[cocos2dx]製作有邊框文字/圖片(Stroke Font)

文章撰寫日期︰2013/08/14 14:01
cocos2dx使用版本︰v 2.0.4
cocosBuilder使用版本︰v 2.0 alpha 1

一、前言

想要將CCSpirte或CCLabelTTF增加邊框，
該怎麼做？

二、本文開始

爬文至cocos2dx討論版後，
發現網友Alexandr Gerasimov熱心地將另一位網友cocos2d的code改成c++語法，
供我們使用。
但是我在使用時，
發現物件一旦被設定過AnchorPoint，
這個繪製岀來的邊框就會跑掉。
因此加了AnchorPoint的判斷，
更改的源碼如下︰

    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;
    }

結果如下