cocos2d-x 之虚拟摇杆实现

其实要实现这个功能并不难，直接把以前在java上实现的逻辑照搬过来就是了。。。直接看下文吧：

首先，把摇杆当成一个独立的类，具有自身的一系列功能，代码中只列举一部分最常用的功能点：

Joystick.h：

#include "cocos2d.h"



using namespace cocos2d;



class Joystick :

	public CCLayer

{

public:

	Joystick(void);

	~Joystick(void);

public:

	CCPoint centerPoint;	// 摇杆中心

	CCPoint currentPoint;	// 摇杆当前位置

	bool active;			// 是否激活摇杆

	float radius;			// 摇杆半径

	CCSprite *jsSprite;		// 摇杆实例



	//************************************

	// Method:    Active

	// FullName:  Joystick::Active

	// Access:    public 

	// Returns:   void

	// Qualifier: 设置摇杆功能可用

	//************************************

	void Active();

	//************************************

	// Method:    Inactive

	// FullName:  Joystick::Inactive

	// Access:    public 

	// Returns:   void

	// Qualifier: 设置摇杆功能不可用

	//************************************

	void Inactive();

	//************************************

	// Method:    getDirection

	// FullName:  Joystick::getDirection

	// Access:    public 

	// Returns:   cocos2d::CCPoint

	// Qualifier: 获取摇杆方向，这里返回的是单位向量

	//************************************

	CCPoint getDirection();

	//************************************

	// Method:    getVelocity

	// FullName:  Joystick::getVelocity

	// Access:    public 

	// Returns:   float

	// Qualifier: 获取摇杆的力度

	//************************************

	float getVelocity();

	//************************************

	// Method:    updatePos

	// FullName:  Joystick::updatePos

	// Access:    public 

	// Returns:   void

	// Qualifier: 刷新函数，交给日程管理器

	// Parameter: ccTime dt

	//************************************

	void updatePos(ccTime dt);



	//************************************

	// Method:    JoystickWithCenter

	// FullName:  Joystick::JoystickWithCenter

	// Access:    public static 

	// Returns:   Joystick*

	// Qualifier: 初始化摇杆

	// Parameter: CCPoint aPoint 摇杆中心

	// Parameter: float aRadius 摇杆半径

	// Parameter: CCSprite * aJsSprite 摇杆控制点

	// Parameter: CCSprite * aJsBg 摇杆背景

	//************************************

	static Joystick* JoystickWithCenter(CCPoint aPoint, float aRadius, CCSprite* aJsSprite, CCSprite* aJsBg);

	Joystick* initWithCenter(CCPoint aPoint, float aRadius, CCSprite* aJsSprite, CCSprite* aJsBg);



	// 以下是复写Touch响应函数

	virtual bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent);

	virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);

	virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);



	LAYER_NODE_FUNC(Joystick);

};

Joystick.cpp

#include "Joystick.h"



Joystick::Joystick(void)

{

}



Joystick::~Joystick(void)

{

}



void Joystick::updatePos(ccTime dt)

{

	jsSprite->setPosition(ccpAdd(jsSprite->getPosition(), ccpMult(ccpSub(currentPoint, jsSprite->getPosition()), 0.5)));

}



void Joystick::Active()

{

	if(!active)

	{

		active = true;

		schedule(schedule_selector(Joystick::updatePos));	// 添加刷新函数

		CCTouchDispatcher::sharedDispatcher()->addTargetedDelegate(this, 0, false);	// 添加触摸委托

	}

}



void Joystick::Inactive()

{

	if(active)

	{

		active = false;

		this->unschedule(schedule_selector(Joystick::updatePos));	// 删除刷新函数

		CCTouchDispatcher::sharedDispatcher()->removeDelegate(this);	// 删除委托

	}

}



bool Joystick::ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent)

{

	if(!active)

		return false;



	CCPoint touchPoint = pTouch->locationInView(pTouch->view());

	touchPoint = CCDirector::sharedDirector()->convertToGL(touchPoint);

	if(ccpDistance(touchPoint, centerPoint) > radius)

		return false;



	currentPoint = touchPoint;

	return true;

}



void Joystick::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent)

{

	CCPoint touchPoint = pTouch->locationInView(pTouch->view());

	touchPoint = CCDirector::sharedDirector()->convertToGL(touchPoint);

	if(ccpDistance(touchPoint, centerPoint) > radius)

	{

		currentPoint = ccpAdd(centerPoint, ccpMult(ccpNormalize(ccpSub(touchPoint, centerPoint)), radius));

	}

	else

	{

		currentPoint = touchPoint;

	}

}



void Joystick::ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent)

{

	currentPoint = centerPoint;

}



CCPoint Joystick::getDirection()

{

	return ccpNormalize(ccpSub(centerPoint, currentPoint));  

}  



float Joystick::getVelocity()  

{  

	return ccpDistance(centerPoint, currentPoint);  

}  



Joystick* Joystick:: JoystickWithCenter(CCPoint aPoint, float aRadius, CCSprite* aJsSprite, CCSprite* aJsBg)

{  

	Joystick *jstick=Joystick::node();  

	jstick->initWithCenter(aPoint,aRadius,aJsSprite,aJsBg);  



	return jstick;  

}  



Joystick* Joystick::initWithCenter(CCPoint aPoint, float aRadius, CCSprite* aJsSprite, CCSprite* aJsBg)

{  

	active = false;  

	radius = aRadius;  

	centerPoint = aPoint;  

	currentPoint = centerPoint;  

	jsSprite = aJsSprite;  

	jsSprite->setPosition(centerPoint);  

	aJsBg->setPosition(centerPoint);  

	this->addChild(jsSprite);  

	this->addChild(aJsBg);  



	return this;  

}

完成了摇杆类后，直接在HelloWorld中测试效果吧，在init函数中加上下面的代码即可：

		CCSprite *testPointL = CCSprite::spriteWithFile("point.png");

		CCSprite *testBGL = CCSprite::spriteWithFile("joystickbg.png");

		Joystick *testJSL = Joystick::JoystickWithCenter(ccp(80.0f, 80.0f), 60.0f, testPointL, testBGL);

		this->addChild(testJSL);

		testJSL->Active();

看效果图：

资源文件：

Point.png     

joystickbg.png