cocos2d-x的初步学习十二之虚拟摇杆Joystick

这篇文章中，我们讲下虚拟摇杆，一般游戏中都会有虚拟摇杆，看了下别人写的Joystick，发现版本都是比较老的了，一些api已经改变了，稍微修改了下。OK，上代码：

摇杆类头文件：

#include "cocos2d.h"

using namespace cocos2d;

class HRocker :public CCLayer {
    public :
    //初始化 aPoint是摇杆中心 aRadius是摇杆半径 aJsSprite是摇杆控制点 aJsBg是摇杆背景
    static HRocker*  HRockerWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg,bool _isFollowRole);
    //启动摇杆
    void Active();
    //解除摇杆
    void Inactive();
    CCPoint getDirection();

private:
    HRocker * initWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg,bool _isFollowRole);
    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;
    bool isFollowRole;//是否跟随用户点击
    float getVelocity();
    void  updatePos(CCTime dt);
    virtual bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent);
    virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
    virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);
    
    CREATE_FUNC(HRocker);
};

.cpp:

#include "Joystick.h"

using namespace cocos2d;


void HRocker::updatePos(CCTime dt){
    jsSprite->setPosition(ccpAdd(jsSprite->getPosition(),ccpMult(ccpSub(currentPoint, jsSprite->getPosition()),0.5)));
}
//启动摇杆
void HRocker::Active()
{
    if (!active) {
        active=true;
        schedule(schedule_selector(HRocker::updatePos));//添加刷新函数
        CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, 0,false);
    }else {
    }
}
//解除摇杆
void   HRocker::Inactive()
{
    if (active) {
        active=false;
        this->unschedule(schedule_selector(HRocker::updatePos));//删除刷新
         CCDirector::sharedDirector()->getTouchDispatcher()->removeDelegate(this);//删除委托
    }else {
    }
}
//摇杆方位
CCPoint HRocker::getDirection()
{
    
    return ccpNormalize(ccpSub(centerPoint, currentPoint));
}
//摇杆力度
float HRocker::getVelocity()
{
    return ccpDistance(centerPoint, currentPoint);
}
HRocker* HRocker:: HRockerWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg,bool _isFollowRole){
    HRocker *jstick=HRocker::create();
    jstick->initWithCenter(aPoint,aRadius,aJsSprite,aJsBg,_isFollowRole);
    return jstick;
}
bool HRocker::ccTouchBegan(CCTouch* touch, CCEvent* event)
{
    if (!active)
        return false;
    this->setVisible(true);
    CCPoint touchPoint = touch->getLocationInView();
    touchPoint = CCDirector:: sharedDirector()->convertToGL(touchPoint);
    if(!isFollowRole){
        if (ccpDistance(touchPoint, centerPoint) > radius){
            return false;
        }
    }
    currentPoint = touchPoint;
    if(isFollowRole){
        centerPoint=currentPoint;
        jsSprite->setPosition(currentPoint);
        this->getChildByTag(88)->setPosition(currentPoint);
    }
    return true;
}
void  HRocker::ccTouchMoved(CCTouch* touch, CCEvent* event)
{
    CCPoint touchPoint = touch->getLocationInView();
    touchPoint = CCDirector:: sharedDirector()->convertToGL(touchPoint);
    if (ccpDistance(touchPoint, centerPoint) > radius)
    {
        currentPoint =ccpAdd(centerPoint,ccpMult(ccpNormalize(ccpSub(touchPoint, centerPoint)), radius));
    }else {
        currentPoint = touchPoint;
    }
}
void  HRocker::ccTouchEnded(CCTouch* touch, CCEvent* event)
{
    currentPoint = centerPoint;
    if(isFollowRole){
        this->setVisible(false);
    }
}
HRocker* HRocker::initWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg,bool _isFollowRole){
    isFollowRole =_isFollowRole;
    active = false;
    radius = aRadius;
    if(!_isFollowRole){
        centerPoint =aPoint;
    }else{
        centerPoint =ccp(0,0);
    }
    currentPoint = centerPoint;
    jsSprite = aJsSprite;
    jsSprite->setPosition(centerPoint);
    aJsBg->setPosition(centerPoint);
    aJsBg->setTag(88);
    this->addChild(aJsBg);
    this->addChild(jsSprite);
    if(isFollowRole){
        this->setVisible(false);
    }
    this->Active();//激活摇杆
    return this;
}

OK,我们看下实现加载这个类：

 //摇杆
    CCSprite *controlSprite=CCSprite::create("cen.png");
    //摇杆背景
    CCSprite *bgSprite=CCSprite::create("control_bg.png");
    
    
    joystick=HRocker::HRockerWithCenter(ccp(200.0f,200.0f),60.0f ,controlSprite ,bgSprite,false);

    this->addChild(joystick,1);
    
   
    this->scheduleUpdate();

发现里面有个getDirection ()方法，可以作为判断方向，大家可以试试，我们看下效果图：