cocos2dx A*算法

头文件和源文件拷贝到项目中就能用了! have fun

使用cocos2dx 3.2 原理都一样

淡蓝色的点是地图

深蓝色的点是障碍物

绿色的点是路径

暗绿色的点是搜寻过的点

红色的点是按路径行走的点

dijkstra算法 会发现路径最短,但寻找过的路径比較多(计算速度慢)

最佳优先搜索算法会发现寻找过的路径少了(计算速度提高了),但走了很多弯路

A星算法 结合了上面2种算法 即寻找到了最短路径, 搜寻过的路径也比較少

#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__

#include "cocos2d.h"
#include "vector"
using namespace std;
USING_NS_CC;

class PathSprite : public cocos2d::Sprite//继承Sprite类, 由于要在里面加些其它变量
{
    PathSprite():Sprite()
    {
        m_parent = NULL;
        m_child = NULL;
        m_costToSource = 0;
        m_FValue = 0;
    };
public:
    static PathSprite* create(const char* ch)
    {
        PathSprite *pRet = new PathSprite();
        if (pRet )
        {
            pRet->initWithFile(ch);
            pRet->autorelease();
            return pRet;
        }
        else
        {
            delete pRet;
            pRet = NULL;
            return NULL;
        }
    }
    PathSprite* m_parent;//父节点
    PathSprite* m_child;//子节点
    float m_costToSource;//到起始点的距离
    int m_x;//地图坐标
    int m_y;
    float m_FValue;
};

class PathSearchInfo//寻路类(主要负责寻路的參数和逻辑)
{
public:

    static int m_startX;//開始点
    static int m_startY;
    static int m_endX;//结束点
    static int m_endY;

    static vector<PathSprite*> m_openList;//开放列表(里面存放相邻节点)
    static vector<PathSprite*> m_inspectList;//检測列表(里面存放除了障碍物的节点)
    static vector<PathSprite*> m_pathList;//路径列表
    static void  barrierTest( vector<PathSprite*> &pathList,int x, int y)//模拟障碍物
    {
        PathSprite* _z = getObjByPointOfMapCoord(pathList, x, y);
        if (_z)
        {
            _z->setColor(ccColor3B::MAGENTA);
            removeObjFromList(pathList, _z);
        }
    }
    static float calculateTwoObjDistance(PathSprite* obj1, PathSprite* obj2)//计算两个物体间的距离
    {
//        float _offsetX = obj1->m_x - obj2->m_x;
//        float _offsetY = obj1->m_y - obj2->m_y;
//        return sqrt( _offsetX * _offsetX + _offsetY * _offsetY);

        float _x = abs(obj2->m_x - obj1->m_x);
        float _y = abs(obj2->m_y - obj1->m_y);

        return _x + _y;
    }
    static void inspectTheAdjacentNodes(PathSprite* node, PathSprite* adjacent, PathSprite* endNode)//把相邻的节点放入开放节点中
    {
        if (adjacent)
        {
            float _x = abs(endNode->m_x - adjacent->m_x);
            float _y = abs(endNode->m_y - adjacent->m_y);

            float F , G, H1, H2, H3;
            adjacent->m_costToSource = node->m_costToSource + calculateTwoObjDistance(node, adjacent);//获得累计的路程
            G = adjacent->m_costToSource;

            //三种算法, 感觉H2不错
            H1 = _x + _y;
            H2 = hypot(_x, _y);
            H3 = max(_x, _y);

#if 1 //A*算法 = Dijkstra算法 + 最佳优先搜索
            F = G + H2;
#endif
#if 0//Dijkstra算法
            F = G;
#endif
#if 0//最佳优先搜索
            F = H2;
#endif
            adjacent->m_FValue = F;

            adjacent->m_parent = node;//设置父节点
            adjacent->setColor(Color3B::ORANGE);//搜寻过的节点设为橘色
            node->m_child = adjacent;//设置子节点
            PathSearchInfo::removeObjFromList(PathSearchInfo::m_inspectList, adjacent);//把检測过的点从检測列表中删除
            PathSearchInfo::m_openList.push_back(adjacent);//增加开放列表
        }
    }
    static PathSprite* getMinPathFormOpenList()//从开放节点中获取路径最小值
    {
        if (m_openList.size()>0) {
            PathSprite* _sp =* m_openList.begin();
            for (vector<PathSprite*>::iterator iter = m_openList.begin(); iter !=  m_openList.end(); iter++)
            {
                if ((*iter)->m_FValue < _sp->m_FValue)
                {
                    _sp = *iter;
                }
            }
            return _sp;
        }
        else
        {
            return NULL;
        }

    }
    static PathSprite* getObjByPointOfMapCoord( vector<PathSprite*> &spriteVector,  int x, int y)//依据点获取对象
    {
        for (int i = 0; i < spriteVector.size(); i++)
        {
            if (spriteVector[i]->m_x == x && spriteVector[i]->m_y == y)
            {
                return spriteVector[i];
            }
        }
        return NULL;
    }
    static bool removeObjFromList(vector<PathSprite*> &spriteVector, PathSprite* sprite)//从容器中移除对象
    {
        for (vector<PathSprite*>::iterator iter = spriteVector.begin(); iter !=  spriteVector.end(); iter++)
        {
            if (*iter == sprite)
            {
                spriteVector.erase(iter);
                return true;
            }
        }
        return false;

    }
};

class HelloWorld : public cocos2d::Layer
{
public:
    // there's no 'id' in cpp, so we recommend returning the class instance pointer
    static cocos2d::Scene* createScene();

    // Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone
    virtual bool init();  

    // a selector callback
    void menuCloseCallback(cocos2d::Ref* pSender);

    // implement the "static create()" method manually
    CREATE_FUNC(HelloWorld);

    bool onTouchBegan(Touch* touch, Event* event);
    void onTouchMoved(Touch* touch, Event* event);
    void onTouchEnded(Touch* touch, Event* event);

    void calculatePath();//计算路径
    void drawPath();//绘制路径
    vector<PathSprite*> m_mapList;//地图

    void clearPath();//清理路径

    PathSprite* m_player;//人物 用于演示行走
    int m_playerMoveStep;//人物当前的行程
    void playerMove();//人物走动
};

#endif // __HELLOWORLD_SCENE_H__

#include "HelloWorldScene.h"

vector<PathSprite*> PathSearchInfo::m_openList;

vector<PathSprite*> PathSearchInfo::m_inspectList;

vector<PathSprite*> PathSearchInfo::m_pathList;

int PathSearchInfo::m_startX;

int PathSearchInfo::m_startY;

int PathSearchInfo::m_endX;

int PathSearchInfo::m_endY;

Scene* HelloWorld::createScene()
{
    // 'scene' is an autorelease object
    auto scene = Scene::create();

    // 'layer' is an autorelease object
    auto layer = HelloWorld::create();

    // add layer as a child to scene
    scene->addChild(layer);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }

    Size visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();
    Size winSize = Director::getInstance()->getWinSize();

    /////////////////////////////
    // 2. add a menu item with "X" image, which is clicked to quit the program
    //    you may modify it.

    // add a "close" icon to exit the progress. it's an autorelease object

    auto listener = EventListenerTouchOneByOne::create();
    listener->setSwallowTouches(true);

    listener->onTouchBegan = CC_CALLBACK_2(HelloWorld::onTouchBegan, this);
    listener->onTouchMoved = CC_CALLBACK_2(HelloWorld::onTouchMoved, this);
    listener->onTouchEnded = CC_CALLBACK_2(HelloWorld::onTouchEnded, this);

    _eventDispatcher->addEventListenerWithSceneGraphPriority(listener, this);

    //模拟一张地图 左上角 为(0,0) 主要是模拟tiledmap  每块的宽度为1
    int _width = 25;
    int _heigth = 15;
    for (int i = 0; i < _heigth; i++)
    {
        for (int j = 0; j < _width; j++)
        {
            PathSprite* _sp = PathSprite::create("CloseNormal.png");
            _sp->m_x = j;
            _sp->m_y = i;
            Size _size = _sp->getContentSize();
            _sp->setPosition(CCPoint(j * _size.width + 100, - i * _size.height + 600));
            m_mapList.push_back(_sp);
            this->addChild(_sp);
        }
    }

    //设置障碍物
//    for (int i = 0; i < _heigth*_width/2; i++)
//    {
//
//        int _x = CCRANDOM_0_1()*_width;
//        int _y = CCRANDOM_0_1()*_heigth;
//        if (_x ==0 && _y == 0) {
//            continue;
//        }
//        PathSearchInfo::barrierTest(m_mapList,_x,_y);
//    }
    for (int i = 0; i < 10; i++) {
        PathSearchInfo::barrierTest(m_mapList,5+i,10);
        PathSearchInfo::barrierTest(m_mapList,15,i+1);
    }

        //PathSprite::getObjByPointOfMapCoord(m_inspectList, 2, 5)->removeFromParent();

    //设置起始和终点
    PathSearchInfo::m_startX =0;
    PathSearchInfo::m_startY = 0;

    PathSearchInfo::m_endX = 4;
    PathSearchInfo::m_endY = 9;

    m_player = PathSprite::create("CloseSelected1.png");
    m_player->setColor(Color3B::RED);
    this->addChild(m_player);

    m_player->m_x = PathSearchInfo::m_startX;
    m_player->m_y = PathSearchInfo::m_startY;
    m_player->setPosition(PathSearchInfo::getObjByPointOfMapCoord(m_mapList, PathSearchInfo::m_startX, PathSearchInfo::m_startY)->getPosition());
    return true;
}

void HelloWorld::calculatePath()
{

    //得到開始点的节点
    PathSprite* _sp = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, PathSearchInfo::m_startX, PathSearchInfo::m_startY);
    //得到開始点的节点
    PathSprite* _endNode = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, PathSearchInfo::m_endX, PathSearchInfo::m_endY);
    //由于是開始点 把到起始点的距离设为0
    _sp->m_costToSource = 0;
    _sp->m_FValue = 0;
    //把已经检測过的点从检測列表中删除
    PathSearchInfo::removeObjFromList(PathSearchInfo::m_inspectList, _sp);
    //然后增加开放列表
    PathSearchInfo::m_openList.push_back(_sp);

    PathSprite* _node = NULL;
    while (true)
    {
        //得到离起始点近期的点
        _node = PathSearchInfo::getMinPathFormOpenList();
        if (!_node)
        {
            //找不到路径
            break;
        }
        //把计算过的点从开放列表中删除
        PathSearchInfo::removeObjFromList(PathSearchInfo::m_openList, _node);
        int _x = _node->m_x;
        int _y = _node->m_y;

        //
        if (_x ==PathSearchInfo::m_endX && _y == PathSearchInfo::m_endY)
        {
            break;
        }

        //检測8个方向的相邻节点能否够放入开放列表中
        PathSprite* _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x + 1, _y + 1);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x +1, _y);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x +1, _y-1);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x , _y -1);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x -1, _y - 1);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x -1, _y);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x -1, _y+1);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

        _adjacent = PathSearchInfo::getObjByPointOfMapCoord(PathSearchInfo::m_inspectList, _x , _y+1);
        PathSearchInfo::inspectTheAdjacentNodes(_node, _adjacent, _endNode);

    }

    while (_node)
    {
        //PathSprite* _sp = node;
        PathSearchInfo::m_pathList.insert(PathSearchInfo::m_pathList.begin(), _node);
        _node = _node->m_parent;
    }
}

void HelloWorld::drawPath(  )
{
    for (vector<PathSprite*>::iterator iter = PathSearchInfo::m_pathList.begin(); iter !=  PathSearchInfo::m_pathList.end(); iter++)
    {
        (*iter)->setColor(ccColor3B::GREEN);
    }

}

bool HelloWorld::onTouchBegan(Touch* touch, Event* event)
{
    //清除之前的路径
    clearPath();

    auto nodePosition = convertToNodeSpace( touch->getLocation() );
    log("%f, %f", nodePosition.x, nodePosition.y);
    for (int i = 0; i < PathSearchInfo::m_inspectList.size(); i++)
    {
        PathSprite* _sp = PathSearchInfo::m_inspectList[i];

        if (_sp->getBoundingBox().containsPoint(nodePosition))
        {
            //获取触摸点, 设置为终点
            PathSearchInfo::m_endX = _sp->m_x;
            PathSearchInfo::m_endY = _sp->m_y;
            //计算路径
            calculatePath();
            //绘制路径
            drawPath(  );
            playerMove();

        }

    }
    return true;
}

void HelloWorld::onTouchMoved(Touch* touch, Event* event)
{
    // If it weren't for the TouchDispatcher, you would need to keep a reference
    // to the touch from touchBegan and check that the current touch is the same
    // as that one.
    // Actually, it would be even more complicated since in the Cocos dispatcher
    // you get Sets instead of 1 UITouch, so you'd need to loop through the set
    // in each touchXXX method.

}
void HelloWorld::onTouchEnded(Touch* touch, Event* event)
{

} 

void HelloWorld::menuCloseCallback(Ref* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT)
    MessageBox("You pressed the close button. Windows Store Apps do not implement a close button.","Alert");
    return;
#endif

    Director::getInstance()->end();

#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
    exit(0);
#endif
}

void HelloWorld::clearPath()
{
    for (vector<PathSprite*>::iterator iter = m_mapList.begin(); iter !=  m_mapList.end(); iter++)
    {
        (*iter)->setColor(ccColor3B::WHITE);
        (*iter)->m_costToSource = 0;
        (*iter)->m_FValue = 0;
        (*iter)->m_parent = NULL;
        (*iter)->m_child = NULL;
    }

    //把移除了障碍物的地图放入检測列表中
    PathSearchInfo::m_inspectList = m_mapList;
    PathSearchInfo::m_openList.clear();
    PathSearchInfo::m_pathList.clear();

    PathSearchInfo::m_startX = m_player->m_x;
    PathSearchInfo::m_startY = m_player->m_y;
    m_player->stopAllActions();

    m_playerMoveStep = 0;
}

void HelloWorld::playerMove()
{
    m_playerMoveStep++;

    if (m_playerMoveStep >= PathSearchInfo::m_pathList.size()) {
        return;
    }

    m_player->m_x = PathSearchInfo::m_pathList[m_playerMoveStep]->m_x;
    m_player->m_y = PathSearchInfo::m_pathList[m_playerMoveStep]->m_y;

    m_player->runAction(Sequence::create(MoveTo::create(0.2, PathSearchInfo::m_pathList[m_playerMoveStep]->getPosition()), CallFunc::create(this, SEL_CallFunc(&HelloWorld::playerMove)) , NULL));

}