PointsToBuffer.js

/*

    2D ARRAY

    0  1  2  3  4 (x)
 0 [ ][ ][ ][ ][ ]
 1 [ ][ ][#][ ][ ]
 2 [ ][ ][ ][ ][ ]
 3 [ ][ ][ ][ ][ ]
 4 [ ][ ][ ][ ][ ]
(y)


                                1D BUFFER
 0  0  0  0  0  0  0  0  0  0  1  1  1  1  1  1  1  1  1  1  2  2  2  2  2
 0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  (offset)
[ ][ ][ ][ ][ ][ ][ ][#][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]


ARRAY(2,1) == OFFSET(7)   ... x+y*width
OFFSET(7)  == ARRAY(2,1)  ... y:floor(off/width) x:off%width

*/

var width  = 100;
var height = 100;

var offset = function(x,y) {
	return x+y*width;
};

var points = function(off) {
	var y = Math.floor(off/width);
	var x = off%width;
	return {x:x,y:y};
};

function test(){

	for(var x=0;x<width;x++) {
		for(var y=0;y<height;y++) {

			var off = offset(x,y);
			var crt = points(off);

			if (crt.x!==x || crt.y!==y) {
				console.log("FAIL!",x,y,crt.x,crt.y);
				return false;
			}

		}
	}

	return true;

}

console.log(test());