code: function init(cols, rows, tilewidth, tileheight) {
           this._super(me.TMXRenderer, "init", [cols, rows, tilewidth, tileheight]);
  
           this.hTilewidth = tilewidth / 2;
           this.hTileheight = tileheight / 2;
           this.originX = this.rows * this.hTilewidth;
         }
docs: constructor