Cocos2d-X游戏【泰然网《跑酷》】JS到C++移植9：Map Loop【地图循环加载】

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Cocos2d-X游戏【泰然网《跑酷》】JS到C++移植8： Jumping and Crouching

目前为止,游戏角色还很孤独的跑在一个黑色的世界,现在要做的是给游戏添加背景图片。 背景由上下两部分组成,当游戏角色在两张图片中间的夹缝上跑动的时候,第一张背景图片会慢 慢被第二张背景图片替换,第一张图片将重新加载。

创建一个名为Map.cpp到VS工程里,添加下面的代码:

#include "Map.h"#include "resource.h"#include "Utils.h"Map::~Map(){}Map::Map(){}/** Constructor    * @param {cc.Layer *}    * @param {cp.Space *}    */Map::Map(CCLayer *layer, cpSpace *space){this->layer = NULL;this->space = NULL;//MapCount应等于在资源文件夹中的文件数量。并应不少于两个this->mapCount = 2;this->spriteWidth = 0;this->map0 = NULL;this->map1 = NULL;this->ground0 = NULL;this->ground1 = NULL;this->curMap = 0;this->layer = layer;this->space = space;// init bg map for the first time//地图的上半部分是一个锚点改为(0,0)的精灵,用更改锚点来简化坐标的计算map0 = CCSprite::create("res/Map00.png");map0->setAnchorPoint(ccp(0, 0));map0->setPosition(ccp(0, 0));layer->addChild(map0);//上层部分跟下层部分的不同之处是它们的位置坐标,将下层部分Y轴坐标设置为 //g_groundHight – ground0->getContentSize().height来确保游戏角色的脚是踏在地面上的。ground0 = CCSprite::create("res/Ground00.png");ground0->setAnchorPoint(ccp(0, 0));CCSize size = ground0->getContentSize();ground0->setPosition(ccp(0, g_groundHight - size.height));layer->addChild(ground0);spriteWidth = map0->getContentSize().width;map1 = CCSprite::create("res/Map01.png");map1->setAnchorPoint(ccp(0, 0));// 第二张地图的开始位置是背景的宽度map1->setPosition(ccp(spriteWidth, 0));layer->addChild(map1);ground1 = CCSprite::create("res/Ground01.png");ground1->setAnchorPoint(ccp(0, 0));ground1->setPosition(ccp(spriteWidth, g_groundHight - size.height));layer->addChild(ground1);}/**    * @return width of the map sprite.    */ float Map::getMapWidth(){return spriteWidth;}/**    * @return which map of the runner current run on.    */ int Map::getCurMap() {    return this->curMap;}/**    * @param {float} X-coordinate of the eye of camera of PlayLayer    */bool Map::checkAndReload(float eyeX) {//用这种方式计算地图坐标int newCur = int(eyeX / spriteWidth);    if (curMap == newCur) {        return false;    }    CCSprite * map;    CCSprite * ground;    if (0 == newCur % 2) {        // change mapSecond        map = this->map1;        ground = this->ground1;    } else {        // change mapFirst        map = this->map0;        ground = this->ground0;    }    CCLOG("==load map:%d", (newCur + 1));    this->curMap = newCur;//在一张背景跑完之后需要切换一张新的图片    // load curMap + 1    //var fileName = "res/Map" + FormatNumberLength((newCur + 1) % mapCount, 2) + ".png";//char fileMapName[100] = {0};//sprintf(fileName, "res/Map%i.png", i);//fileMapName = "res/Map" + FormatNumberLength((newCur + 1) % mapCount, 2) + ".png";//CCTexture2D *texture = CCTextureCache::sharedTextureCache()->addImage(fileMapName);//暂时简化,待扩展std::string fileMapName;if ((newCur + 1) % mapCount){fileMapName = "res/Map00.png";} else{fileMapName = "res/Map01.png";}CCTexture2D *texture = CCTextureCache::sharedTextureCache()->addImage(fileMapName.c_str());    map->setTexture(texture);    map->setPositionX(this->spriteWidth * (newCur + 1));    // load ground#if 0var fileGroundName = "res/Ground" + FormatNumberLength((newCur + 1) % mapCount, 2) + ".png";CCTexture2D *textureGround = CCTextureCache::sharedTextureCache()->addImage(fileGroundName);ground->setTexture(textureGround);ground->setPositionX(this->spriteWidth * (newCur + 1));#elsestd::string fileGroundName;if ((newCur + 1) % mapCount){fileGroundName = "res/Ground00.png";} else{fileGroundName = "res/Ground01.png";}CCTexture2D *textureGround = CCTextureCache::sharedTextureCache()->addImage(fileGroundName.c_str());ground->setTexture(textureGround);ground->setPositionX(this->spriteWidth * (newCur + 1));#endif    return true;}

在PlayScene.cpp的里定义新的变量：

Map *map;

通过添加下面代码到init()初始化地图:

//初始化地图map = new Map(this, space);

将下面代码添加到update()函数中:

// check and reload mapbackgroundLayerif (true == map->checkAndReload(lastEyeX)) {//if (true == backgroundLayer->checkAndReload(lastEyeX)) {objectManager->recycleObjectOfMap(map->getCurMap() - 1);objectManager->initObjectOfMap(map->getCurMap() + 1, map->getMapWidth());//level uprunner->levelUp();}

编译运行后你将看到这样的界面: