Cocos2d-x - 如何设置CCLayer的一部分透明？

Question

我是新手cocos2d-x,我需要你的帮助.

我需要透明一层被触摸的部分.

如何使图层的一部分透明？我曾经想过要用??ClippingNode,但我找不到示例或文档.

我用C++.谢谢.

Answer 1

在TestCpp中,添加到所有cocos2d-x版本的项目中,您可以找到CCClipingNode的示例.

如果要使用CCClipingNode隐藏部分CCNode(例如"layer"),则应将图层添加到CCClipingNode.

这是您可以粘贴到HelloWorld init中的示例:

bool HelloWorld::init()
{

    if ( !CCLayer::init() )
    {
        return false;
    }

    CCSize visibleSize = CCDirector::sharedDirector()->getVisibleSize();
    CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();
    addChild(CCLayerColor::create(ccc4(122, 144, 0, 255), visibleSize.width, visibleSize.height));

    //this is the layer that we want to "cut"
    CCLayer *layer = CCLayer::create();
    CCSprite* pSprite = CCSprite::create("HelloWorld.png");
    pSprite->setPosition(ccp(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));
    layer->addChild(pSprite, 0);

    //we need to create a ccnode, which will be a stencil for ccclipingnode, draw node is a good choice for that
    CCDrawNode * stecil = CCDrawNode::create();
    stecil->drawDot(ccp(visibleSize.width/2 + origin.x - 100, visibleSize.height/2 + origin.y), 30, ccc4f(0, 0, 0, 255));
    stecil->drawSegment(ccp(0, 0), ccp(visibleSize.width, visibleSize.height), 20, ccc4f(0, 0, 0, 255));

    //CCClipingNode show the intersection of stencil and theirs children
    CCClippingNode *cliper = CCClippingNode::create(stecil);
    //you want to hide intersection so we setInverted to true
    cliper->setInverted(true);
    cliper->addChild(layer);
    addChild(cliper);

    return true;
}