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cocos2dx 音频模块分析(5): 音效部分

我们上一篇中分析的音效部分的预加载和播放函数，这一篇来分析下其他函数：1、暂停某个播放中的音效//注意这里的nSoundId不是java端的soundID，而是streamID//不要被参数的名字迷惑了。void SimpleAudioEngine::pauseEffect(unsigned int nSoundId){    pauseEffectJNI(nSoundId);}-->> void pauseEffectJNI(unsigned int nSoundId)    {        // void pauseEffect(int)                JniMethodInfo methodInfo;                if (! getStaticMethodInfo(methodInfo, "pauseEffect", "(I)V"))        {            return ;        }                methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID, (int)nSoundId);        methodInfo.env->DeleteLocalRef(methodInfo.classID);    }---->>//java端方法：//pStreamID 这个参数，是调用unsigned int SimpleAudioEngine::playEffect()放回的StreamIDpublic void pauseEffect(final int pStreamID) {	     /**	     * Pause a playback stream. 暂停一个播放流	     *	     * Pause the stream specified by the streamID. This is the	     * value returned by the play() function. (这个值是play函数的返回值)If the stream is	     * playing, it will be paused. If the stream is not playing	     * (e.g. is stopped or was previously paused), calling this	     * function will have no effect.(如果处于播放状态则暂停，如果不处于播放状态，则无效)	     *	     * @param streamID a streamID returned by the play() function	     */		this.mSoundPool.pause(pStreamID);	}2、 暂停所有音效 void pauseAllEffectsJNI()    {        // void pauseAllEffects()                JniMethodInfo methodInfo;                if (! getStaticMethodInfo(methodInfo, "pauseAllEffects", "()V"))        {            return ;        }                methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID);        methodInfo.env->DeleteLocalRef(methodInfo.classID);    } --->>java端     public void pauseAllEffects() {	  /**	     * Pause all active streams. //暂停所有正在播放的音效	     *	     * Pause all streams that are currently playing. This function	     * iterates through all the active streams and pauses any that	     * are playing. It also sets a flag so that any streams that	     * are playing can be resumed by calling autoResume().	     */	      this.mSoundPool.autoPause();	}3、 恢复播放某个音效 void resumeEffectJNI(unsigned int nSoundId)    {        // void resumeEffect(int)                JniMethodInfo methodInfo;                if (! getStaticMethodInfo(methodInfo, "resumeEffect", "(I)V"))        {            return ;        }                methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID, (int)nSoundId);        methodInfo.env->DeleteLocalRef(methodInfo.classID);    }    --->>    public void resumeEffect(final int pStreamID) {	    /**	     * Resume a playback stream.	     * 只有处于暂停状态的stream，才可以恢复播放。	     * Resume the stream specified by the streamID. This	     * is the value returned by the play() function. If the stream	     * is paused, this will resume playback. If the stream was not	     * previously paused, calling this function will have no effect.	     *	     * @param streamID a streamID returned by the play() function	     */		this.mSoundPool.resume(pStreamID);	}4、void resumeAllEffectsJNI()    {        // void resumeAllEffects()                JniMethodInfo methodInfo;                if (! getStaticMethodInfo(methodInfo, "resumeAllEffects", "()V"))        {            return ;        }                methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID);        methodInfo.env->DeleteLocalRef(methodInfo.classID);    }---->>>java端函数：	public void resumeAllEffects() {		// can not only invoke SoundPool.autoResume() here, because		// it only resumes all effects paused by pauseAllEffects()		// 这里注释的很清楚		if (!this.mPathStreamIDsMap.isEmpty()) {			final Iterator
   
    
     >> iter = this.mPathStreamIDsMap.entrySet().iterator();			while (iter.hasNext()) {				final Entry
     
      > entry = iter.next();				for (final int pStreamID : entry.getValue()) {					this.mSoundPool.resume(pStreamID);				}			}		}	}5、停止播放某个音效，这里的nSoundId同样是pStreamID，停止播放的音效是不能通过resume恢复播放的。void SimpleAudioEngine::stopEffect(unsigned int nSoundId){    stopEffectJNI(nSoundId);}--->>java端：public void stopEffect(final int pStreamID) {                  /**		     * Stop a playback stream.		     *		     * Stop the stream specified by the streamID. This		     * is the value returned by the play() function. If the stream		     * is playing, it will be stopped. It also releases any native		     * resources associated with this stream. (会释放对应的资源)If the stream is not		     * playing, it will have no effect.		     *		     * @param streamID a streamID returned by the play() function		     */		this.mSoundPool.stop(pStreamID);		// remove record		// 从记录列表中移除		for (final String pPath : this.mPathStreamIDsMap.keySet()) {			if (this.mPathStreamIDsMap.get(pPath).contains(pStreamID)) {				this.mPathStreamIDsMap.get(pPath).remove(this.mPathStreamIDsMap.get(pPath).indexOf(pStreamID));				break;			}		}	}6、void stopAllEffectsJNI()    {        // void stopAllEffects()                JniMethodInfo methodInfo;                if (! getStaticMethodInfo(methodInfo, "stopAllEffects", "()V"))        {            return ;        }                methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID);        methodInfo.env->DeleteLocalRef(methodInfo.classID);    }--->>>java端	@SuppressWarnings("unchecked")	public void stopAllEffects() {		// stop effects，停止所有音效的播放		if (!this.mPathStreamIDsMap.isEmpty()) {			final Iterator
       iter = this.mPathStreamIDsMap.entrySet().iterator();			while (iter.hasNext()) {				final Map.Entry
      
       > entry = (Map.Entry
       
        >) iter.next();				for (final int pStreamID : entry.getValue()) {					this.mSoundPool.stop(pStreamID);				}			}		}		// remove records，清空播放记录		this.mPathStreamIDsMap.clear();	}7、卸载加载的音效(重要)//pszFilePath：音效文件名void SimpleAudioEngine::unloadEffect(const char* pszFilePath){    std::string fullPath = getFullPathWithoutAssetsPrefix(pszFilePath);    unloadEffectJNI(fullPath.c_str());}--->> void unloadEffectJNI(const char* path)    {        // void unloadEffect(String)                JniMethodInfo methodInfo;                if (! getStaticMethodInfo(methodInfo, "unloadEffect", "(Ljava/lang/String;)V"))        {            return ;        }                jstring stringArg = methodInfo.env->NewStringUTF(path);        methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID, stringArg);        methodInfo.env->DeleteLocalRef(stringArg);        methodInfo.env->DeleteLocalRef(methodInfo.classID);    }--->>>public void unloadEffect(final String pPath) {		// stop effects		// 先停止		final ArrayList
        
          streamIDs = this.mPathStreamIDsMap.get(pPath); if (streamIDs != null) { for (final Integer pStreamID : streamIDs) { this.mSoundPool.stop(pStreamID); } } this.mPathStreamIDsMap.remove(pPath); // unload effect final Integer soundID = this.mPathSoundIDMap.get(pPath); if(soundID != null){ /** * Unload a sound from a sound ID. * * Unloads the sound specified by the soundID. This is the value * returned by the load() function. Returns true if the sound is * successfully unloaded, false if the sound was already unloaded. * * @param soundID a soundID returned by the load() function * @return true if just unloaded, false if previously unloaded */ // 卸载音效 this.mSoundPool.unload(soundID); // 从mPathSoundIDMap中移除 this.mPathSoundIDMap.remove(pPath); } }/************************************************总结:音效部分最重要的函数是preloadEffect，unloadEffect，playEffect，stopAllEffects其他的感觉不是很常用，java有两个比较重要的map，一个是：private final HashMap
         
           mPathSoundIDMap = new HashMap
          
           ();这个是用来存放所有加载的音效文件路径和SoundID的map。一个是： // sound path and stream ids map cocos2dx原本注释 // a file may be played many times at the same time // so there is an array map to a file pathprivate final HashMap
           
            > mPathStreamIDsMap = new HashMap
            
             >();用来存放所有播放的音效文件路径和StreamIDs的map。注意：这里的SoundID和StreamID不是一个概念，一个音效文件只对应一个SoundID，而却可以对应多个StreamID，因为一个音效文件可以播放多次(StreamID)，但是只需要加载一次(SoundID).************************************************/
            
           
          
         
        
       
      
     
    
   

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