cocos2dx混合模式应用———制作新手引导高亮区域

先看下效果

制造这个椭圆高亮区域所使用原图是

附上代码

bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !CCLayer::init() )
    {
        return false;
    }
 
    CCSize visibleSize = CCDirector::sharedDirector()->getVisibleSize();
    CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();
 
    …………
    …………
 
    m_pTarget = CCRenderTexture::create(visibleSize.width, visibleSize.height, kCCTexture2DPixelFormat_RGBA8888);
    m_pTarget->setPosition(ccp(visibleSize.width / , visibleSize.height / ));
    addChild(m_pTarget, );
 
    return true;
}
 
void HelloWorld::setHighlightRect(const cocos2d::CCRect& rect)
{
    CCSprite* pMask = CCSprite::create("btn-about-normal.png");
    pMask->setPosition(ccp(rect.origin.x,rect.origin.y));
    pMask->setAnchorPoint(ccp(,));
    pMask->setScaleX(rect.size.width/pMask->getContentSize().width);
    pMask->setScaleY(rect.size.height/pMask->getContentSize().height);
 
    ccBlendFunc blend;
    blend.src = GL_ZERO;
    blend.dst = GL_ONE_MINUS_SRC_ALPHA;
    pMask->setBlendFunc(blend);
 
    m_pTarget->clear(,,,0.8f);
    m_pTarget->begin();
    pMask->visit();
    m_pTarget->end();
}