实例化一个 Texture2D

bool Image::initWithImageFile(const std::string& path)  
{  
    bool ret = false;  
    _filePath = FileUtils::getInstance()->fullPathForFilename(path);  
  
#ifdef EMSCRIPTEN  
    // Emscripten includes a re-implementation of SDL that uses HTML5 canvas  
    // operations underneath. Consequently, loading images via IMG_Load (an SDL  
    // API) will be a lot faster than running libpng et al as compiled with  
    // Emscripten.  
    SDL_Surface *iSurf = IMG_Load(fullPath.c_str());  
  
    int size = 4 * (iSurf->w * iSurf->h);  
    ret = initWithRawData((const unsigned char*)iSurf->pixels, size, iSurf->w, iSurf->h, 8, true);  
  
    unsigned int *tmp = (unsigned int *)_data;  
    int nrPixels = iSurf->w * iSurf->h;  
    for(int i = 0; i < nrPixels; i++)  
    {  
        unsigned char *p = _data + i * 4;  
        tmp[i] = CC_RGB_PREMULTIPLY_ALPHA( p[0], p[1], p[2], p[3] );  
    }  
  
    SDL_FreeSurface(iSurf);  
#else  
    Data data = FileUtils::getInstance()->getDataFromFile(_filePath);  
  
    if (!data.isNull())  
    {  
        ret = initWithImageData(data.getBytes(), data.getSize());  
    }  
#endif // EMSCRIPTEN  
  
    return ret;  
}  

c++

for(int i = 0; i < nrPixels; i++)  
    {  
        unsigned char *p = _data + i * 4;  
        tmp[i] = CC_RGB_PREMULTIPLY_ALPHA( p[0], p[1], p[2], p[3] );  
    }  
  
    SDL_FreeSurface(iSurf);  
#else  
    Data data = FileUtils::getInstance()->getDataFromFile(_filePath);  
  
    if (!data.isNull())  
    {  
        ret = initWithImageData(data.getBytes(), data.getSize());  
    }  

java

for(int i = 0; i < nrPixels; i++)  
    {  
        unsigned char *p = _data + i * 4;  
        tmp[i] = CC_RGB_PREMULTIPLY_ALPHA( p[0], p[1], p[2], p[3] );  
    }  
  
    SDL_FreeSurface(iSurf);  
#else  
    Data data = FileUtils::getInstance()->getDataFromFile(_filePath);  
  
    if (!data.isNull())  
    {  
        ret = initWithImageData(data.getBytes(), data.getSize());  
    }