Hey guys! Several days ago i found a cocs2d-iphone examples "stroke effect for CCLabelTTF objects". Here is the link to the cocos2d-iphone forum: http://www.cocos2d-iphone.org/forum/topic/12126

I made little modifications in this example and rewrote it for c++. Here is my code:

1CCRenderTexture* createStroke(CCSprite
 
* label, int size, ccColor3B color, GLubyte opacity)
 2 {
 3
 4    CCRenderTexture* rt = CCRenderTexture::renderTextureWithWidthAndHeight(
 5        label->getTexture()->getContentSize().width + size * 2,
 6        label->getTexture()->getContentSize().height+size * 2
 7        );
 8
 9    CCPoint
 
 originalPos = label->getPosition();
10
11    ccColor3B originalColor = label->getColor();
12
13    GLubyte originalOpacity = label->getOpacity();
14
15    bool originalVisibility = label->getIsVisible();
16
17    label->setColor(color);
18
19    label->setOpacity(opacity);
20
21    label->setIsVisible(true
 
);
22
23    ccBlendFunc originalBlend = label->getBlendFunc();
24
25    ccBlendFunc bf = {GL_SRC_ALPHA, GL_ONE};
26
27    label->setBlendFunc(bf);
28
29    CCPoint bottomLeft = ccp(
30        label->getTexture()->getContentSize().width * label->getAnchorPoint().x + size, 
31        label->getTexture()->getContentSize().height * label->getAnchorPoint().y + size);
32
33    CCPoint positionOffset= ccp(
34        - label->getTexture()->getContentSize().width / 2,
35        - label->getTexture()->getContentSize().height / 2);
36
37    CCPoint position = ccpSub(originalPos, positionOffset);
38
39    rt->begin();
40
41    for (int i=0; i<360; i+= 15) // you should optimize that for your needs
42    {
43        label->setPosition(
44            ccp(bottomLeft.x + sin(CC_DEGREES_TO_RADIANS(i))*size, bottomLeft.y + cos(CC_DEGREES_TO_RADIANS(i))*size)
45            );
46        label->visit();
47    }
48    rt->end();
49
50    label->setPosition(originalPos);
51    label->setColor(originalColor);
52    label->setBlendFunc(originalBlend);
53    label->setIsVisible(originalVisibility);
54    label->setOpacity(originalOpacity);
55
56    rt->setPosition(position);
57
58    return rt;
59}

 CCSprite* sprite = CCSprite::spriteWithFile("some_sprite.png");
2
3    addChild(sprite);
4
5    CCRenderTexture* tex = createStroke(sprite, 2 /*size*/, ccc3(0, 255, 0)/*color*/, 50 /*opacity*/);
6
7    addChild(tex, sprite->getZOrder() - 1);

static CCRenderTexture* createStroke(CCSprite* label, int size, ccColor3B color, GLubyte opacity){
        CCRenderTexture* rt = CCRenderTexture::create(label->getTexture()->getContentSize().width + size * 2,
                                                      label->getTexture()->getContentSize().height+size * 2);
        CCPoint originalPos = label->getPosition();
        ccColor3B originalColor = label->getColor();
        GLubyte originalOpacity = label->getOpacity();
        label->setColor(color);
        label->setOpacity(opacity);
        bool originalVisibility = label->isVisible();
        ccBlendFunc originalBlend = label->getBlendFunc();
        ccBlendFunc bf = {GL_SRC_ALPHA, GL_ONE};
        label->setBlendFunc(bf);
        CCPoint bottomLeft = ccp(
                                 label->getTexture()->getContentSize().width * label->getAnchorPoint().x + size,
                                 label->getTexture()->getContentSize().height * label->getAnchorPoint().y + size);
        //原來沒有判斷AnchorPoint的寫法
        //  CCPoint positionOffset= ccp(   - label->getTexture()->getContentSize().width / 2,
        //                                  - label->getTexture()->getContentSize().height / 2);
        //SetAnchorPoint會影響到positionOffset，所以要做判斷
        CCPoint positionOffset = CCPointZero;
        if(label->getAnchorPoint().x == 0.5f){
            positionOffset.x = 0;
        }else if(label->getAnchorPoint().x == 0.0f){
            positionOffset.x =- label->getTexture()->getContentSize().width / 2;
        }else{
            positionOffset.x = label->getTexture()->getContentSize().width/2;
        }
        if(label->getAnchorPoint().y == 0.5f){
            positionOffset.y = 0;
        }else if(label->getAnchorPoint().y == 0.0f){
            positionOffset.y =- label->getTexture()->getContentSize().height / 2;
        }else{
            positionOffset.y =  label->getTexture()->getContentSize().height/2;
        }
        CCPoint position = ccpSub(originalPos, positionOffset);
        rt->begin();
        for (int i=0; i<360 data-blogger-escaped-for="" data-blogger-escaped-i="" data-blogger-escaped-label-="" data-blogger-escaped-needs="" data-blogger-escaped-optimize="" data-blogger-escaped-should="" data-blogger-escaped-that="" data-blogger-escaped-you="" data-blogger-escaped-your="">setPosition(
                               ccp(bottomLeft.x + sin(CC_DEGREES_TO_RADIANS(i))*size, bottomLeft.y + cos(CC_DEGREES_TO_RADIANS(i))*size)
                               );
            label->visit();
        }
        rt->end();
        label->setPosition(originalPos);
        label->setColor(originalColor);
        label->setBlendFunc(originalBlend);
        label->setVisible(originalVisibility);
        label->setOpacity(originalOpacity);
        rt->setPosition(position);
        //反踞齒
        rt->getSprite()->getTexture()->setAntiAliasTexParameters();
        return rt;
    }