Rise or Fall Tile Rendering

/** * TileWriter.js, a tile 'rendering' library for Rise or Fall * Requires: MooTools and Bija, or compatible. *  * @author:	 Matan Lurey * @version: 1.0a */TileWriter = {	init: function(element){		this.element = element;	},		write: function(x, y, terrain, tile){		var xpos = (!this.last.coords) ? 0 : this.last.position[0] + (x - this.last.coords[0]) * 128;		var ypos = (!this.last.coords) ? 0 : this.last.position[1] + (y - this.last.coords[1]) * 32;s				this.last.coords    = [x, y];		this.last.position  = [xpos, ypos];				var tile = new Element('div', {			styles: {				left: xpos+'px',				top:  ypos+'px',				backgroundPosition: '-'+(tile[0]*128)+'px ' + '-'+(tile[1]*64)+'px'			}		}).addClass(terrain).addClass((y % 2) ? 'odd' : 'even').inject(this.element);	},		last: {		coords:   null,		position: null	}};