使用2.1.3时字体描边正常，升级到2.2.5后描边的文字都出现了底色

Cocos2d-x
#1

如题，使用2.1.3时字体描边正常，升级了引擎之后描边的文字都出现了底色，如何解决？
if (needsShadow || needsStroke) {
CCTexture2D *tex = this->getTexture();
m_rdSprite->initWithTexture(tex);
m_rdSprite->setFlipY(false);
ccBlendFunc blend = {GL_ONE, GL_ONE_MINUS_SRC_ALPHA };
m_rdSprite->setBlendFunc(blend);

    if (needsStroke){
        
        int italic = strstr(getFontName(), "Italic") ? 2 : 0; // 斜体字
        
        float offsetX = (m_strokeSize * 2 + fabs(m_shadowOffset.x*2)) + italic;
        float offsetY = m_strokeSize * 2 + fabs(m_shadowOffset.y*2);
        
        float x=tex->getContentSize().width + offsetX;
        float y=tex->getContentSize().height+ offsetY;
        
        m_rdTexture = CCRenderTexture::create(x, y);
        m_rdTexture->retain();
        m_rdTexture->begin();
        {
            m_rdSprite->setOpacity(255);
            m_rdSprite->setColor(ccWHITE);
            renderStrokeTexture(x, y);
        }
        m_rdTexture->end();
        m_rdTexture->getSprite()->setColor(ccc3(m_strokeColor.r, m_strokeColor.g, m_strokeColor.b));
        m_rdTexture->getSprite()->setOpacity(opMult(m_strokeColor.a, getOpacity()));
        m_rdTexture->getSprite()->setAnchorPoint(ccp(0, 1));
 
        setTextureRect(CCRectMake(-offsetX/2, -offsetY/2, x, y));
        
    }
}