function data2d() {
	
	//全部墙
	this.wallIds=[];
	//默认是当前屏幕显示的全部墙
	this.showWallIds=[];
	this.symbol2DIds=[];
	//楼梯
	this.stairIds=[];
	//还没有确定的wall，表示正在添加的墙
	this.temp_wallId=null;
	//还没有确定的元素
	this.temp_symbol2DIds=[];
	//当前显示的元素
	this.show_symbol2DIds=[];  
	//节点
	//通过nodes计算wall上的joins，如果节点对应的是墙角，则endIndex为-1
	//value大部分情况是二个元素的数组，如果大于两个元素，表示指向同一个join
	//key是整型
	//{1:{info:[{startIndex:1,endIndex:2,wallId:26}],join:point},2:{info:[],join:point2}}
	this.nodes={};
	this.currentnodeskey = 1;
};

//根据wallid的值删除
data2d.prototype.deleteWallid = function(value)
{
	if(this.wallIds!=null&&this.wallIds.length>0)
	{
		for(var i=0;i<this.wallIds.length;++i)
		{
			if(this.wallIds[i]==value)
			{
				this.wallIds.splice(i,1);
				return ;
			}
		}
	}
};

//移动墙面
data2d.prototype.moveNodeForWall = function(np1,np2)
{
	for(var key in this.nodes){
	    var node = this.nodes[key]["info"];
	    for(var i=0;i<node.length;++i)
	    {
		   if(node[i].wallId == np1.wallId&&node[i].startIndex == np1.startIndex&&node[i].endIndex == np1.endIndex)
		   {
			   if(node.length==2)
			   {
				   delete this.nodes[key];
			   }
			   else
			   {
				   this.nodes[key]["info"].splice(i,1);
			   }
		   }
		   else if(node[i].wallId == np2.wallId&&node[i].startIndex == np2.startIndex&&node[i].endIndex == np2.endIndex)
		   {
			   if(node.length==2)
			   {
				   delete this.nodes[key];
			   }
			   else
			   {
				   this.nodes[key]["info"].splice(i,1);
			   }
		   }
		   else if(node[i].wallId == np1.wallId&&node[i].startIndex == np1.startIndex&&node[i].endIndex == np2.startIndex)
		   {
			   if(node.length==2)
			   {
				   delete this.nodes[key];
			   }
			   else
			   {
				   this.nodes[key]["info"].splice(i,1);
			   }
		   }
	    }
	}
};

//移动墙角
data2d.prototype.moveNodeForWallCorner = function(np)
{
	for(var key in this.nodes){
	    var node = this.nodes[key]["info"];
	    for(var i=0;i<node.length;++i)
	    {
		   if(node[i].wallId == np.wallId&&node[i].startIndex == np.startIndex&&node[i].endIndex == np.endIndex)
		   {
			   if(node.length==2)
			   {
				   delete this.nodes[key];
			   }
			   else
			   {
				   this.nodes[key]["info"].splice(i,1);
			   }
		   }
	    }
	}
};

//对应的墙角,墙面消失了
data2d.prototype.deleteNode = function(np,nextIndex)
{
	for(var key in this.nodes){
	    var node = this.nodes[key]["info"];
	    for(var i=0;i<node.length;++i)
	    {
		   if(node[i].wallId == np.wallId&&node[i].startIndex == np.startIndex&&node[i].endIndex == np.endIndex)
		   {
			   if(node.length==2)
			   {
				   delete this.nodes[key];
			   }
			   else
			   {
				   this.nodes[key]["info"].splice(i,1);
			   }
		   }
		   else if(node[i].wallId == np.wallId&&node[i].startIndex == np.startIndex&&node[i].endIndex == nextIndex)
		   {
			   if(node.length==2)
			   {
				   delete this.nodes[key];
			   }
			   else
			   {
				   this.nodes[key]["info"].splice(i,1);
			   }
		   }
		   else if(node[i].wallId == np.wallId)
		   {
			   var index = Math.max(np.startIndex,np.endIndex);
			   if(node[i].startIndex>index)
			   {
				   --node[i].startIndex;
				   if(node[i].endIndex>index)
				   {
					   --node[i].endIndex;
				   }
				   this.nodes[key]["info"][i] = node[i];
			   }
		   }
	    }
	}
};

data2d.prototype.addNode = function(np1,np2,join)
{
	var interval=layer.parameter.wallThickness;
	for(var key in this.nodes){
		var node = this.nodes[key];
		var point = node["join"];
		
		var distance=BABYLON.Vector2.Distance(point,join);
		//重合
		if(distance<interval)
		{
			var info = this.nodes[key]["info"];
			var flag1=false;
			var flag2=false;
			for(var j=0;j<info.length;++j)
			{
				if(!flag1)
				{
					if(info.wallId == np1.wallId&&info.startIndex == np1.wallId&&info.endIndex == np1.wallId)
					{
						flag1 = true;
					}
				}
				if(!flag2)
				{
					if(info.wallId == np2.wallId&&info.startIndex == np2.wallId&&info.endIndex == np2.wallId)
					{
						flag2 = true;
					}
				}
			}
			if(!flag1)
			{
				this.nodes[key]["info"].push(np1);
			}
			if(!flag2)
			{
				this.nodes[key]["info"].push(np2);
			}
			return;
		}
	}
	this.nodes[this.currentnodeskey]={};
	this.nodes[this.currentnodeskey]["info"]=[];
	this.nodes[this.currentnodeskey]["info"].push(np1);
	this.nodes[this.currentnodeskey]["info"].push(np2);
	this.nodes[this.currentnodeskey]["join"] = join;
	++this.currentnodeskey;
};