JS1k: The JavaScript code golfing competition

(function(){function k(b,h,f){f=f*n()-f/2;b=(b+h)/2+f;if(mh>b)mh=b;if(xh<b)xh=b;return b}function u(b,h,f,j){var q=o((b+f)/2),p=o((h+j)/2);g[q][h]=k(g[b][h],g[f][h],f-b);g[b][p]=k(g[b][h],g[b][j],j-h);g[f][p]=k(g[f][h],g[f][j],j-h);g[q][j]=k(g[b][j],g[f][j],f-b);g[q][p]=k(g[b][p],g[f][p],f-b)}d=s=512;c=document.body.children[0];t=c.getContext("2d");g=[];r=513;mh=255;xh=0;M=Math;o=M.round;m=4294967296;a=1103515245;cc=12345;for(n=new (function(){state=M.floor(M.random()*(m-1));return function(){return(state=
(a*state+cc)%m)/(m-1)}});r--;){g.push([]);for(sd=d+1;sd--;)g[g.length-1].push(0)}for(;s>1;){for(y=0;y<d;y+=s)for(x=0;x<d;x+=s)u(x,y,x+s,y+s);s=o(s/2)}l=255/(xh-mh);c.width=d;c.height=d;img=t.createImageData?t.createImageData(d,d):t.getImageData(0,0,d,d);pix=img.data;for(x=d;x--;)for(y=d;y--;){e=o((g[x][y]-mh)*l);cl=e<100?[,,12]:e<120?[6,6,16]:e<130?[12,11,9]:e<160?[6,12,6]:e<180?[6,16,6]:e<200?[5,6,30]:e<220?[9,9,6]:[16,16,16];for(i=4;i--;)pix[x*4+y*d*4+i]=i>2?255:cl[i]*16}t.putImageData(img,0,0)})();

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

(function() {
	d=s=512,c=document.body.children[0],t=c.getContext("2d"),g=[],r=513,mh=255,xh=0,M=Math,o=M.round,
		m = 0x100000000, a = 1103515245, cc = 12345,
		n = new (function() {
			state = M.floor(M.random() * (m-1));	
			return function() {
				// returns in range [0,1]
				return (state = (a * state + cc) % m) / (m - 1);
			}
		})
	while(r--) {
		g.push([]);
		sd=d+1;
		while(sd--)
			g[g.length-1].push(0);
	}
	while(s>1) {
		for(y=0;y<d;y+=s)
			for(x=0;x<d;x+=s)
				subdivide(x,y,x+s,y+s);
		s = o(s/2);
	}
	l = 255/(xh-mh);
	
	function getheight(z0, z1, dl) {
		var fc = dl*n()-dl/2, 
			e = (z0+z1)/2 + fc;
		if(mh>e) mh=e;
		if(xh<e) xh=e;
		return e;
	}
	
	function subdivide(x0, y0, x1, y1) {
		var xn = o((x0+x1)/2), yn = o((y0+y1)/2);
		g[xn][y0] = getheight(g[x0][y0], g[x1][y0], x1-x0);
		g[x0][yn] = getheight(g[x0][y0], g[x0][y1], y1-y0);
		
		g[x1][yn] = getheight(g[x1][y0], g[x1][y1], y1-y0);
		g[xn][y1] = getheight(g[x0][y1], g[x1][y1], x1-x0);
		
		g[xn][yn] = getheight(g[x0][yn], g[x1][yn], x1-x0);
	}
	
	c.width=d;
	c.height=d;
	img=t.createImageData?t.createImageData(d,d):t.getImageData(0,0,d,d), pix=img.data;
	x=d;while(x--) {
		y=d;while(y--) {
			e=o((g[x][y]-mh)*l), // e = ld elevation
			cl = e<100?[,,12]:e<120?[6,6,16]:e<130?[12,11,9]:e<160?[6,12,6]:e<180?[6,16,6]:e<200?[5,6,30]:e<220?[9,9,6]:[16,16,16];
			i=4;while(i--)
				pix[x*4+(y*d)*4+i] = i>2?255:cl[i]*16;
		}
	}
	t.putImageData(img,0,0);
})();