Question

如何使用Cocos2d-x3.0来给Sprite添加遮罩

Answer 1

//a static method
Sprite* HelloWorld::maskedSpriteWithSprite(Sprite* textureSprite, Sprite* maskSprite)
{
// 1
RenderTexture * rt = RenderTexture::create( maskSprite->getContentSize().width,
maskSprite->getContentSize().height );

// 2
maskSprite->setPosition(maskSprite->getContentSize().width/2,
maskSprite->getContentSize().height/2);
textureSprite->setPosition(textureSprite->getContentSize().width/2,
textureSprite->getContentSize().height/2);

// 3
maskSprite->setBlendFunc( BlendFunc{GL_ONE, GL_ZERO} );
textureSprite->setBlendFunc( BlendFunc{GL_DST_ALPHA, GL_ZERO} );

// 4
rt->begin();
maskSprite->visit();
textureSprite->visit();
rt->end();

// 5
Sprite *retval = Sprite::createWithTexture(rt->getSprite()->getTexture());
retval->setFlippedY(true);
return retval;
}
..