本文实践自 Allen Tan 的文章《How To Make A Side-Scrolling Beat ‘Em Up Game Like Scott Pilgrim with Cocos2D – Part 1》,文中使用Cocos2D,我在这里使用Cocos2D-x 2.0.4进行学习和移植。在这篇文章,将会学习到如何制作一个简单的横版格斗过关游戏。在这当中,学习如何跟踪动画状态、碰撞盒、添加方向键、添加简单敌人AI和更多其它的。
步骤如下:
1.新建Cocos2d-win32工程,工程名为"PompaDroid",去除"Box2D"选项,勾选"Simple Audio Engine in Cocos Denshion"选项;
2.添加游戏场景类GameScene,派生自CCScene类。添加GameLayer类和HudLayer类,派生自CCLayer类。删除HelloWorldScene.h和HelloWorldScene.cpp文件。
3.文件GameScene.h代码如下:
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#pragma once
#include "cocos2d.h" #include "GameLayer.h" #include "HudLayer.h" class GameScene : public cocos2d::CCScene { public: GameScene( void); ~GameScene( void); virtual bool init(); CREATE_FUNC(GameScene); CC_SYNTHESIZE(GameLayer*, _gameLayer, GameLayer); CC_SYNTHESIZE(HudLayer*, _hudLayer, HudLayer); }; |
文件GameScene.cpp代码如下:
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#include
"GameScene.h"
using namespace cocos2d; GameScene::GameScene( void) { _gameLayer = NULL; _hudLayer = NULL; } GameScene::~GameScene( void) { } bool GameScene::init() { bool bRet = false; do { CC_BREAK_IF(!CCScene::init()); _gameLayer = GameLayer::create(); this->addChild(_gameLayer, 0); _hudLayer = HudLayer::create(); this->addChild(_hudLayer, 1); bRet = true; } while ( 0); return bRet; } |
4.HudLayer类增加一个方法:
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CREATE_FUNC(HudLayer);
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CREATE_FUNC(GameLayer);
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//#include "HelloWorldScene.h" #include "GameScene.h" bool AppDelegate::applicationDidFinishLaunching() { //... // create a scene. it's an autorelease object //CCScene *pScene = HelloWorld::scene(); CCScene *pScene = GameScene::create(); //... } |
6.编译运行,此时只是空空的界面。
7.下载本游戏所需资源,将资源放置"Resources"目录下;
8.用Tiled工具打开pd_tilemap.tmx,就可以看到游戏的整个地图:
地图上有两个图层:Wall和Floor,即墙和地板。去掉每个图层前的打钩,可以查看层的组成。你会发现下数第四行是由两个图层一起组成的。每个tile都是32x32大小。可行走的地板tile位于下数三行。
9.打开GameLayer.h文件,添加如下代码:
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bool init();
void initTileMap(); cocos2d::CCTMXTiledMap *_tileMap; |
打开GameLayer.cpp,在构造函数,添加如下代码:
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_tileMap =
NULL;
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bool GameLayer::init()
{ bool bRet = false; do { CC_BREAK_IF(!CCLayer::init()); this->initTileMap(); bRet = true; } while ( 0); return bRet; } void GameLayer::initTileMap() { _tileMap = CCTMXTiledMap::create( "pd_tilemap.tmx"); CCObject *pObject = NULL; CCARRAY_FOREACH(_tileMap->getChildren(), pObject) { CCTMXLayer *child = (CCTMXLayer*)pObject; child->getTexture()->setAliasTexParameters(); } this->addChild(_tileMap, - 6); } |
对所有图层进行setAliasTexParameters设置,该方法是关闭抗锯齿功能,这样就能保持像素风格。
10.编译运行,可以看到地图显示在屏幕上,如下图所示:
11.创建英雄。在大多数2D横版游戏中,角色有不同的动画代表不同类型的动作。我们需要知道什么时候播放哪个动画。这里采用状态机来解决这个问题。状态机就是某种通过切换状态来改变行为的东西。单一状态机在同一时间只能有一个状态,但可以从一种状态过渡到另一种状态。在这个游戏中,角色共有五种状态,空闲、行走、出拳、受伤、死亡,如下图所示:
为了有一个完整的状态流,每个状态应该有一个必要条件和结果。例如:行走状态不能突然转变到死亡状态,因为你的英雄在死亡前必须先受伤。
12.添加ActionSprite类,派生自CCSprite类,ActionSprite.h文件代码如下:
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#pragma once
#include "cocos2d.h" #include "Defines.h" class ActionSprite : public cocos2d::CCSprite { public: ActionSprite( void); ~ActionSprite( void); //action methods void idle(); void attack(); void hurtWithDamage( float damage); void knockout(); void walkWithDirection(cocos2d::CCPoint direction); //scheduled methods void update( float dt); //actions CC_SYNTHESIZE_RETAIN(cocos2d::CCAction*, _idleAction, IdleAction); CC_SYNTHESIZE_RETAIN(cocos2d::CCAction*, _attackAction, AttackAction); CC_SYNTHESIZE_RETAIN(cocos2d::CCAction*, _walkAction, WalkAction); CC_SYNTHESIZE_RETAIN(cocos2d::CCAction*, _hurtAction, HurtAction); CC_SYNTHESIZE_RETAIN(cocos2d::CCAction*, _knockedOutAction, KnockedOutAction); //states CC_SYNTHESIZE(ActionState, _actionState, ActionState); //attributes CC_SYNTHESIZE( float, _walkSpeed, WalkSpeed); CC_SYNTHESIZE( float, _hitPoints, HitPoints); CC_SYNTHESIZE( float, _damage, Damage); //movement CC_SYNTHESIZE(cocos2d::CCPoint, _velocity, Velocity); CC_SYNTHESIZE(cocos2d::CCPoint, _desiredPosition, DesiredPosition); //measurements CC_SYNTHESIZE( float, _centerToSides, CenterToSides); CC_SYNTHESIZE( float, _centerToBottom, CenterToBottom); }; |
打开ActionSprite.cpp文件,构造函数如下:
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ActionSprite::ActionSprite(
void)
{ _idleAction = NULL; _attackAction = NULL; _walkAction = NULL; _hurtAction = NULL; _knockedOutAction = NULL; } |
新建一个头文件Defines.h,代码如下:
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#pragma once
#include "cocos2d.h" // 1 - convenience measurements #define SCREEN CCDirector::sharedDirector()->getWinSize() #define CENTER ccp(SCREEN.width / 2, SCREEN.height / 2) #define CURTIME do { \ timeval time; \ gettimeofday(&time, NULL); \ unsigned long millisecs = (time.tv_sec * 1000) + (time.tv_usec / 1000); \ return ( float)millisecs; \ } while ( 0) // 2 - convenience functions #define random_range(low, high) (rand() % (high - low + 1)) + low #define frandom ( float)rand() / UINT64_C(0x100000000) #define frandom_range(low, high) ((high - low) * frandom) + low // 3 - enumerations typedef enum _ActionState { kActionStateNone = 0, kActionStateIdle, kActionStateAttack, kActionStateWalk, kActionStateHurt, kActionStateKnockedOut } ActionState; // 4 - structures typedef struct _BoundingBox { cocos2d::CCRect actual; cocos2d::CCRect original; } BoundingBox; |
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cocos2d::CCSpriteBatchNode *_actors;
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CCSpriteFrameCache::sharedSpriteFrameCache()->addSpriteFramesWithFile(
"pd_sprites.plist");
_actors = CCSpriteBatchNode::create( "pd_sprites.pvr.ccz"); _actors->getTexture()->setAliasTexParameters(); this->addChild(_actors, - 5); |
加载精灵表单,创建一个CCSpriteBatchNode。这个精灵表单包含我们的所有精灵。它的z值高于CCTMXTiledMap对象,这样才能出现在地图前。
添加Hero类,派生自ActionSprite类,添加如下代码:
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CREATE_FUNC(Hero);
bool init(); |
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bool Hero::init()
{ bool bRet = false; do { CC_BREAK_IF(!ActionSprite::initWithSpriteFrameName( "hero_idle_00.png")); int i; //idle animation CCArray *idleFrames = CCArray::createWithCapacity( 6); for (i = 0; i < 6; i++) { CCSpriteFrame *frame = CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName(CCString::createWithFormat( "hero_idle_%02d.png", i)->getCString()); idleFrames->addObject(frame); } CCAnimation *idleAnimation = CCAnimation::createWithSpriteFrames(idleFrames, 1. 0 / 12. 0); this->setIdleAction(CCRepeatForever::create(CCAnimate::create(idleAnimation))); this->setCenterToBottom( 39. 0); this->setCenterToSides( 29. 0); this->setHitPoints( 100. 0); this->setDamage( 20. 0); this->setWalkSpeed( 80. 0); bRet = true; } while ( 0); return bRet; } |
我们用初始空闲精灵帧创建了英雄角色,配备了一个CCArray数组包含所有的属于空闲动画的精灵帧,然后创建一个CCAction动作播放来这个动画。以每秒12帧的速率进行播放。接下去,为英雄设置初始属性,包括精灵中心到边到底部的值。如下图所示:
英雄的每个精灵帧都在280x150像素大小的画布上创建,但实际上英雄精灵只占据这个空间的一部分。所以需要两个测量值,以便更好的设置精灵的位置。需要额外的空间,是因为每个动画精灵绘制的方式是不同的,而有些就需要更多的空间。
打开GameLayer.h文件,添加头文件声明:
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#include
"Hero.h"
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Hero *_hero;
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_hero =
NULL;
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this->initHero();
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void GameLayer::initHero()
{ _hero = Hero::create(); _actors->addChild(_hero); _hero->setPosition(ccp(_hero->getCenterToSides(), 80)); _hero->setDesiredPosition(_hero->getPosition()); _hero->idle(); } |
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void ActionSprite::idle()
{ if (_actionState != kActionStateIdle) { this->stopAllActions(); this->runAction(_idleAction); _actionState = kActionStateIdle; _velocity = CCPointZero; } } |
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//attack animation CCArray *attackFrames = CCArray::createWithCapacity( 3); for (i = 0; i < 3; i++) { CCSpriteFrame *frame = CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName(CCString::createWithFormat( "hero_attack_00_%02d.png", i)->getCString()); attackFrames->addObject(frame); } CCAnimation *attackAnimation = CCAnimation::createWithSpriteFrames(attackFrames, 1. 0 / 24. 0); this->setAttackAction(CCSequence::create(CCAnimate::create(attackAnimation), CCCallFunc::create( this, callfunc_selector(Hero::idle)), NULL)); |
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void ActionSprite::attack()
{ if (_actionState == kActionStateIdle || _actionState == kActionStateAttack || _actionState == kActionStateWalk) { this->stopAllActions(); this->runAction(_attackAction); _actionState = kActionStateAttack; } } |
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this->setTouchEnabled(
true);
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void GameLayer::ccTouchesBegan(CCSet *pTouches, CCEvent *pEvent)
{ _hero->attack(); } |
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#pragma once
#include "cocos2d.h" class SimpleDPad; class SimpleDPadDelegate { public: virtual void didChangeDirectionTo(SimpleDPad *simpleDPad, cocos2d::CCPoint direction) = 0; virtual void isHoldingDirection(SimpleDPad *simpleDPad, cocos2d::CCPoint direction) = 0; virtual void simpleDPadTouchEnded(SimpleDPad *simpleDPad) = 0; }; class SimpleDPad : public cocos2d::CCSprite, public cocos2d::CCTargetedTouchDelegate { public: SimpleDPad( void); ~SimpleDPad( void); static SimpleDPad* dPadWithFile(cocos2d::CCString *fileName, float radius); bool initWithFile(cocos2d::CCString *filename, float radius); void onEnterTransitionDidFinish(); void onExit(); void update( float dt); virtual bool ccTouchBegan(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent); virtual void ccTouchMoved(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent); virtual void ccTouchEnded(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent); void updateDirectionForTouchLocation(cocos2d::CCPoint location); CC_SYNTHESIZE(SimpleDPadDelegate*, _delegate, Delegate); CC_SYNTHESIZE( bool, _isHeld, IsHeld); protected: float _radius; cocos2d::CCPoint _direction; }; |
对以上的一些声明,解释如下:
对于SimpleDPad类,使用了委托模式。意味着一个委托类(并非SimpleDPad),将会处理由被委托类(SimpleDPad)启动的任务。在某些你指定的点上,主要是当涉及到处理任何游戏相关的东西,SimpleDPad将会将职责传递给委托类。这使得SimpleDPad无需知道任何游戏逻辑,从而允许你在开发任何其他游戏时,可以进行重用。如下图所示:
当SimpleDPad检测到在方向键内的触摸,它会计算触摸的方向,然后发送消息到委托类指明方向。在这之后的任何事情都不是SimpleDPad所关心的了。为了实施这个模式,SimpleDPad需要至少了解其委托的有关信息,特别是将触摸方向传递给委托的方法。这是另一种设计模式:协议。可以看到SimpleDPad的委托定义了所需的方法,在这种方式中,SimpleDPad强制其委托有三个指定的方法,以便确保每当它想传递东西放到委托中时,它能调用这些方法中的任何一种。事实上,SimpleDPad也遵循一种协议,即CCTargetedTouchDelegate。当SimpleDPad被触摸时,进行处理触摸事件,而GameLayer将不会得到触摸。否则的话,在触摸方向键的时候,英雄就会出拳攻击,显然,这不是希望看到的。打开SimpleDPad.cpp文件,添加如下代码:
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#include
"SimpleDPad.h"
using namespace cocos2d; SimpleDPad::SimpleDPad( void) { _delegate = NULL; } SimpleDPad::~SimpleDPad( void) { } SimpleDPad* SimpleDPad::dPadWithFile(CCString *fileName, float radius) { SimpleDPad *pRet = new SimpleDPad(); if (pRet && pRet->initWithFile(fileName, radius)) { return pRet; } else { delete pRet; pRet = NULL; return NULL; } } bool SimpleDPad::initWithFile(CCString *filename, float radius) { bool bRet = false; do { CC_BREAK_IF(!CCSprite::initWithFile(filename->getCString())); _radius = radius; _direction = CCPointZero; _isHeld = false; this->scheduleUpdate(); bRet = true; } while ( 0); return bRet; } void SimpleDPad::onEnterTransitionDidFinish() { CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate( this, 1, true); } void SimpleDPad::onExit() { CCDirector::sharedDirector()->getTouchDispatcher()->removeDelegate( this); } void SimpleDPad::update( float dt) { if (_isHeld) { _delegate->isHoldingDirection( this, _direction); } } bool SimpleDPad::ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent) { CCPoint location = pTouch->getLocation(); float distanceSQ = ccpDistanceSQ(location, this->getPosition()); if (distanceSQ <= _radius * _radius) { this->updateDirectionForTouchLocation(location); _isHeld = true; return true; } return false; } void SimpleDPad::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent) { CCPoint location = pTouch->getLocation(); this->updateDirectionForTouchLocation(location); } void SimpleDPad::ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent) { _direction = CCPointZero; _isHeld = false; _delegate->simpleDPadTouchEnded( this); } void SimpleDPad::updateDirectionForTouchLocation(CCPoint location) { float radians = ccpToAngle(ccpSub(location, this->getPosition())); float degrees = - 1 * CC_RADIANS_TO_DEGREES(radians); if (degrees <= 22. 5 && degrees >= - 22. 5) { //right _direction = ccp( 1. 0, 0. 0); } else if (degrees > 22. 5 && degrees < 67. 5) { //bottomright _direction = ccp( 1. 0, - 1. 0); } else if (degrees >= 67. 5 && degrees <= 112. 5) { //bottom _direction = ccp( 0. 0, - 1. 0); } else if (degrees > 112. 5 && degrees < 157. 5) { //bottomleft _direction = ccp(- 1. 0, - 1. 0); } else if (degrees >= 157. 5 || degrees <= - 157. 5) { //left _direction = ccp(- 1. 0, 0. 0); } else if (degrees < - 22. 5 && degrees > - 67. 5) { //topright _direction = ccp( 1. 0, 1. 0); } else if (degrees <= - 67. 5 && degrees >= - 112. 5) { //top _direction = ccp( 0. 0, 1. 0); } else if (degrees < - 112. 5 && degrees > - 157. 5) { //topleft _direction = ccp(- 1. 0, 1. 0); } _delegate->didChangeDirectionTo( this, _direction); } |
打开HudLayer.h文件,添加头文件声明:
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#include
"SimpleDPad.h"
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bool init();
CC_SYNTHESIZE(SimpleDPad*, _dPad, DPad); |
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HudLayer::HudLayer(
void)
{ _dPad = NULL; } bool HudLayer::init() { bool bRet = false; do { CC_BREAK_IF(!CCLayer::init()); _dPad = SimpleDPad::dPadWithFile(CCString::create( "pd_dpad.png"), 64); _dPad->setPosition(ccp( 64. 0, 64. 0)); _dPad->setOpacity( 100); this->addChild(_dPad); bRet = true; } while ( 0); return bRet; } |
以上代码实例化SimpleDPad,并且添加到HudLayer上。现在GameScene同时控制GameLayer和HudLayer,但有时候想直接通过HudLayer访问GameLayer。打开GameLayer.h文件,添加头文件声明:
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#include
"SimpleDPad.h"
#include "HudLayer.h" |
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class GameLayer :
public cocos2d::CCLayer,
public SimpleDPadDelegate
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virtual
void didChangeDirectionTo(SimpleDPad *simpleDPad, cocos2d::CCPoint direction);
virtual void isHoldingDirection(SimpleDPad *simpleDPad, cocos2d::CCPoint direction); virtual void simpleDPadTouchEnded(SimpleDPad *simpleDPad); CC_SYNTHESIZE(HudLayer*, _hud, Hud); |
以上方法的实现暂时为空。这样我们就在GameLayer中添加了HudLayer的引用,同时还让GameLayer遵循SimpleDPad所创建的协议。打开GameScene.cpp文件,在init函数this->addChild(_hudLayer, 1);后面,添加如下代码:
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_hudLayer->getDPad()->setDelegate(_gameLayer);
_gameLayer->setHud(_hudLayer); |
参考资料:
1.How To Make A Side-Scrolling Beat ‘Em Up Game Like Scott Pilgrim with Cocos2D – Part 1http://www.raywenderlich.com/24155/how-to-make-a-side-scrolling
2.如何使用cocos2d制作类似Scott Pilgrim的2D横版格斗过关游戏part1(翻译) http://blog.sina.com.cn/s/blog_4b55f6860101a9b7.html
3.如何使用Cocos2d-x做一DNF类的游戏-part1 http://blog.csdn.net/jyzgo/article/details/8471306
非常感谢以上资料,本例子源代码附加资源下载地址:http://download.csdn.net/detail/akof1314/5038013
如文章存在错误之处,欢迎指出,以便改正。