3.10 調(diào)通了
G:\Mycocos310Cpp\touchAlpha\Classes\HelloWorldScene.h

#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__

#include "cocos2d.h"

class HelloWorld : public cocos2d::Layer
{
public:
    // there's no 'id' in cpp, so we recommend returning the class instance pointer
    static cocos2d::Scene* createScene();

    // Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone
    virtual bool init();
    bool onTouchBegan(cocos2d::Touch* pTouch, cocos2d::Event* pEvent);
    //void onTouchMoved(cocos2d::Touch* touch, cocos2d::Event* event);
    void onTouchEnded(cocos2d::Touch* pTouch, cocos2d::Event* pEvent);

    // implement the "static create()" method manually
    CREATE_FUNC(HelloWorld);
private:
    cocos2d::CCSprite* m_imgMan;
    cocos2d::CCRenderTexture* m_pRenderTexture;

    cocos2d::LabelTTF* m_pLabTips;

    cocos2d::EventListenerTouchOneByOne* _touchListener;
};

#endif // __HELLOWORLD_SCENE_H__

#include "HelloWorldScene.h"
#include "cocostudio/CocoStudio.h"
#include "ui/CocosGUI.h"

USING_NS_CC;

using namespace cocostudio::timeline;

Scene* HelloWorld::createScene()
{
    // 'scene' is an autorelease object
    auto scene = Scene::create();
    
    // 'layer' is an autorelease object
    auto 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 ( !Layer::init() )
    {
        return false;
    }

    m_imgMan = NULL;
    m_pRenderTexture = NULL;
    m_pLabTips = NULL;
    
    m_imgMan = CCSprite::create("ui_force_20001.png");
    m_imgMan->setPosition(ccp(100, 100));
    m_imgMan->setAnchorPoint(Vec2(0.5f, 0.5f));
    addChild(m_imgMan, 1);

    //這里參數(shù)很固定 沒(méi)有什么可改的余地
    //參數(shù)1 你需要渲染出來(lái)區(qū)域的寬
    //參數(shù)2 你需要渲染出來(lái)區(qū)域的高
    //參數(shù)3 必須是這個(gè)模式 否則后面復(fù)制內(nèi)存好像會(huì)有問(wèn)題Texture2D::PixelFormat::RGBA8888
    m_pRenderTexture = RenderTexture::create(m_imgMan->getContentSize().width, m_imgMan->getContentSize().height, Texture2D::PixelFormat::RGBA8888);
    m_pRenderTexture->setPosition(ccp(100, 100));
    //m_pRenderTexture->setAnchorPoint(Vec2(0, 0));//設(shè)置錨點(diǎn)無(wú)效 錨點(diǎn)默認(rèn)0.5f, 0.5f
    addChild(m_pRenderTexture, 2);

    // Adds touch event listener
    auto listener = EventListenerTouchOneByOne::create();
    listener->setSwallowTouches(true);

    listener->onTouchBegan = CC_CALLBACK_2(HelloWorld::onTouchBegan, this);
    listener->onTouchMoved = CC_CALLBACK_2(HelloWorld::onTouchMoved, this);

    _eventDispatcher->addEventListenerWithFixedPriority(listener, 1);

    _touchListener = listener;

    return true;
}

bool HelloWorld::onTouchBegan(cocos2d::Touch *pTouch, cocos2d::Event *pEvent) {
    //CCLOG("123");
    bool isTouched = false;

    CCPoint touchPoint = pTouch->getLocationInView();
    CCPoint glPoint = CCDirector::sharedDirector()->convertToGL(touchPoint);


    if (m_imgMan->boundingBox().containsPoint(glPoint)) {

        Color4B color4B = { 0, 0, 0, 0 };

        CCPoint nodePos = m_imgMan->convertTouchToNodeSpace(pTouch);
        unsigned int x = nodePos.x;
        unsigned int y = m_imgMan->getContentSize().height - nodePos.y;

        CCPoint point = m_imgMan->getPosition();
        //開(kāi)始準(zhǔn)備繪制
        m_pRenderTexture->begin();
        //繪制使用的臨時(shí)精靈床绪，與原圖是同一圖片
        CCSprite* pTempSpr = CCSprite::createWithSpriteFrame(m_imgMan->displayFrame());
        pTempSpr->setPosition(ccp(pTempSpr->getContentSize().width / 2, pTempSpr->getContentSize().height / 2));
        //繪制
        pTempSpr->visit();
        //結(jié)束繪制
        m_pRenderTexture->end();

        //解決方案原文 找了一下午原因 竟是這樣 http://blog.csdn.net/super_level/article/details/41707687
        Director::getInstance()->getRenderer()->render();//在3.0此處必須寫(xiě)上這個(gè)，否則newImage整張圖片都為黑色,或者在下一幀獲取  

        //通過(guò)畫(huà)布拿到這張畫(huà)布上每個(gè)像素點(diǎn)的信息，封裝到CCImage中
        Image* pImage = m_pRenderTexture->newImage();
        //獲取像素?cái)?shù)據(jù)
        unsigned char* data_ = pImage->getData();
        unsigned int *pixel = (unsigned int *)data_;
        pixel = pixel + (y * (int)pTempSpr->getContentSize().width) * 1 + x * 1;
        //R通道
        color4B.r = *pixel & 0xff;
        //G通道
        color4B.g = (*pixel >> 8) & 0xff;
        //B通過(guò)
        color4B.b = (*pixel >> 16) & 0xff;
        //Alpha通道，我們有用的就是Alpha
        color4B.a = (*pixel >> 24) & 0xff;

        CCLOG("cur click color: alpha = %d", color4B.a);

        if (color4B.a > 50) {
            isTouched = true;
        }
        else {
            isTouched = false;
        }

        //繪制完成后清理畫(huà)布的內(nèi)容
        m_pRenderTexture->clear(0, 0, 0, 0);
    }


    if (m_pLabTips) {
        m_pLabTips->removeFromParentAndCleanup(true);
        m_pLabTips = NULL;
    }

    return isTouched;
}

void HelloWorld::onTouchEnded(cocos2d::Touch *pTouch, cocos2d::Event *pEvent) {

    if (m_pLabTips) {
        m_pLabTips->removeFromParentAndCleanup(true);
        m_pLabTips = NULL;
    }

    m_pLabTips = CCLabelTTF::create("點(diǎn)擊到非透明的像素點(diǎn)", "Courier", 30);
    m_pLabTips->setAnchorPoint(Vec2(0.5f, 0.5f));
    m_pLabTips->setPosition(ccp(300.0f, 100.0f));
    m_pLabTips->setColor(ccc3(150, 150, 100));
    addChild(m_pLabTips, 1);

}

點(diǎn)擊白色圖片 以及邊緣區(qū)域 測(cè)試結(jié)果

ui_force_20001.png

image.png

image.png