ClippingNode 实现类似子弹打穿纸片效果



auto target = Sprite::create("Images/blocks.png");

target->setAnchorPoint(Vec2::ZERO);

target->setScale(3);

_outerClipper = ClippingNode::create();

_outerClipper->retain();

AffineTransform tranform = AffineTransform::IDENTITY;

tranform = AffineTransformScale(tranform,target->getScale(),target->getScale());

_outerClipper->setContentSize(SizeApplyAffineTransform(target->getContentSize(),tranform));

_outerClipper->setAnchorPoint(Vec2(0.5,0.5));

_outerClipper->setPosition(Vec2(300,300));

_outerClipper->runAction(RepeatForever::create(RotateBy::create(1,45)));

_outerClipper->setStencil(target);

auto holesClipper = ClippingNode::create();

holesClipper->setInverted(true);

holesClipper->setAlphaThreshold(0.05f);

holesClipper->addChild(target);

_holes = Node::create();

_holes->retain();

holesClipper->addChild(_holes);

_holesStencil = Node::create();

_holesStencil->retain();

holesClipper->setStencil(_holesStencil);

_outerClipper->addChild(holesClipper);

this->addChild(_outerClipper);

auto listener = EventListenerTouchAllAtOnce::create();

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

_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this);

void HelloWorld::onTouchesBegan(const std::vector<Touch*>& touches,Event* event){

Touch* touch = (Touch*)touches[0];

Vec2 point = _outerClipper->convertToNodeSpace(Director::getInstance()->convertToGL(touch->getLocationInView()));

auto rect = Rect(0,0,_outerClipper->getContentSize().width,_outerClipper->getContentSize().height);

if (!rect.containsPoint(point))

{

return;

}

this->pokeHoleAtPoint(point);

}

void HelloWorld::pokeHoleAtPoint(Vec2 point){

float scale = CCRANDOM_0_1()*0.2 + 0.9;

float rotation = CCRANDOM_0_1() * 360;

auto hole = Sprite::create("Images/hole_effect.png");

hole->setPosition(point);

hole->setRotation(rotation);

hole->setScale(scale);

_holes->addChild(hole);

auto holeStencil = Sprite::create("Images/hole_stencil.png");

holeStencil->setPosition(point);

holeStencil->setRotation(rotation);

holeStencil->setScale(scale);

_holesStencil->addChild(holeStencil);

_outerClipper->runAction(Sequence::createWithTwoActions(ScaleBy::create(0.05f,0.95f),ScaleTo::create(0.125f,1)));

}