CCSpriteFrameCache解析

代码：

/** @class SpriteFrameCache
 * @brief Singleton that handles the loading of the sprite frames.
 It saves in a cache the sprite frames.
 @since v0.9
 @js cc.spriteFrameCache
 */
 // 精灵帧缓存区
 // 加载精灵帧的单例控制器
 // 他将精灵帧存入一个缓存中
class CC_DLL SpriteFrameCache : public Ref
{
public:
    /** Returns the shared instance of the Sprite Frame cache.
     *
     * @return The instance of the Sprite Frame Cache.
     * @js NA
     */
	 // 得到单例
    static SpriteFrameCache* getInstance();

    /** @deprecated Use getInstance() instead 
     @js NA 
	*/
    CC_DEPRECATED_ATTRIBUTE static SpriteFrameCache* sharedSpriteFrameCache() { return SpriteFrameCache::getInstance(); }

    /** Destroys the cache. It releases all the Sprite Frames and the retained instance.
	 * @js NA
     */
	 // 销毁单例
    static void destroyInstance();

    /** @deprecated Use destroyInstance() instead 
     * @js NA
     */
    CC_DEPRECATED_ATTRIBUTE static void purgeSharedSpriteFrameCache() { return SpriteFrameCache::destroyInstance(); }

    /** Destructor.
     * @js NA
     * @lua NA
     */
    virtual ~SpriteFrameCache();
    
    /** Initialize method.
     *
     * @return if success return true.
     */
	 // 初始化
    bool init();

    /** Adds multiple Sprite Frames from a plist file.
     * A texture will be loaded automatically. The texture name will composed by replacing the .plist suffix with .png.
     * If you want to use another texture, you should use the addSpriteFramesWithFile(const std::string& plist, const std::string& textureFileName) method.
     * @js addSpriteFrames
     * @lua addSpriteFrames
     *
     * @param plist Plist file name.
     */
	 // 通过文件添加精灵帧
    void addSpriteFramesWithFile(const std::string& plist);

    /** Adds multiple Sprite Frames from a plist file. The texture will be associated with the created sprite frames.
     @since v0.99.5
     * @js addSpriteFrames
     * @lua addSpriteFrames
     *
     * @param plist Plist file name.
     * @param textureFileName Texture file name.
     */
	 // 通过plist和纹理文件添加精灵帧
    void addSpriteFramesWithFile(const std::string& plist, const std::string& textureFileName);

    /** Adds multiple Sprite Frames from a plist file. The texture will be associated with the created sprite frames. 
     * @js addSpriteFrames
     * @lua addSpriteFrames
     *
     * @param plist Plist file name.
     * @param texture Texture pointer.
     */
	 // 通过plist和纹理添加精灵帧
    void addSpriteFramesWithFile(const std::string&plist, Texture2D *texture);

    /** Adds multiple Sprite Frames from a plist file content. The texture will be associated with the created sprite frames. 
     * @js NA
     * @lua addSpriteFrames
     *
     * @param plist_content Plist file content string.
     * @param texture Texture pointer.
     */
	 // 添加多个精灵帧从一个plist中
    void addSpriteFramesWithFileContent(const std::string& plist_content, Texture2D *texture);

    /** Adds an sprite frame with a given name.
     If the name already exists, then the contents of the old name will be replaced with the new one.
     *
     * @param frame A certain sprite frame.
     * @param frameName The name of the sprite frame.
     */
	 // 添加精灵帧
    void addSpriteFrame(SpriteFrame *frame, const std::string& frameName);

    /** Check if multiple Sprite Frames from a plist file have been loaded.
    * @js NA
    * @lua NA
    *
    * @param plist Plist file name.
    * @return True if the file is loaded.
    */
	// plist是否被加载
    bool isSpriteFramesWithFileLoaded(const std::string& plist) const;

    /** Purges the dictionary of loaded sprite frames.
     * Call this method if you receive the "Memory Warning".
     * In the short term: it will free some resources preventing your app from being killed.
     * In the medium term: it will allocate more resources.
     * In the long term: it will be the same.
     */
	 // 移除精灵帧
    void removeSpriteFrames();

    /** Removes unused sprite frames.
     * Sprite Frames that have a retain count of 1 will be deleted.
     * It is convenient to call this method after when starting a new Scene.
	 * @js NA
     */
	 // 移除没有用的精灵帧
    void removeUnusedSpriteFrames();

    /** Deletes an sprite frame from the sprite frame cache. 
     *
     * @param name The name of the sprite frame that needs to removed.
     */
	 // 通过名字移除精灵帧
    void removeSpriteFrameByName(const std::string& name);

    /** Removes multiple Sprite Frames from a plist file.
    * Sprite Frames stored in this file will be removed.
    * It is convenient to call this method when a specific texture needs to be removed.
    * @since v0.99.5
    *
    * @param plist The name of the plist that needs to removed.
    */
	// 通过plist移除精灵帧
    void removeSpriteFramesFromFile(const std::string& plist);

    /** Removes multiple Sprite Frames from a plist file content.
    * Sprite Frames stored in this file will be removed.
    * It is convenient to call this method when a specific texture needs to be removed.
    *
    * @param plist_content The string of the plist content that needs to removed.
    * @js NA
    */
	// 移除plist中包含的精灵帧
    void removeSpriteFramesFromFileContent(const std::string& plist_content);

    /** Removes all Sprite Frames associated with the specified textures.
     * It is convenient to call this method when a specific texture needs to be removed.
     * @since v0.995.
     *
     * @param texture The texture that needs to removed.
     */
	 // 移除纹理包含的精灵帧
    void removeSpriteFramesFromTexture(Texture2D* texture);

    /** Returns an Sprite Frame that was previously added.
     If the name is not found it will return nil.
     You should retain the returned copy if you are going to use it.
     * @js getSpriteFrame
     * @lua getSpriteFrame
     *
     * @param name A certain sprite frame name.
     * @return The sprite frame.
     */
	 // 通过名字得到精灵帧
    SpriteFrame* getSpriteFrameByName(const std::string& name);

    /** @deprecated use getSpriteFrameByName() instead */
    CC_DEPRECATED_ATTRIBUTE SpriteFrame* spriteFrameByName(const std::string&name) { return getSpriteFrameByName(name); }

protected:
    // MARMALADE: Made this protected not private, as deriving from this class is pretty useful
    SpriteFrameCache(){}

    /*Adds multiple Sprite Frames with a dictionary. The texture will be associated with the created sprite frames.
     */
	 // 通过字典和纹理添加精灵帧
    void addSpriteFramesWithDictionary(ValueMap& dictionary, Texture2D *texture);

    /** Removes multiple Sprite Frames from Dictionary.
    * @since v0.99.5
    */
	// 通过字典移除精灵帧
    void removeSpriteFramesFromDictionary(ValueMap& dictionary);


    Map<std::string, SpriteFrame*> _spriteFrames;
    ValueMap _spriteFramesAliases;
    std::set<std::string>*  _loadedFileNames;
};