beg_PaU(mov:al_:i()}}Ky(c.clearRect?W,hb";8]^+X`4OHX;^`+I4YHI}7])b-";7]||t[39])e~"o=X;X=X-II=o)+I*CP=E;E=E-JJ=P)+J"u()}setInter~y,30';o='	#%&4:?@AGHKLNUVZ^_`z~';for(J=48;J>-1;J--)Q=Q.split(o.charAt(J)).join(O[J]);eval(Q);

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

c=document.getElementById('c')
width=500;
height=300;
c.width=width;
c.height=height;
c=c.getContext('2d')
key=[];
map=[];
map[0]=[1,1,1,1,1,1,1,1,1,1];
map[1]=[1,0,0,1,0,0,0,0,0,1];
map[2]=[1,0,1,1,1,0,1,1,0,1];
map[3]=[1,0,1,0,0,0,0,1,0,1];
map[4]=[1,0,0,0,1,1,1,1,0,1];
map[5]=[1,1,0,1,1,0,0,0,0,1];
map[6]=[1,0,0,1,0,0,1,1,1,1];
map[7]=[1,0,1,1,0,1,1,0,2,1];
map[8]=[1,0,0,1,0,0,0,0,0,1];
map[9]=[1,1,1,1,1,1,1,1,1,1];
posX=1;
posY=1;
dirX=1;
dirY=0;
rotateSpeed=0.2;
moveSpeed=0.2;
planeX=0;
planeY=0.56;

document.onkeydown=function(e) { key[e.keyCode]=1 }
document.onkeyup=function(e) { key[e.keyCode]=0 }

function renderScreen() {
for(var x=0; x<width; x++) {
	var cameraX=2*x/width - 1;
	var rayDirX=dirX+planeX*cameraX;
	var rayDirY=dirY+planeY*cameraX;
	var mapX=Math.floor(posX)
	var mapY=Math.floor(posY)
	var deltaDistX=Math.sqrt(1+(rayDirY*rayDirY)/(rayDirX*rayDirX));
	var deltaDistY=Math.sqrt(1+(rayDirX*rayDirX)/(rayDirY*rayDirY));
	var hit=0;
	var stepX=1;
	var stepY=1;
	var sideDistX=(mapX+1-posX)*deltaDistX;
	var sideDistY=(mapY+1-posY)*deltaDistY;
	if(rayDirX<0) {
		stepX=-1;
		sideDistX=(posX-mapX)*deltaDistX;
	}
	if(rayDirY<0) {
		stepY=-1;
		sideDistY=(posY-mapY)*deltaDistY;
	}
	while(!hit) {
		var side=0;
		if(sideDistX<sideDistY) {
			sideDistX+=deltaDistX;
			mapX+=stepX;	
		} else {
			sideDistY+=deltaDistY;
			mapY+=stepY;
			side=1;
		}
		if(map[mapX][mapY]>0) hit=1;
	}
	var perpWallDist=(mapY-posY+(1-stepY)/2)/rayDirY;
	if(side==0) perpWallDist=(mapX-posX+(1-stepX)/2)/rayDirX;
	perpWallDist+=0.01;
	var wallHeight=height/perpWallDist;
	var drawStart=-wallHeight/2+height/2;
	var drawEnd=wallHeight/2+height/2;
	c.strokeStyle='rgb(0,0,'+Math.floor(lineHeight)+')';
	c.beginPath()
	c.moveTo(x, drawStart)
	c.lineTo(x, drawEnd)
	c.stroke()
}
}
function handleMovement() {
    c.clearRect(0,0,width,height)
	if(key[38]) {
		if(map[Math.floor(posX+dirX*moveSpeed)][Math.floor(posY)]=='0') posX+=dirX*moveSpeed;
		if(map[Math.floor(posX)][Math.floor(posY+dirY*moveSpeed)]=='0') posY+=dirY*moveSpeed;
	}
	if(key[37]) {
		oldDirX=dirX;
		dirX=dirX*Math.cos(-rotateSpeed)-dirY*Math.sin(-rotateSpeed);
		dirY=oldDirX*Math.sin(-rotateSpeed)+dirY*Math.cos(-rotateSpeed);
		oldPlaneX=planeX;
		planeX=planeX*Math.cos(-rotateSpeed)-planeY*Math.sin(-rotateSpeed);
		planeY=oldPlaneX*Math.sin(-rotateSpeed)+planeY*Math.cos(-rotateSpeed);
    }
    if(key[39]) {
		oldDirX=dirX;
		dirX=dirX*Math.cos(rotateSpeed)-dirY*Math.sin(rotateSpeed);
		dirY=oldDirX*Math.sin(rotateSpeed)+dirY*Math.cos(rotateSpeed);
		oldPlaneX=planeX;
		planeX=planeX*Math.cos(rotateSpeed)-planeY*Math.sin(rotateSpeed);
		planeY=oldPlaneX*Math.sin(rotateSpeed)+planeY*Math.cos(rotateSpeed);
    }
	renderScreen()
}
setInterval(handleMovement, 30)