关于cocos2d-x精灵加亮及变灰效果

//根据现有CCSprite，变亮和变灰

static CCSprite* graylightWithCCSprite(CCSprite* oldSprite,bool isLight)

{

    //CCSprite转成CCimage

    CCPoint p = oldSprite->getAnchorPoint();

    oldSprite->setAnchorPoint(ccp(0,0));

    CCRenderTexture *outTexture = CCRenderTexture::create((int)oldSprite->getContentSize().width,(int)oldSprite->getContentSize().height);

    outTexture->begin();

    oldSprite->visit();

    outTexture->end();

    oldSprite->setAnchorPoint(p);

    

    CCImage* finalImage = outTexture->newCCImage();

    unsigned char *pData = finalImage->getData();

    int iIndex = 0;

    

    if(isLight)

    {

        for (int i = 0; i < finalImage->getHeight(); i ++)

        {

            for (int j = 0; j < finalImage->getWidth(); j ++)

            {

                // highlight

                int iHightlightPlus = 50;

                int iBPos = iIndex;

                unsigned int iB = pData[iIndex];

                iIndex ++;

                unsigned int iG = pData[iIndex];

                iIndex ++;

                unsigned int iR = pData[iIndex];

                iIndex ++;

                //unsigned int o = pData[iIndex];

                iIndex ++;  //原来的示例缺少

                iB = (iB + iHightlightPlus > 255 ? 255 : iB + iHightlightPlus);

                iG = (iG + iHightlightPlus > 255 ? 255 : iG + iHightlightPlus);

                iR = (iR + iHightlightPlus > 255 ? 255 : iR + iHightlightPlus);

                //            iR = (iR < 0 ? 0 : iR);

                //            iG = (iG < 0 ? 0 : iG);

                //            iB = (iB < 0 ? 0 : iB);

                pData[iBPos] = (unsigned char)iB;

                pData[iBPos + 1] = (unsigned char)iG;

                pData[iBPos + 2] = (unsigned char)iR;

            }

        }

    }else{

        for (int i = 0; i < finalImage->getHeight(); i ++)

        {

            for (int j = 0; j < finalImage->getWidth(); j ++)

            {

                // gray

                int iBPos = iIndex;

                unsigned int iB = pData[iIndex];

                iIndex ++;

                unsigned int iG = pData[iIndex];

                iIndex ++;

                unsigned int iR = pData[iIndex];

                iIndex ++;

                //unsigned int o = pData[iIndex];

                iIndex ++; //原来的示例缺少

                unsigned int iGray = 0.3 * iR + 0.4 * iG + 0.2 * iB;

                pData[iBPos] = pData[iBPos + 1] = pData[iBPos + 2] = (unsigned char)iGray;

            }

        }

    }

    

    CCTexture2D *texture = new CCTexture2D;

    texture->initWithImage(finalImage);

    CCSprite* newSprite = CCSprite::createWithTexture(texture);

    delete finalImage;

    texture->release();

    return newSprite;

}

http://blog.csdn.net/chenli0741/article/details/8860036

在这个博客提供的png图片alpha通道的精灵变灰与变亮的。

但是，在变灰的时候，如果图片是有红色的话，则会出现不同的效果，不是叠加，而图片直接变灰。

可以看出，第二种情况，不是叠加上去的，而是把图片都变灰了。由于不怎么熟悉ARGB，还未解决的办法。