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我在cocos2d-x中工作有助於解決問題。錯誤在這行使用未聲明的標識符C++ xcode
string route = pathFind(xA, yA, xB, yB);
代碼HelloWorldScene.cpp
#include "HelloWorldScene.h"
#include "SimpleAudioEngine.h"
#include <iostream>
#include <iomanip>
#include <math.h>
#include <queue>
#include <string>
using namespace std;
using namespace cocos2d;
using namespace CocosDenshion;
const int n = 20; // horizontal size of the map
const int m = 20; // vertical size size of the map
static int MAPP[n][m];
static int putX[100];
static int putY[100];
static int closed_nodes_map[n][m]; // map of closed (tried-out) nodes
static int open_nodes_map[n][m]; // map of open (not-yet-tried) nodes
static int dir_map[n][m]; // map of directions
const int dir = 8; // number of possible directions to go at any position
static int dx[dir] = { 1, 1, 0, -1, -1, -1, 0, 1 };
static int dy[dir] = { 0, 1, 1, 1, 0, -1, -1, -1 };
class node
{
// current position
int xPos;
int yPos;
// total distance already travelled to reach the node
int level;
// priority=level+remaining distance estimate
int priority; // smaller: higher priority
public:
node(int xp, int yp, int d, int p)
{
xPos = xp; yPos = yp; level = d; priority = p;
}
int getxPos() const { return xPos; }
int getyPos() const { return yPos; }
int getLevel() const { return level; }
int getPriority() const { return priority; }
void updatePriority(const int & xDest, const int & yDest)
{
priority = level + estimate(xDest, yDest) * 10; //A*
}
// give better priority to going strait instead of diagonally
void nextLevel(const int & i) // i: direction
{
level += (dir == 8 ? (i % 2 == 0 ? 10 : 14) : 10);
}
// Estimation function for the remaining distance to the goal.
const int & estimate(const int & xDest, const int & yDest) const
{
static int xd, yd, d;
xd = xDest - xPos;
yd = yDest - yPos;
// Euclidian Distance
d = static_cast<int>(sqrt(xd*xd + yd*yd));
// Manhattan distance
//d=abs(xd)+abs(yd);
// Chebyshev distance
//d=max(abs(xd), abs(yd));
return(d);
}
};
CCScene* HelloWorld::scene()
{
// 'scene' is an autorelease object
CCScene *scene = CCScene::create();
// 'layer' is an autorelease object
HelloWorld *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 (!CCLayer::init())
{
return false;
}
for (int y = 0; y < m; y++)
{
for (int x = 0; x < n; x++) MAPP[x][y] = 0;
}
int xA=0, yA=0, xB=7, yB=5;
// get the route
string route = pathFind(xA, yA, xB, yB);
// follow the route on the map and display it
if (route.length() > 0)
{
int j; char c;
int x = xA;
int y = yA;
MAPP[x][y] = 2;
for (int i = 0; i < route.length(); i++)
{
c = route.at(i);
j = atoi(&c);
x = x + dx[j];
y = y + dy[j];
MAPP[x][y] = 3;
}
MAPP[x][y] = 4;
}
int putS=0;
for (int y = 0; y < m; y++)
{
for (int x = 0; x < n; x++)
{
if (MAPP[x][y] == 3)
{
putY[putS] = y;
putX[putS] = x;
putS++;
}
}
}
return true;
}
bool operator < (const node & a, const node & b)
{
return a.getPriority() > b.getPriority();
}
// A-star algorithm.
// The route returned is a string of direction digits.
string pathFind(const int & xStart, const int & yStart,
const int & xFinish, const int & yFinish)
{
static priority_queue<node> pq[2]; // list of open (not-yet-tried) nodes
static int pqi; // pq index
static node* n0;
static node* m0;
static int i, j, x, y, xdx, ydy;
static char c;
pqi = 0;
// reset the node maps
for (y = 0; y < m; y++)
{
for (x = 0; x < n; x++)
{
closed_nodes_map[x][y] = 0;
open_nodes_map[x][y] = 0;
}
}
// create the start node and push into list of open nodes
n0 = new node(xStart, yStart, 0, 0);
n0->updatePriority(xFinish, yFinish);
pq[pqi].push(*n0);
open_nodes_map[x][y] = n0->getPriority(); // mark it on the open nodes map
// A* search
while (!pq[pqi].empty())
{
// get the current node w/ the highest priority
// from the list of open nodes
n0 = new node(pq[pqi].top().getxPos(), pq[pqi].top().getyPos(),
pq[pqi].top().getLevel(), pq[pqi].top().getPriority());
x = n0->getxPos(); y = n0->getyPos();
pq[pqi].pop(); // remove the node from the open list
open_nodes_map[x][y] = 0;
// mark it on the closed nodes map
closed_nodes_map[x][y] = 1;
// quit searching when the goal state is reached
//if((*n0).estimate(xFinish, yFinish) == 0)
if (x == xFinish && y == yFinish)
{
// generate the path from finish to start
// by following the directions
string path = "";
while (!(x == xStart && y == yStart))
{
j = dir_map[x][y];
c = '0' + (j + dir/2)%dir;
path = c + path;
x += dx[j];
y += dy[j];
}
// garbage collection
delete n0;
// empty the leftover nodes
while (!pq[pqi].empty()) pq[pqi].pop();
return path;
}
// generate moves (child nodes) in all possible directions
for (i = 0; i < dir; i++)
{
xdx = x + dx[i]; ydy = y + dy[i];
if (!(xdx<0 || xdx>n - 1 || ydy<0 || ydy>m - 1 || MAPP[xdx][ydy] == 1
|| closed_nodes_map[xdx][ydy] == 1))
{
// generate a child node
m0 = new node(xdx, ydy, n0->getLevel(),
n0->getPriority());
m0->nextLevel(i);
m0->updatePriority(xFinish, yFinish);
// if it is not in the open list then add into that
if (open_nodes_map[xdx][ydy] == 0)
{
open_nodes_map[xdx][ydy] = m0->getPriority();
pq[pqi].push(*m0);
// mark its parent node direction
dir_map[xdx][ydy] = (i + dir/2)%dir;
}
else if (open_nodes_map[xdx][ydy] > m0->getPriority())
{
// update the priority info
open_nodes_map[xdx][ydy] = m0->getPriority();
// update the parent direction info
dir_map[xdx][ydy] = (i + dir/2)%dir;
// replace the node
// by emptying one pq to the other one
// except the node to be replaced will be ignored
// and the new node will be pushed in instead
while (!(pq[pqi].top().getxPos() == xdx &&
pq[pqi].top().getyPos() == ydy))
{
pq[1 - pqi].push(pq[pqi].top());
pq[pqi].pop();
}
pq[pqi].pop(); // remove the wanted node
// empty the larger size pq to the smaller one
if (pq[pqi].size() > pq[1 - pqi].size()) pqi = 1 - pqi;
while (!pq[pqi].empty())
{
pq[1 - pqi].push(pq[pqi].top());
pq[pqi].pop();
}
pqi = 1 - pqi;
pq[pqi].push(*m0); // add the better node instead
}
else delete m0; // garbage collection
}
}
delete n0; // garbage collection
}
return ""; // no route found
}
void HelloWorld::menuCloseCallback(CCObject* pSender)
{
CCDirector::sharedDirector()->end();
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
exit(0);
#endif
}
代碼HelloWorldScene.h
#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__
#include "cocos2d.h"
class HelloWorld : public cocos2d::CCLayer
{
public:
// Method 'init' in cocos2d-x returns bool, instead of 'id' in cocos2d-iphone (an object pointer)
virtual bool init();
// there's no 'id' in cpp, so we recommend to return the class instance pointer
static cocos2d::CCScene* scene();
// a selector callback
void menuCloseCallback(CCObject* pSender);
// preprocessor macro for "static create()" constructor (node() deprecated)
CREATE_FUNC(HelloWorld);
};
#endif // __HELLOWORLD_SCENE_H__