A*寻路的原理，网上很多，可以看这里

  1 var A_STAR_DISTANCE = 7; //像素大小，越小越精确，同时越耗时
  2 var A_STAR_G_EXPEND_MIN = 10; //上下左右G值消耗数
  3 var A_STAR_G_EXPEND_MAX = 14; //斜角G值消耗数
  4 
  5 var HelloWorldLayer = cc.Layer.extend({
  6 sprite:null, //角色
  7 aStarPathArray:[], //最终角色要行走的路径
  8 aStarBarrierArray:[], //地图障碍物
  9 testNumber:1,
 10 ctor:function () {
 11 //////////////////////////////
 12 // 1. super init first
 13 this._super();
 14 /////////////////////////////
 15 // 2. add a menu item with "X" image, which is clicked to quit the program
 16 // you may modify it.
 17 // ask director the window size
 18 var size = cc.director.getWinSize();
 19 
 20 this.sprite = cc.Sprite.create(res.Plane_png); //角色初始化
 21 this.sprite.attr({
 22 x: 150,
 23 y: 50,
 24 rotation: 90
 25 });
 26 this.addChild(this.sprite, 0);
 27 
 28 var barrier1 = cc.rect(200,50,50,350); //绘制障碍物
 29 var barrier2 = cc.rect(250,50,350,50);
 30 var barrier3 = cc.rect(250,350,350,50);
 31 this.aStarBarrierArray.push(barrier1);
 32 this.aStarBarrierArray.push(barrier2);
 33 this.aStarBarrierArray.push(barrier3);
 34 
 35 var drawBarrier = cc.DrawNode.create(); //在屏幕上显示障碍物
 36 this.addChild(drawBarrier, 10);
 37 var vertices = [cc.p(200,50),cc.p(600,50),cc.p(600,100),cc.p(250,100),cc.p(250,350),cc.p(600,350),cc.p(600,400),cc.p(200,400)];
 38 drawBarrier.drawPoly(vertices,null,2,cc.color(255,0,0,255));
 39 
 40 if ('mouse' in cc.sys.capabilities)
 41 cc.eventManager.addListener({
 42 event: cc.EventListener.MOUSE,
 43 onMouseUp:function(event){
 44 if(event.getButton() != undefined)
 45 {
 46 var t = new Date().getTime();
 47 event.getCurrentTarget().getStartAndEndPoint(event); //A*算法开始
 48 cc.log("算法耗时:"+(new Date().getTime() - t)+"ms"); //计算起点到终点的算法耗时
 49 }
 50 }
 51 }, this);
 52 
 53 
 54 return true;
 55 },
 56 getStartAndEndPoint:function (event) { //得到起始点和终点坐标
 57 var sp = {coordX:parseInt(this.sprite.x,10),coordY:parseInt(this.sprite.y,10)};
 58 var ep = {coordX:parseInt(event.getLocation().x,10),coordY:parseInt(event.getLocation().y,10)};
 59 var endPointIsObstacle = false; //判断终点是否在障碍物上，是的话就提示路径走不了
 60 for (var theBarrierIndex=0; theBarrierIndex<this.aStarBarrierArray.length; theBarrierIndex++){
 61 if(cc.rectContainsPoint(this.aStarBarrierArray[theBarrierIndex],cc.p(ep.coordX,ep.coordY)))
 62 {
 63 endPointIsObstacle = true;
 64 cc.log("你要去的位置有障碍物，请换条路线");
 65 break;
 66 }
 67 }
 68 if(!endPointIsObstacle)
 69 this.findingPath(sp,ep);
 70 },
 71 findingPath:function(startPoint,endPoint){ //A*算法
 72 var openList = []; //初始化开启列表
 73 var closeList = []; //初始化关闭列表
 74 startPoint.ag = 0;
 75 startPoint.ah = 0;
 76 startPoint.af = startPoint.ag + startPoint.ah; //起点的G,H,F值为0
 77 openList.push(startPoint); //起点加入开启列表
 78 var findTheWay = false;
 79 do{
 80 var centerNode = this.findMinNode(openList); //寻找F值最低的节点
 81 openList.remove(centerNode); //将此节点从开启列表中删除，为了下次遍历开启列表的时候不再出现此节点
 82 closeList.push(centerNode); //并将此节点加入到关闭列表
 83 for(var i=0;i<8;i++) //遍历此节点周围的节点，并给这些节点加入坐标属性和G值
 84 {
 85 var aroundNode = {};
 86 switch (i){
 87 case 0:
 88 aroundNode.coordX = centerNode.coordX+A_STAR_DISTANCE; //坐标属性
 89 aroundNode.coordY = centerNode.coordY+A_STAR_DISTANCE;
 90 break;
 91 case 1:
 92 aroundNode.coordX = centerNode.coordX+A_STAR_DISTANCE;
 93 aroundNode.coordY = centerNode.coordY;
 94 break;
 95 case 2:
 96 aroundNode.coordX = centerNode.coordX+A_STAR_DISTANCE;
 97 aroundNode.coordY = centerNode.coordY-A_STAR_DISTANCE;
 98 break;
 99 case 3:
100 aroundNode.coordX = centerNode.coordX;
101 aroundNode.coordY = centerNode.coordY-A_STAR_DISTANCE;
102 break;
103 case 4:
104 aroundNode.coordX = centerNode.coordX-A_STAR_DISTANCE;
105 aroundNode.coordY = centerNode.coordY-A_STAR_DISTANCE;
106 break;
107 case 5:
108 aroundNode.coordX = centerNode.coordX-A_STAR_DISTANCE;
109 aroundNode.coordY = centerNode.coordY;
110 break;
111 case 6:
112 aroundNode.coordX = centerNode.coordX-A_STAR_DISTANCE;
113 aroundNode.coordY = centerNode.coordY+A_STAR_DISTANCE;
114 break;
115 case 7:
116 aroundNode.coordX = centerNode.coordX;
117 aroundNode.coordY = centerNode.coordY+A_STAR_DISTANCE;
118 break;
119 }
120 for (var barrierIndex=0; barrierIndex<this.aStarBarrierArray.length; barrierIndex++){
121 aroundNode.isOb = cc.rectContainsPoint(this.aStarBarrierArray[barrierIndex],cc.p(aroundNode.coordX,aroundNode.coordY)); //判断当前节点是否在障碍物形成的方框里
122 if(aroundNode.isOb)
123 break;
124 }
125 if (aroundNode.isOb){ //如果是障碍物，跳过
126 
127 }
128 else if(closeList.hasObject(aroundNode)){ //如果在关闭列表里，跳过
129 
130 }
131 else if(!openList.hasObject(aroundNode)){ //如果不在开启列表里，加入到开启列表
132 aroundNode.parentPath = centerNode;
133 if (Math.abs(aroundNode.coordX-endPoint.coordX)<=A_STAR_DISTANCE/2 && Math.abs(aroundNode.coordY-endPoint.coordY)<=A_STAR_DISTANCE/2) //如果节点和终点的值相近，那么A*算法结束，得到路径
134 {
135 findTheWay = true;
136 var pathArry = [];
137 this.gettingAStarPath(aroundNode,pathArry); //寻找路径
138 pathArry.splice(0,0,{starX:endPoint.coordX,starY:endPoint.coordY}); //加终点到数组头部
139 pathArry.splice(pathArry.length-1,1); //删一项数组底部的起点数据，此时的数组是最终的路径数组
140 
141 this.aStarPathArray = [];
142 this.aStarPathArray = pathArry;
143 this.aStarPathArray.theIndex = this.aStarPathArray.length;
144 
145 this.unschedule(this.thePathSelector);
146 this.schedule(this.thePathSelector,null,pathArry.length-1);
147 break; //找到最短路径并跳出循环
148 }
149 if (aroundNode.coordX!=centerNode.coordX && aroundNode.coordY!=centerNode.coordY) //确定中心节点和周围节点形成的角度，正交G值消耗10*像素，斜角G值消耗14*像素
150 aroundNode.ag = centerNode.ag + A_STAR_G_EXPEND_MAX*A_STAR_DISTANCE;
151 else
152 aroundNode.ag = centerNode.ag + A_STAR_G_EXPEND_MIN*A_STAR_DISTANCE;
153 aroundNode.af = this.getAF(aroundNode,endPoint);
154 openList.push(aroundNode);
155 }
156 else if(openList.hasObject(aroundNode)){ //如果在开启列表里
157 var newExpend = A_STAR_G_EXPEND_MIN*A_STAR_DISTANCE;
158 if (aroundNode.coordX!=centerNode.coordX && aroundNode.coordY!=centerNode.coordY) //确定中心节点和周围节点形成的角度，正交G值消耗10*像素，斜角G值消耗14*像素
159 newExpend = A_STAR_G_EXPEND_MAX*A_STAR_DISTANCE;
160 if (centerNode.ag + newExpend < aroundNode.ag){ //如果新的g值小于周围节点本身的g值，那么周围节点的父节点改为当前中心节点，并重新计算其F值
161 aroundNode.parentPath = centerNode;
162 aroundNode.ag = centerNode.ag + newExpend;
163 aroundNode.af = this.getAF(aroundNode,endPoint);
164 }
165 }
166 }
167 }while(!findTheWay)
168 
169 },
170 findMinNode:function(openListArray){
171 var minNode = openListArray[0];
172 for (var i=0;i<openListArray.length;i++)
173 {
174 if (minNode.af>openListArray[i].af) minNode=openListArray[i];
175 }
176 return minNode;
177 },
178 getAF:function(thisNode,endNode){
179 var aHExpend = (Math.abs(thisNode.coordX-endNode.coordX) + Math.abs(thisNode.coordY-endNode.coordY))*A_STAR_G_EXPEND_MIN;
180 return aHExpend+thisNode.ag;
181 },
182 gettingAStarPath:function(laseNode,array){
183 if(laseNode.parentPath != null)
184 {
185 array.push({starX:laseNode.parentPath.coordX,starY:laseNode.parentPath.coordY});
186 this.gettingAStarPath(laseNode.parentPath,array);
187 }
188 },
189 thePathSelector:function(){
190 this.roleRunThePath(this.aStarPathArray);
191 },
192 roleRunThePath:function(array){
193 this.sprite.x = array[--array.theIndex].starX;
194 this.sprite.y = array[array.theIndex].starY;
195 }
196 });
197 
198 var HelloWorldScene = cc.Scene.extend({
199 onEnter:function () {
200 this._super();
201 var layer = new HelloWorldLayer();
202 this.addChild(layer);
203 }
204 });
205 
206 //这里给Array数组添加3个实例方法
207 Array.prototype.aStarIndexOf = function(val) { //通过对象寻找index值
208 for (var i = 0; i < this.length; i++) {
209 if (this[i].coordX==val.coordX && this[i].coordY==val.coordY) return i;
210 }
211 return -1;
212 };
213 Array.prototype.remove = function(val) { //删除相应的对象
214 var index = this.aStarIndexOf(val);
215 if (index > -1) {
216 this.splice(index, 1);
217 }
218 };
219 
220 Array.prototype.hasObject = function(val){ //判断是否是同一个对象
221 for (var i = 0; i < this.length; i++){
222 if (this[i].coordX==val.coordX && this[i].coordY==val.coordY)
223 return true;
224 }
225 return false;
226 };