如果你还不熟悉A*寻路，请先看下这篇文章http://blog.csdn.net/dssdss123/article/details/11494065
一、先介绍几个函数和结构：
1、virtual void draw()
这个函数跟与MFC上单文档里的OnDraw函数很像，这里只是少了dc，这个函数会一直被调用，无需刷新，也就是说，你无需像在MFC上一样调用Invalidate或者InvalidateRect
2、virtual void ccTouchBegan(CCTouch* pTouch, CCEvent* pEvent)
这个函数是下响应触摸的，当你点击屏幕时，就会进到这个函数。要使这个函数有效，你需要在init中调用
setTouchEnabled(true); // 允许该层响应触摸 CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, 0, false); // 注册单点触摸在这个例子中，我们不需要多点触摸
3、ccColor4F结构
这个结构在ccDrawSolidRect函数中将会使用到，ccDrawSolidRect是画某种颜色的矩形，对应在MFC中，我们使用的是FillSolidRect。ccColor4F是RGBA的结构，RGB是三颜色，红绿蓝，最后一个alpha值，他表示这个颜色的透明度。为1是完全不透明，0时则完全透明。
二、实现
1、去掉coco自带的乱七八糟的显示
1）去掉帧频显示
在函数bool AppDelegate::applicationDidFinishLaunching()中
// turn on display FPS
//pDirector->setDisplayStats(true);将pDirector->setDisplayStats(true)，注释掉
2）去掉menu，Hello World文字标签
在函数void HelloWorld::init()中
// Add the menu to HelloWorld layer as a child layer.
//this->addChild(pMenu, 1); // Add the label to HelloWorld layer as a child layer. //this->addChild(pLabel, 1);将menu和label注释掉
3）替换背景图，并置于最底层
// 3. Add add a splash screen, show the cocos2d splash image.
CCSprite* pSprite = CCSprite::create("map.jpg"); // 将原先的HelloWorld.png，替换为自己的图片，这里我换成map.jpg CC_BREAK_IF(! pSprite);2、初始化地图
声明结构表示格子掩码等一些信息，我们的例子中，只需掩码，所以结构如下：
struct ST_GRID { ST_GRID() { gf = GRID_FLAG_DEFAULT; } GRID_FLAG gf; }; typedef vector VEC_GRID; VEC_GRID m_vecGrid; // 保存地图产生的所有格子
初始化地图的格子掩码，如下：
void HelloWorld::InitMap(){ // 初始化格子掩码 srand((unsigned int)time(NULL)); for (int i = 0; i < GetRow() * GetCol(); i++) { int nRandFlag = ((int)(CCRANDOM_0_1() * 10)) % 4 == 0 ? GRID_FLAG_OBSTACLE : GRID_FLAG_DEFAULT; // 十分之四的概率产生障碍 ST_GRID* pGrid = new ST_GRID; if (!pGrid) { return ; } pGrid->gf = (GRID_FLAG)nRandFlag; m_vecGrid.push_back(pGrid); }} 3、寻路
定义一个结构，用于寻路过程中，记录每个格子的信息
struct NODE { NODE() {nIndex = 0; nG = 0; pParent = NULL;} int nIndex; int nG; NODE* pParent; }; vector m_vecPath; // 寻路的路径 下面开始寻路
void HelloWorld::FindPath(){ vector vecClose; // close表 vector vecOpen; // open表 if (m_nStartIndex == -1 || m_nEndIndex == -1) { return ; } m_vecPath.clear(); // 这里，我们并没有delete，但却不会内存泄漏，因为cocos2d-x使用了跟java一样的技术 -- 内存回收机制，自动处理垃圾 // 先添加开始点 NODE* pNode = new NODE; pNode->nIndex = m_nStartIndex; vecClose.push_back(pNode); int nStep = 0; while(true) { if (nStep++ >= 200) // 最多寻200格 { break; } NODE* pNextNode = vecClose[vecClose.size() - 1]; // 取下一个路径 if (!pNextNode) { break; } if (pNextNode->nIndex == m_nEndIndex) // 找到终点，就不再找了 { break; } for (int i = 0; i < 8; i++) { int nIndex = GetIndexByDir(pNextNode->nIndex, i); // 根据方向取索引 if (-1 == nIndex) { continue; } if (m_vecGrid[nIndex]->gf == GRID_FLAG_OBSTACLE) // 障碍 { continue; } if (InTable(nIndex, vecClose) != NULL) // 在close表里 { continue; } NODE* pNode = InTable(nIndex, vecOpen); // 在open表里，比较G值，取G值更小的为新路径 if (pNode) { int nNewG = pNextNode->nG + GetGByIndex(pNextNode->nIndex, pNode->nIndex); if (pNode->nG > nNewG) { pNode->nG = nNewG; pNode->pParent = pNextNode; // 改变节点的父节点 } continue; } // 新搜索到的格子，添加到开放列表 pNode = new NODE; pNode->nIndex = nIndex; pNode->nG = pNextNode->nG + GetGByIndex(pNextNode->nIndex, pNode->nIndex); pNode->pParent = pNextNode; vecOpen.push_back(pNode); } // 找下一个路径，open表里F值最小的就是了 int nMinF = 0xFFFFFF; pNextNode = NULL; int nNextNodeIndex = 0; for (int i = 0; i < (int)vecOpen.size(); i++) { NODE* pNode = vecOpen[i]; if (!pNode) { continue; } int nH = GetHByIndex(pNode->nIndex); // 计算该点与终点的H值，即路径长度 int nF = nH + pNode->nG; // F = H + G if (nF < nMinF) { nMinF = nF; pNextNode = pNode; nNextNodeIndex = i; } } // 找到F值最小的，放入close表，并从open表里删除 if (nNextNodeIndex >= 0 && nNextNodeIndex < (int)vecOpen.size()) { vecClose.push_back(pNextNode); vecOpen.erase(vecOpen.begin() + nNextNodeIndex); } } // 寻路结束，找最优路径 pNode = vecClose[vecClose.size() - 1]; while (pNode) { m_vecPath.push_back(pNode); pNode = pNode->pParent; }} 4、展示到界面上
void HelloWorld::draw(){ // 画背景表格 CCSize size = CCDirector::sharedDirector()->getWinSize(); for (int i = 0; i < GetRow(); i++) { ccDrawLine(ccp(0, i * GRID_SIDELEN), ccp(size.width, i * GRID_SIDELEN)); } for (int i = 0; i < GetCol(); i++) { ccDrawLine(ccp(i * GRID_SIDELEN, 0), ccp(i * GRID_SIDELEN, size.height)); } // 画特殊格子颜色 // 寻路得到的路径 for (int i = 0; i < (int)m_vecPath.size(); i++) { CCPoint ptObstacleLT; CCPoint ptObstacleRD; GetRectPointByIndex(m_vecPath[i]->nIndex, ptObstacleLT, ptObstacleRD); ccColor4F clrObstacle = {0, 1, 1, 0}; ccDrawSolidRect(ptObstacleLT, ptObstacleRD, clrObstacle); } // 开始点 CCPoint ptStartLT; CCPoint ptStartRD; GetRectPointByIndex(m_nStartIndex, ptStartLT, ptStartRD); ccColor4F clrStart = {1, 0, 0, 1}; ccDrawSolidRect(ptStartLT, ptStartRD, clrStart); // 结束点 CCPoint ptEndLT; CCPoint ptEndRD; GetRectPointByIndex(m_nEndIndex, ptEndLT, ptEndRD); ccColor4F clrEnd = {0, 1, 0, 1}; ccDrawSolidRect(ptEndLT, ptEndRD, clrEnd); // 障碍 for (int i = 0; i < (int)m_vecGrid.size(); i++) { if (m_vecGrid[i]->gf == GRID_FLAG_OBSTACLE) { CCPoint ptObstacleLT; CCPoint ptObstacleRD; GetRectPointByIndex(i, ptObstacleLT, ptObstacleRD); ccColor4F clrObstacle = {0, 0, 1, 1}; ccDrawSolidRect(ptObstacleLT, ptObstacleRD, clrObstacle); } }} 这里，我只介绍几个比较重要的函数，其他的就不赘述了，资源已上传到CSDN，但还没显示出来，等显示出来了，再把链接发到此处，有疑问的童鞋留言哈
。。。。。。。。
啊，我还是直接上源码吧
#ifndef __HELLOWORLD_SCENE_H__#define __HELLOWORLD_SCENE_H__#include "cocos2d.h"#include "Box2D/Box2D.h"#include "SimpleAudioEngine.h"USING_NS_CC;enum STEP{ STEP_DEFAULT = 0, STEP_STARTPOINT = 1, STEP_ENDPOINT = 2,};enum GRID_FLAG{ GRID_FLAG_DEFAULT = 0, // 默认可通过 GRID_FLAG_OBSTACLE = 1, // 障碍};const int GRID_SIDELEN = 20; // 不能为0//class HelloWorld : public cocos2d::CCLayer{public: // Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone virtual bool init(); // there's no 'id' in cpp, so we recommand to return the exactly class pointer static cocos2d::CCScene* scene(); // a selector callback void menuCloseCallback(CCObject* pSender); // implement the "static node()" method manually CREATE_FUNC(HelloWorld);public: virtual void draw(); virtual bool ccTouchBegan(CCTouch* pTouch, CCEvent* pEvent);private: void InitMap();private: int GetRow(); int GetCol(); int GetIndexByPoint(CCPoint pt); void GetRectPointByIndex(int nIndex, CCPoint &ptLT, CCPoint &ptRD);private: int m_nStartIndex; int m_nEndIndex; struct ST_GRID { ST_GRID() { gf = GRID_FLAG_DEFAULT; } GRID_FLAG gf; }; typedef vector VEC_GRID; VEC_GRID m_vecGrid; struct NODE { NODE() {nIndex = 0; nG = 0; pParent = NULL;} int nIndex; int nG; NODE* pParent; }; vector m_vecPath; // 寻路的路径public: void FindPath();private: int GetIndexByDir(int nIndex, int nDir); int GetGByIndex(int nStartIndex, int nEndIndex); int GetHByIndex(int nIndex); NODE *InTable(int nIndex, vector &vecTbl);private: int m_nStep;};#endif // __HELLOWORLD_SCENE_H__
#include "HelloWorldScene.h"using namespace cocos2d;CCScene* HelloWorld::scene(){ CCScene * scene = NULL; do { // 'scene' is an autorelease object scene = CCScene::create(); CC_BREAK_IF(! scene); // 'layer' is an autorelease object HelloWorld *layer = HelloWorld::create(); CC_BREAK_IF(! layer); // add layer as a child to scene scene->addChild(layer); } while (0); // return the scene return scene;}// on "init" you need to initialize your instancebool HelloWorld::init(){ bool bRet = false; do { // // super init first // CC_BREAK_IF(! CCLayer::init()); // // add your codes below... // // 1. Add a menu item with "X" image, which is clicked to quit the program. // Create a "close" menu item with close icon, it's an auto release object. CCMenuItemImage *pCloseItem = CCMenuItemImage::create( "CloseNormal.png", "CloseSelected.png", this, menu_selector(HelloWorld::menuCloseCallback)); CC_BREAK_IF(! pCloseItem); // Place the menu item bottom-right conner. pCloseItem->setPosition(ccp(CCDirector::sharedDirector()->getWinSize().width - 20, 20)); // Create a menu with the "close" menu item, it's an auto release object. CCMenu* pMenu = CCMenu::create(pCloseItem, NULL); pMenu->setPosition(CCPointZero); CC_BREAK_IF(! pMenu); // Add the menu to HelloWorld layer as a child layer. //this->addChild(pMenu, 1); // 2. Add a label shows "Hello World". // Create a label and initialize with string "Hello World". CCLabelTTF* pLabel = CCLabelTTF::create("Hello World", "Arial", 24); CC_BREAK_IF(! pLabel); // Get window size and place the label upper. CCSize size = CCDirector::sharedDirector()->getWinSize(); pLabel->setPosition(ccp(size.width / 2, size.height - 50)); // Add the label to HelloWorld layer as a child layer. //this->addChild(pLabel, 1); // 3. Add add a splash screen, show the cocos2d splash image. CCSprite* pSprite = CCSprite::create("map.jpg"); CC_BREAK_IF(! pSprite); // Place the sprite on the center of the screen pSprite->setPosition(ccp(size.width/2, size.height/2)); // Add the sprite to HelloWorld layer as a child layer. this->addChild(pSprite, -1); setTouchEnabled(true); CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this,0,false); m_nStep = STEP_STARTPOINT; m_nStartIndex = -1; m_nEndIndex = -1; InitMap(); bRet = true; } while (0); return bRet;}void HelloWorld::menuCloseCallback(CCObject* pSender){ // "close" menu item clicked CCDirector::sharedDirector()->end();}//void HelloWorld::InitMap(){ srand((unsigned int)time(NULL)); for (int i = 0; i < GetRow() * GetCol(); i++) { int nRandFlag = ((int)(CCRANDOM_0_1() * 10)) % 4 == 0 ? GRID_FLAG_OBSTACLE : GRID_FLAG_DEFAULT; ST_GRID* pGrid = new ST_GRID; if (!pGrid) { return ; } pGrid->gf = (GRID_FLAG)nRandFlag; m_vecGrid.push_back(pGrid); }}//void HelloWorld::FindPath(){ vector vecClose; vector vecOpen; if (m_nStartIndex == -1 || m_nEndIndex == -1) { return ; } m_vecPath.clear(); // 先添加开始点 NODE* pNode = new NODE; pNode->nIndex = m_nStartIndex; vecClose.push_back(pNode); int nStep = 0; while(true) { if (nStep++ >= 200) { break; } NODE* pNextNode = vecClose[vecClose.size() - 1]; if (!pNextNode) { break; } if (pNextNode->nIndex == m_nEndIndex) { break; } for (int i = 0; i < 8; i++) { int nIndex = GetIndexByDir(pNextNode->nIndex, i); if (-1 == nIndex) { continue; } if (m_vecGrid[nIndex]->gf == GRID_FLAG_OBSTACLE) // 障碍 { continue; } if (InTable(nIndex, vecClose) != NULL) // 在close表里 { continue; } NODE* pNode = InTable(nIndex, vecOpen); // 在open表里 if (pNode) { int nNewG = pNextNode->nG + GetGByIndex(pNextNode->nIndex, pNode->nIndex); if (pNode->nG > nNewG) { pNode->nG = nNewG; pNode->pParent = pNextNode; } continue; } // 新搜索到的格子 pNode = new NODE; pNode->nIndex = nIndex; pNode->nG = pNextNode->nG + GetGByIndex(pNextNode->nIndex, pNode->nIndex); pNode->pParent = pNextNode; vecOpen.push_back(pNode); } int nMinF = 0xFFFFFF; pNextNode = NULL; int nNextNodeIndex = 0; for (int i = 0; i < (int)vecOpen.size(); i++) { NODE* pNode = vecOpen[i]; if (!pNode) { continue; } int nH = GetHByIndex(pNode->nIndex); int nF = nH + pNode->nG; if (nF < nMinF) { nMinF = nF; pNextNode = pNode; nNextNodeIndex = i; } } if (nNextNodeIndex >= 0 && nNextNodeIndex < (int)vecOpen.size()) { vecClose.push_back(pNextNode); vecOpen.erase(vecOpen.begin() + nNextNodeIndex); } } // 寻路结束，找最优路径 pNode = vecClose[vecClose.size() - 1]; while (pNode) { m_vecPath.push_back(pNode); pNode = pNode->pParent; }}//int HelloWorld::GetIndexByDir(int nIndex, int nDir){ if (nIndex < 0 || nIndex >= (int)m_vecGrid.size()) { return -1; } int nRow = nIndex / GetCol(); int nCol = nIndex % GetCol(); switch(nDir) { case 0: // 上 nRow += 1; break; case 1: // 右上 nRow += 1; nCol +=1; break; case 2: // 右 nCol += 1; break; case 3: // 右下 nRow -= 1; nCol += 1; break; case 4: // 下 nRow -= 1; break; case 5: // 左下 nRow -= 1; nCol -= 1; break; case 6: // 左 nCol -= 1; break; case 7: // 左上 nRow += 1; nCol -= 1; break; default: break; } if (nRow < 0 || nRow >= GetRow() || nCol < 0 || nCol >= GetCol()) { return -1; } return nRow * GetCol() + nCol;}//int HelloWorld::GetGByIndex(int nStartIndex, int nEndIndex){ int nStartRow = nStartIndex / GetCol(); int nStartCol = nStartIndex % GetCol(); int nEndRow = nEndIndex / GetCol(); int nEndCol = nEndIndex % GetCol(); if (nStartRow == nEndRow || nStartCol == nEndCol) { return 10; } return 14;}//int HelloWorld::GetHByIndex(int nIndex){ int nRow = nIndex / GetCol(); int nCol = nIndex % GetCol(); int nEndRow = m_nEndIndex / GetCol(); int nEndCol = m_nEndIndex % GetCol(); return (abs(nEndRow - nRow) + abs(nEndCol - nCol))*10;}//HelloWorld::NODE *HelloWorld::InTable(int nIndex, vector &vecTbl){ for (int i = 0; i < (int)vecTbl.size(); i++) { if (nIndex == vecTbl[i]->nIndex) { return vecTbl[i]; } } return NULL;}//int HelloWorld::GetRow(){ CCSize size = CCDirector::sharedDirector()->getWinSize(); return size.height / GRID_SIDELEN;}//int HelloWorld::GetCol(){ CCSize size = CCDirector::sharedDirector()->getWinSize(); return size.width / GRID_SIDELEN;}//int HelloWorld::GetIndexByPoint(CCPoint pt){ pt.x = pt.x > (int)pt.x ? pt.x + 1 : pt.x; pt.y = pt.y > (int)pt.y ? pt.y + 1 : pt.y; return (int)pt.y / GRID_SIDELEN * GetCol() + (int)pt.x / GRID_SIDELEN;}//void HelloWorld::draw(){ // 画背景表格 CCSize size = CCDirector::sharedDirector()->getWinSize(); for (int i = 0; i < GetRow(); i++) { ccDrawLine(ccp(0, i * GRID_SIDELEN), ccp(size.width, i * GRID_SIDELEN)); } for (int i = 0; i < GetCol(); i++) { ccDrawLine(ccp(i * GRID_SIDELEN, 0), ccp(i * GRID_SIDELEN, size.height)); } // 画特殊格子颜色 // 寻路得到的路径 for (int i = 0; i < (int)m_vecPath.size(); i++) { CCPoint ptObstacleLT; CCPoint ptObstacleRD; GetRectPointByIndex(m_vecPath[i]->nIndex, ptObstacleLT, ptObstacleRD); ccColor4F clrObstacle = {0, 1, 1, 1}; ccDrawSolidRect(ptObstacleLT, ptObstacleRD, clrObstacle); } // 开始点 CCPoint ptStartLT; CCPoint ptStartRD; GetRectPointByIndex(m_nStartIndex, ptStartLT, ptStartRD); ccColor4F clrStart = {1, 0, 0, 1}; ccDrawSolidRect(ptStartLT, ptStartRD, clrStart); // 结束点 CCPoint ptEndLT; CCPoint ptEndRD; GetRectPointByIndex(m_nEndIndex, ptEndLT, ptEndRD); ccColor4F clrEnd = {0, 1, 0, 1}; ccDrawSolidRect(ptEndLT, ptEndRD, clrEnd); // 障碍 for (int i = 0; i < (int)m_vecGrid.size(); i++) { if (m_vecGrid[i]->gf == GRID_FLAG_OBSTACLE) { CCPoint ptObstacleLT; CCPoint ptObstacleRD; GetRectPointByIndex(i, ptObstacleLT, ptObstacleRD); ccColor4F clrObstacle = {0, 0, 1, 1}; ccDrawSolidRect(ptObstacleLT, ptObstacleRD, clrObstacle); } }}//void HelloWorld::GetRectPointByIndex(int nIndex, CCPoint &ptLT, CCPoint &ptRD){ ptLT.x = nIndex % GetCol() * GRID_SIDELEN; ptLT.y = nIndex / GetCol() * GRID_SIDELEN; ptRD.x = ptLT.x + GRID_SIDELEN; ptRD.y = ptLT.y + GRID_SIDELEN;}//bool HelloWorld::ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent){ if (!pTouch) { return false; } int nIndex = GetIndexByPoint(pTouch->getLocation()); if (m_vecGrid[nIndex]->gf == GRID_FLAG_OBSTACLE) { return false; } if (STEP_STARTPOINT == m_nStep) { m_nStartIndex = nIndex; m_nStep = STEP_ENDPOINT; } else if (STEP_ENDPOINT == m_nStep) { m_nEndIndex = nIndex; m_nStep = STEP_STARTPOINT; FindPath(); } return true;}
哎，想来想去，还是直接上源码比较直截了当。。。。。寻路效果如下，红色是起点，绿色是终点，蓝色是障碍物，浅蓝色是最终寻路路径：
