gistfile1.txt

var neighbor = {"none":0,"same":1,"other":2};


var tileSheetDataMap = function(){
  this.map = {};
};
tileSheetDataMap.prototype.addCell = function(data) {
  var key = data.n + "," + data.e + "," + data.s + "," + data.w;
  this.map[key] = this.map[key] || [];
  this.map[key].push([data.x, data.y]);
};

var dirtSheet = new tileSheetDataMap();

dirtSheet.addCell({x:0, y:0, n: neighbor.same, e: neighbor.same, s: neighbor.same, w: neighbor.none});
dirtSheet.addCell({x:1, y:0, n: neighbor.none, e: neighbor.same, s: neighbor.same, w: neighbor.same});
dirtSheet.addCell({x:2, y:0, n: neighbor.none, e: neighbor.same, s: neighbor.same, w: neighbor.same});
dirtSheet.addCell({x:3, y:0, n: neighbor.none, e: neighbor.same, s: neighbor.same, w: neighbor.same});