cocos2d-X 显示不规则图片方法（遮罩）

游戏中经常会使用一些mask， 来做遮罩，实现不规则图的显示，在cocos2d-x中

函数实现如下:

.h

static CCSprite* createMaskedSprite(CCSprite* src, const char* maskFile);

.cpp

CCSprite*  GOEUtilies::createMaskedSprite(CCSprite* src, const char* maskFile)
{
CCSprite * mask = CCSprite::create(maskFile);

assert(src);
assert(mask);

CCSize srcContent = src->getContentSize();
CCSize maskContent = mask->getContentSize();

CCRenderTexture * rt = CCRenderTexture::create(srcContent.width, srcContent.height, kTexture2DPixelFormat_RGBA8888);

float ratiow = srcContent.width / maskContent.width;
float ratioh = srcContent.height / maskContent.height;
mask->setScaleX(ratiow);
mask->setScaleY(ratioh);

mask->setPosition(ccp(srcContent.width / 2, srcContent.height / 2));
src->setPosition(ccp(srcContent.width / 2, srcContent.height / 2));

ccBlendFunc blendFunc2 = { GL_ONE, GL_ZERO };
mask->setBlendFunc(blendFunc2);
ccBlendFunc blendFunc3 = { GL_DST_ALPHA, GL_ZERO };
src->setBlendFunc(blendFunc3);

rt->begin();
mask->visit();
src->visit();
rt->end();

CCSprite * retval = CCSprite::createWithTexture(rt->getSprite()->getTexture());
retval->setFlipY(true);
return retval;
}

使用方法为：

GOEUtilies::createMaskedSprite(sprite,"mask.png")；

本文出自 “游戏人” 博客，请务必保留此出处http://zgame.blog.51cto.com/6144241/1061822