enum class PixelFormat{//! auto detect the type
        AUTO,//! 32-bit texture: BGRA8888
        BGRA8888,//! 32-bit texture: RGBA8888
        RGBA8888,//! 24-bit texture: RGBA888
        RGB888,//! 16-bit texture without Alpha channel
        RGB565,//! 8-bit textures used as masks
        A8,//! 8-bit intensity texture
        I8,//! 16-bit textures used as masks
        AI88,//! 16-bit textures: RGBA4444
        RGBA4444,//! 16-bit textures: RGB5A1
        RGB5A1,//! 4-bit PVRTC-compressed texture: PVRTC4
        PVRTC4,//! 4-bit PVRTC-compressed texture: PVRTC4 (has alpha channel)
        PVRTC4A,//! 2-bit PVRTC-compressed texture: PVRTC2
        PVRTC2,//! 2-bit PVRTC-compressed texture: PVRTC2 (has alpha channel)
        PVRTC2A,//! ETC-compressed texture: ETC
        ETC,//! S3TC-compressed texture: S3TC_Dxt1
        S3TC_DXT1,//! S3TC-compressed texture: S3TC_Dxt3
        S3TC_DXT3,//! S3TC-compressed texture: S3TC_Dxt5
        S3TC_DXT5,//! ATITC-compressed texture: ATC_RGB
        ATC_RGB,//! ATITC-compressed texture: ATC_EXPLICIT_ALPHA
        ATC_EXPLICIT_ALPHA,//! ATITC-compresed texture: ATC_INTERPOLATED_ALPHA
        ATC_INTERPOLATED_ALPHA,//! Default texture format: AUTODEFAULT = AUTO,NONE = -1};

bool Sprite::initWithFile(const std::string &filename, const Rect& rect)
{CCASSERT(filename.size()>0, "Invalid filename");Texture2D *texture = Director::getInstance()->getTextureCache()->addImage(filename);if (texture){return initWithTexture(texture, rect);}// don't release here.// when load texture failed, it's better to get a "transparent" sprite then a crashed program// this->release();return false;
}

TextureCache* Director::getTextureCache() const
{return _textureCache;
}

//texture cache belongs to this directorTextureCache *_textureCache;

/** Returns a Texture2D object given an filename.* If the filename was not previously loaded, it will create a new Texture2D*  object and it will return it. It will use the filename as a key.* Otherwise it will return a reference of a previously loaded image.* Supported image extensions: .png, .bmp, .tiff, .jpeg, .pvr*/Texture2D* addImage(const std::string &filepath);

Texture2D *texture = Director::getInstance()->getTextureCache()->addImage(filename);